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* [PATCH v14 1/6] dt-bindings: iio: adc: add AD4691 family
From: Radu Sabau via B4 Relay @ 2026-05-29 10:15 UTC (permalink / raw)
  To: Lars-Peter Clausen, Michael Hennerich, Jonathan Cameron,
	David Lechner, Nuno Sá, Andy Shevchenko, Rob Herring,
	Krzysztof Kozlowski, Conor Dooley, Uwe Kleine-König,
	Liam Girdwood, Mark Brown, Linus Walleij, Bartosz Golaszewski,
	Philipp Zabel, Jonathan Corbet, Shuah Khan
  Cc: linux-iio, devicetree, linux-kernel, linux-pwm, linux-gpio,
	linux-doc, Radu Sabau, Conor Dooley
In-Reply-To: <20260529-ad4692-multichannel-sar-adc-driver-v14-0-e93c2747dc1f@analog.com>

From: Radu Sabau <radu.sabau@analog.com>

Add DT bindings for the Analog Devices AD4691 family of multichannel
SAR ADCs (AD4691, AD4692, AD4693, AD4694).

The four variants are not compatible with each other: AD4691/AD4692 have
16 analog input channels while AD4693/AD4694 have 8, and AD4691/AD4693
top out at 500 kSPS while AD4692/AD4694 reach 1 MSPS. These differences
in channel count and maximum sample rate require distinct compatible
strings so the driver can select the correct channel configuration and
rate limits.

Acked-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Radu Sabau <radu.sabau@analog.com>
---
 .../devicetree/bindings/iio/adc/adi,ad4691.yaml    | 180 +++++++++++++++++++++
 MAINTAINERS                                        |   7 +
 2 files changed, 187 insertions(+)

diff --git a/Documentation/devicetree/bindings/iio/adc/adi,ad4691.yaml b/Documentation/devicetree/bindings/iio/adc/adi,ad4691.yaml
new file mode 100644
index 000000000000..af28a0c1cfa9
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/adc/adi,ad4691.yaml
@@ -0,0 +1,180 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/adc/adi,ad4691.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Analog Devices AD4691 Family Multichannel SAR ADCs
+
+maintainers:
+  - Radu Sabau <radu.sabau@analog.com>
+
+description: |
+  The AD4691 family are high-speed, low-power, multichannel successive
+  approximation register (SAR) analog-to-digital converters (ADCs) with
+  an SPI-compatible serial interface. The ADC supports CNV Burst Mode,
+  where an external PWM drives the CNV pin, and Manual Mode, where CNV
+  is directly tied to the SPI chip-select.
+
+  Datasheets:
+    * https://www.analog.com/en/products/ad4691.html
+    * https://www.analog.com/en/products/ad4692.html
+    * https://www.analog.com/en/products/ad4693.html
+    * https://www.analog.com/en/products/ad4694.html
+
+$ref: /schemas/spi/spi-peripheral-props.yaml#
+
+properties:
+  compatible:
+    enum:
+      - adi,ad4691
+      - adi,ad4692
+      - adi,ad4693
+      - adi,ad4694
+
+  reg:
+    maxItems: 1
+
+  spi-max-frequency:
+    maximum: 40000000
+
+  spi-cpol: true
+  spi-cpha: true
+
+  avdd-supply:
+    description: Analog power supply (4.5V to 5.5V).
+
+  vdd-supply:
+    description:
+      External 1.8V digital core supply. When present, the internal LDO is
+      disabled (LDO_EN = 0). Mutually exclusive with ldo-in-supply.
+
+  ldo-in-supply:
+    description:
+      LDO input supply (2.4V to 5.5V). When present and vdd-supply is absent,
+      the internal LDO generates 1.8V VDD from this input (LDO_EN = 1).
+      Mutually exclusive with vdd-supply.
+
+  vio-supply:
+    description: I/O voltage supply (1.71V to 1.89V or VDD).
+
+  ref-supply:
+    description: External reference voltage supply (2.4V to 5.25V).
+
+  refin-supply:
+    description: Internal reference buffer input supply.
+
+  reset-gpios:
+    description:
+      GPIO line controlling the hardware reset pin (active-low).
+    maxItems: 1
+
+  pwms:
+    description:
+      PWM connected to the CNV pin. When present, selects CNV Burst Mode where
+      the PWM drives the conversion rate. When absent, Manual Mode is used
+      (CNV tied to SPI CS).
+    maxItems: 1
+
+  interrupts:
+    description:
+      Interrupt lines connected to the ADC GP pins. Each GP pin can be
+      physically wired to an interrupt-capable input on the SoC.
+    maxItems: 4
+
+  interrupt-names:
+    description: Names of the interrupt lines, matching the GP pin names.
+    minItems: 1
+    maxItems: 4
+    items:
+      enum:
+        - gp0
+        - gp1
+        - gp2
+        - gp3
+
+  gpio-controller: true
+
+  '#gpio-cells':
+    const: 2
+
+  '#trigger-source-cells':
+    description:
+      This node can act as a trigger source. The single cell in a consumer
+      reference specifies the GP pin number (0-3) used as the trigger output.
+    const: 1
+
+required:
+  - compatible
+  - reg
+  - avdd-supply
+  - vio-supply
+
+allOf:
+  # vdd-supply and ldo-in-supply are mutually exclusive, one is required:
+  # either an external 1.8V VDD is provided or the internal LDO is fed from
+  # ldo-in-supply to generate VDD.
+  - oneOf:
+      - required:
+          - vdd-supply
+      - required:
+          - ldo-in-supply
+  # ref-supply and refin-supply are mutually exclusive, one is required
+  - oneOf:
+      - required:
+          - ref-supply
+      - required:
+          - refin-supply
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    /* AD4692 in CNV Burst Mode with SPI offload */
+    spi {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        adc@0 {
+            compatible = "adi,ad4692";
+            reg = <0>;
+            spi-cpol;
+            spi-cpha;
+            spi-max-frequency = <40000000>;
+
+            avdd-supply = <&avdd_supply>;
+            ldo-in-supply = <&avdd_supply>;
+            vio-supply = <&vio_supply>;
+            ref-supply = <&ref_5v>;
+
+            reset-gpios = <&gpio0 15 GPIO_ACTIVE_LOW>;
+
+            pwms = <&pwm_gen 0 0>;
+
+            #trigger-source-cells = <1>;
+        };
+    };
+
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    /* AD4692 in Manual Mode (CNV tied to SPI CS) */
+    spi {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        adc@0 {
+            compatible = "adi,ad4692";
+            reg = <0>;
+            spi-cpol;
+            spi-cpha;
+            spi-max-frequency = <31250000>;
+
+            avdd-supply = <&avdd_supply>;
+            ldo-in-supply = <&avdd_supply>;
+            vio-supply = <&vio_supply>;
+            refin-supply = <&refin_supply>;
+
+            reset-gpios = <&gpio0 15 GPIO_ACTIVE_LOW>;
+        };
+    };
diff --git a/MAINTAINERS b/MAINTAINERS
index c2c6d79275c6..7d31c38921e8 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1482,6 +1482,13 @@ W:	https://ez.analog.com/linux-software-drivers
 F:	Documentation/devicetree/bindings/iio/adc/adi,ad4170-4.yaml
 F:	drivers/iio/adc/ad4170-4.c
 
+ANALOG DEVICES INC AD4691 DRIVER
+M:	Radu Sabau <radu.sabau@analog.com>
+L:	linux-iio@vger.kernel.org
+S:	Supported
+W:	https://ez.analog.com/linux-software-drivers
+F:	Documentation/devicetree/bindings/iio/adc/adi,ad4691.yaml
+
 ANALOG DEVICES INC AD4695 DRIVER
 M:	Michael Hennerich <michael.hennerich@analog.com>
 M:	Nuno Sá <nuno.sa@analog.com>

-- 
2.43.0



^ permalink raw reply related

* [PATCH v14 0/6] iio: adc: ad4691: add driver for AD4691 multichannel SAR ADC family
From: Radu Sabau via B4 Relay @ 2026-05-29 10:14 UTC (permalink / raw)
  To: Lars-Peter Clausen, Michael Hennerich, Jonathan Cameron,
	David Lechner, Nuno Sá, Andy Shevchenko, Rob Herring,
	Krzysztof Kozlowski, Conor Dooley, Uwe Kleine-König,
	Liam Girdwood, Mark Brown, Linus Walleij, Bartosz Golaszewski,
	Philipp Zabel, Jonathan Corbet, Shuah Khan
  Cc: linux-iio, devicetree, linux-kernel, linux-pwm, linux-gpio,
	linux-doc, Radu Sabau, Conor Dooley

This series adds support for the Analog Devices AD4691 family of
high-speed, low-power multichannel successive approximation register
(SAR) ADCs with an SPI-compatible serial interface.

The family includes:
  - AD4691: 16-channel, 500 kSPS
  - AD4692: 16-channel, 1 MSPS
  - AD4693: 8-channel, 500 kSPS
  - AD4694: 8-channel, 1 MSPS

The devices support two operating modes, auto-detected from the device
tree:
  - CNV Burst Mode: external PWM drives CNV independently of SPI;
                    DATA_READY on a GP pin signals end of conversion
  - Manual Mode: CNV tied to SPI CS; each SPI transfer reads
                 the previous conversion result and starts the
                 next (pipelined N+1 scheme)

A new driver is warranted rather than extending ad4695: the AD4691
data path uses an accumulator-register model — results are read from
AVG_IN registers, with ACC_MASK, ADC_SETUP, DEVICE_SETUP, and
GPIO_MODE registers controlling the sequencer — none of which exist
in AD4695. CNV Burst Mode (PWM drives CNV independently of SPI) and
Manual Mode (pipelined N+1 transfers) also have no equivalent in
AD4695's command-embedded single-cycle protocol.

The series is structured as follows:
  1/6 - DT bindings (YAML schema) and MAINTAINERS entry
  2/6 - Initial driver: register map via custom regmap callbacks,
        IIO read_raw/write_raw, both operating modes, single-channel
        reads via internal oscillator (Autonomous Mode)
  3/6 - Triggered buffer support: IRQ-driven (DATA_READY on a GP pin
        selected via interrupt-names) for CNV Burst Mode; external IIO
        trigger for Manual Mode to handle the pipelined N+1 SPI protocol
  4/6 - SPI Engine offload support: DMA-backed high-throughput
        capture path using the SPI offload subsystem
  5/6 - Shared oversampling ratio support for CNV Burst Mode
  6/6 - Driver documentation (Documentation/iio/ad4691.rst)

Datasheets:
  https://www.analog.com/en/products/ad4691.html
  https://www.analog.com/en/products/ad4692.html
  https://www.analog.com/en/products/ad4693.html
  https://www.analog.com/en/products/ad4694.html

Signed-off-by: Radu Sabau <radu.sabau@analog.com>
---
Changes in v14:
- clean up volatile_reg — fold result register ranges into the
  switch statement (same pattern as ACC_SAT_OVR_REG); remove misleading
  comment about debugfs (readable_reg is what gates access); fix commit
  message reset description to match the code (assert → deassert → wait
  300 µs for internal reset sequence)
- fix manual mode exit bug — add AD4691_EXIT_COMMAND (0x5000)
  and ad4691_transfer() to send the raw SPI command that returns the chip
  to Autonomous Mode;
- update commit message to reflect single shared OSR
  (in_voltage_sampling_frequency / in_voltage_oversampling_ratio are
  info_mask_shared_by_all); replace all per-channel osr[N] /
  in_voltageN_* references
- Link to v13: https://lore.kernel.org/r/20260525-ad4692-multichannel-sar-adc-driver-v13-0-1b7626d3b35c@analog.com

Changes in v13:
- IIO_CHAN_INFO_SAMP_FREQ and IIO_CHAN_INFO_OVERSAMPLING_RATIO moved to
  info_mask_shared_by_all: the hardware uses a single internal oscillator
  and a single ACC_DEPTH_IN(0) register shared across all channels, so
  per-channel sysfs attributes were incorrect.
- ad4691_reset: refactor to share the fsleep(300) call between hardware
  and software reset paths.
- ad4691_read_scan: check spi_sync() return value; skip push and emit
  rate-limited error on failure.
- Drop stale info_mask_separate rationale from commit 2 message.
- Documentation updated to reflect shared sampling_frequency and
  oversampling_ratio attributes (in_voltage_* instead of in_voltageN_*).
- Link to v12: https://lore.kernel.org/r/20260519-ad4692-multichannel-sar-adc-driver-v12-0-5b335162aa51@analog.com

Changes in v12:
- IIO_DEV_ACQUIRE_DIRECT_MODE moved from set_sampling_freq into write_raw
- enum ad4691_ref_ctrl: remove explicit values
- .sign = 'u' → .format = 'u' throughout — the field has a new name
- device_property_present(dev, "vdd-supply") / device_property_present(dev, "ref-supply")
  pattern instead of handling -ENODEV
- AD4691_STATE_RESET_ALL 0x01 → BIT(0)
- spi_device_id: use named initializers instead of (kernel_ulong_t)&... cast
- ad4691_reset: 300 µs sleep belongs after reset_control_deassert, not
  between assert and deassert — actual RESETL minimum time (~10 ns) is
  covered by overhead; add post-deassert sleep
- Add guard(mutex)(&st->lock) in get_sampling_freq
- Don't register or attach iio_trigger in manual mode
- Remove the if (i >= indio_dev->num_channels - 1) break guards
- ad4691_read_scan return type → void
- Remove (u16) cast: st->scan_tx[k] = AD4691_ADC_CHAN(bit) << 8
- sizeof(st->scan_tx[k]) → sizeof(*st->scan_tx)
- Remove & from iio_buffer_setup_ops in offload structs
- Add args[0] <= 3 check in ad4691_offload_trigger_request
- Embed offload, offload_trigger, trigger_hz directly in struct ad4691_state
- Link to v11: https://lore.kernel.org/r/20260515-ad4692-multichannel-sar-adc-driver-v11-0-eab27d852ac2@analog.com

Changes in v11:
- initial driver: fix commit message — IIO_CHAN_INFO_SAMP_FREQ is
  info_mask_separate throughout the series, not info_mask_shared_by_all
- initial driver: readable_reg / volatile_reg: replace open switch ranges
  for multi-byte sparse arrays with stride checks; intermediate (unaligned)
  addresses are now excluded so debugfs cannot trigger cross-boundary reads
- initial driver: add comment in ad4691_get_sampling_freq noting that
  AD4691_OSC_FREQ_REG is non-volatile and served from regcache; no lock
  is needed
- triggered buffer: restore .endianness = IIO_BE on AD4691_CHANNEL
  scan_type; accidentally dropped in v10
- triggered buffer: add early break in both iio_for_each_active_channel
  loops to skip the soft timestamp scan index; prevents out-of-bounds
  writes into scan_tx[] and scan_xfers[]
- triggered buffer: fix DMA aliasing in manual mode preenable — set
  rx_buf = NULL for the first transfer (pipeline residual) instead of
  aliasing it to vals[0] alongside the second transfer
- triggered buffer: add cs_change_delay of 430 ns on channel transfers
  to satisfy the minimum CNV high time requirement
- triggered buffer: remove cs_change=1 from the state-reset transfer;
  must not be set on the final transfer of a SPI message
- triggered buffer: move enable_irq() from the trigger handler into a
  reenable callback on ad4691_trigger_ops, closing the race between
  enable_irq and iio_trigger_notify_done; fix reenable return type
  (void, not int)
- triggered buffer: use two separate iio_info structs so that
  validate_trigger (iio_validate_own_trigger) is enforced only in CNV
  burst mode; manual mode must accept external triggers
- triggered buffer: add comment explaining STATE_RESET_ALL sequencing
  in CNV burst mode
- triggered buffer: fix STD_SEQ_CONFIG write in both preenable paths —
  apply & GENMASK(15, 0) to strip the soft timestamp bit before writing,
  matching the existing acc_mask computation
- oversampling: fix commit message — writing oversampling_ratio snaps
  target_osc_freq_Hz to preserve integer sampling_frequency read-back;
  the two attributes are not orthogonal
- docs: add missing Buffer data format section covering the __be16
  software path and the CPU-native offload DMA path
- Link to v10: https://lore.kernel.org/r/20260511-ad4692-multichannel-sar-adc-driver-v10-0-e1fbb1744e38@analog.com

Changes in v10:
- initial driver: depends on REGULATOR || COMPILE_TEST
- triggered buffer: fix vals[] layout — index vals[] with slot counter k,
  not channel index i; fixes sparse active_scan_mask producing garbage in
  userspace buffer
- triggered buffer: add comment to cnv_burst_buffer_postenable explaining
  why sampling_enable()/enable_irq() cannot be called from preenable
- triggered buffer + offload: scan_tx changed from __be16 to u16;
  non-offload path uses put_unaligned_be16() (bits_per_word=8); offload
  path uses plain native u16 assignments (bits_per_word=16); also fixes
  byte-order bug in manual preenable: command byte was in the low byte,
  now correctly shifted to the high byte
- oversampling: remove incorrect iio_for_each_active_channel() timestamp
  guards; active_scan_mask never includes the timestamp channel
- Link to v9: https://lore.kernel.org/r/20260430-ad4692-multichannel-sar-adc-driver-v9-0-33e439e4fb87@analog.com

Changes in v9:
- devm_regulator_get_enable() → devm_regulator_get_enable_optional() for
  vdd-supply. The non-optional variant silently returns a dummy regulator
  (ret=0) when the supply is absent from DT, so st->ldo_en was never set
  and the internal LDO was never enabled when only ldo-in-supply was provided.
- struct ad4691_channel_info (factoring channels + num_channels out of
  struct ad4691_chip_info into a sw_info pointer) is now introduced in
  commit 1 instead of commit 2. It is a pure struct cleanup with no
  relation to triggered buffers.
- channels and manual_channels fields in struct ad4691_channel_info
  are now annotated with __counted_by_ptr(num_channels).
- Link to v8: https://lore.kernel.org/r/20260416-ad4692-multichannel-sar-adc-driver-v8-0-c415bd048fa3@analog.com

Changes in v8:
- dt-bindings: add commit message note explaining why four separate
  compatible strings are required (channel count and max rate both
  differ between variants);
- initial driver: sizeof(tx) instead of literal 2 in ad4691_reg_read;
  U8_MAX/U16_MAX instead of 0xFF/0xFFFF in ad4691_reg_write
- initial driver: extract ad4691_samp_freq_start() helper
- initial driver: fix regulator model — vdd-supply (external 1.8V,
  internal LDO disabled) and ldo-in-supply (feeds internal LDO) are
  mutually exclusive; add vdd-supply to binding and driver
- initial driver: add comment in ad4691_reset explaining why
  devm_reset_control_get_optional_exclusive_deasserted() cannot be
  used (datasheet requires ≥300 µs reset pulse)
- initial driver: REF_CTRL and OSC_FREQ_REG: regmap_update_bits /
  regmap_assign_bits → regmap_write (reserved bits are 0 at reset)
- initial driver: use dev instead of &spi->dev in devm_iio_device_alloc
- triggered buffer: scan_tx: add __aligned(IIO_DMA_MINALIGN);
  scan struct: IIO_DECLARE_DMA_BUFFER_WITH_TS(__be16, vals, 16)
- triggered buffer: full memset of scan_xfers and scan_tx in both
  preenable functions; move buffer-dma.h / buffer-dmaengine.h to
  commit 4; spi_optimize_message fail path: return ret directly in
  cnv_burst_buffer_preenable; reduce devm_iio_trigger_alloc wrapping
- SPI offload: drop AD4691_OFFLOAD_BITS_PER_WORD; use local
  bpw = channels[0].scan_type.realbits; num_channels: ARRAY_SIZE - 1
- SPI offload: rename offload_state.spi → .offload; remove spurious
  STD_SEQ_CONFIG write from cnv_burst_offload predisable; extract
  local acc_mask variable for ACC_MASK_REG write
- SPI offload: sampling_frequency_store: IIO_DEV_ACQUIRE_DIRECT_MODE
  for auto-release; remove explicit iio_device_release_direct calls
- oversampling: in_voltageN_sampling_frequency now represents the
  effective output rate (osc_freq / osr[N]), matching ad4695
- oversampling: in_voltageN_sampling_frequency_available computed
  dynamically from the channel's current OSR; only oscillator entries
  divisible by osr[N] shown as effective rates; list becomes sparser
  as OSR increases, capping at max_rate / osr[N]
- oversampling: writing sampling_frequency snaps down to the largest
  oscillator entry ≤ freq * osr[N] that is divisible by osr[N],
  guaranteeing integer read-back; writing oversampling_ratio stores
  the new depth only — target_osc_freq_Hz unchanged; the two
  attributes are orthogonal
- oversampling: ad4691_write_osc_freq() called from
  ad4691_enter_conversion_mode() after manual mode early return,
  covering all CNV burst buffer enable paths
- oversampling: (osr + 1) oscillator period wait in single_shot_read
  (osr for accumulation, +1 pipeline margin)
- docs: new commit — Documentation/iio/ad4691.rst, userspace-facing
  only; oversampling section describes effective-rate SF semantics;
  LDO supply section corrected (vdd-supply vs ldo-in-supply)
- Link to v7: https://lore.kernel.org/r/20260409-ad4692-multichannel-sar-adc-driver-v7-0-be375d4df2c5@analog.com

Changes in v7:
- Fix CNV burst triggered-buffer preenable: the state-reset value
  transfer had tx_buf assigned the return value of cpu_to_be16()
  (an integer) instead of a pointer to a buffer, which would cause
  a kernel oops on buffer enable; extend scan_tx[] from 17 to 18
  entries to hold the extra slot and fix the pointer assignment
- Extend memset in ad4691_cnv_burst_buffer_preenable to cover the
  two state-reset transfer slots (previously left with stale data
  across buffer enable/disable cycles if the active channel count
  changed)
- Fix format specifier %u -> %lu for NSEC_PER_SEC in
  sampling_frequency_show (NSEC_PER_SEC is unsigned long on 32-bit)
- Fix missing iio_device_release_direct() on spi_offload_trigger_-
  validate() error path in sampling_frequency_store
- Correct SPI offload commit message: the implementation uses 16-bit
  SPI frames (bits_per_word=16, len=2), not 32-bit; storagebits
  remains 16 (not promoted to 32); there is no shift=16 for manual
  mode; ad4691_manual_channels[] hides IIO_CHAN_INFO_OVERSAMPLING_-
  RATIO (not applicable in manual mode), not encodes shift=16
- Link to v6: https://lore.kernel.org/r/20260403-ad4692-multichannel-sar-adc-driver-v6-0-fa2a01a57c4e@analog.com

Changes in v6:
- Replace device.h with dev_printk.h + device/devres.h; add array_size.h
- Rename osc_freqs[] → osc_freqs_Hz[] with explicit [0xN] index designators
- Move loop variable into for() declaration in set_sampling_freq
- Convert multi-line block comment to single-line in single_shot_read
- Replace (u16)~ cast with ~BIT() & GENMASK(15, 0) for ACC_MASK_REG write;
  GENMASK(15, 0) is still needed, otherwise maximum value condition line
  in reg_write() would fail.
- Extract osc_idx/period_us temporaries in single_shot_read; add comment
- Use devm_regulator_bulk_get_enable() for avdd + vio supplies
- Reformat reset_gpio_probe() comment; remove (GPIOD_OUT_HIGH) detail
- Extract REF_CTRL value into temporary before regmap_update_bits
- Use regmap_assign_bits for OSC_FREQ_REG in config
- Remove ad4691_free_scan_bufs NULL assignments; they are not checked.
- Replace indio_dev->masklength with iio_get_masklength() throughout
- Fix spi_optimize_message error path to use goto err in preenable
- Add iio_buffer_enabled() guard in sampling_frequency_store and
  set_oversampling_ratio
- Move ad4691_gpio_setup call from ad4691_config into
  setup_triggered_buffer after IRQ lookup; remove duplicate
  fwnode_irq_get_byname loop
- Replace oversampling ratio search loop with is_power_of_2 + ilog2
- Link to v5: https://lore.kernel.org/r/20260327-ad4692-multichannel-sar-adc-driver-v5-0-11f789de47b8@analog.com

Changes in v5:
- Reorder datasheets numerically
- Fix interrupt-names: use enum with minItems/maxItems
- Remove if/then block requiring interrupts — driver detail, not hardware constraint
- Remove redundant .shift = 0 from channel macro
- Write max_rate comparison as 1 * HZ_PER_MHZ
- Invert set_sampling_freq loop to use continue
- Fix fsleep() line break; remove blank line in read_raw
- Reorder supply init: vio immediately after avdd
- Move comment rewrites and OSC_FREQ_REG condition into the base driver patch
- Add bit-15 READ comment in reg_read
- Rewrite ldo-in handling with cleaner if/else-if pattern
- Drop redundant refbuf_en = false; invert if (!rst) in reset
- Drop reset_control_assert() — GPIO already asserted at probe
- Use regmap_update_bits/assign_bits in config
- Remove tab-column alignment of state struct members
- Declare osc_freqs[] as const int, eliminating explicit casts
- Drop obvious AUTONOMOUS mode comment
- Rename ACC_COUNT_LIMIT → ACC_DEPTH_IN to match datasheet
- Use bitmap_weight()/bitmap_read() for active_scan_mask access;
  add #include <linux/bitmap.h>
- Fix channel macro line-continuation tab alignment
- Use IIO_CHAN_SOFT_TIMESTAMP(8) for 8-channel variants
- Use aligned_s64 ts in scan struct
- Add comment explaining start-index removal in set_sampling_freq
- Remove trailing comma after NULL in buffer_attrs[]
- Add IRQF_NO_AUTOEN rationale comment
- Remove unreachable manual_mode guards in sampling_frequency_show/store
- Remove st->trig; use indio_dev->trig directly
- Move max_speed_hz param to the offload patch where it is used
- Use DIV_ROUND_UP for CNV period; use compound pwm_state initializer
- Move offload fields into a separately allocated sub-struct
- Build TX words via u8* byte-fill; fixes sparse __be32 warnings
- Add three scan types (NORMAL/OFFLOAD_CNV/OFFLOAD_MANUAL) with
  get_current_scan_type; triggered buffer path uses storagebits=16
- Fix IIO_CHAN_INFO_SCALE: use iio_get_current_scan_type() for realbits
- Add MODULE_IMPORT_NS("IIO_DMAENGINE_BUFFER")
- Add Documentation/iio/ad4691.rst
- Link to v4: https://lore.kernel.org/r/20260320-ad4692-multichannel-sar-adc-driver-v4-0-052c1050507a@analog.com

Changes in v4:
- dt-bindings: add avdd-supply (required) and ldo-in-supply (optional);
  rename vref-supply → ref-supply, vrefin-supply → refin-supply;
  corrected reset-gpios polarity (active-high → active-low); remove
  clocks and pwm-names; extend interrupts to up to 4 GP pins with
  interrupt-names "gp0".."gp3"; reduce #trigger-source-cells to
  const: 1 (GP pin number); add gpio-controller / #gpio-cells = <2>;
  drop adi,ad4691.h header; update binding examples
- driver: rename CNV Clock Mode → CNV Burst Mode throughout
- driver: add avdd-supply (required) and ldo-in-supply; track ref vs.
  refin supply for REFBUF_EN; set LDO_EN in DEVICE_SETUP when ldo-in
  is present; add software reset fallback via SPI_CONFIG_A register
- driver: merge ACC_MASK1_REG / ACC_MASK2_REG into ACC_MASK_REG with
  a single ADDR_DESCENDING 16-bit SPI write
- driver: remove clocks usage; set PWM rate directly without ref clock
- driver: rename chip info structs (ad4691_chip_info etc.); rename
  *chip → *info in state struct; replace adc_mode enum with manual_mode
  bool; replace ktime sampling_period with u32 cnv_period_ns
- driver: move IIO_CHAN_INFO_SAMP_FREQ to info_mask_separate with an
  available list for the internal oscillator frequency
- driver: use regcache MAPLE instead of RBTREE
- triggered buffer: derive DATA_READY GP pin from interrupt-names in
  firmware ("gp0".."gp3") instead of assuming GP0
- triggered buffer: use regmap_update_bits for DEVICE_SETUP mode toggle
  to avoid clobbering LDO_EN when toggling MANUAL_MODE bit
- triggered buffer: split buffer setup ops into separate Manual and
  CNV Burst variants (mirrors offload path structure)
- SPI offload: promote channel storagebits from 16 to 32 to match DMA
  word size; introduce ad4691_manual_channels[] with shift=16 (data in
  upper 16 bits of the 32-bit word); update triggered-buffer paths to
  the same layout for consistency
- SPI offload: derive GP pin from trigger-source args[0] instead of
  hardcoding GP0; split offload buffer setup ops per mode
- replace put_unaligned_be32() + FIELD_PREP() with cpu_to_be32() and
  plain bit-shift ops for SPI offload message construction
- multiple reviewer-requested code style and correctness fixes
  (Andy Shevchenko, Nuno Sá, Uwe Kleine-König, David Lechner)
- Link to v3: https://lore.kernel.org/r/20260313-ad4692-multichannel-sar-adc-driver-v3-0-b4d14d81a181@analog.com

Changes in v3:
- Replace GPIO reset handling with reset controller framework
- Replace two regmap_write() calls for ACC_MASK1/ACC_MASK2 with regmap_bulk_write()
- Move conv_us declaration closer to its first use
- Derive spi_device/dev from regmap instead of storing st->spi
- ad4691_trigger_handler(): use guard(mutex)() and iio_for_each_active_channel()
- ad4691_setup_triggered_buffer(): return -ENOMEM/-ENOENT directly instead of
  wrapping in dev_err_probe(); fix fwnode_irq_get() check (irq <= 0 → irq < 0)
- Add GENMASK defines for SPI offload 32-bit message layout; replace manual
  bit-shifts with put_unaligned_be32() + FIELD_PREP()
- Use DIV_ROUND_CLOSEST_ULL() instead of div64_u64()
- ad4691_set_sampling_freq(): fix indentation; drop unnecessary else after return
- ad4691_probe(): use PTR_ERR_OR_ZERO() for devm_spi_offload_get()
- Link to v2: https://lore.kernel.org/r/20260310-ad4692-multichannel-sar-adc-driver-v2-0-d9bb8aeb5e17@analog.com

Changes in v2:
- Drop adi,spi-mode DT property; operating mode now auto-detected
  from pwms presence (CNV Clock Mode if present, Manual Mode if not)
- Reduce from 5 operating modes to 2 (CNV Clock Mode, Manual Mode);
  Autonomous, SPI Burst and CNV Burst modes removed as user-selectable
  modes; Autonomous Mode is now the internal idle/single-shot state
- Single-shot read_raw always uses internal oscillator (Autonomous
  Mode), independent of the configured buffer mode
- Replace bulk regulator API with devm_regulator_get_enable() and
  devm_regulator_get_enable_read_voltage()
- Use guard(mutex) and IIO_DEV_ACQUIRE_DIRECT_MODE scoped helpers
- Replace enum + indexed chip_info array with named chip_info structs
- Remove product_id field and hardware ID check from probe
- Factor IIO_CHAN_INFO_RAW body into ad4691_single_shot_read() helper
- Use fwnode_irq_get(dev_fwnode(dev), 0); drop interrupt-names from
  DT binding
- Use devm_clk_get_enabled(dev, NULL); drop clock-names from DT
  binding
- Use spi_write_then_read() for DMA-safe register writes
- Use put_unaligned_be16() for SPI header construction
- fsleep() instead of usleep_range() in single-shot path
- storagebits 24->32 for manual-mode channels (uniform DMA layout)
- Collect full scan into vals[16], single iio_push_to_buffers_with_ts()
- Use pf->timestamp instead of iio_get_time_ns() in trigger handler
- Remove IRQF_TRIGGER_FALLING (comes from firmware/DT)
- Fix offload xfer array size ([17]: N channels + 1 state reset)
- Drop third DT binding example per reviewer request
- Link to v1: https://lore.kernel.org/r/20260305-ad4692-multichannel-sar-adc-driver-v1-0-336229a8dcc7@analog.com

---
Radu Sabau (6):
      dt-bindings: iio: adc: add AD4691 family
      iio: adc: ad4691: add initial driver for AD4691 family
      iio: adc: ad4691: add triggered buffer support
      iio: adc: ad4691: add SPI offload support
      iio: adc: ad4691: add oversampling support
      docs: iio: adc: ad4691: add driver documentation

 .../devicetree/bindings/iio/adc/adi,ad4691.yaml    |  180 ++
 Documentation/iio/ad4691.rst                       |  227 +++
 Documentation/iio/index.rst                        |    1 +
 MAINTAINERS                                        |    9 +
 drivers/iio/adc/Kconfig                            |   16 +
 drivers/iio/adc/Makefile                           |    1 +
 drivers/iio/adc/ad4691.c                           | 2084 ++++++++++++++++++++
 7 files changed, 2518 insertions(+)
---
base-commit: 5200f5f493f79f14bbdc349e402a40dfb32f23c8
change-id: 20260302-ad4692-multichannel-sar-adc-driver-78e4d44d24b2

Best regards,
-- 
Radu Sabau <radu.sabau@analog.com>



^ permalink raw reply

* [PATCH v14 2/6] iio: adc: ad4691: add initial driver for AD4691 family
From: Radu Sabau via B4 Relay @ 2026-05-29 10:15 UTC (permalink / raw)
  To: Lars-Peter Clausen, Michael Hennerich, Jonathan Cameron,
	David Lechner, Nuno Sá, Andy Shevchenko, Rob Herring,
	Krzysztof Kozlowski, Conor Dooley, Uwe Kleine-König,
	Liam Girdwood, Mark Brown, Linus Walleij, Bartosz Golaszewski,
	Philipp Zabel, Jonathan Corbet, Shuah Khan
  Cc: linux-iio, devicetree, linux-kernel, linux-pwm, linux-gpio,
	linux-doc, Radu Sabau
In-Reply-To: <20260529-ad4692-multichannel-sar-adc-driver-v14-0-e93c2747dc1f@analog.com>

From: Radu Sabau <radu.sabau@analog.com>

Add support for the Analog Devices AD4691 family of high-speed,
low-power multichannel SAR ADCs: AD4691 (16-ch, 500 kSPS),
AD4692 (16-ch, 1 MSPS), AD4693 (8-ch, 500 kSPS) and
AD4694 (8-ch, 1 MSPS).

The driver implements a custom regmap layer over raw SPI to handle the
device's mixed 1/2/3/4-byte register widths and uses the standard IIO
read_raw/write_raw interface for single-channel reads.

The chip idles in Autonomous Mode so that single-shot read_raw can use
the internal oscillator without disturbing the hardware configuration.

Three voltage supply domains are managed: avdd (required), vio, and a
reference supply on either the REF pin (ref-supply, external buffer)
or the REFIN pin (refin-supply, uses the on-chip reference buffer;
REFBUF_EN is set accordingly). Hardware reset is performed by asserting
then deasserting the reset-gpios GPIO line (tRESETL minimum pulse width
is 10 ns, satisfied by function-call overhead); the driver then waits
300 µs for the chip to complete its internal reset sequence. A software
reset via SPI_CONFIG_A is used as fallback when no reset GPIO is
provided.

Accumulator channel masking for single-shot reads uses ACC_MASK_REG via
an ADDR_DESCENDING SPI write, which covers both mask bytes in a single
16-bit transfer.

Reviewed-by: David Lechner <dlechner@baylibre.com>
Signed-off-by: Radu Sabau <radu.sabau@analog.com>
---
 MAINTAINERS              |   1 +
 drivers/iio/adc/Kconfig  |  12 +
 drivers/iio/adc/Makefile |   1 +
 drivers/iio/adc/ad4691.c | 783 +++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 797 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 7d31c38921e8..020c1ffae31b 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1488,6 +1488,7 @@ L:	linux-iio@vger.kernel.org
 S:	Supported
 W:	https://ez.analog.com/linux-software-drivers
 F:	Documentation/devicetree/bindings/iio/adc/adi,ad4691.yaml
+F:	drivers/iio/adc/ad4691.c
 
 ANALOG DEVICES INC AD4695 DRIVER
 M:	Michael Hennerich <michael.hennerich@analog.com>
diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index a9dedbb8eb46..c9aca0d08e41 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -144,6 +144,18 @@ config AD4170_4
 	  To compile this driver as a module, choose M here: the module will be
 	  called ad4170-4.
 
+config AD4691
+	tristate "Analog Devices AD4691 Family ADC Driver"
+	depends on SPI
+	depends on REGULATOR || COMPILE_TEST
+	select REGMAP
+	help
+	  Say yes here to build support for Analog Devices AD4691 Family MuxSAR
+	  SPI analog to digital converters (ADC).
+
+	  To compile this driver as a module, choose M here: the module will be
+	  called ad4691.
+
 config AD4695
 	tristate "Analog Device AD4695 ADC Driver"
 	depends on SPI
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index 097357d146ba..707dd708912f 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -16,6 +16,7 @@ obj-$(CONFIG_AD4080) += ad4080.o
 obj-$(CONFIG_AD4130) += ad4130.o
 obj-$(CONFIG_AD4134) += ad4134.o
 obj-$(CONFIG_AD4170_4) += ad4170-4.o
+obj-$(CONFIG_AD4691) += ad4691.o
 obj-$(CONFIG_AD4695) += ad4695.o
 obj-$(CONFIG_AD4851) += ad4851.o
 obj-$(CONFIG_AD7091R) += ad7091r-base.o
diff --git a/drivers/iio/adc/ad4691.c b/drivers/iio/adc/ad4691.c
new file mode 100644
index 000000000000..e1febf80f21d
--- /dev/null
+++ b/drivers/iio/adc/ad4691.c
@@ -0,0 +1,783 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2024-2026 Analog Devices, Inc.
+ * Author: Radu Sabau <radu.sabau@analog.com>
+ */
+#include <linux/array_size.h>
+#include <linux/bitfield.h>
+#include <linux/bitmap.h>
+#include <linux/cleanup.h>
+#include <linux/delay.h>
+#include <linux/dev_printk.h>
+#include <linux/device/devres.h>
+#include <linux/err.h>
+#include <linux/limits.h>
+#include <linux/math.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+#include <linux/reset.h>
+#include <linux/spi/spi.h>
+#include <linux/types.h>
+#include <linux/units.h>
+#include <linux/unaligned.h>
+
+#include <linux/iio/iio.h>
+
+#define AD4691_VREF_uV_MIN			2400000
+#define AD4691_VREF_uV_MAX			5250000
+#define AD4691_VREF_2P5_uV_MAX			2750000
+#define AD4691_VREF_3P0_uV_MAX			3250000
+#define AD4691_VREF_3P3_uV_MAX			3750000
+#define AD4691_VREF_4P096_uV_MAX		4500000
+
+#define AD4691_CNV_DUTY_CYCLE_NS		380
+#define AD4691_CNV_HIGH_TIME_NS			430
+
+#define AD4691_SPI_CONFIG_A_REG			0x000
+#define AD4691_SW_RESET				(BIT(7) | BIT(0))
+
+#define AD4691_STATUS_REG			0x014
+#define AD4691_CLAMP_STATUS1_REG		0x01A
+#define AD4691_CLAMP_STATUS2_REG		0x01B
+#define AD4691_DEVICE_SETUP			0x020
+#define AD4691_MANUAL_MODE			BIT(2)
+#define AD4691_LDO_EN				BIT(4)
+#define AD4691_REF_CTRL				0x021
+#define AD4691_REF_CTRL_MASK			GENMASK(4, 2)
+#define AD4691_REFBUF_EN			BIT(0)
+#define AD4691_OSC_FREQ_REG			0x023
+#define AD4691_OSC_FREQ_MASK			GENMASK(3, 0)
+#define AD4691_STD_SEQ_CONFIG			0x025
+#define AD4691_SEQ_ALL_CHANNELS_OFF		0x00
+#define AD4691_SPARE_CONTROL			0x02A
+
+#define AD4691_MAX_CHANNELS			16
+
+#define AD4691_NOOP				0x00
+#define AD4691_ADC_CHAN(ch)			((0x10 + (ch)) << 3)
+
+#define AD4691_OSC_EN_REG			0x180
+#define AD4691_STATE_RESET_REG			0x181
+#define AD4691_STATE_RESET_ALL			BIT(0)
+#define AD4691_ADC_SETUP			0x182
+#define AD4691_ADC_MODE_MASK			GENMASK(1, 0)
+#define AD4691_CNV_BURST_MODE			0x01
+#define AD4691_AUTONOMOUS_MODE			0x02
+/*
+ * ACC_MASK_REG covers both mask bytes via ADDR_DESCENDING SPI: writing a
+ * 16-bit BE value to 0x185 auto-decrements to 0x184 for the second byte.
+ */
+#define AD4691_ACC_MASK_REG			0x185
+#define AD4691_ACC_DEPTH_IN(n)			(0x186 + (n))
+#define AD4691_GPIO_MODE1_REG			0x196
+#define AD4691_GPIO_MODE2_REG			0x197
+#define AD4691_GP_MODE_MASK			GENMASK(3, 0)
+#define AD4691_GP_MODE_DATA_READY		0x06
+#define AD4691_GPIO_READ			0x1A0
+#define AD4691_ACC_STATUS_FULL1_REG		0x1B0
+#define AD4691_ACC_STATUS_FULL2_REG		0x1B1
+#define AD4691_ACC_STATUS_OVERRUN1_REG		0x1B2
+#define AD4691_ACC_STATUS_OVERRUN2_REG		0x1B3
+#define AD4691_ACC_STATUS_SAT1_REG		0x1B4
+#define AD4691_ACC_STATUS_SAT2_REG		0x1BE
+#define AD4691_ACC_SAT_OVR_REG(n)		(0x1C0 + (n))
+#define AD4691_AVG_IN(n)			(0x201 + (2 * (n)))
+#define AD4691_AVG_STS_IN(n)			(0x222 + (3 * (n)))
+#define AD4691_ACC_IN(n)			(0x252 + (3 * (n)))
+#define AD4691_ACC_STS_DATA(n)			(0x283 + (4 * (n)))
+
+
+static const char * const ad4691_supplies[] = { "avdd", "vio" };
+
+enum ad4691_ref_ctrl {
+	AD4691_VREF_2P5,
+	AD4691_VREF_3P0,
+	AD4691_VREF_3P3,
+	AD4691_VREF_4P096,
+	AD4691_VREF_5P0
+};
+
+struct ad4691_channel_info {
+	const struct iio_chan_spec *channels __counted_by_ptr(num_channels);
+	unsigned int num_channels;
+};
+
+struct ad4691_chip_info {
+	const char *name;
+	unsigned int max_rate;
+	const struct ad4691_channel_info *sw_info;
+};
+
+#define AD4691_CHANNEL(ch)						\
+	{								\
+		.type = IIO_VOLTAGE,					\
+		.indexed = 1,						\
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
+		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SCALE)	\
+				    | BIT(IIO_CHAN_INFO_SAMP_FREQ),	\
+		.info_mask_shared_by_all_available =			\
+				      BIT(IIO_CHAN_INFO_SAMP_FREQ),	\
+		.channel = ch,						\
+		.scan_type = {						\
+			.realbits = 16,					\
+		},							\
+	}
+
+static const struct iio_chan_spec ad4691_channels[] = {
+	AD4691_CHANNEL(0),
+	AD4691_CHANNEL(1),
+	AD4691_CHANNEL(2),
+	AD4691_CHANNEL(3),
+	AD4691_CHANNEL(4),
+	AD4691_CHANNEL(5),
+	AD4691_CHANNEL(6),
+	AD4691_CHANNEL(7),
+	AD4691_CHANNEL(8),
+	AD4691_CHANNEL(9),
+	AD4691_CHANNEL(10),
+	AD4691_CHANNEL(11),
+	AD4691_CHANNEL(12),
+	AD4691_CHANNEL(13),
+	AD4691_CHANNEL(14),
+	AD4691_CHANNEL(15),
+};
+
+static const struct iio_chan_spec ad4693_channels[] = {
+	AD4691_CHANNEL(0),
+	AD4691_CHANNEL(1),
+	AD4691_CHANNEL(2),
+	AD4691_CHANNEL(3),
+	AD4691_CHANNEL(4),
+	AD4691_CHANNEL(5),
+	AD4691_CHANNEL(6),
+	AD4691_CHANNEL(7),
+};
+
+static const struct ad4691_channel_info ad4691_sw_info = {
+	.channels = ad4691_channels,
+	.num_channels = ARRAY_SIZE(ad4691_channels),
+};
+
+static const struct ad4691_channel_info ad4693_sw_info = {
+	.channels = ad4693_channels,
+	.num_channels = ARRAY_SIZE(ad4693_channels),
+};
+
+/*
+ * Internal oscillator frequency table. Index is the OSC_FREQ_REG[3:0] value.
+ * Index 0 (1 MHz) is only valid for AD4692/AD4694; AD4691/AD4693 support
+ * up to 500 kHz and use index 1 as their highest valid rate.
+ */
+static const int ad4691_osc_freqs_Hz[] = {
+	[0x0] = 1000000,
+	[0x1] = 500000,
+	[0x2] = 400000,
+	[0x3] = 250000,
+	[0x4] = 200000,
+	[0x5] = 167000,
+	[0x6] = 133000,
+	[0x7] = 125000,
+	[0x8] = 100000,
+	[0x9] = 50000,
+	[0xA] = 25000,
+	[0xB] = 12500,
+	[0xC] = 10000,
+	[0xD] = 5000,
+	[0xE] = 2500,
+	[0xF] = 1250,
+};
+
+static const struct ad4691_chip_info ad4691_chip_info = {
+	.name = "ad4691",
+	.max_rate = 500 * HZ_PER_KHZ,
+	.sw_info = &ad4691_sw_info,
+};
+
+static const struct ad4691_chip_info ad4692_chip_info = {
+	.name = "ad4692",
+	.max_rate = 1 * HZ_PER_MHZ,
+	.sw_info = &ad4691_sw_info,
+};
+
+static const struct ad4691_chip_info ad4693_chip_info = {
+	.name = "ad4693",
+	.max_rate = 500 * HZ_PER_KHZ,
+	.sw_info = &ad4693_sw_info,
+};
+
+static const struct ad4691_chip_info ad4694_chip_info = {
+	.name = "ad4694",
+	.max_rate = 1 * HZ_PER_MHZ,
+	.sw_info = &ad4693_sw_info,
+};
+
+struct ad4691_state {
+	const struct ad4691_chip_info *info;
+	struct regmap *regmap;
+	struct spi_device *spi;
+
+	int vref_uV;
+
+	bool refbuf_en;
+	bool ldo_en;
+	/*
+	 * Synchronize access to members of the driver state, and ensure
+	 * atomicity of consecutive SPI operations.
+	 */
+	struct mutex lock;
+};
+
+static int ad4691_reg_read(void *context, unsigned int reg, unsigned int *val)
+{
+	struct spi_device *spi = context;
+	u8 tx[2], rx[4];
+	int ret;
+
+	/* Set bit 15 to mark the operation as READ. */
+	put_unaligned_be16(0x8000 | reg, tx);
+
+	switch (reg) {
+	case 0 ... AD4691_OSC_FREQ_REG:
+	case AD4691_SPARE_CONTROL ... AD4691_ACC_MASK_REG - 1:
+	case AD4691_ACC_MASK_REG + 1 ... AD4691_ACC_SAT_OVR_REG(15):
+		ret = spi_write_then_read(spi, tx, sizeof(tx), rx, 1);
+		if (ret)
+			return ret;
+		*val = rx[0];
+		return 0;
+	case AD4691_ACC_MASK_REG:
+	case AD4691_STD_SEQ_CONFIG:
+	case AD4691_AVG_IN(0) ... AD4691_AVG_IN(15):
+		ret = spi_write_then_read(spi, tx, sizeof(tx), rx, 2);
+		if (ret)
+			return ret;
+		*val = get_unaligned_be16(rx);
+		return 0;
+	case AD4691_AVG_STS_IN(0) ... AD4691_AVG_STS_IN(15):
+	case AD4691_ACC_IN(0) ... AD4691_ACC_IN(15):
+		ret = spi_write_then_read(spi, tx, sizeof(tx), rx, 3);
+		if (ret)
+			return ret;
+		*val = get_unaligned_be24(rx);
+		return 0;
+	case AD4691_ACC_STS_DATA(0) ... AD4691_ACC_STS_DATA(15):
+		ret = spi_write_then_read(spi, tx, sizeof(tx), rx, 4);
+		if (ret)
+			return ret;
+		*val = get_unaligned_be32(rx);
+		return 0;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int ad4691_reg_write(void *context, unsigned int reg, unsigned int val)
+{
+	struct spi_device *spi = context;
+	u8 tx[4];
+
+	put_unaligned_be16(reg, tx);
+
+	switch (reg) {
+	case 0 ... AD4691_OSC_FREQ_REG:
+	case AD4691_SPARE_CONTROL ... AD4691_ACC_MASK_REG - 1:
+	case AD4691_ACC_MASK_REG + 1 ... AD4691_GPIO_MODE2_REG:
+		if (val > U8_MAX)
+			return -EINVAL;
+		tx[2] = val;
+		return spi_write_then_read(spi, tx, 3, NULL, 0);
+	case AD4691_ACC_MASK_REG:
+	case AD4691_STD_SEQ_CONFIG:
+		if (val > U16_MAX)
+			return -EINVAL;
+		put_unaligned_be16(val, &tx[2]);
+		return spi_write_then_read(spi, tx, 4, NULL, 0);
+	default:
+		return -EINVAL;
+	}
+}
+
+static bool ad4691_volatile_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case AD4691_STATUS_REG:
+	case AD4691_CLAMP_STATUS1_REG:
+	case AD4691_CLAMP_STATUS2_REG:
+	case AD4691_GPIO_READ:
+	case AD4691_ACC_STATUS_FULL1_REG ... AD4691_ACC_STATUS_SAT2_REG:
+	case AD4691_ACC_SAT_OVR_REG(0) ... AD4691_ACC_SAT_OVR_REG(15):
+	case AD4691_AVG_IN(0) ... AD4691_AVG_IN(15):
+	case AD4691_AVG_STS_IN(0) ... AD4691_AVG_STS_IN(15):
+	case AD4691_ACC_IN(0) ... AD4691_ACC_IN(15):
+	case AD4691_ACC_STS_DATA(0) ... AD4691_ACC_STS_DATA(15):
+		return true;
+	default:
+		return false;
+	}
+}
+
+static bool ad4691_readable_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case 0 ... AD4691_OSC_FREQ_REG:
+	case AD4691_SPARE_CONTROL ... AD4691_ACC_SAT_OVR_REG(15):
+	case AD4691_STD_SEQ_CONFIG:
+		return true;
+	default:
+		break;
+	}
+
+	/*
+	 * Multi-byte result registers have non-unit strides; only the base
+	 * address of each entry is a valid single-register read.
+	 */
+	if (reg >= AD4691_AVG_IN(0) && reg <= AD4691_AVG_IN(15))
+		return (reg - AD4691_AVG_IN(0)) % 2 == 0;
+	if (reg >= AD4691_AVG_STS_IN(0) && reg <= AD4691_AVG_STS_IN(15))
+		return (reg - AD4691_AVG_STS_IN(0)) % 3 == 0;
+	if (reg >= AD4691_ACC_IN(0) && reg <= AD4691_ACC_IN(15))
+		return (reg - AD4691_ACC_IN(0)) % 3 == 0;
+	if (reg >= AD4691_ACC_STS_DATA(0) && reg <= AD4691_ACC_STS_DATA(15))
+		return (reg - AD4691_ACC_STS_DATA(0)) % 4 == 0;
+
+	return false;
+}
+
+static bool ad4691_writeable_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case 0 ... AD4691_OSC_FREQ_REG:
+	case AD4691_STD_SEQ_CONFIG:
+	case AD4691_SPARE_CONTROL ... AD4691_GPIO_MODE2_REG:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static const struct regmap_config ad4691_regmap_config = {
+	.reg_bits = 16,
+	.val_bits = 32,
+	.reg_read = ad4691_reg_read,
+	.reg_write = ad4691_reg_write,
+	.volatile_reg = ad4691_volatile_reg,
+	.readable_reg = ad4691_readable_reg,
+	.writeable_reg = ad4691_writeable_reg,
+	.max_register = AD4691_ACC_STS_DATA(15),
+	.cache_type = REGCACHE_MAPLE,
+};
+
+/*
+ * Index 0 in ad4691_osc_freqs_Hz is 1 MHz — valid only for AD4692/AD4694
+ * (max_rate == 1 MHz). AD4691/AD4693 cap at 500 kHz so their valid range
+ * starts at index 1.
+ */
+static unsigned int ad4691_samp_freq_start(const struct ad4691_chip_info *info)
+{
+	return (info->max_rate == 1 * HZ_PER_MHZ) ? 0 : 1;
+}
+
+static int ad4691_get_sampling_freq(struct ad4691_state *st, int *val)
+{
+	unsigned int reg_val;
+	int ret;
+
+	guard(mutex)(&st->lock);
+
+	ret = regmap_read(st->regmap, AD4691_OSC_FREQ_REG, &reg_val);
+	if (ret)
+		return ret;
+
+	*val = ad4691_osc_freqs_Hz[FIELD_GET(AD4691_OSC_FREQ_MASK, reg_val)];
+	return IIO_VAL_INT;
+}
+
+static int ad4691_set_sampling_freq(struct ad4691_state *st, int freq)
+{
+	unsigned int start = ad4691_samp_freq_start(st->info);
+
+	guard(mutex)(&st->lock);
+
+	for (unsigned int i = start; i < ARRAY_SIZE(ad4691_osc_freqs_Hz); i++) {
+		if (ad4691_osc_freqs_Hz[i] != freq)
+			continue;
+		return regmap_update_bits(st->regmap, AD4691_OSC_FREQ_REG,
+					  AD4691_OSC_FREQ_MASK, i);
+	}
+
+	return -EINVAL;
+}
+
+static int ad4691_read_avail(struct iio_dev *indio_dev,
+			     struct iio_chan_spec const *chan,
+			     const int **vals, int *type,
+			     int *length, long mask)
+{
+	struct ad4691_state *st = iio_priv(indio_dev);
+	unsigned int start = ad4691_samp_freq_start(st->info);
+
+	switch (mask) {
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		*vals = &ad4691_osc_freqs_Hz[start];
+		*type = IIO_VAL_INT;
+		*length = ARRAY_SIZE(ad4691_osc_freqs_Hz) - start;
+		return IIO_AVAIL_LIST;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int ad4691_single_shot_read(struct iio_dev *indio_dev,
+				   struct iio_chan_spec const *chan, int *val)
+{
+	struct ad4691_state *st = iio_priv(indio_dev);
+	unsigned int reg_val, osc_idx, period_us;
+	int ret;
+
+	guard(mutex)(&st->lock);
+
+	/* Use AUTONOMOUS mode for single-shot reads. */
+	ret = regmap_write(st->regmap, AD4691_STATE_RESET_REG, AD4691_STATE_RESET_ALL);
+	if (ret)
+		return ret;
+
+	ret = regmap_write(st->regmap, AD4691_STD_SEQ_CONFIG,
+			   BIT(chan->channel));
+	if (ret)
+		return ret;
+
+	ret = regmap_write(st->regmap, AD4691_ACC_MASK_REG,
+			   ~BIT(chan->channel) & GENMASK(15, 0));
+	if (ret)
+		return ret;
+
+	ret = regmap_read(st->regmap, AD4691_OSC_FREQ_REG, &reg_val);
+	if (ret)
+		return ret;
+
+	ret = regmap_write(st->regmap, AD4691_OSC_EN_REG, 1);
+	if (ret)
+		return ret;
+
+	osc_idx = FIELD_GET(AD4691_OSC_FREQ_MASK, reg_val);
+	/* Wait 2 oscillator periods for the conversion to complete. */
+	period_us = DIV_ROUND_UP(2UL * USEC_PER_SEC, ad4691_osc_freqs_Hz[osc_idx]);
+	fsleep(period_us);
+
+	ret = regmap_write(st->regmap, AD4691_OSC_EN_REG, 0);
+	if (ret)
+		return ret;
+
+	ret = regmap_read(st->regmap, AD4691_AVG_IN(chan->channel), &reg_val);
+	if (ret)
+		return ret;
+
+	*val = reg_val;
+
+	ret = regmap_write(st->regmap, AD4691_STATE_RESET_REG, AD4691_STATE_RESET_ALL);
+	if (ret)
+		return ret;
+
+	return IIO_VAL_INT;
+}
+
+static int ad4691_read_raw(struct iio_dev *indio_dev,
+			   struct iio_chan_spec const *chan, int *val,
+			   int *val2, long info)
+{
+	struct ad4691_state *st = iio_priv(indio_dev);
+
+	switch (info) {
+	case IIO_CHAN_INFO_RAW: {
+		IIO_DEV_ACQUIRE_DIRECT_MODE(indio_dev, claim);
+		if (IIO_DEV_ACQUIRE_FAILED(claim))
+			return -EBUSY;
+
+		return ad4691_single_shot_read(indio_dev, chan, val);
+	}
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		return ad4691_get_sampling_freq(st, val);
+	case IIO_CHAN_INFO_SCALE:
+		*val = st->vref_uV / (MICRO / MILLI);
+		*val2 = chan->scan_type.realbits;
+		return IIO_VAL_FRACTIONAL_LOG2;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int ad4691_write_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *chan,
+			    int val, int val2, long mask)
+{
+	struct ad4691_state *st = iio_priv(indio_dev);
+
+	IIO_DEV_ACQUIRE_DIRECT_MODE(indio_dev, claim);
+	if (IIO_DEV_ACQUIRE_FAILED(claim))
+		return -EBUSY;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		return ad4691_set_sampling_freq(st, val);
+	default:
+		return -EINVAL;
+	}
+}
+
+static int ad4691_reg_access(struct iio_dev *indio_dev, unsigned int reg,
+			     unsigned int writeval, unsigned int *readval)
+{
+	struct ad4691_state *st = iio_priv(indio_dev);
+
+	guard(mutex)(&st->lock);
+
+	if (readval)
+		return regmap_read(st->regmap, reg, readval);
+
+	return regmap_write(st->regmap, reg, writeval);
+}
+
+static const struct iio_info ad4691_info = {
+	.read_raw = ad4691_read_raw,
+	.write_raw = ad4691_write_raw,
+	.read_avail = ad4691_read_avail,
+	.debugfs_reg_access = ad4691_reg_access,
+};
+
+static int ad4691_regulator_setup(struct ad4691_state *st)
+{
+	struct device *dev = regmap_get_device(st->regmap);
+	int ret;
+
+	ret = devm_regulator_bulk_get_enable(dev, ARRAY_SIZE(ad4691_supplies),
+					     ad4691_supplies);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to get and enable supplies\n");
+
+	/*
+	 * vdd-supply and ldo-in-supply are mutually exclusive:
+	 *   vdd-supply present  → external 1.8V VDD; disable internal LDO.
+	 *   vdd-supply absent   → enable internal LDO fed from ldo-in-supply.
+	 * Having both simultaneously is strongly inadvisable per the datasheet.
+	 */
+	if (device_property_present(dev, "vdd-supply")) {
+		ret = devm_regulator_get_enable(dev, "vdd");
+		if (ret)
+			return dev_err_probe(dev, ret,
+					     "Failed to get and enable VDD\n");
+	} else if (device_property_present(dev, "ldo-in-supply")) {
+		ret = devm_regulator_get_enable(dev, "ldo-in");
+		if (ret)
+			return dev_err_probe(dev, ret,
+					     "Failed to get and enable LDO-IN\n");
+		st->ldo_en = true;
+	} else {
+		return dev_err_probe(dev, -EINVAL,
+				     "missing one of vdd-supply, ldo-in-supply\n");
+	}
+
+	if (device_property_present(dev, "ref-supply")) {
+		st->vref_uV = devm_regulator_get_enable_read_voltage(dev, "ref");
+		if (st->vref_uV < 0)
+			return dev_err_probe(dev, st->vref_uV,
+					     "Failed to get REF supply voltage\n");
+	} else if (device_property_present(dev, "refin-supply")) {
+		st->vref_uV = devm_regulator_get_enable_read_voltage(dev, "refin");
+		if (st->vref_uV < 0)
+			return dev_err_probe(dev, st->vref_uV,
+					     "Failed to get REFIN supply voltage\n");
+		st->refbuf_en = true;
+	} else {
+		return dev_err_probe(dev, -EINVAL,
+				     "missing one of ref-supply, refin-supply\n");
+	}
+
+	if (st->vref_uV < AD4691_VREF_uV_MIN || st->vref_uV > AD4691_VREF_uV_MAX)
+		return dev_err_probe(dev, -EINVAL,
+				     "vref(%d) must be in the range [%u...%u]\n",
+				     st->vref_uV, AD4691_VREF_uV_MIN,
+				     AD4691_VREF_uV_MAX);
+
+	return 0;
+}
+
+static int ad4691_reset(struct ad4691_state *st)
+{
+	struct device *dev = regmap_get_device(st->regmap);
+	struct reset_control *rst;
+	int ret;
+
+	rst = devm_reset_control_get_optional_exclusive(dev, NULL);
+	if (IS_ERR(rst))
+		return dev_err_probe(dev, PTR_ERR(rst), "Failed to get reset\n");
+
+	if (rst) {
+		/*
+		 * Assert the reset line to guarantee a clean reset pulse on
+		 * every probe, including driver reloads where the line may
+		 * already be deasserted (reset_control_put() does not
+		 * re-assert on release). tRESETL (minimum pulse width) = 10 ns
+		 * (Table 5); kernel function-call overhead alone exceeds this,
+		 * so no explicit delay is needed between assert and deassert.
+		 */
+		reset_control_assert(rst);
+		ret = reset_control_deassert(rst);
+		if (ret)
+			return ret;
+	} else {
+		/* No hardware reset available, fall back to software reset. */
+		ret = regmap_write(st->regmap, AD4691_SPI_CONFIG_A_REG,
+				   AD4691_SW_RESET);
+		if (ret)
+			return ret;
+	}
+
+	/*
+	 * Wait 300 µs (Table 5) for the device to complete its internal reset
+	 * sequence before accepting SPI commands.
+	 */
+	fsleep(300);
+	return 0;
+}
+
+static int ad4691_config(struct ad4691_state *st)
+{
+	struct device *dev = regmap_get_device(st->regmap);
+	enum ad4691_ref_ctrl ref_val;
+	unsigned int val;
+	int ret;
+
+	switch (st->vref_uV) {
+	case AD4691_VREF_uV_MIN ... AD4691_VREF_2P5_uV_MAX:
+		ref_val = AD4691_VREF_2P5;
+		break;
+	case AD4691_VREF_2P5_uV_MAX + 1 ... AD4691_VREF_3P0_uV_MAX:
+		ref_val = AD4691_VREF_3P0;
+		break;
+	case AD4691_VREF_3P0_uV_MAX + 1 ... AD4691_VREF_3P3_uV_MAX:
+		ref_val = AD4691_VREF_3P3;
+		break;
+	case AD4691_VREF_3P3_uV_MAX + 1 ... AD4691_VREF_4P096_uV_MAX:
+		ref_val = AD4691_VREF_4P096;
+		break;
+	case AD4691_VREF_4P096_uV_MAX + 1 ... AD4691_VREF_uV_MAX:
+		ref_val = AD4691_VREF_5P0;
+		break;
+	default:
+		return dev_err_probe(dev, -EINVAL,
+				     "Unsupported vref voltage: %d uV\n",
+				     st->vref_uV);
+	}
+
+	val = FIELD_PREP(AD4691_REF_CTRL_MASK, ref_val);
+	if (st->refbuf_en)
+		val |= AD4691_REFBUF_EN;
+
+	ret = regmap_write(st->regmap, AD4691_REF_CTRL, val);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to write REF_CTRL\n");
+
+	ret = regmap_assign_bits(st->regmap, AD4691_DEVICE_SETUP,
+				 AD4691_LDO_EN, st->ldo_en);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to write DEVICE_SETUP\n");
+
+	/*
+	 * Set the internal oscillator to the highest rate this chip supports.
+	 * Index 0 (1 MHz) exceeds the 500 kHz max of AD4691/AD4693, so those
+	 * chips start at index 1 (500 kHz).
+	 */
+	ret = regmap_write(st->regmap, AD4691_OSC_FREQ_REG,
+			   ad4691_samp_freq_start(st->info));
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to write OSC_FREQ\n");
+
+	ret = regmap_update_bits(st->regmap, AD4691_ADC_SETUP,
+				 AD4691_ADC_MODE_MASK, AD4691_AUTONOMOUS_MODE);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to write ADC_SETUP\n");
+
+	return 0;
+}
+
+static int ad4691_probe(struct spi_device *spi)
+{
+	struct device *dev = &spi->dev;
+	struct iio_dev *indio_dev;
+	struct ad4691_state *st;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	st = iio_priv(indio_dev);
+	st->spi = spi;
+	st->info = spi_get_device_match_data(spi);
+	if (!st->info)
+		return -ENODEV;
+
+	ret = devm_mutex_init(dev, &st->lock);
+	if (ret)
+		return ret;
+
+	st->regmap = devm_regmap_init(dev, NULL, spi, &ad4691_regmap_config);
+	if (IS_ERR(st->regmap))
+		return dev_err_probe(dev, PTR_ERR(st->regmap),
+				     "Failed to initialize regmap\n");
+
+	ret = ad4691_regulator_setup(st);
+	if (ret)
+		return ret;
+
+	ret = ad4691_reset(st);
+	if (ret)
+		return ret;
+
+	ret = ad4691_config(st);
+	if (ret)
+		return ret;
+
+	indio_dev->name = st->info->name;
+	indio_dev->info = &ad4691_info;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+
+	indio_dev->channels = st->info->sw_info->channels;
+	indio_dev->num_channels = st->info->sw_info->num_channels;
+
+	return devm_iio_device_register(dev, indio_dev);
+}
+
+static const struct of_device_id ad4691_of_match[] = {
+	{ .compatible = "adi,ad4691", .data = &ad4691_chip_info },
+	{ .compatible = "adi,ad4692", .data = &ad4692_chip_info },
+	{ .compatible = "adi,ad4693", .data = &ad4693_chip_info },
+	{ .compatible = "adi,ad4694", .data = &ad4694_chip_info },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ad4691_of_match);
+
+static const struct spi_device_id ad4691_id[] = {
+	{ .name = "ad4691", .driver_data = (kernel_ulong_t)&ad4691_chip_info },
+	{ .name = "ad4692", .driver_data = (kernel_ulong_t)&ad4692_chip_info },
+	{ .name = "ad4693", .driver_data = (kernel_ulong_t)&ad4693_chip_info },
+	{ .name = "ad4694", .driver_data = (kernel_ulong_t)&ad4694_chip_info },
+	{ }
+};
+MODULE_DEVICE_TABLE(spi, ad4691_id);
+
+static struct spi_driver ad4691_driver = {
+	.driver = {
+		.name = "ad4691",
+		.of_match_table = ad4691_of_match,
+	},
+	.probe = ad4691_probe,
+	.id_table = ad4691_id,
+};
+module_spi_driver(ad4691_driver);
+
+MODULE_AUTHOR("Radu Sabau <radu.sabau@analog.com>");
+MODULE_DESCRIPTION("Analog Devices AD4691 Family ADC Driver");
+MODULE_LICENSE("GPL");

-- 
2.43.0



^ permalink raw reply related

* [PATCH v5 10/10] RAS: add firmware-first CPER provider
From: Ahmed Tiba @ 2026-05-29  9:50 UTC (permalink / raw)
  To: will, jic23, xueshuai, saket.dumbre, mchehab, dave, djbw, bp,
	tony.luck, guohanjun, lenb, skhan, vishal.l.verma, rafael, corbet,
	ira.weiny, dave.jiang, krzk+dt, robh, catalin.marinas,
	alison.schofield, conor+dt
  Cc: Ahmed Tiba, linux-arm-kernel, Michael.Zhao2, linux-doc,
	linux-kernel, linux-cxl, Dmitry.Lamerov, devicetree, linux-acpi,
	linux-edac, acpica-devel
In-Reply-To: <20260529-topics-ahmtib01-ras_ffh_arm_internal_review-v5-0-2e0500d42642@arm.com>

Add a firmware-first CPER provider that reuses the shared
GHES helpers, wire it into the RAS Kconfig/Makefile and
document it in the admin guide.

Update MAINTAINERS now that the driver exists.

Signed-off-by: Ahmed Tiba <ahmed.tiba@arm.com>
---
 Documentation/admin-guide/RAS/main.rst |  18 +++
 MAINTAINERS                            |   1 +
 drivers/acpi/apei/apei-internal.h      |  10 +-
 drivers/acpi/apei/ghes_cper.c          |   2 +
 drivers/ras/Kconfig                    |  11 ++
 drivers/ras/Makefile                   |   1 +
 drivers/ras/cper-esource.c             | 257 +++++++++++++++++++++++++++++++++
 include/acpi/ghes_cper.h               |  10 ++
 8 files changed, 301 insertions(+), 9 deletions(-)

diff --git a/Documentation/admin-guide/RAS/main.rst b/Documentation/admin-guide/RAS/main.rst
index 5a45db32c49b..84219d25a072 100644
--- a/Documentation/admin-guide/RAS/main.rst
+++ b/Documentation/admin-guide/RAS/main.rst
@@ -205,6 +205,24 @@ Architecture (MCA)\ [#f3]_.
 .. [#f3] For more details about the Machine Check Architecture (MCA),
   please read Documentation/arch/x86/x86_64/machinecheck.rst at the Kernel tree.
 
+Firmware-first CPER providers
+-----------------------------
+
+Some systems expose Common Platform Error Record (CPER) data
+through platform firmware instead of ACPI HEST tables.
+Enable ``CONFIG_RAS_CPER_ESOURCE`` to build the ``drivers/ras/cper-esource.c``
+driver. The current in-tree firmware description uses the
+``Documentation/devicetree/bindings/firmware/arm,ras-cper.yaml`` binding.
+The driver reuses the GHES CPER helper object in
+``drivers/acpi/apei/ghes_cper.c`` so the logging, notifier chains, and
+memory failure handling match the ACPI GHES behaviour even when
+ACPI is disabled.
+
+Once a platform describes a firmware-first provider, both ACPI GHES and the
+firmware-described driver reuse the same code paths. This keeps the
+behaviour consistent regardless of whether the error source is described
+by ACPI tables or another firmware description.
+
 EDAC - Error Detection And Correction
 *************************************
 
diff --git a/MAINTAINERS b/MAINTAINERS
index 8a9714603a7d..c14638cd97f6 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -22265,6 +22265,7 @@ RAS ERROR STATUS
 M:	Ahmed Tiba <ahmed.tiba@arm.com>
 S:	Maintained
 F:	Documentation/devicetree/bindings/firmware/arm,ras-cper.yaml
+F:	drivers/ras/cper-esource.c
 
 RAS INFRASTRUCTURE
 M:	Tony Luck <tony.luck@intel.com>
diff --git a/drivers/acpi/apei/apei-internal.h b/drivers/acpi/apei/apei-internal.h
index 77c10a7a7a9f..c16ac541f15b 100644
--- a/drivers/acpi/apei/apei-internal.h
+++ b/drivers/acpi/apei/apei-internal.h
@@ -8,6 +8,7 @@
 #define APEI_INTERNAL_H
 
 #include <linux/acpi.h>
+#include <acpi/ghes_cper.h>
 
 struct apei_exec_context;
 
@@ -120,15 +121,6 @@ int apei_exec_collect_resources(struct apei_exec_context *ctx,
 struct dentry;
 struct dentry *apei_get_debugfs_dir(void);
 
-static inline u32 cper_estatus_len(struct acpi_hest_generic_status *estatus)
-{
-	if (estatus->raw_data_length)
-		return estatus->raw_data_offset + \
-			estatus->raw_data_length;
-	else
-		return sizeof(*estatus) + estatus->data_length;
-}
-
 int apei_osc_setup(void);
 
 int einj_get_available_error_type(u32 *type, int einj_action);
diff --git a/drivers/acpi/apei/ghes_cper.c b/drivers/acpi/apei/ghes_cper.c
index 0ff9d06eb78f..a7691aa5011c 100644
--- a/drivers/acpi/apei/ghes_cper.c
+++ b/drivers/acpi/apei/ghes_cper.c
@@ -46,7 +46,9 @@
 #include <asm/fixmap.h>
 #include <asm/tlbflush.h>
 
+#ifdef CONFIG_ACPI_APEI
 #include "apei-internal.h"
+#endif
 
 ATOMIC_NOTIFIER_HEAD(ghes_report_chain);
 
diff --git a/drivers/ras/Kconfig b/drivers/ras/Kconfig
index fc4f4bb94a4c..3c1c63b2fefc 100644
--- a/drivers/ras/Kconfig
+++ b/drivers/ras/Kconfig
@@ -34,6 +34,17 @@ if RAS
 source "arch/x86/ras/Kconfig"
 source "drivers/ras/amd/atl/Kconfig"
 
+config RAS_CPER_ESOURCE
+	bool "Firmware-first CPER error source block provider"
+	select GHES_CPER_HELPERS
+	help
+	  Enable support for firmware-first Common Platform Error Record
+	  (CPER) error source block providers. The current in-tree user is
+	  described by the arm,ras-cper DeviceTree binding. The driver
+	  reuses the existing GHES CPER helpers so the error processing
+	  matches the ACPI code paths, but it can be built even when ACPI is
+	  disabled.
+
 config RAS_FMPM
 	tristate "FRU Memory Poison Manager"
 	default m
diff --git a/drivers/ras/Makefile b/drivers/ras/Makefile
index 11f95d59d397..0de069557f31 100644
--- a/drivers/ras/Makefile
+++ b/drivers/ras/Makefile
@@ -2,6 +2,7 @@
 obj-$(CONFIG_RAS)	+= ras.o
 obj-$(CONFIG_DEBUG_FS)	+= debugfs.o
 obj-$(CONFIG_RAS_CEC)	+= cec.o
+obj-$(CONFIG_RAS_CPER_ESOURCE)	+= cper-esource.o
 
 obj-$(CONFIG_RAS_FMPM)	+= amd/fmpm.o
 obj-y			+= amd/atl/
diff --git a/drivers/ras/cper-esource.c b/drivers/ras/cper-esource.c
new file mode 100644
index 000000000000..83f7a910e50a
--- /dev/null
+++ b/drivers/ras/cper-esource.c
@@ -0,0 +1,257 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Firmware-first CPER error source provider.
+ *
+ * This driver shares the GHES CPER helpers so we keep the reporting and
+ * notifier behaviour identical to ACPI GHES.
+ *
+ * Copyright (C) 2026 ARM Ltd.
+ * Author: Ahmed Tiba <ahmed.tiba@arm.com>
+ */
+
+#include <linux/bitops.h>
+#include <linux/cleanup.h>
+#include <linux/idr.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/panic.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+
+#include <acpi/ghes.h>
+#include <acpi/ghes_cper.h>
+
+static DEFINE_IDA(cper_esource_source_ids);
+
+struct cper_esource_ack {
+	void __iomem *addr;
+	u64 preserve;
+	u64 set;
+	u8 width;
+	bool present;
+};
+
+struct cper_esource {
+	struct device *dev;
+	void __iomem *status;
+	size_t status_len;
+
+	struct cper_esource_ack ack;
+
+	struct acpi_hest_generic *generic;
+	struct acpi_hest_generic_status *estatus;
+
+	bool sync;
+	int irq;
+
+	/* Serializes access while firmware and the OS share the status buffer. */
+	spinlock_t lock;
+};
+
+static void cper_esource_release_source_id(void *data)
+{
+	struct acpi_hest_generic *generic = data;
+
+	ida_free(&cper_esource_source_ids, generic->header.source_id);
+}
+
+static int cper_esource_init_pool(void)
+{
+	if (ghes_estatus_pool)
+		return 0;
+
+	return ghes_estatus_pool_init(1);
+}
+
+static int cper_esource_copy_status(struct cper_esource *ctx)
+{
+	memcpy_fromio(ctx->estatus, ctx->status, ctx->status_len);
+	return 0;
+}
+
+static void cper_esource_ack(struct cper_esource *ctx)
+{
+	u64 val;
+
+	if (!ctx->ack.present)
+		return;
+
+	if (ctx->ack.width == 64) {
+		val = readq(ctx->ack.addr);
+		val &= ctx->ack.preserve;
+		val |= ctx->ack.set;
+		writeq(val, ctx->ack.addr);
+	} else {
+		val = readl(ctx->ack.addr);
+		val &= (u32)ctx->ack.preserve;
+		val |= (u32)ctx->ack.set;
+		writel(val, ctx->ack.addr);
+	}
+}
+
+static void cper_esource_fatal(struct cper_esource *ctx)
+{
+	__ghes_print_estatus(KERN_EMERG, ctx->generic, ctx->estatus);
+	add_taint(TAINT_MACHINE_CHECK, LOCKDEP_STILL_OK);
+	panic("GHES: fatal firmware-first CPER record from %s\n",
+	      dev_name(ctx->dev));
+}
+
+static void cper_esource_process(struct cper_esource *ctx)
+{
+	int sev;
+
+	guard(spinlock_irqsave)(&ctx->lock);
+
+	if (cper_esource_copy_status(ctx))
+		return;
+
+	sev = ghes_severity(ctx->estatus->error_severity);
+	if (sev >= GHES_SEV_PANIC)
+		cper_esource_fatal(ctx);
+
+	if (!ghes_estatus_cached(ctx->estatus) &&
+	    ghes_print_estatus(NULL, ctx->generic, ctx->estatus))
+		ghes_estatus_cache_add(ctx->generic, ctx->estatus);
+
+	ghes_cper_handle_status(ctx->dev, ctx->generic, ctx->estatus, ctx->sync);
+	cper_esource_ack(ctx);
+}
+
+static irqreturn_t cper_esource_irq(int irq, void *data)
+{
+	struct cper_esource *ctx = data;
+
+	cper_esource_process(ctx);
+
+	return IRQ_HANDLED;
+}
+
+static int cper_esource_init_ack(struct platform_device *pdev,
+				 struct cper_esource *ctx)
+{
+	struct device *dev = &pdev->dev;
+	struct resource *res;
+	size_t size;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	if (!res)
+		return 0;
+
+	ctx->ack.addr = devm_platform_get_and_ioremap_resource(pdev, 1, &res);
+	if (IS_ERR(ctx->ack.addr))
+		return PTR_ERR(ctx->ack.addr);
+
+	size = resource_size(res);
+	switch (size) {
+	case 4:
+		ctx->ack.width = 32;
+		ctx->ack.preserve = ~0U;
+		break;
+	case 8:
+		ctx->ack.width = 64;
+		ctx->ack.preserve = ~0ULL;
+		break;
+	default:
+		return dev_err_probe(dev, -EINVAL,
+				     "unsupported ack resource size %zu\n", size);
+	}
+
+	ctx->ack.set = BIT_ULL(0);
+	ctx->ack.present = true;
+	return 0;
+}
+
+static int cper_esource_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct cper_esource *ctx;
+	struct resource *res;
+	int source_id;
+	int rc;
+
+	ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
+	if (!ctx)
+		return -ENOMEM;
+
+	spin_lock_init(&ctx->lock);
+	ctx->dev = dev;
+	ctx->sync = device_property_read_bool(dev, "arm,sea-notify");
+
+	ctx->status = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
+	if (IS_ERR(ctx->status))
+		return dev_err_probe(dev, PTR_ERR(ctx->status),
+				     "failed to map status region\n");
+
+	ctx->status_len = resource_size(res);
+	if (!ctx->status_len)
+		return dev_err_probe(dev, -EINVAL, "status region has zero length\n");
+
+	rc = cper_esource_init_ack(pdev, ctx);
+	if (rc)
+		return rc;
+
+	rc = cper_esource_init_pool();
+	if (rc)
+		return rc;
+
+	ctx->estatus = devm_kzalloc(dev, ctx->status_len, GFP_KERNEL);
+	if (!ctx->estatus)
+		return -ENOMEM;
+
+	ctx->generic = devm_kzalloc(dev, sizeof(*ctx->generic), GFP_KERNEL);
+	if (!ctx->generic)
+		return -ENOMEM;
+
+	source_id = ida_alloc_min(&cper_esource_source_ids, 1, GFP_KERNEL);
+	if (source_id < 0)
+		return source_id;
+
+	ctx->generic->header.type = ACPI_HEST_TYPE_GENERIC_ERROR;
+	ctx->generic->header.source_id = source_id;
+
+	rc = devm_add_action_or_reset(dev, cper_esource_release_source_id,
+				      ctx->generic);
+	if (rc)
+		return rc;
+
+	ctx->generic->notify.type = ctx->sync ?
+		ACPI_HEST_NOTIFY_SEA : ACPI_HEST_NOTIFY_EXTERNAL;
+	ctx->generic->error_block_length = ctx->status_len;
+
+	ctx->irq = platform_get_irq(pdev, 0);
+	if (ctx->irq < 0)
+		return ctx->irq;
+
+	rc = devm_request_threaded_irq(dev, ctx->irq, NULL, cper_esource_irq,
+				       IRQF_ONESHOT,
+				       dev_name(dev), ctx);
+	if (rc)
+		return dev_err_probe(dev, rc, "failed to request interrupt\n");
+
+	return 0;
+}
+
+static const struct of_device_id cper_esource_of_match[] = {
+	{ .compatible = "arm,ras-cper" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, cper_esource_of_match);
+
+static struct platform_driver cper_esource_driver = {
+	.driver = {
+		.name = "cper-esource",
+		.of_match_table = cper_esource_of_match,
+	},
+	.probe = cper_esource_probe,
+};
+
+module_platform_driver(cper_esource_driver);
+
+MODULE_AUTHOR("Ahmed Tiba <ahmed.tiba@arm.com>");
+MODULE_DESCRIPTION("Firmware-first CPER provider");
+MODULE_LICENSE("GPL");
diff --git a/include/acpi/ghes_cper.h b/include/acpi/ghes_cper.h
index 511b95b50911..a78d4a773129 100644
--- a/include/acpi/ghes_cper.h
+++ b/include/acpi/ghes_cper.h
@@ -80,6 +80,14 @@ static inline bool is_hest_sync_notify(struct ghes *ghes)
 	return notify_type == ACPI_HEST_NOTIFY_SEA;
 }
 
+static inline u32 cper_estatus_len(struct acpi_hest_generic_status *estatus)
+{
+	if (estatus->raw_data_length)
+		return estatus->raw_data_offset + estatus->raw_data_length;
+	else
+		return sizeof(*estatus) + estatus->data_length;
+}
+
 struct ghes_vendor_record_entry {
 	struct work_struct work;
 	int error_severity;
@@ -108,6 +116,8 @@ int __ghes_read_estatus(struct acpi_hest_generic_status *estatus,
 int ghes_estatus_cached(struct acpi_hest_generic_status *estatus);
 void ghes_estatus_cache_add(struct acpi_hest_generic *generic,
 			    struct acpi_hest_generic_status *estatus);
+int ghes_register_vendor_record_notifier(struct notifier_block *nb);
+void ghes_unregister_vendor_record_notifier(struct notifier_block *nb);
 void ghes_defer_non_standard_event(struct acpi_hest_generic_data *gdata,
 				   int sev);
 int ghes_severity(int severity);

-- 
2.43.0


^ permalink raw reply related

* [PATCH v5 09/10] dt-bindings: firmware: add arm,ras-cper
From: Ahmed Tiba @ 2026-05-29  9:50 UTC (permalink / raw)
  To: will, jic23, xueshuai, saket.dumbre, mchehab, dave, djbw, bp,
	tony.luck, guohanjun, lenb, skhan, vishal.l.verma, rafael, corbet,
	ira.weiny, dave.jiang, krzk+dt, robh, catalin.marinas,
	alison.schofield, conor+dt
  Cc: Ahmed Tiba, linux-arm-kernel, Michael.Zhao2, linux-doc,
	linux-kernel, linux-cxl, Dmitry.Lamerov, devicetree, linux-acpi,
	linux-edac, acpica-devel
In-Reply-To: <20260529-topics-ahmtib01-ras_ffh_arm_internal_review-v5-0-2e0500d42642@arm.com>

Describe the DeviceTree node that exposes the Arm firmware-first
CPER provider and hook the file into MAINTAINERS so the
binding has an owner.

Signed-off-by: Ahmed Tiba <ahmed.tiba@arm.com>
---
 .../devicetree/bindings/firmware/arm,ras-cper.yaml | 54 ++++++++++++++++++++++
 MAINTAINERS                                        |  5 ++
 2 files changed, 59 insertions(+)

diff --git a/Documentation/devicetree/bindings/firmware/arm,ras-cper.yaml b/Documentation/devicetree/bindings/firmware/arm,ras-cper.yaml
new file mode 100644
index 000000000000..3d4de096093f
--- /dev/null
+++ b/Documentation/devicetree/bindings/firmware/arm,ras-cper.yaml
@@ -0,0 +1,54 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/firmware/arm,ras-cper.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Arm RAS CPER provider
+
+maintainers:
+  - Ahmed Tiba <ahmed.tiba@arm.com>
+
+description:
+  Arm Reliability, Availability and Serviceability (RAS) firmware can expose
+  a firmware-first CPER error source directly via DeviceTree. Firmware
+  provides the CPER Generic Error Status block and notifies the OS through
+  an interrupt.
+
+properties:
+  compatible:
+    const: arm,ras-cper
+
+  memory-region:
+    minItems: 1
+    items:
+      - description:
+          CPER Generic Error Status block exposed by firmware.
+      - description:
+          Optional firmware-owned ack buffer used on platforms
+          where firmware needs an explicit "ack" handshake before overwriting
+          the CPER buffer. Firmware watches bit 0 and expects the OS to set it
+          once the current status block has been consumed.
+
+  interrupts:
+    maxItems: 1
+    description:
+      Interrupt used to signal that a new status record is ready.
+
+required:
+  - compatible
+  - memory-region
+  - interrupts
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+
+    error-handler {
+      compatible = "arm,ras-cper";
+      memory-region = <&ras_cper_buffer>, <&ras_cper_ack>;
+      interrupts = <GIC_SPI 32 IRQ_TYPE_LEVEL_HIGH>;
+    };
+...
diff --git a/MAINTAINERS b/MAINTAINERS
index 461a3eed6129..8a9714603a7d 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -22261,6 +22261,11 @@ M:	Alexandre Bounine <alex.bou9@gmail.com>
 S:	Maintained
 F:	drivers/rapidio/
 
+RAS ERROR STATUS
+M:	Ahmed Tiba <ahmed.tiba@arm.com>
+S:	Maintained
+F:	Documentation/devicetree/bindings/firmware/arm,ras-cper.yaml
+
 RAS INFRASTRUCTURE
 M:	Tony Luck <tony.luck@intel.com>
 M:	Borislav Petkov <bp@alien8.de>

-- 
2.43.0


^ permalink raw reply related

* [PATCH v5 08/10] ACPI: APEI: share GHES CPER helpers
From: Ahmed Tiba @ 2026-05-29  9:50 UTC (permalink / raw)
  To: will, jic23, xueshuai, saket.dumbre, mchehab, dave, djbw, bp,
	tony.luck, guohanjun, lenb, skhan, vishal.l.verma, rafael, corbet,
	ira.weiny, dave.jiang, krzk+dt, robh, catalin.marinas,
	alison.schofield, conor+dt
  Cc: Ahmed Tiba, linux-arm-kernel, Michael.Zhao2, linux-doc,
	linux-kernel, linux-cxl, Dmitry.Lamerov, devicetree, linux-acpi,
	linux-edac, acpica-devel
In-Reply-To: <20260529-topics-ahmtib01-ras_ffh_arm_internal_review-v5-0-2e0500d42642@arm.com>

Wire GHES up to the helper routines in ghes_cper.c and remove the local
copies from ghes.c. This keeps the control flow identical while letting
the helpers be shared with other firmware-first providers.

Signed-off-by: Ahmed Tiba <ahmed.tiba@arm.com>
---
 drivers/acpi/apei/ghes.c      | 416 +--------------------------------------
 drivers/acpi/apei/ghes_cper.c | 438 +++++++++++++++++++++++++++++++++++++++++-
 include/acpi/ghes_cper.h      |  20 ++
 3 files changed, 459 insertions(+), 415 deletions(-)

diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
index 85be2ebf4d3e..f85b97c4db4c 100644
--- a/drivers/acpi/apei/ghes.c
+++ b/drivers/acpi/apei/ghes.c
@@ -67,8 +67,6 @@
 #define FIX_APEI_GHES_SDEI_CRITICAL	__end_of_fixed_addresses
 #endif
 
-static ATOMIC_NOTIFIER_HEAD(ghes_report_chain);
-
 /*
  * This driver isn't really modular, however for the time being,
  * continuing to use module_param is the easiest way to remain
@@ -113,276 +111,6 @@ static DEFINE_MUTEX(ghes_devs_mutex);
  */
 static DEFINE_SPINLOCK(ghes_notify_lock_irq);
 
-struct gen_pool *ghes_estatus_pool;
-
-int ghes_estatus_pool_init(unsigned int num_ghes)
-{
-	unsigned long addr, len;
-	int rc;
-
-	ghes_estatus_pool = gen_pool_create(GHES_ESTATUS_POOL_MIN_ALLOC_ORDER, -1);
-	if (!ghes_estatus_pool)
-		return -ENOMEM;
-
-	len = GHES_ESTATUS_CACHE_AVG_SIZE * GHES_ESTATUS_CACHE_ALLOCED_MAX;
-	len += (num_ghes * GHES_ESOURCE_PREALLOC_MAX_SIZE);
-
-	addr = (unsigned long)vmalloc(PAGE_ALIGN(len));
-	if (!addr)
-		goto err_pool_alloc;
-
-	rc = gen_pool_add(ghes_estatus_pool, addr, PAGE_ALIGN(len), -1);
-	if (rc)
-		goto err_pool_add;
-
-	return 0;
-
-err_pool_add:
-	vfree((void *)addr);
-
-err_pool_alloc:
-	gen_pool_destroy(ghes_estatus_pool);
-
-	return -ENOMEM;
-}
-
-/**
- * ghes_estatus_pool_region_free - free previously allocated memory
- *				   from the ghes_estatus_pool.
- * @addr: address of memory to free.
- * @size: size of memory to free.
- *
- * Returns none.
- */
-void ghes_estatus_pool_region_free(unsigned long addr, u32 size)
-{
-	gen_pool_free(ghes_estatus_pool, addr, size);
-}
-EXPORT_SYMBOL_GPL(ghes_estatus_pool_region_free);
-
-static inline int ghes_severity(int severity)
-{
-	switch (severity) {
-	case CPER_SEV_INFORMATIONAL:
-		return GHES_SEV_NO;
-	case CPER_SEV_CORRECTED:
-		return GHES_SEV_CORRECTED;
-	case CPER_SEV_RECOVERABLE:
-		return GHES_SEV_RECOVERABLE;
-	case CPER_SEV_FATAL:
-		return GHES_SEV_PANIC;
-	default:
-		/* Unknown, go panic */
-		return GHES_SEV_PANIC;
-	}
-}
-
-
-/**
- * struct ghes_task_work - for synchronous RAS event
- *
- * @twork:                callback_head for task work
- * @pfn:                  page frame number of corrupted page
- * @flags:                work control flags
- *
- * Structure to pass task work to be handled before
- * returning to user-space via task_work_add().
- */
-struct ghes_task_work {
-	struct callback_head twork;
-	u64 pfn;
-	int flags;
-};
-
-static void memory_failure_cb(struct callback_head *twork)
-{
-	struct ghes_task_work *twcb = container_of(twork, struct ghes_task_work, twork);
-	int ret;
-
-	ret = memory_failure(twcb->pfn, twcb->flags);
-	gen_pool_free(ghes_estatus_pool, (unsigned long)twcb, sizeof(*twcb));
-
-	if (!ret || ret == -EHWPOISON || ret == -EOPNOTSUPP)
-		return;
-
-	pr_err("%#llx: Sending SIGBUS to %s:%d due to hardware memory corruption\n",
-			twcb->pfn, current->comm, task_pid_nr(current));
-	force_sig(SIGBUS);
-}
-
-static bool ghes_do_memory_failure(u64 physical_addr, int flags)
-{
-	struct ghes_task_work *twcb;
-	unsigned long pfn;
-
-	if (!IS_ENABLED(CONFIG_ACPI_APEI_MEMORY_FAILURE))
-		return false;
-
-	pfn = PHYS_PFN(physical_addr);
-
-	if (flags == MF_ACTION_REQUIRED && current->mm) {
-		twcb = (void *)gen_pool_alloc(ghes_estatus_pool, sizeof(*twcb));
-		if (!twcb)
-			return false;
-
-		twcb->pfn = pfn;
-		twcb->flags = flags;
-		init_task_work(&twcb->twork, memory_failure_cb);
-		task_work_add(current, &twcb->twork, TWA_RESUME);
-		return true;
-	}
-
-	memory_failure_queue(pfn, flags);
-	return true;
-}
-
-static bool ghes_handle_memory_failure(struct acpi_hest_generic_data *gdata,
-				       int sev, bool sync)
-{
-	int flags = -1;
-	int sec_sev = ghes_severity(gdata->error_severity);
-	struct cper_sec_mem_err *mem_err = acpi_hest_get_payload(gdata);
-
-	if (!(mem_err->validation_bits & CPER_MEM_VALID_PA))
-		return false;
-
-	/* iff following two events can be handled properly by now */
-	if (sec_sev == GHES_SEV_CORRECTED &&
-	    (gdata->flags & CPER_SEC_ERROR_THRESHOLD_EXCEEDED))
-		flags = MF_SOFT_OFFLINE;
-	if (sev == GHES_SEV_RECOVERABLE && sec_sev == GHES_SEV_RECOVERABLE)
-		flags = sync ? MF_ACTION_REQUIRED : 0;
-
-	if (flags != -1)
-		return ghes_do_memory_failure(mem_err->physical_addr, flags);
-
-	return false;
-}
-
-static bool ghes_handle_arm_hw_error(struct acpi_hest_generic_data *gdata,
-				     int sev, bool sync)
-{
-	struct cper_sec_proc_arm *err = acpi_hest_get_payload(gdata);
-	int flags = sync ? MF_ACTION_REQUIRED : 0;
-	int length = gdata->error_data_length;
-	char error_type[120];
-	bool queued = false;
-	int sec_sev, i;
-	char *p;
-
-	sec_sev = ghes_severity(gdata->error_severity);
-	if (length >= sizeof(*err)) {
-		log_arm_hw_error(err, sec_sev);
-	} else {
-		pr_warn(FW_BUG "arm error length: %d\n", length);
-		pr_warn(FW_BUG "length is too small\n");
-		pr_warn(FW_BUG "firmware-generated error record is incorrect\n");
-		return false;
-	}
-
-	if (sev != GHES_SEV_RECOVERABLE || sec_sev != GHES_SEV_RECOVERABLE)
-		return false;
-
-	p = (char *)(err + 1);
-	length -= sizeof(err);
-
-	for (i = 0; i < err->err_info_num; i++) {
-		struct cper_arm_err_info *err_info;
-		bool is_cache, has_pa;
-
-		/* Ensure we have enough data for the error info header */
-		if (length < sizeof(*err_info))
-			break;
-
-		err_info = (struct cper_arm_err_info *)p;
-
-		/* Validate the claimed length before using it */
-		length -= err_info->length;
-		if (length < 0)
-			break;
-
-		is_cache = err_info->type & CPER_ARM_CACHE_ERROR;
-		has_pa = (err_info->validation_bits & CPER_ARM_INFO_VALID_PHYSICAL_ADDR);
-
-		/*
-		 * The field (err_info->error_info & BIT(26)) is fixed to set to
-		 * 1 in some old firmware of HiSilicon Kunpeng920. We assume that
-		 * firmware won't mix corrected errors in an uncorrected section,
-		 * and don't filter out 'corrected' error here.
-		 */
-		if (is_cache && has_pa) {
-			queued = ghes_do_memory_failure(err_info->physical_fault_addr, flags);
-			p += err_info->length;
-			continue;
-		}
-
-		cper_bits_to_str(error_type, sizeof(error_type),
-				 FIELD_GET(CPER_ARM_ERR_TYPE_MASK, err_info->type),
-				 cper_proc_error_type_strs,
-				 ARRAY_SIZE(cper_proc_error_type_strs));
-
-		pr_warn_ratelimited(FW_WARN GHES_PFX
-				    "Unhandled processor error type 0x%02x: %s%s\n",
-				    err_info->type, error_type,
-				    (err_info->type & ~CPER_ARM_ERR_TYPE_MASK) ? " with reserved bit(s)" : "");
-		p += err_info->length;
-	}
-
-	return queued;
-}
-
-/*
- * PCIe AER errors need to be sent to the AER driver for reporting and
- * recovery. The GHES severities map to the following AER severities and
- * require the following handling:
- *
- * GHES_SEV_CORRECTABLE -> AER_CORRECTABLE
- *     These need to be reported by the AER driver but no recovery is
- *     necessary.
- * GHES_SEV_RECOVERABLE -> AER_NONFATAL
- * GHES_SEV_RECOVERABLE && CPER_SEC_RESET -> AER_FATAL
- *     These both need to be reported and recovered from by the AER driver.
- * GHES_SEV_PANIC does not make it to this handling since the kernel must
- *     panic.
- */
-static void ghes_handle_aer(struct acpi_hest_generic_data *gdata)
-{
-#ifdef CONFIG_ACPI_APEI_PCIEAER
-	struct cper_sec_pcie *pcie_err = acpi_hest_get_payload(gdata);
-
-	if (pcie_err->validation_bits & CPER_PCIE_VALID_DEVICE_ID &&
-	    pcie_err->validation_bits & CPER_PCIE_VALID_AER_INFO) {
-		unsigned int devfn;
-		int aer_severity;
-		u8 *aer_info;
-
-		devfn = PCI_DEVFN(pcie_err->device_id.device,
-				  pcie_err->device_id.function);
-		aer_severity = cper_severity_to_aer(gdata->error_severity);
-
-		/*
-		 * If firmware reset the component to contain
-		 * the error, we must reinitialize it before
-		 * use, so treat it as a fatal AER error.
-		 */
-		if (gdata->flags & CPER_SEC_RESET)
-			aer_severity = AER_FATAL;
-
-		aer_info = (void *)gen_pool_alloc(ghes_estatus_pool,
-						  sizeof(struct aer_capability_regs));
-		if (!aer_info)
-			return;
-		memcpy(aer_info, pcie_err->aer_info, sizeof(struct aer_capability_regs));
-
-		aer_recover_queue(pcie_err->device_id.segment,
-				  pcie_err->device_id.bus,
-				  devfn, aer_severity,
-				  (struct aer_capability_regs *)
-				  aer_info);
-	}
-#endif
-}
-
 static void ghes_vendor_record_notifier_destroy(void *nb)
 {
 	ghes_unregister_vendor_record_notifier(nb);
@@ -401,151 +129,11 @@ int devm_ghes_register_vendor_record_notifier(struct device *dev,
 }
 EXPORT_SYMBOL_GPL(devm_ghes_register_vendor_record_notifier);
 
-static void ghes_log_hwerr(int sev, guid_t *sec_type)
-{
-	if (sev != CPER_SEV_RECOVERABLE)
-		return;
-
-	if (guid_equal(sec_type, &CPER_SEC_PROC_ARM) ||
-	    guid_equal(sec_type, &CPER_SEC_PROC_GENERIC) ||
-	    guid_equal(sec_type, &CPER_SEC_PROC_IA)) {
-		hwerr_log_error_type(HWERR_RECOV_CPU);
-		return;
-	}
-
-	if (guid_equal(sec_type, &CPER_SEC_CXL_PROT_ERR) ||
-	    guid_equal(sec_type, &CPER_SEC_CXL_GEN_MEDIA_GUID) ||
-	    guid_equal(sec_type, &CPER_SEC_CXL_DRAM_GUID) ||
-	    guid_equal(sec_type, &CPER_SEC_CXL_MEM_MODULE_GUID)) {
-		hwerr_log_error_type(HWERR_RECOV_CXL);
-		return;
-	}
-
-	if (guid_equal(sec_type, &CPER_SEC_PCIE) ||
-	    guid_equal(sec_type, &CPER_SEC_PCI_X_BUS)) {
-		hwerr_log_error_type(HWERR_RECOV_PCI);
-		return;
-	}
-
-	if (guid_equal(sec_type, &CPER_SEC_PLATFORM_MEM)) {
-		hwerr_log_error_type(HWERR_RECOV_MEMORY);
-		return;
-	}
-
-	hwerr_log_error_type(HWERR_RECOV_OTHERS);
-}
-
 static void ghes_do_proc(struct ghes *ghes,
 			 const struct acpi_hest_generic_status *estatus)
 {
-	int sev, sec_sev;
-	struct acpi_hest_generic_data *gdata;
-	guid_t *sec_type;
-	const guid_t *fru_id = &guid_null;
-	char *fru_text = "";
-	bool queued = false;
-	bool sync = is_hest_sync_notify(ghes);
-
-	sev = ghes_severity(estatus->error_severity);
-	apei_estatus_for_each_section(estatus, gdata) {
-		sec_type = (guid_t *)gdata->section_type;
-		sec_sev = ghes_severity(gdata->error_severity);
-		if (gdata->validation_bits & CPER_SEC_VALID_FRU_ID)
-			fru_id = (guid_t *)gdata->fru_id;
-
-		if (gdata->validation_bits & CPER_SEC_VALID_FRU_TEXT)
-			fru_text = gdata->fru_text;
-
-		ghes_log_hwerr(sev, sec_type);
-		if (guid_equal(sec_type, &CPER_SEC_PLATFORM_MEM)) {
-			struct cper_sec_mem_err *mem_err = acpi_hest_get_payload(gdata);
-
-			atomic_notifier_call_chain(&ghes_report_chain, sev, mem_err);
-
-			arch_apei_report_mem_error(sev, mem_err);
-			queued = ghes_handle_memory_failure(gdata, sev, sync);
-		} else if (guid_equal(sec_type, &CPER_SEC_PCIE)) {
-			ghes_handle_aer(gdata);
-		} else if (guid_equal(sec_type, &CPER_SEC_PROC_ARM)) {
-			queued = ghes_handle_arm_hw_error(gdata, sev, sync);
-		} else if (guid_equal(sec_type, &CPER_SEC_CXL_PROT_ERR)) {
-			struct cxl_cper_sec_prot_err *prot_err = acpi_hest_get_payload(gdata);
-
-			cxl_cper_post_prot_err(prot_err, gdata->error_severity);
-		} else if (guid_equal(sec_type, &CPER_SEC_CXL_GEN_MEDIA_GUID)) {
-			struct cxl_cper_event_rec *rec = acpi_hest_get_payload(gdata);
-
-			cxl_cper_post_event(CXL_CPER_EVENT_GEN_MEDIA, rec);
-		} else if (guid_equal(sec_type, &CPER_SEC_CXL_DRAM_GUID)) {
-			struct cxl_cper_event_rec *rec = acpi_hest_get_payload(gdata);
-
-			cxl_cper_post_event(CXL_CPER_EVENT_DRAM, rec);
-		} else if (guid_equal(sec_type, &CPER_SEC_CXL_MEM_MODULE_GUID)) {
-			struct cxl_cper_event_rec *rec = acpi_hest_get_payload(gdata);
-
-			cxl_cper_post_event(CXL_CPER_EVENT_MEM_MODULE, rec);
-		} else {
-			void *err = acpi_hest_get_payload(gdata);
-
-			ghes_defer_non_standard_event(gdata, sev);
-			log_non_standard_event(sec_type, fru_id, fru_text,
-					       sec_sev, err,
-					       gdata->error_data_length);
-		}
-	}
-
-	/*
-	 * If no memory failure work is queued for abnormal synchronous
-	 * errors, do a force kill.
-	 */
-	if (sync && !queued) {
-		dev_err(ghes->dev,
-			HW_ERR GHES_PFX "%s:%d: synchronous unrecoverable error (SIGBUS)\n",
-			current->comm, task_pid_nr(current));
-		force_sig(SIGBUS);
-	}
-}
-
-static void __ghes_print_estatus(const char *pfx,
-				 const struct acpi_hest_generic *generic,
-				 const struct acpi_hest_generic_status *estatus)
-{
-	static atomic_t seqno;
-	unsigned int curr_seqno;
-	char pfx_seq[64];
-
-	if (pfx == NULL) {
-		if (ghes_severity(estatus->error_severity) <=
-		    GHES_SEV_CORRECTED)
-			pfx = KERN_WARNING;
-		else
-			pfx = KERN_ERR;
-	}
-	curr_seqno = atomic_inc_return(&seqno);
-	snprintf(pfx_seq, sizeof(pfx_seq), "%s{%u}" HW_ERR, pfx, curr_seqno);
-	printk("%s""Hardware error from APEI Generic Hardware Error Source: %d\n",
-	       pfx_seq, generic->header.source_id);
-	cper_estatus_print(pfx_seq, estatus);
-}
-
-static int ghes_print_estatus(const char *pfx,
-			      const struct acpi_hest_generic *generic,
-			      const struct acpi_hest_generic_status *estatus)
-{
-	/* Not more than 2 messages every 5 seconds */
-	static DEFINE_RATELIMIT_STATE(ratelimit_corrected, 5*HZ, 2);
-	static DEFINE_RATELIMIT_STATE(ratelimit_uncorrected, 5*HZ, 2);
-	struct ratelimit_state *ratelimit;
-
-	if (ghes_severity(estatus->error_severity) <= GHES_SEV_CORRECTED)
-		ratelimit = &ratelimit_corrected;
-	else
-		ratelimit = &ratelimit_uncorrected;
-	if (__ratelimit(ratelimit)) {
-		__ghes_print_estatus(pfx, generic, estatus);
-		return 1;
-	}
-	return 0;
+	ghes_cper_handle_status(ghes->dev, ghes->generic,
+				estatus, is_hest_sync_notify(ghes));
 }
 
 static void __ghes_panic(struct ghes *ghes,
diff --git a/drivers/acpi/apei/ghes_cper.c b/drivers/acpi/apei/ghes_cper.c
index d7a666a163c3..0ff9d06eb78f 100644
--- a/drivers/acpi/apei/ghes_cper.c
+++ b/drivers/acpi/apei/ghes_cper.c
@@ -13,22 +13,32 @@
  */
 
 #include <linux/aer.h>
+#include <linux/bitfield.h>
+#include <linux/device.h>
 #include <linux/err.h>
 #include <linux/genalloc.h>
-#include <linux/irq_work.h>
 #include <linux/io.h>
+#include <linux/irq_work.h>
 #include <linux/kfifo.h>
 #include <linux/kernel.h>
 #include <linux/list.h>
 #include <linux/math64.h>
 #include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/uuid.h>
+#include <linux/sched/signal.h>
+#include <linux/task_work.h>
 #include <linux/notifier.h>
 #include <linux/llist.h>
+#include <linux/ras.h>
+#include <ras/ras_event.h>
 #include <linux/ratelimit.h>
 #include <linux/rcupdate.h>
 #include <linux/rculist.h>
 #include <linux/sched/clock.h>
 #include <linux/slab.h>
+#include <linux/vmcore_info.h>
+#include <linux/vmalloc.h>
 
 #include <acpi/apei.h>
 #include <acpi/ghes_cper.h>
@@ -38,9 +48,363 @@
 
 #include "apei-internal.h"
 
+ATOMIC_NOTIFIER_HEAD(ghes_report_chain);
+
+#ifndef CONFIG_ACPI_APEI
+void __weak arch_apei_report_mem_error(int sev, struct cper_sec_mem_err *mem_err) { }
+#endif
+
 static struct ghes_estatus_cache __rcu *ghes_estatus_caches[GHES_ESTATUS_CACHES_SIZE];
 static atomic_t ghes_estatus_cache_alloced;
 
+struct gen_pool *ghes_estatus_pool;
+
+int ghes_estatus_pool_init(unsigned int num_ghes)
+{
+	unsigned long addr, len;
+	int rc;
+
+	ghes_estatus_pool = gen_pool_create(GHES_ESTATUS_POOL_MIN_ALLOC_ORDER, -1);
+	if (!ghes_estatus_pool)
+		return -ENOMEM;
+
+	len = GHES_ESTATUS_CACHE_AVG_SIZE * GHES_ESTATUS_CACHE_ALLOCED_MAX;
+	len += (num_ghes * GHES_ESOURCE_PREALLOC_MAX_SIZE);
+
+	addr = (unsigned long)vmalloc(PAGE_ALIGN(len));
+	if (!addr)
+		goto err_pool_alloc;
+
+	rc = gen_pool_add(ghes_estatus_pool, addr, PAGE_ALIGN(len), -1);
+	if (rc)
+		goto err_pool_add;
+
+	return 0;
+
+err_pool_add:
+	vfree((void *)addr);
+
+err_pool_alloc:
+	gen_pool_destroy(ghes_estatus_pool);
+
+	return -ENOMEM;
+}
+EXPORT_SYMBOL_GPL(ghes_estatus_pool_init);
+
+/**
+ * ghes_estatus_pool_region_free - free previously allocated memory
+ *				   from the ghes_estatus_pool.
+ * @addr: address of memory to free.
+ * @size: size of memory to free.
+ *
+ * Returns none.
+ */
+void ghes_estatus_pool_region_free(unsigned long addr, u32 size)
+{
+	gen_pool_free(ghes_estatus_pool, addr, size);
+}
+EXPORT_SYMBOL_GPL(ghes_estatus_pool_region_free);
+
+int ghes_severity(int severity)
+{
+	switch (severity) {
+	case CPER_SEV_INFORMATIONAL:
+		return GHES_SEV_NO;
+	case CPER_SEV_CORRECTED:
+		return GHES_SEV_CORRECTED;
+	case CPER_SEV_RECOVERABLE:
+		return GHES_SEV_RECOVERABLE;
+	case CPER_SEV_FATAL:
+		return GHES_SEV_PANIC;
+	default:
+		/* Unknown, go panic */
+		return GHES_SEV_PANIC;
+	}
+}
+
+/**
+ * struct ghes_task_work - for synchronous RAS event
+ *
+ * @twork:                callback_head for task work
+ * @pfn:                  page frame number of corrupted page
+ * @flags:                work control flags
+ *
+ * Structure to pass task work to be handled before
+ * returning to user-space via task_work_add().
+ */
+struct ghes_task_work {
+	struct callback_head twork;
+	u64 pfn;
+	int flags;
+};
+
+static void memory_failure_cb(struct callback_head *twork)
+{
+	struct ghes_task_work *twcb = container_of(twork, struct ghes_task_work, twork);
+	int ret;
+
+	ret = memory_failure(twcb->pfn, twcb->flags);
+	gen_pool_free(ghes_estatus_pool, (unsigned long)twcb, sizeof(*twcb));
+
+	if (!ret || ret == -EHWPOISON || ret == -EOPNOTSUPP)
+		return;
+
+	pr_err("%#llx: Sending SIGBUS to %s:%d due to hardware memory corruption\n",
+	       twcb->pfn, current->comm, task_pid_nr(current));
+	force_sig(SIGBUS);
+}
+
+static bool ghes_do_memory_failure(u64 physical_addr, int flags)
+{
+	struct ghes_task_work *twcb;
+	unsigned long pfn;
+
+	if (!IS_ENABLED(CONFIG_ACPI_APEI_MEMORY_FAILURE))
+		return false;
+
+	pfn = PHYS_PFN(physical_addr);
+
+	if (flags == MF_ACTION_REQUIRED && current->mm) {
+		twcb = (void *)gen_pool_alloc(ghes_estatus_pool, sizeof(*twcb));
+		if (!twcb)
+			return false;
+
+		twcb->pfn = pfn;
+		twcb->flags = flags;
+		init_task_work(&twcb->twork, memory_failure_cb);
+		task_work_add(current, &twcb->twork, TWA_RESUME);
+		return true;
+	}
+
+	memory_failure_queue(pfn, flags);
+	return true;
+}
+
+bool ghes_handle_memory_failure(struct acpi_hest_generic_data *gdata,
+				int sev, bool sync)
+{
+	int flags = -1;
+	int sec_sev = ghes_severity(gdata->error_severity);
+	struct cper_sec_mem_err *mem_err = acpi_hest_get_payload(gdata);
+
+	if (!(mem_err->validation_bits & CPER_MEM_VALID_PA))
+		return false;
+
+	/* iff following two events can be handled properly by now */
+	if (sec_sev == GHES_SEV_CORRECTED &&
+	    (gdata->flags & CPER_SEC_ERROR_THRESHOLD_EXCEEDED))
+		flags = MF_SOFT_OFFLINE;
+	if (sev == GHES_SEV_RECOVERABLE && sec_sev == GHES_SEV_RECOVERABLE)
+		flags = sync ? MF_ACTION_REQUIRED : 0;
+
+	if (flags != -1)
+		return ghes_do_memory_failure(mem_err->physical_addr, flags);
+
+	return false;
+}
+
+bool ghes_handle_arm_hw_error(struct acpi_hest_generic_data *gdata,
+			      int sev, bool sync)
+{
+	struct cper_sec_proc_arm *err = acpi_hest_get_payload(gdata);
+	int flags = sync ? MF_ACTION_REQUIRED : 0;
+	int length = gdata->error_data_length;
+	char error_type[120];
+	bool queued = false;
+	int sec_sev, i;
+	char *p;
+
+	sec_sev = ghes_severity(gdata->error_severity);
+	if (length >= sizeof(*err)) {
+		log_arm_hw_error(err, sec_sev);
+	} else {
+		pr_warn(FW_BUG "arm error length: %d\n", length);
+		pr_warn(FW_BUG "length is too small\n");
+		pr_warn(FW_BUG "firmware-generated error record is incorrect\n");
+		return false;
+	}
+
+	if (sev != GHES_SEV_RECOVERABLE || sec_sev != GHES_SEV_RECOVERABLE)
+		return false;
+
+	p = (char *)(err + 1);
+	length -= sizeof(err);
+
+	for (i = 0; i < err->err_info_num; i++) {
+		struct cper_arm_err_info *err_info;
+		bool is_cache, has_pa;
+
+		/* Ensure we have enough data for the error info header */
+		if (length < sizeof(*err_info))
+			break;
+
+		err_info = (struct cper_arm_err_info *)p;
+
+		/* Validate the claimed length before using it */
+		length -= err_info->length;
+		if (length < 0)
+			break;
+
+		is_cache = err_info->type & CPER_ARM_CACHE_ERROR;
+		has_pa = (err_info->validation_bits & CPER_ARM_INFO_VALID_PHYSICAL_ADDR);
+
+		/*
+		 * The field (err_info->error_info & BIT(26)) is fixed to set to
+		 * 1 in some old firmware of HiSilicon Kunpeng920. We assume that
+		 * firmware won't mix corrected errors in an uncorrected section,
+		 * and don't filter out 'corrected' error here.
+		 */
+		if (is_cache && has_pa) {
+			queued = ghes_do_memory_failure(err_info->physical_fault_addr, flags);
+			p += err_info->length;
+			continue;
+		}
+
+		cper_bits_to_str(error_type, sizeof(error_type),
+				 FIELD_GET(CPER_ARM_ERR_TYPE_MASK, err_info->type),
+				 cper_proc_error_type_strs,
+				 ARRAY_SIZE(cper_proc_error_type_strs));
+
+			pr_warn_ratelimited(FW_WARN GHES_PFX
+					    "Unhandled processor error type 0x%02x: %s%s\n",
+					    err_info->type, error_type,
+					    err_info->type & ~CPER_ARM_ERR_TYPE_MASK ?
+					    " with reserved bit(s)" : "");
+		p += err_info->length;
+	}
+
+	return queued;
+}
+
+/*
+ * PCIe AER errors need to be sent to the AER driver for reporting and
+ * recovery. The GHES severities map to the following AER severities and
+ * require the following handling:
+ *
+ * GHES_SEV_CORRECTABLE -> AER_CORRECTABLE
+ *     These need to be reported by the AER driver but no recovery is
+ *     necessary.
+ * GHES_SEV_RECOVERABLE -> AER_NONFATAL
+ * GHES_SEV_RECOVERABLE && CPER_SEC_RESET -> AER_FATAL
+ *     These both need to be reported and recovered from by the AER driver.
+ * GHES_SEV_PANIC does not make it to this handling since the kernel must
+ *     panic.
+ */
+void ghes_handle_aer(struct acpi_hest_generic_data *gdata)
+{
+#ifdef CONFIG_ACPI_APEI_PCIEAER
+	struct cper_sec_pcie *pcie_err = acpi_hest_get_payload(gdata);
+
+	if (pcie_err->validation_bits & CPER_PCIE_VALID_DEVICE_ID &&
+	    pcie_err->validation_bits & CPER_PCIE_VALID_AER_INFO) {
+		unsigned int devfn;
+		int aer_severity;
+		u8 *aer_info;
+
+		devfn = PCI_DEVFN(pcie_err->device_id.device,
+				  pcie_err->device_id.function);
+		aer_severity = cper_severity_to_aer(gdata->error_severity);
+
+		/*
+		 * If firmware reset the component to contain
+		 * the error, we must reinitialize it before
+		 * use, so treat it as a fatal AER error.
+		 */
+		if (gdata->flags & CPER_SEC_RESET)
+			aer_severity = AER_FATAL;
+
+		aer_info = (void *)gen_pool_alloc(ghes_estatus_pool,
+						  sizeof(struct aer_capability_regs));
+		if (!aer_info)
+			return;
+		memcpy(aer_info, pcie_err->aer_info, sizeof(struct aer_capability_regs));
+
+		aer_recover_queue(pcie_err->device_id.segment,
+				  pcie_err->device_id.bus,
+				  devfn, aer_severity,
+				  (struct aer_capability_regs *)
+				  aer_info);
+	}
+#endif
+}
+
+void ghes_log_hwerr(int sev, guid_t *sec_type)
+{
+	if (sev != CPER_SEV_RECOVERABLE)
+		return;
+
+	if (guid_equal(sec_type, &CPER_SEC_PROC_ARM) ||
+	    guid_equal(sec_type, &CPER_SEC_PROC_GENERIC) ||
+	    guid_equal(sec_type, &CPER_SEC_PROC_IA)) {
+		hwerr_log_error_type(HWERR_RECOV_CPU);
+		return;
+	}
+
+	if (guid_equal(sec_type, &CPER_SEC_CXL_PROT_ERR) ||
+	    guid_equal(sec_type, &CPER_SEC_CXL_GEN_MEDIA_GUID) ||
+	    guid_equal(sec_type, &CPER_SEC_CXL_DRAM_GUID) ||
+	    guid_equal(sec_type, &CPER_SEC_CXL_MEM_MODULE_GUID)) {
+		hwerr_log_error_type(HWERR_RECOV_CXL);
+		return;
+	}
+
+	if (guid_equal(sec_type, &CPER_SEC_PCIE) ||
+	    guid_equal(sec_type, &CPER_SEC_PCI_X_BUS)) {
+		hwerr_log_error_type(HWERR_RECOV_PCI);
+		return;
+	}
+
+	if (guid_equal(sec_type, &CPER_SEC_PLATFORM_MEM)) {
+		hwerr_log_error_type(HWERR_RECOV_MEMORY);
+		return;
+	}
+
+	hwerr_log_error_type(HWERR_RECOV_OTHERS);
+}
+
+void __ghes_print_estatus(const char *pfx,
+			  const struct acpi_hest_generic *generic,
+			  const struct acpi_hest_generic_status *estatus)
+{
+	static atomic_t seqno;
+	unsigned int curr_seqno;
+	char pfx_seq[64];
+
+	if (!pfx) {
+		if (ghes_severity(estatus->error_severity) <=
+		    GHES_SEV_CORRECTED)
+			pfx = KERN_WARNING;
+		else
+			pfx = KERN_ERR;
+	}
+	curr_seqno = atomic_inc_return(&seqno);
+	snprintf(pfx_seq, sizeof(pfx_seq), "%s{%u}" HW_ERR, pfx, curr_seqno);
+	printk("%sHardware error from APEI Generic Hardware Error Source: %d\n",
+	       pfx_seq, generic->header.source_id);
+	cper_estatus_print(pfx_seq, estatus);
+}
+
+int ghes_print_estatus(const char *pfx,
+		       const struct acpi_hest_generic *generic,
+		       const struct acpi_hest_generic_status *estatus)
+{
+	/* Not more than 2 messages every 5 seconds */
+	static DEFINE_RATELIMIT_STATE(ratelimit_corrected, 5 * HZ, 2);
+	static DEFINE_RATELIMIT_STATE(ratelimit_uncorrected, 5 * HZ, 2);
+	struct ratelimit_state *ratelimit;
+
+	if (ghes_severity(estatus->error_severity) <= GHES_SEV_CORRECTED)
+		ratelimit = &ratelimit_corrected;
+	else
+		ratelimit = &ratelimit_uncorrected;
+	if (__ratelimit(ratelimit)) {
+		__ghes_print_estatus(pfx, generic, estatus);
+		return 1;
+	}
+	return 0;
+}
+
+#ifdef CONFIG_ACPI_APEI
 static void __iomem *ghes_map(u64 pfn, enum fixed_addresses fixmap_idx)
 {
 	phys_addr_t paddr;
@@ -272,6 +636,7 @@ void ghes_clear_estatus(struct ghes *ghes,
 	if (is_hest_type_generic_v2(ghes))
 		ghes_ack_error(ghes->generic_v2);
 }
+#endif /* CONFIG_ACPI_APEI */
 
 static BLOCKING_NOTIFIER_HEAD(vendor_record_notify_list);
 
@@ -323,6 +688,77 @@ void ghes_defer_non_standard_event(struct acpi_hest_generic_data *gdata,
 	schedule_work(&entry->work);
 }
 
+void ghes_cper_handle_status(struct device *dev,
+			     const struct acpi_hest_generic *generic,
+			     const struct acpi_hest_generic_status *estatus,
+			     bool sync)
+{
+	int sev, sec_sev;
+	struct acpi_hest_generic_data *gdata;
+	guid_t *sec_type;
+	const guid_t *fru_id = &guid_null;
+	char *fru_text = "";
+	bool queued = false;
+
+	sev = ghes_severity(estatus->error_severity);
+	apei_estatus_for_each_section(estatus, gdata) {
+		sec_type = (guid_t *)gdata->section_type;
+		sec_sev = ghes_severity(gdata->error_severity);
+		if (gdata->validation_bits & CPER_SEC_VALID_FRU_ID)
+			fru_id = (guid_t *)gdata->fru_id;
+
+		if (gdata->validation_bits & CPER_SEC_VALID_FRU_TEXT)
+			fru_text = gdata->fru_text;
+
+		ghes_log_hwerr(sev, sec_type);
+		if (guid_equal(sec_type, &CPER_SEC_PLATFORM_MEM)) {
+			struct cper_sec_mem_err *mem_err = acpi_hest_get_payload(gdata);
+
+			atomic_notifier_call_chain(&ghes_report_chain, sev, mem_err);
+
+			arch_apei_report_mem_error(sev, mem_err);
+			queued = ghes_handle_memory_failure(gdata, sev, sync);
+		} else if (guid_equal(sec_type, &CPER_SEC_PCIE)) {
+			ghes_handle_aer(gdata);
+		} else if (guid_equal(sec_type, &CPER_SEC_PROC_ARM)) {
+			queued = ghes_handle_arm_hw_error(gdata, sev, sync);
+		} else if (guid_equal(sec_type, &CPER_SEC_CXL_PROT_ERR)) {
+			struct cxl_cper_sec_prot_err *prot_err = acpi_hest_get_payload(gdata);
+
+			cxl_cper_post_prot_err(prot_err, gdata->error_severity);
+		} else if (guid_equal(sec_type, &CPER_SEC_CXL_GEN_MEDIA_GUID)) {
+			struct cxl_cper_event_rec *rec = acpi_hest_get_payload(gdata);
+
+			cxl_cper_post_event(CXL_CPER_EVENT_GEN_MEDIA, rec);
+		} else if (guid_equal(sec_type, &CPER_SEC_CXL_DRAM_GUID)) {
+			struct cxl_cper_event_rec *rec = acpi_hest_get_payload(gdata);
+
+			cxl_cper_post_event(CXL_CPER_EVENT_DRAM, rec);
+		} else if (guid_equal(sec_type, &CPER_SEC_CXL_MEM_MODULE_GUID)) {
+			struct cxl_cper_event_rec *rec = acpi_hest_get_payload(gdata);
+
+			cxl_cper_post_event(CXL_CPER_EVENT_MEM_MODULE, rec);
+		} else {
+			void *err = acpi_hest_get_payload(gdata);
+
+			ghes_defer_non_standard_event(gdata, sev);
+			log_non_standard_event(sec_type, fru_id, fru_text,
+					       sec_sev, err,
+					       gdata->error_data_length);
+		}
+	}
+
+	/*
+	 * If no memory failure work is queued for abnormal synchronous
+	 * errors, do a force kill.
+	 */
+	if (sync && !queued) {
+		dev_err(dev,
+			HW_ERR GHES_PFX "%s:%d: synchronous unrecoverable error (SIGBUS)\n",
+			current->comm, task_pid_nr(current));
+		force_sig(SIGBUS);
+	}
+}
 /* Room for 8 entries */
 #define CXL_CPER_PROT_ERR_FIFO_DEPTH 8
 static DEFINE_KFIFO(cxl_cper_prot_err_fifo, struct cxl_cper_prot_err_work_data,
diff --git a/include/acpi/ghes_cper.h b/include/acpi/ghes_cper.h
index dd49e9179b63..511b95b50911 100644
--- a/include/acpi/ghes_cper.h
+++ b/include/acpi/ghes_cper.h
@@ -17,6 +17,8 @@
 #define ACPI_APEI_GHES_CPER_H
 
 #include <linux/atomic.h>
+#include <linux/device.h>
+#include <linux/notifier.h>
 #include <linux/workqueue.h>
 
 #include <acpi/ghes.h>
@@ -57,6 +59,7 @@
 	((struct ghes_vendor_record_entry *)(vendor_entry) + 1))
 
 extern struct gen_pool *ghes_estatus_pool;
+extern struct atomic_notifier_head ghes_report_chain;
 
 static inline bool is_hest_type_generic_v2(struct ghes *ghes)
 {
@@ -107,6 +110,23 @@ void ghes_estatus_cache_add(struct acpi_hest_generic *generic,
 			    struct acpi_hest_generic_status *estatus);
 void ghes_defer_non_standard_event(struct acpi_hest_generic_data *gdata,
 				   int sev);
+int ghes_severity(int severity);
+bool ghes_handle_memory_failure(struct acpi_hest_generic_data *gdata,
+				int sev, bool sync);
+bool ghes_handle_arm_hw_error(struct acpi_hest_generic_data *gdata,
+			      int sev, bool sync);
+void ghes_handle_aer(struct acpi_hest_generic_data *gdata);
+void ghes_log_hwerr(int sev, guid_t *sec_type);
+void __ghes_print_estatus(const char *pfx,
+			  const struct acpi_hest_generic *generic,
+			  const struct acpi_hest_generic_status *estatus);
+int ghes_print_estatus(const char *pfx,
+		       const struct acpi_hest_generic *generic,
+		       const struct acpi_hest_generic_status *estatus);
+void ghes_cper_handle_status(struct device *dev,
+			     const struct acpi_hest_generic *generic,
+			     const struct acpi_hest_generic_status *estatus,
+			     bool sync);
 void cxl_cper_post_prot_err(struct cxl_cper_sec_prot_err *prot_err,
 			    int severity);
 int cxl_cper_register_prot_err_work(struct work_struct *work);

-- 
2.43.0


^ permalink raw reply related

* [PATCH v5 07/10] ACPI: APEI: introduce GHES helper
From: Ahmed Tiba @ 2026-05-29  9:50 UTC (permalink / raw)
  To: will, jic23, xueshuai, saket.dumbre, mchehab, dave, djbw, bp,
	tony.luck, guohanjun, lenb, skhan, vishal.l.verma, rafael, corbet,
	ira.weiny, dave.jiang, krzk+dt, robh, catalin.marinas,
	alison.schofield, conor+dt
  Cc: Ahmed Tiba, linux-arm-kernel, Michael.Zhao2, linux-doc,
	linux-kernel, linux-cxl, Dmitry.Lamerov, devicetree, linux-acpi,
	linux-edac, acpica-devel
In-Reply-To: <20260529-topics-ahmtib01-ras_ffh_arm_internal_review-v5-0-2e0500d42642@arm.com>

Add a dedicated GHES_CPER_HELPERS Kconfig entry so the shared helper code
can be built even when ACPI_APEI_GHES is disabled. Update the build glue
and headers to depend on the new symbol.

Signed-off-by: Ahmed Tiba <ahmed.tiba@arm.com>
---
 drivers/Makefile           |  1 +
 drivers/acpi/Kconfig       |  4 ++++
 drivers/acpi/apei/Kconfig  |  1 +
 drivers/acpi/apei/Makefile |  2 +-
 include/acpi/ghes.h        | 10 ++++++----
 include/cxl/event.h        |  2 +-
 6 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/drivers/Makefile b/drivers/Makefile
index 0841ea851847..27a664cb45ea 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -31,6 +31,7 @@ obj-y				+= idle/
 obj-y				+= char/ipmi/
 
 obj-$(CONFIG_ACPI)		+= acpi/
+obj-$(CONFIG_GHES_CPER_HELPERS)	+= acpi/apei/ghes_cper.o
 
 # PnP must come after ACPI since it will eventually need to check if acpi
 # was used and do nothing if so
diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index f165d14cf61a..13ef0e99f840 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -6,6 +6,10 @@
 config ARCH_SUPPORTS_ACPI
 	bool
 
+config GHES_CPER_HELPERS
+	bool
+	select UEFI_CPER
+
 menuconfig ACPI
 	bool "ACPI (Advanced Configuration and Power Interface) Support"
 	depends on ARCH_SUPPORTS_ACPI
diff --git a/drivers/acpi/apei/Kconfig b/drivers/acpi/apei/Kconfig
index 428458c623f0..ddb62638eb02 100644
--- a/drivers/acpi/apei/Kconfig
+++ b/drivers/acpi/apei/Kconfig
@@ -21,6 +21,7 @@ config ACPI_APEI_GHES
 	bool "APEI Generic Hardware Error Source"
 	depends on ACPI_APEI
 	select ACPI_HED
+	select GHES_CPER_HELPERS
 	select IRQ_WORK
 	select GENERIC_ALLOCATOR
 	select ARM_SDE_INTERFACE if ARM64
diff --git a/drivers/acpi/apei/Makefile b/drivers/acpi/apei/Makefile
index f57f3b009d8e..66588d6be56f 100644
--- a/drivers/acpi/apei/Makefile
+++ b/drivers/acpi/apei/Makefile
@@ -1,6 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0
 obj-$(CONFIG_ACPI_APEI)		+= apei.o
-obj-$(CONFIG_ACPI_APEI_GHES)	+= ghes.o ghes_cper.o
+obj-$(CONFIG_ACPI_APEI_GHES)	+= ghes.o
 # clang versions prior to 18 may blow out the stack with KASAN
 ifeq ($(CONFIG_COMPILE_TEST)_$(CONFIG_CC_IS_CLANG)_$(call clang-min-version, 180000),y_y_)
 KASAN_SANITIZE_ghes.o := n
diff --git a/include/acpi/ghes.h b/include/acpi/ghes.h
index 8d7e5caef3f1..2ffab36b6154 100644
--- a/include/acpi/ghes.h
+++ b/include/acpi/ghes.h
@@ -83,15 +83,17 @@ int devm_ghes_register_vendor_record_notifier(struct device *dev,
 					      struct notifier_block *nb);
 
 struct list_head *ghes_get_devices(void);
-
-void ghes_estatus_pool_region_free(unsigned long addr, u32 size);
 #else
 static inline struct list_head *ghes_get_devices(void) { return NULL; }
-
-static inline void ghes_estatus_pool_region_free(unsigned long addr, u32 size) { return; }
 #endif
 
+#ifdef CONFIG_GHES_CPER_HELPERS
 int ghes_estatus_pool_init(unsigned int num_ghes);
+void ghes_estatus_pool_region_free(unsigned long addr, u32 size);
+#else
+static inline int ghes_estatus_pool_init(unsigned int num_ghes) { return -ENODEV; }
+static inline void ghes_estatus_pool_region_free(unsigned long addr, u32 size) { }
+#endif
 
 static inline int acpi_hest_get_version(struct acpi_hest_generic_data *gdata)
 {
diff --git a/include/cxl/event.h b/include/cxl/event.h
index ff97fea718d2..2ebd65b0d9d6 100644
--- a/include/cxl/event.h
+++ b/include/cxl/event.h
@@ -285,7 +285,7 @@ struct cxl_cper_prot_err_work_data {
 	int severity;
 };
 
-#ifdef CONFIG_ACPI_APEI_GHES
+#ifdef CONFIG_GHES_CPER_HELPERS
 int cxl_cper_register_work(struct work_struct *work);
 int cxl_cper_unregister_work(struct work_struct *work);
 int cxl_cper_kfifo_get(struct cxl_cper_work_data *wd);

-- 
2.43.0


^ permalink raw reply related

* [PATCH v5 06/10] ACPI: APEI: GHES: move CXL CPER helpers
From: Ahmed Tiba @ 2026-05-29  9:50 UTC (permalink / raw)
  To: will, jic23, xueshuai, saket.dumbre, mchehab, dave, djbw, bp,
	tony.luck, guohanjun, lenb, skhan, vishal.l.verma, rafael, corbet,
	ira.weiny, dave.jiang, krzk+dt, robh, catalin.marinas,
	alison.schofield, conor+dt
  Cc: Ahmed Tiba, linux-arm-kernel, Michael.Zhao2, linux-doc,
	linux-kernel, linux-cxl, Dmitry.Lamerov, devicetree, linux-acpi,
	linux-edac, acpica-devel
In-Reply-To: <20260529-topics-ahmtib01-ras_ffh_arm_internal_review-v5-0-2e0500d42642@arm.com>

Move the CXL CPER handling paths out of ghes.c and into ghes_cper.c so the
helpers can be reused. The code is moved as-is, with the public
prototypes updated so GHES keeps calling into the new translation unit.

Signed-off-by: Ahmed Tiba <ahmed.tiba@arm.com>
---
 drivers/acpi/apei/ghes.c      | 132 -----------------------------------------
 drivers/acpi/apei/ghes_cper.c | 134 ++++++++++++++++++++++++++++++++++++++++++
 include/acpi/ghes_cper.h      |  11 ++++
 3 files changed, 145 insertions(+), 132 deletions(-)

diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
index 81ac51632f21..85be2ebf4d3e 100644
--- a/drivers/acpi/apei/ghes.c
+++ b/drivers/acpi/apei/ghes.c
@@ -383,69 +383,6 @@ static void ghes_handle_aer(struct acpi_hest_generic_data *gdata)
 #endif
 }
 
-/* Room for 8 entries */
-#define CXL_CPER_PROT_ERR_FIFO_DEPTH 8
-static DEFINE_KFIFO(cxl_cper_prot_err_fifo, struct cxl_cper_prot_err_work_data,
-		    CXL_CPER_PROT_ERR_FIFO_DEPTH);
-
-/* Synchronize schedule_work() with cxl_cper_prot_err_work changes */
-static DEFINE_SPINLOCK(cxl_cper_prot_err_work_lock);
-struct work_struct *cxl_cper_prot_err_work;
-
-static void cxl_cper_post_prot_err(struct cxl_cper_sec_prot_err *prot_err,
-				   int severity)
-{
-#ifdef CONFIG_ACPI_APEI_PCIEAER
-	struct cxl_cper_prot_err_work_data wd;
-
-	if (cxl_cper_sec_prot_err_valid(prot_err))
-		return;
-
-	guard(spinlock_irqsave)(&cxl_cper_prot_err_work_lock);
-
-	if (!cxl_cper_prot_err_work)
-		return;
-
-	if (cxl_cper_setup_prot_err_work_data(&wd, prot_err, severity))
-		return;
-
-	if (!kfifo_put(&cxl_cper_prot_err_fifo, wd)) {
-		pr_err_ratelimited("CXL CPER kfifo overflow\n");
-		return;
-	}
-
-	schedule_work(cxl_cper_prot_err_work);
-#endif
-}
-
-int cxl_cper_register_prot_err_work(struct work_struct *work)
-{
-	if (cxl_cper_prot_err_work)
-		return -EINVAL;
-
-	guard(spinlock)(&cxl_cper_prot_err_work_lock);
-	cxl_cper_prot_err_work = work;
-	return 0;
-}
-EXPORT_SYMBOL_NS_GPL(cxl_cper_register_prot_err_work, "CXL");
-
-int cxl_cper_unregister_prot_err_work(struct work_struct *work)
-{
-	if (cxl_cper_prot_err_work != work)
-		return -EINVAL;
-
-	guard(spinlock)(&cxl_cper_prot_err_work_lock);
-	cxl_cper_prot_err_work = NULL;
-	return 0;
-}
-EXPORT_SYMBOL_NS_GPL(cxl_cper_unregister_prot_err_work, "CXL");
-
-int cxl_cper_prot_err_kfifo_get(struct cxl_cper_prot_err_work_data *wd)
-{
-	return kfifo_get(&cxl_cper_prot_err_fifo, wd);
-}
-EXPORT_SYMBOL_NS_GPL(cxl_cper_prot_err_kfifo_get, "CXL");
-
 static void ghes_vendor_record_notifier_destroy(void *nb)
 {
 	ghes_unregister_vendor_record_notifier(nb);
@@ -464,75 +401,6 @@ int devm_ghes_register_vendor_record_notifier(struct device *dev,
 }
 EXPORT_SYMBOL_GPL(devm_ghes_register_vendor_record_notifier);
 
-/* Room for 8 entries for each of the 4 event log queues */
-#define CXL_CPER_FIFO_DEPTH 32
-DEFINE_KFIFO(cxl_cper_fifo, struct cxl_cper_work_data, CXL_CPER_FIFO_DEPTH);
-
-/* Synchronize schedule_work() with cxl_cper_work changes */
-static DEFINE_SPINLOCK(cxl_cper_work_lock);
-struct work_struct *cxl_cper_work;
-
-static void cxl_cper_post_event(enum cxl_event_type event_type,
-				struct cxl_cper_event_rec *rec)
-{
-	struct cxl_cper_work_data wd;
-
-	if (rec->hdr.length <= sizeof(rec->hdr) ||
-	    rec->hdr.length > sizeof(*rec)) {
-		pr_err(FW_WARN "CXL CPER Invalid section length (%u)\n",
-		       rec->hdr.length);
-		return;
-	}
-
-	if (!(rec->hdr.validation_bits & CPER_CXL_COMP_EVENT_LOG_VALID)) {
-		pr_err(FW_WARN "CXL CPER invalid event\n");
-		return;
-	}
-
-	guard(spinlock_irqsave)(&cxl_cper_work_lock);
-
-	if (!cxl_cper_work)
-		return;
-
-	wd.event_type = event_type;
-	memcpy(&wd.rec, rec, sizeof(wd.rec));
-
-	if (!kfifo_put(&cxl_cper_fifo, wd)) {
-		pr_err_ratelimited("CXL CPER kfifo overflow\n");
-		return;
-	}
-
-	schedule_work(cxl_cper_work);
-}
-
-int cxl_cper_register_work(struct work_struct *work)
-{
-	if (cxl_cper_work)
-		return -EINVAL;
-
-	guard(spinlock)(&cxl_cper_work_lock);
-	cxl_cper_work = work;
-	return 0;
-}
-EXPORT_SYMBOL_NS_GPL(cxl_cper_register_work, "CXL");
-
-int cxl_cper_unregister_work(struct work_struct *work)
-{
-	if (cxl_cper_work != work)
-		return -EINVAL;
-
-	guard(spinlock)(&cxl_cper_work_lock);
-	cxl_cper_work = NULL;
-	return 0;
-}
-EXPORT_SYMBOL_NS_GPL(cxl_cper_unregister_work, "CXL");
-
-int cxl_cper_kfifo_get(struct cxl_cper_work_data *wd)
-{
-	return kfifo_get(&cxl_cper_fifo, wd);
-}
-EXPORT_SYMBOL_NS_GPL(cxl_cper_kfifo_get, "CXL");
-
 static void ghes_log_hwerr(int sev, guid_t *sec_type)
 {
 	if (sev != CPER_SEV_RECOVERABLE)
diff --git a/drivers/acpi/apei/ghes_cper.c b/drivers/acpi/apei/ghes_cper.c
index 131980d36064..d7a666a163c3 100644
--- a/drivers/acpi/apei/ghes_cper.c
+++ b/drivers/acpi/apei/ghes_cper.c
@@ -12,10 +12,12 @@
  *   Author: Huang Ying <ying.huang@intel.com>
  */
 
+#include <linux/aer.h>
 #include <linux/err.h>
 #include <linux/genalloc.h>
 #include <linux/irq_work.h>
 #include <linux/io.h>
+#include <linux/kfifo.h>
 #include <linux/kernel.h>
 #include <linux/list.h>
 #include <linux/math64.h>
@@ -321,6 +323,138 @@ void ghes_defer_non_standard_event(struct acpi_hest_generic_data *gdata,
 	schedule_work(&entry->work);
 }
 
+/* Room for 8 entries */
+#define CXL_CPER_PROT_ERR_FIFO_DEPTH 8
+static DEFINE_KFIFO(cxl_cper_prot_err_fifo, struct cxl_cper_prot_err_work_data,
+		    CXL_CPER_PROT_ERR_FIFO_DEPTH);
+
+/* Synchronize schedule_work() with cxl_cper_prot_err_work changes */
+static DEFINE_SPINLOCK(cxl_cper_prot_err_work_lock);
+struct work_struct *cxl_cper_prot_err_work;
+
+void cxl_cper_post_prot_err(struct cxl_cper_sec_prot_err *prot_err,
+			    int severity)
+{
+#ifdef CONFIG_ACPI_APEI_PCIEAER
+	struct cxl_cper_prot_err_work_data wd;
+
+	if (cxl_cper_sec_prot_err_valid(prot_err))
+		return;
+
+	guard(spinlock_irqsave)(&cxl_cper_prot_err_work_lock);
+
+	if (!cxl_cper_prot_err_work)
+		return;
+
+	if (cxl_cper_setup_prot_err_work_data(&wd, prot_err, severity))
+		return;
+
+	if (!kfifo_put(&cxl_cper_prot_err_fifo, wd)) {
+		pr_err_ratelimited("CXL CPER kfifo overflow\n");
+		return;
+	}
+
+	schedule_work(cxl_cper_prot_err_work);
+#endif
+}
+
+int cxl_cper_register_prot_err_work(struct work_struct *work)
+{
+	if (cxl_cper_prot_err_work)
+		return -EINVAL;
+
+	guard(spinlock)(&cxl_cper_prot_err_work_lock);
+	cxl_cper_prot_err_work = work;
+	return 0;
+}
+EXPORT_SYMBOL_NS_GPL(cxl_cper_register_prot_err_work, "CXL");
+
+int cxl_cper_unregister_prot_err_work(struct work_struct *work)
+{
+	if (cxl_cper_prot_err_work != work)
+		return -EINVAL;
+
+	guard(spinlock)(&cxl_cper_prot_err_work_lock);
+	cxl_cper_prot_err_work = NULL;
+	return 0;
+}
+EXPORT_SYMBOL_NS_GPL(cxl_cper_unregister_prot_err_work, "CXL");
+
+int cxl_cper_prot_err_kfifo_get(struct cxl_cper_prot_err_work_data *wd)
+{
+	return kfifo_get(&cxl_cper_prot_err_fifo, wd);
+}
+EXPORT_SYMBOL_NS_GPL(cxl_cper_prot_err_kfifo_get, "CXL");
+
+/* Room for 8 entries for each of the 4 event log queues */
+#define CXL_CPER_FIFO_DEPTH 32
+static DEFINE_KFIFO(cxl_cper_fifo, struct cxl_cper_work_data, CXL_CPER_FIFO_DEPTH);
+
+/* Synchronize schedule_work() with cxl_cper_work changes */
+static DEFINE_SPINLOCK(cxl_cper_work_lock);
+struct work_struct *cxl_cper_work;
+
+void cxl_cper_post_event(enum cxl_event_type event_type,
+			 struct cxl_cper_event_rec *rec)
+{
+	struct cxl_cper_work_data wd;
+
+	if (rec->hdr.length <= sizeof(rec->hdr) ||
+	    rec->hdr.length > sizeof(*rec)) {
+		pr_err(FW_WARN "CXL CPER Invalid section length (%u)\n",
+		       rec->hdr.length);
+		return;
+	}
+
+	if (!(rec->hdr.validation_bits & CPER_CXL_COMP_EVENT_LOG_VALID)) {
+		pr_err(FW_WARN "CXL CPER invalid event\n");
+		return;
+	}
+
+	guard(spinlock_irqsave)(&cxl_cper_work_lock);
+
+	if (!cxl_cper_work)
+		return;
+
+	wd.event_type = event_type;
+	memcpy(&wd.rec, rec, sizeof(wd.rec));
+
+	if (!kfifo_put(&cxl_cper_fifo, wd)) {
+		pr_err_ratelimited("CXL CPER kfifo overflow\n");
+		return;
+	}
+
+	schedule_work(cxl_cper_work);
+}
+
+int cxl_cper_register_work(struct work_struct *work)
+{
+	if (cxl_cper_work)
+		return -EINVAL;
+
+	guard(spinlock)(&cxl_cper_work_lock);
+	cxl_cper_work = work;
+	return 0;
+}
+EXPORT_SYMBOL_NS_GPL(cxl_cper_register_work, "CXL");
+
+int cxl_cper_unregister_work(struct work_struct *work)
+{
+	if (cxl_cper_work != work)
+		return -EINVAL;
+
+	guard(spinlock)(&cxl_cper_work_lock);
+	cxl_cper_work = NULL;
+	return 0;
+}
+EXPORT_SYMBOL_NS_GPL(cxl_cper_unregister_work, "CXL");
+
+int cxl_cper_kfifo_get(struct cxl_cper_work_data *wd)
+{
+	return kfifo_get(&cxl_cper_fifo, wd);
+}
+EXPORT_SYMBOL_NS_GPL(cxl_cper_kfifo_get, "CXL");
+
 /*
  * GHES error status reporting throttle, to report more kinds of
  * errors, instead of just most frequently occurred errors.
diff --git a/include/acpi/ghes_cper.h b/include/acpi/ghes_cper.h
index 51725f25c516..dd49e9179b63 100644
--- a/include/acpi/ghes_cper.h
+++ b/include/acpi/ghes_cper.h
@@ -20,6 +20,7 @@
 #include <linux/workqueue.h>
 
 #include <acpi/ghes.h>
+#include <cxl/event.h>
 
 #define GHES_PFX	"GHES: "
 
@@ -106,5 +107,15 @@ void ghes_estatus_cache_add(struct acpi_hest_generic *generic,
 			    struct acpi_hest_generic_status *estatus);
 void ghes_defer_non_standard_event(struct acpi_hest_generic_data *gdata,
 				   int sev);
+void cxl_cper_post_prot_err(struct cxl_cper_sec_prot_err *prot_err,
+			    int severity);
+int cxl_cper_register_prot_err_work(struct work_struct *work);
+int cxl_cper_unregister_prot_err_work(struct work_struct *work);
+int cxl_cper_prot_err_kfifo_get(struct cxl_cper_prot_err_work_data *wd);
+void cxl_cper_post_event(enum cxl_event_type event_type,
+			 struct cxl_cper_event_rec *rec);
+int cxl_cper_register_work(struct work_struct *work);
+int cxl_cper_unregister_work(struct work_struct *work);
+int cxl_cper_kfifo_get(struct cxl_cper_work_data *wd);
 
 #endif /* ACPI_APEI_GHES_CPER_H */

-- 
2.43.0


^ permalink raw reply related

* [PATCH v5 05/10] ACPI: APEI: GHES: move vendor record helpers
From: Ahmed Tiba @ 2026-05-29  9:50 UTC (permalink / raw)
  To: will, jic23, xueshuai, saket.dumbre, mchehab, dave, djbw, bp,
	tony.luck, guohanjun, lenb, skhan, vishal.l.verma, rafael, corbet,
	ira.weiny, dave.jiang, krzk+dt, robh, catalin.marinas,
	alison.schofield, conor+dt
  Cc: Ahmed Tiba, linux-arm-kernel, Michael.Zhao2, linux-doc,
	linux-kernel, linux-cxl, Dmitry.Lamerov, devicetree, linux-acpi,
	linux-edac, acpica-devel
In-Reply-To: <20260529-topics-ahmtib01-ras_ffh_arm_internal_review-v5-0-2e0500d42642@arm.com>

Shift the vendor record workqueue helpers into ghes_cper.c so both GHES
and future DT-based providers can use the same implementation. The change
is mechanical and keeps the notifier behavior identical.

Signed-off-by: Ahmed Tiba <ahmed.tiba@arm.com>
---
 drivers/acpi/apei/ghes.c      | 86 +++++++++----------------------------------
 drivers/acpi/apei/ghes_cper.c | 55 +++++++++++++++++++++++++++
 include/acpi/ghes_cper.h      |  2 +
 3 files changed, 75 insertions(+), 68 deletions(-)

diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
index adab7404310e..81ac51632f21 100644
--- a/drivers/acpi/apei/ghes.c
+++ b/drivers/acpi/apei/ghes.c
@@ -383,74 +383,6 @@ static void ghes_handle_aer(struct acpi_hest_generic_data *gdata)
 #endif
 }
 
-static BLOCKING_NOTIFIER_HEAD(vendor_record_notify_list);
-
-int ghes_register_vendor_record_notifier(struct notifier_block *nb)
-{
-	return blocking_notifier_chain_register(&vendor_record_notify_list, nb);
-}
-EXPORT_SYMBOL_GPL(ghes_register_vendor_record_notifier);
-
-void ghes_unregister_vendor_record_notifier(struct notifier_block *nb)
-{
-	blocking_notifier_chain_unregister(&vendor_record_notify_list, nb);
-}
-EXPORT_SYMBOL_GPL(ghes_unregister_vendor_record_notifier);
-
-static void ghes_vendor_record_notifier_destroy(void *nb)
-{
-	ghes_unregister_vendor_record_notifier(nb);
-}
-
-int devm_ghes_register_vendor_record_notifier(struct device *dev,
-					      struct notifier_block *nb)
-{
-	int ret;
-
-	ret = ghes_register_vendor_record_notifier(nb);
-	if (ret)
-		return ret;
-
-	return devm_add_action_or_reset(dev, ghes_vendor_record_notifier_destroy, nb);
-}
-EXPORT_SYMBOL_GPL(devm_ghes_register_vendor_record_notifier);
-
-static void ghes_vendor_record_work_func(struct work_struct *work)
-{
-	struct ghes_vendor_record_entry *entry;
-	struct acpi_hest_generic_data *gdata;
-	u32 len;
-
-	entry = container_of(work, struct ghes_vendor_record_entry, work);
-	gdata = GHES_GDATA_FROM_VENDOR_ENTRY(entry);
-
-	blocking_notifier_call_chain(&vendor_record_notify_list,
-				     entry->error_severity, gdata);
-
-	len = GHES_VENDOR_ENTRY_LEN(acpi_hest_get_record_size(gdata));
-	gen_pool_free(ghes_estatus_pool, (unsigned long)entry, len);
-}
-
-static void ghes_defer_non_standard_event(struct acpi_hest_generic_data *gdata,
-					  int sev)
-{
-	struct acpi_hest_generic_data *copied_gdata;
-	struct ghes_vendor_record_entry *entry;
-	u32 len;
-
-	len = GHES_VENDOR_ENTRY_LEN(acpi_hest_get_record_size(gdata));
-	entry = (void *)gen_pool_alloc(ghes_estatus_pool, len);
-	if (!entry)
-		return;
-
-	copied_gdata = GHES_GDATA_FROM_VENDOR_ENTRY(entry);
-	memcpy(copied_gdata, gdata, acpi_hest_get_record_size(gdata));
-	entry->error_severity = sev;
-
-	INIT_WORK(&entry->work, ghes_vendor_record_work_func);
-	schedule_work(&entry->work);
-}
-
 /* Room for 8 entries */
 #define CXL_CPER_PROT_ERR_FIFO_DEPTH 8
 static DEFINE_KFIFO(cxl_cper_prot_err_fifo, struct cxl_cper_prot_err_work_data,
@@ -514,6 +446,24 @@ int cxl_cper_prot_err_kfifo_get(struct cxl_cper_prot_err_work_data *wd)
 }
 EXPORT_SYMBOL_NS_GPL(cxl_cper_prot_err_kfifo_get, "CXL");
 
+static void ghes_vendor_record_notifier_destroy(void *nb)
+{
+	ghes_unregister_vendor_record_notifier(nb);
+}
+
+int devm_ghes_register_vendor_record_notifier(struct device *dev,
+					      struct notifier_block *nb)
+{
+	int ret;
+
+	ret = ghes_register_vendor_record_notifier(nb);
+	if (ret)
+		return ret;
+
+	return devm_add_action_or_reset(dev, ghes_vendor_record_notifier_destroy, nb);
+}
+EXPORT_SYMBOL_GPL(devm_ghes_register_vendor_record_notifier);
+
 /* Room for 8 entries for each of the 4 event log queues */
 #define CXL_CPER_FIFO_DEPTH 32
 DEFINE_KFIFO(cxl_cper_fifo, struct cxl_cper_work_data, CXL_CPER_FIFO_DEPTH);
diff --git a/drivers/acpi/apei/ghes_cper.c b/drivers/acpi/apei/ghes_cper.c
index 0a117f478afb..131980d36064 100644
--- a/drivers/acpi/apei/ghes_cper.c
+++ b/drivers/acpi/apei/ghes_cper.c
@@ -14,12 +14,17 @@
 
 #include <linux/err.h>
 #include <linux/genalloc.h>
+#include <linux/irq_work.h>
 #include <linux/io.h>
 #include <linux/kernel.h>
+#include <linux/list.h>
 #include <linux/math64.h>
 #include <linux/mm.h>
+#include <linux/notifier.h>
+#include <linux/llist.h>
 #include <linux/ratelimit.h>
 #include <linux/rcupdate.h>
+#include <linux/rculist.h>
 #include <linux/sched/clock.h>
 #include <linux/slab.h>
 
@@ -266,6 +271,56 @@ void ghes_clear_estatus(struct ghes *ghes,
 		ghes_ack_error(ghes->generic_v2);
 }
 
+static BLOCKING_NOTIFIER_HEAD(vendor_record_notify_list);
+
+int ghes_register_vendor_record_notifier(struct notifier_block *nb)
+{
+	return blocking_notifier_chain_register(&vendor_record_notify_list, nb);
+}
+EXPORT_SYMBOL_GPL(ghes_register_vendor_record_notifier);
+
+void ghes_unregister_vendor_record_notifier(struct notifier_block *nb)
+{
+	blocking_notifier_chain_unregister(&vendor_record_notify_list, nb);
+}
+EXPORT_SYMBOL_GPL(ghes_unregister_vendor_record_notifier);
+
+static void ghes_vendor_record_work_func(struct work_struct *work)
+{
+	struct ghes_vendor_record_entry *entry;
+	struct acpi_hest_generic_data *gdata;
+	u32 len;
+
+	entry = container_of(work, struct ghes_vendor_record_entry, work);
+	gdata = GHES_GDATA_FROM_VENDOR_ENTRY(entry);
+
+	blocking_notifier_call_chain(&vendor_record_notify_list,
+				     entry->error_severity, gdata);
+
+	len = GHES_VENDOR_ENTRY_LEN(acpi_hest_get_record_size(gdata));
+	gen_pool_free(ghes_estatus_pool, (unsigned long)entry, len);
+}
+
+void ghes_defer_non_standard_event(struct acpi_hest_generic_data *gdata,
+				   int sev)
+{
+	struct acpi_hest_generic_data *copied_gdata;
+	struct ghes_vendor_record_entry *entry;
+	u32 len;
+
+	len = GHES_VENDOR_ENTRY_LEN(acpi_hest_get_record_size(gdata));
+	entry = (void *)gen_pool_alloc(ghes_estatus_pool, len);
+	if (!entry)
+		return;
+
+	copied_gdata = GHES_GDATA_FROM_VENDOR_ENTRY(entry);
+	memcpy(copied_gdata, gdata, acpi_hest_get_record_size(gdata));
+	entry->error_severity = sev;
+
+	INIT_WORK(&entry->work, ghes_vendor_record_work_func);
+	schedule_work(&entry->work);
+}
+
 /*
  * GHES error status reporting throttle, to report more kinds of
  * errors, instead of just most frequently occurred errors.
diff --git a/include/acpi/ghes_cper.h b/include/acpi/ghes_cper.h
index 1b5dbeca9bb6..51725f25c516 100644
--- a/include/acpi/ghes_cper.h
+++ b/include/acpi/ghes_cper.h
@@ -104,5 +104,7 @@ int __ghes_read_estatus(struct acpi_hest_generic_status *estatus,
 int ghes_estatus_cached(struct acpi_hest_generic_status *estatus);
 void ghes_estatus_cache_add(struct acpi_hest_generic *generic,
 			    struct acpi_hest_generic_status *estatus);
+void ghes_defer_non_standard_event(struct acpi_hest_generic_data *gdata,
+				   int sev);
 
 #endif /* ACPI_APEI_GHES_CPER_H */

-- 
2.43.0


^ permalink raw reply related

* [PATCH v5 04/10] ACPI: APEI: GHES: move estatus cache helpers
From: Ahmed Tiba @ 2026-05-29  9:50 UTC (permalink / raw)
  To: will, jic23, xueshuai, saket.dumbre, mchehab, dave, djbw, bp,
	tony.luck, guohanjun, lenb, skhan, vishal.l.verma, rafael, corbet,
	ira.weiny, dave.jiang, krzk+dt, robh, catalin.marinas,
	alison.schofield, conor+dt
  Cc: Ahmed Tiba, linux-arm-kernel, Michael.Zhao2, linux-doc,
	linux-kernel, linux-cxl, Dmitry.Lamerov, devicetree, linux-acpi,
	linux-edac, acpica-devel
In-Reply-To: <20260529-topics-ahmtib01-ras_ffh_arm_internal_review-v5-0-2e0500d42642@arm.com>

Relocate the estatus cache allocation and lookup helpers from ghes.c into
ghes_cper.c. This code move keeps the logic intact while making the cache
implementation available to forthcoming users.

Signed-off-by: Ahmed Tiba <ahmed.tiba@arm.com>
---
 drivers/acpi/apei/ghes.c      | 138 +----------------------------------------
 drivers/acpi/apei/ghes_cper.c | 140 ++++++++++++++++++++++++++++++++++++++++++
 include/acpi/ghes_cper.h      |   6 ++
 3 files changed, 147 insertions(+), 137 deletions(-)

diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
index 91638ae7e05e..adab7404310e 100644
--- a/drivers/acpi/apei/ghes.c
+++ b/drivers/acpi/apei/ghes.c
@@ -113,10 +113,7 @@ static DEFINE_MUTEX(ghes_devs_mutex);
  */
 static DEFINE_SPINLOCK(ghes_notify_lock_irq);
 
-static struct gen_pool *ghes_estatus_pool;
-
-static struct ghes_estatus_cache __rcu *ghes_estatus_caches[GHES_ESTATUS_CACHES_SIZE];
-static atomic_t ghes_estatus_cache_alloced;
+struct gen_pool *ghes_estatus_pool;
 
 int ghes_estatus_pool_init(unsigned int num_ghes)
 {
@@ -733,139 +730,6 @@ static int ghes_print_estatus(const char *pfx,
 	return 0;
 }
 
-/*
- * GHES error status reporting throttle, to report more kinds of
- * errors, instead of just most frequently occurred errors.
- */
-static int ghes_estatus_cached(struct acpi_hest_generic_status *estatus)
-{
-	u32 len;
-	int i, cached = 0;
-	unsigned long long now;
-	struct ghes_estatus_cache *cache;
-	struct acpi_hest_generic_status *cache_estatus;
-
-	len = cper_estatus_len(estatus);
-	rcu_read_lock();
-	for (i = 0; i < GHES_ESTATUS_CACHES_SIZE; i++) {
-		cache = rcu_dereference(ghes_estatus_caches[i]);
-		if (cache == NULL)
-			continue;
-		if (len != cache->estatus_len)
-			continue;
-		cache_estatus = GHES_ESTATUS_FROM_CACHE(cache);
-		if (memcmp(estatus, cache_estatus, len))
-			continue;
-		atomic_inc(&cache->count);
-		now = sched_clock();
-		if (now - cache->time_in < GHES_ESTATUS_IN_CACHE_MAX_NSEC)
-			cached = 1;
-		break;
-	}
-	rcu_read_unlock();
-	return cached;
-}
-
-static struct ghes_estatus_cache *ghes_estatus_cache_alloc(
-	struct acpi_hest_generic *generic,
-	struct acpi_hest_generic_status *estatus)
-{
-	int alloced;
-	u32 len, cache_len;
-	struct ghes_estatus_cache *cache;
-	struct acpi_hest_generic_status *cache_estatus;
-
-	alloced = atomic_add_return(1, &ghes_estatus_cache_alloced);
-	if (alloced > GHES_ESTATUS_CACHE_ALLOCED_MAX) {
-		atomic_dec(&ghes_estatus_cache_alloced);
-		return NULL;
-	}
-	len = cper_estatus_len(estatus);
-	cache_len = GHES_ESTATUS_CACHE_LEN(len);
-	cache = (void *)gen_pool_alloc(ghes_estatus_pool, cache_len);
-	if (!cache) {
-		atomic_dec(&ghes_estatus_cache_alloced);
-		return NULL;
-	}
-	cache_estatus = GHES_ESTATUS_FROM_CACHE(cache);
-	memcpy(cache_estatus, estatus, len);
-	cache->estatus_len = len;
-	atomic_set(&cache->count, 0);
-	cache->generic = generic;
-	cache->time_in = sched_clock();
-	return cache;
-}
-
-static void ghes_estatus_cache_rcu_free(struct rcu_head *head)
-{
-	struct ghes_estatus_cache *cache;
-	u32 len;
-
-	cache = container_of(head, struct ghes_estatus_cache, rcu);
-	len = cper_estatus_len(GHES_ESTATUS_FROM_CACHE(cache));
-	len = GHES_ESTATUS_CACHE_LEN(len);
-	gen_pool_free(ghes_estatus_pool, (unsigned long)cache, len);
-	atomic_dec(&ghes_estatus_cache_alloced);
-}
-
-static void
-ghes_estatus_cache_add(struct acpi_hest_generic *generic,
-		       struct acpi_hest_generic_status *estatus)
-{
-	unsigned long long now, duration, period, max_period = 0;
-	struct ghes_estatus_cache *cache, *new_cache;
-	struct ghes_estatus_cache __rcu *victim;
-	int i, slot = -1, count;
-
-	new_cache = ghes_estatus_cache_alloc(generic, estatus);
-	if (!new_cache)
-		return;
-
-	rcu_read_lock();
-	now = sched_clock();
-	for (i = 0; i < GHES_ESTATUS_CACHES_SIZE; i++) {
-		cache = rcu_dereference(ghes_estatus_caches[i]);
-		if (cache == NULL) {
-			slot = i;
-			break;
-		}
-		duration = now - cache->time_in;
-		if (duration >= GHES_ESTATUS_IN_CACHE_MAX_NSEC) {
-			slot = i;
-			break;
-		}
-		count = atomic_read(&cache->count);
-		period = duration;
-		do_div(period, (count + 1));
-		if (period > max_period) {
-			max_period = period;
-			slot = i;
-		}
-	}
-	rcu_read_unlock();
-
-	if (slot != -1) {
-		/*
-		 * Use release semantics to ensure that ghes_estatus_cached()
-		 * running on another CPU will see the updated cache fields if
-		 * it can see the new value of the pointer.
-		 */
-		victim = xchg_release(&ghes_estatus_caches[slot],
-				      RCU_INITIALIZER(new_cache));
-
-		/*
-		 * At this point, victim may point to a cached item different
-		 * from the one based on which we selected the slot. Instead of
-		 * going to the loop again to pick another slot, let's just
-		 * drop the other item anyway: this may cause a false cache
-		 * miss later on, but that won't cause any problems.
-		 */
-		if (victim)
-			call_rcu(&unrcu_pointer(victim)->rcu,
-				 ghes_estatus_cache_rcu_free);
-	}
-}
-
 static void __ghes_panic(struct ghes *ghes,
 			 struct acpi_hest_generic_status *estatus,
 			 u64 buf_paddr, enum fixed_addresses fixmap_idx)
diff --git a/drivers/acpi/apei/ghes_cper.c b/drivers/acpi/apei/ghes_cper.c
index 8080e0f76dac..0a117f478afb 100644
--- a/drivers/acpi/apei/ghes_cper.c
+++ b/drivers/acpi/apei/ghes_cper.c
@@ -13,10 +13,14 @@
  */
 
 #include <linux/err.h>
+#include <linux/genalloc.h>
 #include <linux/io.h>
 #include <linux/kernel.h>
+#include <linux/math64.h>
 #include <linux/mm.h>
 #include <linux/ratelimit.h>
+#include <linux/rcupdate.h>
+#include <linux/sched/clock.h>
 #include <linux/slab.h>
 
 #include <acpi/apei.h>
@@ -27,6 +31,9 @@
 
 #include "apei-internal.h"
 
+static struct ghes_estatus_cache __rcu *ghes_estatus_caches[GHES_ESTATUS_CACHES_SIZE];
+static atomic_t ghes_estatus_cache_alloced;
+
 static void __iomem *ghes_map(u64 pfn, enum fixed_addresses fixmap_idx)
 {
 	phys_addr_t paddr;
@@ -258,3 +265,136 @@ void ghes_clear_estatus(struct ghes *ghes,
 	if (is_hest_type_generic_v2(ghes))
 		ghes_ack_error(ghes->generic_v2);
 }
+
+/*
+ * GHES error status reporting throttle, to report more kinds of
+ * errors, instead of just most frequently occurred errors.
+ */
+int ghes_estatus_cached(struct acpi_hest_generic_status *estatus)
+{
+	u32 len;
+	int i, cached = 0;
+	unsigned long long now;
+	struct ghes_estatus_cache *cache;
+	struct acpi_hest_generic_status *cache_estatus;
+
+	len = cper_estatus_len(estatus);
+	rcu_read_lock();
+	for (i = 0; i < GHES_ESTATUS_CACHES_SIZE; i++) {
+		cache = rcu_dereference(ghes_estatus_caches[i]);
+		if (cache == NULL)
+			continue;
+		if (len != cache->estatus_len)
+			continue;
+		cache_estatus = GHES_ESTATUS_FROM_CACHE(cache);
+		if (memcmp(estatus, cache_estatus, len))
+			continue;
+		atomic_inc(&cache->count);
+		now = sched_clock();
+		if (now - cache->time_in < GHES_ESTATUS_IN_CACHE_MAX_NSEC)
+			cached = 1;
+		break;
+	}
+	rcu_read_unlock();
+	return cached;
+}
+
+static struct ghes_estatus_cache *ghes_estatus_cache_alloc(
+	struct acpi_hest_generic *generic,
+	struct acpi_hest_generic_status *estatus)
+{
+	int alloced;
+	u32 len, cache_len;
+	struct ghes_estatus_cache *cache;
+	struct acpi_hest_generic_status *cache_estatus;
+
+	alloced = atomic_add_return(1, &ghes_estatus_cache_alloced);
+	if (alloced > GHES_ESTATUS_CACHE_ALLOCED_MAX) {
+		atomic_dec(&ghes_estatus_cache_alloced);
+		return NULL;
+	}
+	len = cper_estatus_len(estatus);
+	cache_len = GHES_ESTATUS_CACHE_LEN(len);
+	cache = (void *)gen_pool_alloc(ghes_estatus_pool, cache_len);
+	if (cache == NULL) {
+		atomic_dec(&ghes_estatus_cache_alloced);
+		return NULL;
+	}
+	cache_estatus = GHES_ESTATUS_FROM_CACHE(cache);
+	memcpy(cache_estatus, estatus, len);
+	cache->estatus_len = len;
+	atomic_set(&cache->count, 0);
+	cache->generic = generic;
+	cache->time_in = sched_clock();
+	return cache;
+}
+
+static void ghes_estatus_cache_rcu_free(struct rcu_head *head)
+{
+	struct ghes_estatus_cache *cache;
+	u32 len;
+
+	cache = container_of(head, struct ghes_estatus_cache, rcu);
+	len = cper_estatus_len(GHES_ESTATUS_FROM_CACHE(cache));
+	len = GHES_ESTATUS_CACHE_LEN(len);
+	gen_pool_free(ghes_estatus_pool, (unsigned long)cache, len);
+	atomic_dec(&ghes_estatus_cache_alloced);
+}
+
+void
+ghes_estatus_cache_add(struct acpi_hest_generic *generic,
+		       struct acpi_hest_generic_status *estatus)
+{
+	unsigned long long now, duration, period, max_period = 0;
+	struct ghes_estatus_cache *cache, *new_cache;
+	struct ghes_estatus_cache __rcu *victim;
+	int i, slot = -1, count;
+
+	new_cache = ghes_estatus_cache_alloc(generic, estatus);
+	if (!new_cache)
+		return;
+
+	rcu_read_lock();
+	now = sched_clock();
+	for (i = 0; i < GHES_ESTATUS_CACHES_SIZE; i++) {
+		cache = rcu_dereference(ghes_estatus_caches[i]);
+		if (cache == NULL) {
+			slot = i;
+			break;
+		}
+		duration = now - cache->time_in;
+		if (duration >= GHES_ESTATUS_IN_CACHE_MAX_NSEC) {
+			slot = i;
+			break;
+		}
+		count = atomic_read(&cache->count);
+		period = duration;
+		do_div(period, (count + 1));
+		if (period > max_period) {
+			max_period = period;
+			slot = i;
+		}
+	}
+	rcu_read_unlock();
+
+	if (slot != -1) {
+		/*
+		 * Use release semantics to ensure that ghes_estatus_cached()
+		 * running on another CPU will see the updated cache fields if
+		 * it can see the new value of the pointer.
+		 */
+		victim = xchg_release(&ghes_estatus_caches[slot],
+				      RCU_INITIALIZER(new_cache));
+
+		/*
+		 * At this point, victim may point to a cached item different
+		 * from the one based on which we selected the slot. Instead of
+		 * going to the loop again to pick another slot, let's just
+		 * drop the other item anyway: this may cause a false cache
+		 * miss later on, but that won't cause any problems.
+		 */
+		if (victim)
+			call_rcu(&unrcu_pointer(victim)->rcu,
+				 ghes_estatus_cache_rcu_free);
+	}
+}
diff --git a/include/acpi/ghes_cper.h b/include/acpi/ghes_cper.h
index 6b7632cfaf66..1b5dbeca9bb6 100644
--- a/include/acpi/ghes_cper.h
+++ b/include/acpi/ghes_cper.h
@@ -16,6 +16,7 @@
 #ifndef ACPI_APEI_GHES_CPER_H
 #define ACPI_APEI_GHES_CPER_H
 
+#include <linux/atomic.h>
 #include <linux/workqueue.h>
 
 #include <acpi/ghes.h>
@@ -54,6 +55,8 @@
 	((struct acpi_hest_generic_data *)                              \
 	((struct ghes_vendor_record_entry *)(vendor_entry) + 1))
 
+extern struct gen_pool *ghes_estatus_pool;
+
 static inline bool is_hest_type_generic_v2(struct ghes *ghes)
 {
 	return ghes->generic->header.type == ACPI_HEST_TYPE_GENERIC_ERROR_V2;
@@ -98,5 +101,8 @@ int __ghes_read_estatus(struct acpi_hest_generic_status *estatus,
 			u64 buf_paddr, enum fixed_addresses fixmap_idx,
 			size_t buf_len);
 #endif
+int ghes_estatus_cached(struct acpi_hest_generic_status *estatus);
+void ghes_estatus_cache_add(struct acpi_hest_generic *generic,
+			    struct acpi_hest_generic_status *estatus);
 
 #endif /* ACPI_APEI_GHES_CPER_H */

-- 
2.43.0


^ permalink raw reply related

* [PATCH v5 03/10] ACPI: APEI: GHES: move GHESv2 ack and alloc helpers
From: Ahmed Tiba @ 2026-05-29  9:50 UTC (permalink / raw)
  To: will, jic23, xueshuai, saket.dumbre, mchehab, dave, djbw, bp,
	tony.luck, guohanjun, lenb, skhan, vishal.l.verma, rafael, corbet,
	ira.weiny, dave.jiang, krzk+dt, robh, catalin.marinas,
	alison.schofield, conor+dt
  Cc: Ahmed Tiba, linux-arm-kernel, Michael.Zhao2, linux-doc,
	linux-kernel, linux-cxl, Dmitry.Lamerov, devicetree, linux-acpi,
	linux-edac, acpica-devel
In-Reply-To: <20260529-topics-ahmtib01-ras_ffh_arm_internal_review-v5-0-2e0500d42642@arm.com>

Move the GHESv2 acknowledgment and error-source allocation helpers from
ghes.c into ghes_cper.c. This is a mechanical refactor that keeps the
logic unchanged while making the helpers reusable.

Signed-off-by: Ahmed Tiba <ahmed.tiba@arm.com>
---
 drivers/acpi/apei/ghes.c      | 65 -------------------------------------------
 drivers/acpi/apei/ghes_cper.c | 65 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 65 insertions(+), 65 deletions(-)

diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
index 3f35580e8efd..91638ae7e05e 100644
--- a/drivers/acpi/apei/ghes.c
+++ b/drivers/acpi/apei/ghes.c
@@ -163,71 +163,6 @@ void ghes_estatus_pool_region_free(unsigned long addr, u32 size)
 }
 EXPORT_SYMBOL_GPL(ghes_estatus_pool_region_free);
 
-static int map_gen_v2(struct ghes *ghes)
-{
-	return apei_map_generic_address(&ghes->generic_v2->read_ack_register);
-}
-
-static void unmap_gen_v2(struct ghes *ghes)
-{
-	apei_unmap_generic_address(&ghes->generic_v2->read_ack_register);
-}
-
-struct ghes *ghes_new(struct acpi_hest_generic *generic)
-{
-	struct ghes *ghes;
-	unsigned int error_block_length;
-	int rc;
-
-	ghes = kzalloc_obj(*ghes);
-	if (!ghes)
-		return ERR_PTR(-ENOMEM);
-
-	ghes->generic = generic;
-	if (is_hest_type_generic_v2(ghes)) {
-		rc = map_gen_v2(ghes);
-		if (rc)
-			goto err_free;
-	}
-
-	rc = apei_map_generic_address(&generic->error_status_address);
-	if (rc)
-		goto err_unmap_read_ack_addr;
-	error_block_length = generic->error_block_length;
-	if (error_block_length > GHES_ESTATUS_MAX_SIZE) {
-		pr_warn(FW_WARN GHES_PFX
-			"Error status block length is too long: %u for "
-			"generic hardware error source: %d.\n",
-			error_block_length, generic->header.source_id);
-		error_block_length = GHES_ESTATUS_MAX_SIZE;
-	}
-	ghes->estatus = kmalloc(error_block_length, GFP_KERNEL);
-	ghes->estatus_length = error_block_length;
-	if (!ghes->estatus) {
-		rc = -ENOMEM;
-		goto err_unmap_status_addr;
-	}
-
-	return ghes;
-
-err_unmap_status_addr:
-	apei_unmap_generic_address(&generic->error_status_address);
-err_unmap_read_ack_addr:
-	if (is_hest_type_generic_v2(ghes))
-		unmap_gen_v2(ghes);
-err_free:
-	kfree(ghes);
-	return ERR_PTR(rc);
-}
-
-void ghes_fini(struct ghes *ghes)
-{
-	kfree(ghes->estatus);
-	apei_unmap_generic_address(&ghes->generic->error_status_address);
-	if (is_hest_type_generic_v2(ghes))
-		unmap_gen_v2(ghes);
-}
-
 static inline int ghes_severity(int severity)
 {
 	switch (severity) {
diff --git a/drivers/acpi/apei/ghes_cper.c b/drivers/acpi/apei/ghes_cper.c
index 7bb72fe57838..8080e0f76dac 100644
--- a/drivers/acpi/apei/ghes_cper.c
+++ b/drivers/acpi/apei/ghes_cper.c
@@ -62,6 +62,71 @@ static void ghes_ack_error(struct acpi_hest_generic_v2 *gv2)
 	apei_write(val, &gv2->read_ack_register);
 }
 
+static int map_gen_v2(struct ghes *ghes)
+{
+	return apei_map_generic_address(&ghes->generic_v2->read_ack_register);
+}
+
+static void unmap_gen_v2(struct ghes *ghes)
+{
+	apei_unmap_generic_address(&ghes->generic_v2->read_ack_register);
+}
+
+struct ghes *ghes_new(struct acpi_hest_generic *generic)
+{
+	struct ghes *ghes;
+	unsigned int error_block_length;
+	int rc;
+
+	ghes = kzalloc_obj(*ghes);
+	if (!ghes)
+		return ERR_PTR(-ENOMEM);
+
+	ghes->generic = generic;
+	if (is_hest_type_generic_v2(ghes)) {
+		rc = map_gen_v2(ghes);
+		if (rc)
+			goto err_free;
+	}
+
+	rc = apei_map_generic_address(&generic->error_status_address);
+	if (rc)
+		goto err_unmap_read_ack_addr;
+	error_block_length = generic->error_block_length;
+	if (error_block_length > GHES_ESTATUS_MAX_SIZE) {
+		pr_warn(FW_WARN GHES_PFX
+			"Error status block length is too long: %u for "
+			"generic hardware error source: %d.\n",
+			error_block_length, generic->header.source_id);
+		error_block_length = GHES_ESTATUS_MAX_SIZE;
+	}
+	ghes->estatus = kmalloc(error_block_length, GFP_KERNEL);
+	ghes->estatus_length = error_block_length;
+	if (!ghes->estatus) {
+		rc = -ENOMEM;
+		goto err_unmap_status_addr;
+	}
+
+	return ghes;
+
+err_unmap_status_addr:
+	apei_unmap_generic_address(&generic->error_status_address);
+err_unmap_read_ack_addr:
+	if (is_hest_type_generic_v2(ghes))
+		unmap_gen_v2(ghes);
+err_free:
+	kfree(ghes);
+	return ERR_PTR(rc);
+}
+
+void ghes_fini(struct ghes *ghes)
+{
+	kfree(ghes->estatus);
+	apei_unmap_generic_address(&ghes->generic->error_status_address);
+	if (is_hest_type_generic_v2(ghes))
+		unmap_gen_v2(ghes);
+}
+
 static void ghes_copy_tofrom_phys(void *buffer, u64 paddr, u32 len,
 				  int from_phys,
 				  enum fixed_addresses fixmap_idx)

-- 
2.43.0


^ permalink raw reply related

* [PATCH v5 02/10] ACPI: APEI: GHES: move CPER read helpers
From: Ahmed Tiba @ 2026-05-29  9:50 UTC (permalink / raw)
  To: will, jic23, xueshuai, saket.dumbre, mchehab, dave, djbw, bp,
	tony.luck, guohanjun, lenb, skhan, vishal.l.verma, rafael, corbet,
	ira.weiny, dave.jiang, krzk+dt, robh, catalin.marinas,
	alison.schofield, conor+dt
  Cc: Ahmed Tiba, linux-arm-kernel, Michael.Zhao2, linux-doc,
	linux-kernel, linux-cxl, Dmitry.Lamerov, devicetree, linux-acpi,
	linux-edac, acpica-devel
In-Reply-To: <20260529-topics-ahmtib01-ras_ffh_arm_internal_review-v5-0-2e0500d42642@arm.com>

Relocate the CPER buffer mapping, peek, and clear helpers from ghes.c into
ghes_cper.c so they can be shared with other firmware-first providers.
This commit only shuffles code; behavior stays the same.

Signed-off-by: Ahmed Tiba <ahmed.tiba@arm.com>
---
 drivers/acpi/apei/Makefile    |   2 +-
 drivers/acpi/apei/ghes.c      | 166 -----------------------------------
 drivers/acpi/apei/ghes_cper.c | 195 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 196 insertions(+), 167 deletions(-)

diff --git a/drivers/acpi/apei/Makefile b/drivers/acpi/apei/Makefile
index 66588d6be56f..f57f3b009d8e 100644
--- a/drivers/acpi/apei/Makefile
+++ b/drivers/acpi/apei/Makefile
@@ -1,6 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0
 obj-$(CONFIG_ACPI_APEI)		+= apei.o
-obj-$(CONFIG_ACPI_APEI_GHES)	+= ghes.o
+obj-$(CONFIG_ACPI_APEI_GHES)	+= ghes.o ghes_cper.o
 # clang versions prior to 18 may blow out the stack with KASAN
 ifeq ($(CONFIG_COMPILE_TEST)_$(CONFIG_CC_IS_CLANG)_$(call clang-min-version, 180000),y_y_)
 KASAN_SANITIZE_ghes.o := n
diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
index 4f67f46410c4..3f35580e8efd 100644
--- a/drivers/acpi/apei/ghes.c
+++ b/drivers/acpi/apei/ghes.c
@@ -118,26 +118,6 @@ static struct gen_pool *ghes_estatus_pool;
 static struct ghes_estatus_cache __rcu *ghes_estatus_caches[GHES_ESTATUS_CACHES_SIZE];
 static atomic_t ghes_estatus_cache_alloced;
 
-static void __iomem *ghes_map(u64 pfn, enum fixed_addresses fixmap_idx)
-{
-	phys_addr_t paddr;
-	pgprot_t prot;
-
-	paddr = PFN_PHYS(pfn);
-	prot = arch_apei_get_mem_attribute(paddr);
-	__set_fixmap(fixmap_idx, paddr, prot);
-
-	return (void __iomem *) __fix_to_virt(fixmap_idx);
-}
-
-static void ghes_unmap(void __iomem *vaddr, enum fixed_addresses fixmap_idx)
-{
-	int _idx = virt_to_fix((unsigned long)vaddr);
-
-	WARN_ON_ONCE(fixmap_idx != _idx);
-	clear_fixmap(fixmap_idx);
-}
-
 int ghes_estatus_pool_init(unsigned int num_ghes)
 {
 	unsigned long addr, len;
@@ -193,21 +173,6 @@ static void unmap_gen_v2(struct ghes *ghes)
 	apei_unmap_generic_address(&ghes->generic_v2->read_ack_register);
 }
 
-static void ghes_ack_error(struct acpi_hest_generic_v2 *gv2)
-{
-	int rc;
-	u64 val = 0;
-
-	rc = apei_read(&val, &gv2->read_ack_register);
-	if (rc)
-		return;
-
-	val &= gv2->read_ack_preserve << gv2->read_ack_register.bit_offset;
-	val |= gv2->read_ack_write    << gv2->read_ack_register.bit_offset;
-
-	apei_write(val, &gv2->read_ack_register);
-}
-
 struct ghes *ghes_new(struct acpi_hest_generic *generic)
 {
 	struct ghes *ghes;
@@ -280,137 +245,6 @@ static inline int ghes_severity(int severity)
 	}
 }
 
-static void ghes_copy_tofrom_phys(void *buffer, u64 paddr, u32 len,
-				  int from_phys,
-				  enum fixed_addresses fixmap_idx)
-{
-	void __iomem *vaddr;
-	u64 offset;
-	u32 trunk;
-
-	while (len > 0) {
-		offset = paddr - (paddr & PAGE_MASK);
-		vaddr = ghes_map(PHYS_PFN(paddr), fixmap_idx);
-		trunk = PAGE_SIZE - offset;
-		trunk = min(trunk, len);
-		if (from_phys)
-			memcpy_fromio(buffer, vaddr + offset, trunk);
-		else
-			memcpy_toio(vaddr + offset, buffer, trunk);
-		len -= trunk;
-		paddr += trunk;
-		buffer += trunk;
-		ghes_unmap(vaddr, fixmap_idx);
-	}
-}
-
-/* Check the top-level record header has an appropriate size. */
-int __ghes_check_estatus(struct ghes *ghes,
-			 struct acpi_hest_generic_status *estatus)
-{
-	u32 len = cper_estatus_len(estatus);
-	u32 max_len = min(ghes->generic->error_block_length,
-			  ghes->estatus_length);
-
-	if (len < sizeof(*estatus)) {
-		pr_warn_ratelimited(FW_WARN GHES_PFX "Truncated error status block!\n");
-		return -EIO;
-	}
-
-	if (!len || len > max_len) {
-		pr_warn_ratelimited(FW_WARN GHES_PFX "Invalid error status block length!\n");
-		return -EIO;
-	}
-
-	if (cper_estatus_check_header(estatus)) {
-		pr_warn_ratelimited(FW_WARN GHES_PFX "Invalid CPER header!\n");
-		return -EIO;
-	}
-
-	return 0;
-}
-
-/* Read the CPER block, returning its address, and header in estatus. */
-int __ghes_peek_estatus(struct ghes *ghes,
-			struct acpi_hest_generic_status *estatus,
-			u64 *buf_paddr, enum fixed_addresses fixmap_idx)
-{
-	struct acpi_hest_generic *g = ghes->generic;
-	int rc;
-
-	rc = apei_read(buf_paddr, &g->error_status_address);
-	if (rc) {
-		*buf_paddr = 0;
-		pr_warn_ratelimited(FW_WARN GHES_PFX
-				    "Failed to read error status block address for hardware error source: %d.\n",
-				   g->header.source_id);
-		return -EIO;
-	}
-	if (!*buf_paddr)
-		return -ENOENT;
-
-	ghes_copy_tofrom_phys(estatus, *buf_paddr, sizeof(*estatus), 1,
-			      fixmap_idx);
-	if (!estatus->block_status) {
-		*buf_paddr = 0;
-		return -ENOENT;
-	}
-
-	return 0;
-}
-
-int __ghes_read_estatus(struct acpi_hest_generic_status *estatus,
-			u64 buf_paddr, enum fixed_addresses fixmap_idx,
-			size_t buf_len)
-{
-	ghes_copy_tofrom_phys(estatus, buf_paddr, buf_len, 1, fixmap_idx);
-	if (cper_estatus_check(estatus)) {
-		pr_warn_ratelimited(FW_WARN GHES_PFX
-				    "Failed to read error status block!\n");
-		return -EIO;
-	}
-
-	return 0;
-}
-
-int ghes_read_estatus(struct ghes *ghes,
-		      struct acpi_hest_generic_status *estatus,
-		      u64 *buf_paddr, enum fixed_addresses fixmap_idx)
-{
-	int rc;
-
-	rc = __ghes_peek_estatus(ghes, estatus, buf_paddr, fixmap_idx);
-	if (rc)
-		return rc;
-
-	rc = __ghes_check_estatus(ghes, estatus);
-	if (rc)
-		return rc;
-
-	return __ghes_read_estatus(estatus, *buf_paddr, fixmap_idx,
-				   cper_estatus_len(estatus));
-}
-
-void ghes_clear_estatus(struct ghes *ghes,
-			struct acpi_hest_generic_status *estatus,
-			u64 buf_paddr, enum fixed_addresses fixmap_idx)
-{
-	estatus->block_status = 0;
-
-	if (!buf_paddr)
-		return;
-
-	ghes_copy_tofrom_phys(estatus, buf_paddr,
-			      sizeof(estatus->block_status), 0,
-			      fixmap_idx);
-
-	/*
-	 * GHESv2 type HEST entries introduce support for error acknowledgment,
-	 * so only acknowledge the error if this support is present.
-	 */
-	if (is_hest_type_generic_v2(ghes))
-		ghes_ack_error(ghes->generic_v2);
-}
 
 /**
  * struct ghes_task_work - for synchronous RAS event
diff --git a/drivers/acpi/apei/ghes_cper.c b/drivers/acpi/apei/ghes_cper.c
new file mode 100644
index 000000000000..7bb72fe57838
--- /dev/null
+++ b/drivers/acpi/apei/ghes_cper.c
@@ -0,0 +1,195 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Shared GHES helpers for firmware-first CPER error handling.
+ *
+ * This file holds the GHES helper code that is shared by the in-tree GHES
+ * driver and by other firmware-first error sources that reuse the same CPER
+ * handling flow.
+ *
+ * Derived from the ACPI APEI GHES driver.
+ *
+ * Copyright 2010,2011 Intel Corp.
+ *   Author: Huang Ying <ying.huang@intel.com>
+ */
+
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/ratelimit.h>
+#include <linux/slab.h>
+
+#include <acpi/apei.h>
+#include <acpi/ghes_cper.h>
+
+#include <asm/fixmap.h>
+#include <asm/tlbflush.h>
+
+#include "apei-internal.h"
+
+static void __iomem *ghes_map(u64 pfn, enum fixed_addresses fixmap_idx)
+{
+	phys_addr_t paddr;
+	pgprot_t prot;
+
+	paddr = PFN_PHYS(pfn);
+	prot = arch_apei_get_mem_attribute(paddr);
+	__set_fixmap(fixmap_idx, paddr, prot);
+
+	return (void __iomem *) __fix_to_virt(fixmap_idx);
+}
+
+static void ghes_unmap(void __iomem *vaddr, enum fixed_addresses fixmap_idx)
+{
+	int _idx = virt_to_fix((unsigned long)vaddr);
+
+	WARN_ON_ONCE(fixmap_idx != _idx);
+	clear_fixmap(fixmap_idx);
+}
+
+static void ghes_ack_error(struct acpi_hest_generic_v2 *gv2)
+{
+	int rc;
+	u64 val = 0;
+
+	rc = apei_read(&val, &gv2->read_ack_register);
+	if (rc)
+		return;
+
+	val &= gv2->read_ack_preserve << gv2->read_ack_register.bit_offset;
+	val |= gv2->read_ack_write    << gv2->read_ack_register.bit_offset;
+
+	apei_write(val, &gv2->read_ack_register);
+}
+
+static void ghes_copy_tofrom_phys(void *buffer, u64 paddr, u32 len,
+				  int from_phys,
+				  enum fixed_addresses fixmap_idx)
+{
+	void __iomem *vaddr;
+	u64 offset;
+	u32 trunk;
+
+	while (len > 0) {
+		offset = paddr - (paddr & PAGE_MASK);
+		vaddr = ghes_map(PHYS_PFN(paddr), fixmap_idx);
+		trunk = PAGE_SIZE - offset;
+		trunk = min(trunk, len);
+		if (from_phys)
+			memcpy_fromio(buffer, vaddr + offset, trunk);
+		else
+			memcpy_toio(vaddr + offset, buffer, trunk);
+		len -= trunk;
+		paddr += trunk;
+		buffer += trunk;
+		ghes_unmap(vaddr, fixmap_idx);
+	}
+}
+
+/* Check the top-level record header has an appropriate size. */
+int __ghes_check_estatus(struct ghes *ghes,
+			 struct acpi_hest_generic_status *estatus)
+{
+	u32 len = cper_estatus_len(estatus);
+	u32 max_len = min(ghes->generic->error_block_length,
+			  ghes->estatus_length);
+
+	if (len < sizeof(*estatus)) {
+		pr_warn_ratelimited(FW_WARN GHES_PFX "Truncated error status block!\n");
+		return -EIO;
+	}
+
+	if (!len || len > max_len) {
+		pr_warn_ratelimited(FW_WARN GHES_PFX "Invalid error status block length!\n");
+		return -EIO;
+	}
+
+	if (cper_estatus_check_header(estatus)) {
+		pr_warn_ratelimited(FW_WARN GHES_PFX "Invalid CPER header!\n");
+		return -EIO;
+	}
+
+	return 0;
+}
+
+/* Read the CPER block, returning its address, and header in estatus. */
+int __ghes_peek_estatus(struct ghes *ghes,
+			struct acpi_hest_generic_status *estatus,
+			u64 *buf_paddr, enum fixed_addresses fixmap_idx)
+{
+	struct acpi_hest_generic *g = ghes->generic;
+	int rc;
+
+	rc = apei_read(buf_paddr, &g->error_status_address);
+	if (rc) {
+		*buf_paddr = 0;
+		pr_warn_ratelimited(FW_WARN GHES_PFX
+				    "Failed to read error status block address for hardware error source: %d.\n",
+				   g->header.source_id);
+		return -EIO;
+	}
+	if (!*buf_paddr)
+		return -ENOENT;
+
+	ghes_copy_tofrom_phys(estatus, *buf_paddr, sizeof(*estatus), 1,
+			      fixmap_idx);
+	if (!estatus->block_status) {
+		*buf_paddr = 0;
+		return -ENOENT;
+	}
+
+	return 0;
+}
+
+int __ghes_read_estatus(struct acpi_hest_generic_status *estatus,
+			u64 buf_paddr, enum fixed_addresses fixmap_idx,
+			size_t buf_len)
+{
+	ghes_copy_tofrom_phys(estatus, buf_paddr, buf_len, 1, fixmap_idx);
+	if (cper_estatus_check(estatus)) {
+		pr_warn_ratelimited(FW_WARN GHES_PFX
+				    "Failed to read error status block!\n");
+		return -EIO;
+	}
+
+	return 0;
+}
+
+int ghes_read_estatus(struct ghes *ghes,
+		      struct acpi_hest_generic_status *estatus,
+		      u64 *buf_paddr, enum fixed_addresses fixmap_idx)
+{
+	int rc;
+
+	rc = __ghes_peek_estatus(ghes, estatus, buf_paddr, fixmap_idx);
+	if (rc)
+		return rc;
+
+	rc = __ghes_check_estatus(ghes, estatus);
+	if (rc)
+		return rc;
+
+	return __ghes_read_estatus(estatus, *buf_paddr, fixmap_idx,
+				   cper_estatus_len(estatus));
+}
+
+void ghes_clear_estatus(struct ghes *ghes,
+			struct acpi_hest_generic_status *estatus,
+			u64 buf_paddr, enum fixed_addresses fixmap_idx)
+{
+	estatus->block_status = 0;
+
+	if (!buf_paddr)
+		return;
+
+	ghes_copy_tofrom_phys(estatus, buf_paddr,
+			      sizeof(estatus->block_status), 0,
+			      fixmap_idx);
+
+	/*
+	 * GHESv2 type HEST entries introduce support for error acknowledgment,
+	 * so only acknowledge the error if this support is present.
+	 */
+	if (is_hest_type_generic_v2(ghes))
+		ghes_ack_error(ghes->generic_v2);
+}

-- 
2.43.0


^ permalink raw reply related

* [PATCH v5 01/10] ACPI: APEI: GHES: share macros via a private header
From: Ahmed Tiba @ 2026-05-29  9:50 UTC (permalink / raw)
  To: will, jic23, xueshuai, saket.dumbre, mchehab, dave, djbw, bp,
	tony.luck, guohanjun, lenb, skhan, vishal.l.verma, rafael, corbet,
	ira.weiny, dave.jiang, krzk+dt, robh, catalin.marinas,
	alison.schofield, conor+dt
  Cc: Ahmed Tiba, linux-arm-kernel, Michael.Zhao2, linux-doc,
	linux-kernel, linux-cxl, Dmitry.Lamerov, devicetree, linux-acpi,
	linux-edac, acpica-devel
In-Reply-To: <20260529-topics-ahmtib01-ras_ffh_arm_internal_review-v5-0-2e0500d42642@arm.com>

Carve the CPER helper macros out of ghes.c and place them in a private
header so they can be shared with upcoming helper files. This is a
mechanical include change with no functional differences.

Signed-off-by: Ahmed Tiba <ahmed.tiba@arm.com>
---
 drivers/acpi/apei/ghes.c |  94 +++++++++----------------------------------
 include/acpi/ghes_cper.h | 102 +++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 120 insertions(+), 76 deletions(-)

diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
index 3236a3ce79d6..4f67f46410c4 100644
--- a/drivers/acpi/apei/ghes.c
+++ b/drivers/acpi/apei/ghes.c
@@ -49,6 +49,7 @@
 
 #include <acpi/actbl1.h>
 #include <acpi/ghes.h>
+#include <acpi/ghes_cper.h>
 #include <acpi/apei.h>
 #include <asm/fixmap.h>
 #include <asm/tlbflush.h>
@@ -57,40 +58,6 @@
 
 #include "apei-internal.h"
 
-#define GHES_PFX	"GHES: "
-
-#define GHES_ESTATUS_MAX_SIZE		65536
-#define GHES_ESOURCE_PREALLOC_MAX_SIZE	65536
-
-#define GHES_ESTATUS_POOL_MIN_ALLOC_ORDER 3
-
-/* This is just an estimation for memory pool allocation */
-#define GHES_ESTATUS_CACHE_AVG_SIZE	512
-
-#define GHES_ESTATUS_CACHES_SIZE	4
-
-#define GHES_ESTATUS_IN_CACHE_MAX_NSEC	10000000000ULL
-/* Prevent too many caches are allocated because of RCU */
-#define GHES_ESTATUS_CACHE_ALLOCED_MAX	(GHES_ESTATUS_CACHES_SIZE * 3 / 2)
-
-#define GHES_ESTATUS_CACHE_LEN(estatus_len)			\
-	(sizeof(struct ghes_estatus_cache) + (estatus_len))
-#define GHES_ESTATUS_FROM_CACHE(estatus_cache)			\
-	((struct acpi_hest_generic_status *)				\
-	 ((struct ghes_estatus_cache *)(estatus_cache) + 1))
-
-#define GHES_ESTATUS_NODE_LEN(estatus_len)			\
-	(sizeof(struct ghes_estatus_node) + (estatus_len))
-#define GHES_ESTATUS_FROM_NODE(estatus_node)			\
-	((struct acpi_hest_generic_status *)				\
-	 ((struct ghes_estatus_node *)(estatus_node) + 1))
-
-#define GHES_VENDOR_ENTRY_LEN(gdata_len)                               \
-	(sizeof(struct ghes_vendor_record_entry) + (gdata_len))
-#define GHES_GDATA_FROM_VENDOR_ENTRY(vendor_entry)                     \
-	((struct acpi_hest_generic_data *)                              \
-	((struct ghes_vendor_record_entry *)(vendor_entry) + 1))
-
 /*
  *  NMI-like notifications vary by architecture, before the compiler can prune
  *  unused static functions it needs a value for these enums.
@@ -102,25 +69,6 @@
 
 static ATOMIC_NOTIFIER_HEAD(ghes_report_chain);
 
-static inline bool is_hest_type_generic_v2(struct ghes *ghes)
-{
-	return ghes->generic->header.type == ACPI_HEST_TYPE_GENERIC_ERROR_V2;
-}
-
-/*
- * A platform may describe one error source for the handling of synchronous
- * errors (e.g. MCE or SEA), or for handling asynchronous errors (e.g. SCI
- * or External Interrupt). On x86, the HEST notifications are always
- * asynchronous, so only SEA on ARM is delivered as a synchronous
- * notification.
- */
-static inline bool is_hest_sync_notify(struct ghes *ghes)
-{
-	u8 notify_type = ghes->generic->notify.type;
-
-	return notify_type == ACPI_HEST_NOTIFY_SEA;
-}
-
 /*
  * This driver isn't really modular, however for the time being,
  * continuing to use module_param is the easiest way to remain
@@ -165,12 +113,6 @@ static DEFINE_MUTEX(ghes_devs_mutex);
  */
 static DEFINE_SPINLOCK(ghes_notify_lock_irq);
 
-struct ghes_vendor_record_entry {
-	struct work_struct work;
-	int error_severity;
-	char vendor_record[];
-};
-
 static struct gen_pool *ghes_estatus_pool;
 
 static struct ghes_estatus_cache __rcu *ghes_estatus_caches[GHES_ESTATUS_CACHES_SIZE];
@@ -266,7 +208,7 @@ static void ghes_ack_error(struct acpi_hest_generic_v2 *gv2)
 	apei_write(val, &gv2->read_ack_register);
 }
 
-static struct ghes *ghes_new(struct acpi_hest_generic *generic)
+struct ghes *ghes_new(struct acpi_hest_generic *generic)
 {
 	struct ghes *ghes;
 	unsigned int error_block_length;
@@ -313,7 +255,7 @@ static struct ghes *ghes_new(struct acpi_hest_generic *generic)
 	return ERR_PTR(rc);
 }
 
-static void ghes_fini(struct ghes *ghes)
+void ghes_fini(struct ghes *ghes)
 {
 	kfree(ghes->estatus);
 	apei_unmap_generic_address(&ghes->generic->error_status_address);
@@ -363,8 +305,8 @@ static void ghes_copy_tofrom_phys(void *buffer, u64 paddr, u32 len,
 }
 
 /* Check the top-level record header has an appropriate size. */
-static int __ghes_check_estatus(struct ghes *ghes,
-				struct acpi_hest_generic_status *estatus)
+int __ghes_check_estatus(struct ghes *ghes,
+			 struct acpi_hest_generic_status *estatus)
 {
 	u32 len = cper_estatus_len(estatus);
 	u32 max_len = min(ghes->generic->error_block_length,
@@ -389,9 +331,9 @@ static int __ghes_check_estatus(struct ghes *ghes,
 }
 
 /* Read the CPER block, returning its address, and header in estatus. */
-static int __ghes_peek_estatus(struct ghes *ghes,
-			       struct acpi_hest_generic_status *estatus,
-			       u64 *buf_paddr, enum fixed_addresses fixmap_idx)
+int __ghes_peek_estatus(struct ghes *ghes,
+			struct acpi_hest_generic_status *estatus,
+			u64 *buf_paddr, enum fixed_addresses fixmap_idx)
 {
 	struct acpi_hest_generic *g = ghes->generic;
 	int rc;
@@ -400,7 +342,7 @@ static int __ghes_peek_estatus(struct ghes *ghes,
 	if (rc) {
 		*buf_paddr = 0;
 		pr_warn_ratelimited(FW_WARN GHES_PFX
-"Failed to read error status block address for hardware error source: %d.\n",
+				    "Failed to read error status block address for hardware error source: %d.\n",
 				   g->header.source_id);
 		return -EIO;
 	}
@@ -417,9 +359,9 @@ static int __ghes_peek_estatus(struct ghes *ghes,
 	return 0;
 }
 
-static int __ghes_read_estatus(struct acpi_hest_generic_status *estatus,
-			       u64 buf_paddr, enum fixed_addresses fixmap_idx,
-			       size_t buf_len)
+int __ghes_read_estatus(struct acpi_hest_generic_status *estatus,
+			u64 buf_paddr, enum fixed_addresses fixmap_idx,
+			size_t buf_len)
 {
 	ghes_copy_tofrom_phys(estatus, buf_paddr, buf_len, 1, fixmap_idx);
 	if (cper_estatus_check(estatus)) {
@@ -431,9 +373,9 @@ static int __ghes_read_estatus(struct acpi_hest_generic_status *estatus,
 	return 0;
 }
 
-static int ghes_read_estatus(struct ghes *ghes,
-			     struct acpi_hest_generic_status *estatus,
-			     u64 *buf_paddr, enum fixed_addresses fixmap_idx)
+int ghes_read_estatus(struct ghes *ghes,
+		      struct acpi_hest_generic_status *estatus,
+		      u64 *buf_paddr, enum fixed_addresses fixmap_idx)
 {
 	int rc;
 
@@ -449,9 +391,9 @@ static int ghes_read_estatus(struct ghes *ghes,
 				   cper_estatus_len(estatus));
 }
 
-static void ghes_clear_estatus(struct ghes *ghes,
-			       struct acpi_hest_generic_status *estatus,
-			       u64 buf_paddr, enum fixed_addresses fixmap_idx)
+void ghes_clear_estatus(struct ghes *ghes,
+			struct acpi_hest_generic_status *estatus,
+			u64 buf_paddr, enum fixed_addresses fixmap_idx)
 {
 	estatus->block_status = 0;
 
diff --git a/include/acpi/ghes_cper.h b/include/acpi/ghes_cper.h
new file mode 100644
index 000000000000..6b7632cfaf66
--- /dev/null
+++ b/include/acpi/ghes_cper.h
@@ -0,0 +1,102 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * GHES declarations used by both the ACPI APEI GHES driver
+ * and the firmware-first CPER provider.
+ *
+ * These declarations lets GHES and other firmware-first error sources use
+ * the same helper so the non-ACPI path follows the same
+ * behavior as GHES instead of carrying a separate copy.
+ *
+ * Derived from the ACPI APEI GHES driver.
+ *
+ * Copyright 2010,2011 Intel Corp.
+ *   Author: Huang Ying <ying.huang@intel.com>
+ */
+
+#ifndef ACPI_APEI_GHES_CPER_H
+#define ACPI_APEI_GHES_CPER_H
+
+#include <linux/workqueue.h>
+
+#include <acpi/ghes.h>
+
+#define GHES_PFX	"GHES: "
+
+#define GHES_ESTATUS_MAX_SIZE		65536
+#define GHES_ESOURCE_PREALLOC_MAX_SIZE	65536
+
+#define GHES_ESTATUS_POOL_MIN_ALLOC_ORDER 3
+
+/* This is just an estimation for memory pool allocation */
+#define GHES_ESTATUS_CACHE_AVG_SIZE	512
+
+#define GHES_ESTATUS_CACHES_SIZE	4
+
+#define GHES_ESTATUS_IN_CACHE_MAX_NSEC	10000000000ULL
+/* Prevent too many caches are allocated because of RCU */
+#define GHES_ESTATUS_CACHE_ALLOCED_MAX	(GHES_ESTATUS_CACHES_SIZE * 3 / 2)
+
+#define GHES_ESTATUS_CACHE_LEN(estatus_len)			\
+	(sizeof(struct ghes_estatus_cache) + (estatus_len))
+#define GHES_ESTATUS_FROM_CACHE(estatus_cache)			\
+	((struct acpi_hest_generic_status *)				\
+	 ((struct ghes_estatus_cache *)(estatus_cache) + 1))
+
+#define GHES_ESTATUS_NODE_LEN(estatus_len)			\
+	(sizeof(struct ghes_estatus_node) + (estatus_len))
+#define GHES_ESTATUS_FROM_NODE(estatus_node)			\
+	((struct acpi_hest_generic_status *)				\
+	 ((struct ghes_estatus_node *)(estatus_node) + 1))
+
+#define GHES_VENDOR_ENTRY_LEN(gdata_len)                               \
+	(sizeof(struct ghes_vendor_record_entry) + (gdata_len))
+#define GHES_GDATA_FROM_VENDOR_ENTRY(vendor_entry)                     \
+	((struct acpi_hest_generic_data *)                              \
+	((struct ghes_vendor_record_entry *)(vendor_entry) + 1))
+
+static inline bool is_hest_type_generic_v2(struct ghes *ghes)
+{
+	return ghes->generic->header.type == ACPI_HEST_TYPE_GENERIC_ERROR_V2;
+}
+
+/*
+ * A platform may describe one error source for the handling of synchronous
+ * errors (e.g. MCE or SEA), or for handling asynchronous errors (e.g. SCI
+ * or External Interrupt). On x86, the HEST notifications are always
+ * asynchronous, so only SEA on ARM is delivered as a synchronous
+ * notification.
+ */
+static inline bool is_hest_sync_notify(struct ghes *ghes)
+{
+	u8 notify_type = ghes->generic->notify.type;
+
+	return notify_type == ACPI_HEST_NOTIFY_SEA;
+}
+
+struct ghes_vendor_record_entry {
+	struct work_struct work;
+	int error_severity;
+	char vendor_record[];
+};
+
+#ifdef CONFIG_ACPI_APEI
+struct ghes *ghes_new(struct acpi_hest_generic *generic);
+void ghes_fini(struct ghes *ghes);
+
+int ghes_read_estatus(struct ghes *ghes,
+		      struct acpi_hest_generic_status *estatus,
+		      u64 *buf_paddr, enum fixed_addresses fixmap_idx);
+void ghes_clear_estatus(struct ghes *ghes,
+			struct acpi_hest_generic_status *estatus,
+			u64 buf_paddr, enum fixed_addresses fixmap_idx);
+int __ghes_peek_estatus(struct ghes *ghes,
+			struct acpi_hest_generic_status *estatus,
+			u64 *buf_paddr, enum fixed_addresses fixmap_idx);
+int __ghes_check_estatus(struct ghes *ghes,
+			 struct acpi_hest_generic_status *estatus);
+int __ghes_read_estatus(struct acpi_hest_generic_status *estatus,
+			u64 buf_paddr, enum fixed_addresses fixmap_idx,
+			size_t buf_len);
+#endif
+
+#endif /* ACPI_APEI_GHES_CPER_H */

-- 
2.43.0


^ permalink raw reply related

* [PATCH v5 00/10] ACPI: APEI: share GHES CPER helpers and add DT FFH provider
From: Ahmed Tiba @ 2026-05-29  9:50 UTC (permalink / raw)
  To: will, jic23, xueshuai, saket.dumbre, mchehab, dave, djbw, bp,
	tony.luck, guohanjun, lenb, skhan, vishal.l.verma, rafael, corbet,
	ira.weiny, dave.jiang, krzk+dt, robh, catalin.marinas,
	alison.schofield, conor+dt
  Cc: Ahmed Tiba, linux-arm-kernel, Michael.Zhao2, linux-doc,
	linux-kernel, linux-cxl, Dmitry.Lamerov, devicetree, linux-acpi,
	linux-edac, acpica-devel

This is v5 of the GHES refactor series. Compared to v4, it only updates
the DT binding to address the latest review comments.

Changes in v5:
- Dropped the `oneOf` from `memory-region` and described it as a plain
  list with `minItems: 1`.
- Simplified the DT example to keep only the `arm,ras-cper` device node.
- Link to v4: https://lore.kernel.org/r/20260518-topics-ahmtib01-ras_ffh_arm_internal_review-v4-0-42698675ba61@arm.com

Signed-off-by: Ahmed Tiba <ahmed.tiba@arm.com>

Changes in v4:
- Reworded the ghes_cper.h header comment and kept the original copyrights.
- Fixed the ghes_cper.h W=1 warnings by limiting the ACPI
  fixmap-based declarations to the ACPI build path.
- Updated the DT binding to describe the CPER buffer
  as firmware-owned shared memory.
- Described the optional ack area as a second memory-region entry.
- Updated the DT example accordingly.
- Link to v3: https://lore.kernel.org/r/20260318-topics-ahmtib01-ras_ffh_arm_internal_review-v3-0-48e6a1c249ef@arm.com

Changes in v3:
- Fixed the new ghes_cper.h header comment and kept the original
  copyrights.
- Added <linux/bitfield.h> to fix the kernel test robot build failure.
- Renamed the binding/compatible and DT-side naming to ras-cper.
- Switched the DT provider to generic firmware property accessors.
- Replaced atomic source IDs with IDA.
- Updated IRQ/error/resource handling as suggested in review
  (platform_get_irq(), dev_err_probe(), devm platform ioremap
  helpers).
- Removed the ARM64 dependency and fixed Kconfig/build coverage.
- Clarified comments and kept the early move patches mechanical.
- Link to v2: https://lore.kernel.org/r/20260220-topics-ahmtib01-ras_ffh_arm_internal_review-v2-0-347fa2d7351b@arm.com

Changes in v2:
- Dropped the proposed "estatus core" and kept GHES naming/flow intact
  (per Borislav Petkov).
- Re-sliced the series into smaller mechanical steps (per Mauro Carvalho Chehab).
- Minor DT binding fixes based on Krzysztof Kozlowski's feedback.
- Removed fixmap slot usage from the DT FFH driver (per Will Deacon).

Series structure:
- Patches 1-8 are mechanical moves only and do not change behavior.
- Patch 9 wires the shared helpers back into GHES.
- The DT firmware-first CPER buffer provider is added in the final patches.
- "ACPI: APEI: introduce GHES helper" is internal build glue only
  and does not introduce a new user-visible configuration option.

- Link to v1: https://lore.kernel.org/r/20251217112845.1814119-1-ahmed.tiba@arm.com

---
Ahmed Tiba (10):
      ACPI: APEI: GHES: share macros via a private header
      ACPI: APEI: GHES: move CPER read helpers
      ACPI: APEI: GHES: move GHESv2 ack and alloc helpers
      ACPI: APEI: GHES: move estatus cache helpers
      ACPI: APEI: GHES: move vendor record helpers
      ACPI: APEI: GHES: move CXL CPER helpers
      ACPI: APEI: introduce GHES helper
      ACPI: APEI: share GHES CPER helpers
      dt-bindings: firmware: add arm,ras-cper
      RAS: add firmware-first CPER provider

 Documentation/admin-guide/RAS/main.rst             |   18 +
 .../devicetree/bindings/firmware/arm,ras-cper.yaml |   54 +
 MAINTAINERS                                        |    6 +
 drivers/Makefile                                   |    1 +
 drivers/acpi/Kconfig                               |    4 +
 drivers/acpi/apei/Kconfig                          |    1 +
 drivers/acpi/apei/apei-internal.h                  |   10 +-
 drivers/acpi/apei/ghes.c                           | 1025 +------------------
 drivers/acpi/apei/ghes_cper.c                      | 1027 ++++++++++++++++++++
 drivers/ras/Kconfig                                |   11 +
 drivers/ras/Makefile                               |    1 +
 drivers/ras/cper-esource.c                         |  257 +++++
 include/acpi/ghes.h                                |   10 +-
 include/acpi/ghes_cper.h                           |  151 +++
 include/cxl/event.h                                |    2 +-
 15 files changed, 1542 insertions(+), 1036 deletions(-)
---
base-commit: 8fde5d1d47f69db6082dfa34500c27f8485389a5
change-id: 20260220-topics-ahmtib01-ras_ffh_arm_internal_review-bfddc7fc7cab

Best regards,
-- 
Ahmed Tiba <ahmed.tiba@arm.com>


^ permalink raw reply

* Re: [PATCH v6 00/19] drm/atomic: Rework initial state allocation
From: Maxime Ripard @ 2026-05-29  9:44 UTC (permalink / raw)
  To: Maarten Lankhorst, Thomas Zimmermann, David Airlie, Simona Vetter,
	Jonathan Corbet, Shuah Khan, Dmitry Baryshkov, Jyri Sarha,
	Tomi Valkeinen, Andrzej Hajda, Neil Armstrong, Robert Foss,
	Laurent Pinchart, Jonas Karlman, Jernej Skrabec, Simon Ser,
	Harry Wentland, Melissa Wen, Sebastian Wick, Alex Hung,
	Jani Nikula, Rodrigo Vivi, Joonas Lahtinen, Tvrtko Ursulin,
	Chen-Yu Tsai, Samuel Holland, Dave Stevenson, Maíra Canal,
	Raspberry Pi Kernel Maintenance, Maxime Ripard
  Cc: dri-devel, linux-doc, linux-kernel, Daniel Stone, intel-gfx,
	intel-xe, linux-arm-kernel, linux-sunxi, Laurent Pinchart,
	Laurent Pinchart
In-Reply-To: <20260526-drm-mode-config-init-v6-0-852346394200@kernel.org>

On Tue, 26 May 2026 18:46:12 +0200, Maxime Ripard wrote:
> This series started from my work on the hardware state readout[1], and
> more specifically a discussion with Thomas[2].
> 
> This series expands the work that has been merged recently to make
> drm_private_obj and drm_private_state allocation a bit more consistent
> and ended up creating a new atomic_create_state callback to allocate a
> new state with no side effect.
> 
> [...]

Applied to misc/kernel.git (drm-misc-next).

Thanks!
Maxime

^ permalink raw reply

* Re: 答复: 答复: [外部邮件] Re: [PATCH] mm/mempool: use static key for boot-time debug enablement
From: Vlastimil Babka (SUSE) @ 2026-05-29  9:39 UTC (permalink / raw)
  To: Usama Arif, Li,Rongqing(ACG CCN)
  Cc: Jonathan Corbet, Shuah Khan, Harry Yoo, Andrew Morton, Hao Li,
	Christoph Lameter, David Rientjes, Roman Gushchin,
	linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-mm@kvack.org
In-Reply-To: <6ca2af4a-90ed-4d7e-9c21-42ebffddc3fe@linux.dev>

On 5/28/26 14:59, Usama Arif wrote:
> 
> 
> On 28/05/2026 11:50, Li,Rongqing(ACG CCN) wrote:
>> 
>> 
>>>
>>> On 28/05/2026 04:00, Li,Rongqing(ACG CCN) wrote:
>>>
>>> I think 32 bit ARM doesnt?
>> 
>> You are right, 32-bit ARM doesn't. 
>> 
>> However, the correct architectural approach should be fixing the boot sequence 
>> inside arch/arm/ to match arm64 , powerpc and m68k, rather than compromising core MM 
>> code with temporary boilerplate variables.
>> 
>> I prefer to keep the mempool implementation clean. If ARM32 triggers the 
>> warning, the proper remedy is a follow-up patch to align its setup_arch() 
>> ordering.
>> 
>> What do you think?
>> 
> 
> I think it would be a prerequisite rather than a follow up patch inorder to not
> break 32 bit arm. I will let ARM and slab maintainers decide on this. 

Yeah we shouldn't just knowingly break it.
But I kind of doubt the argument that crucial mempool allocations happen
that early in the boot and we could miss errors in them? They are mostly
storage drivers, AFAICS. So I don't think we need the debugging to be
enabled early.



^ permalink raw reply

* [PATCH v4 2/2] cred: delete task_euid()
From: Alice Ryhl @ 2026-05-29  9:33 UTC (permalink / raw)
  To: Paul Moore, Serge Hallyn, Jonathan Corbet, Greg Kroah-Hartman,
	Shuah Khan, Alex Shi, Yanteng Si, Dongliang Mu
  Cc: Miguel Ojeda, Boqun Feng, Gary Guo, Björn Roy Baron,
	Benno Lossin, Andreas Hindborg, Trevor Gross, Danilo Krummrich,
	Jann Horn, linux-security-module, linux-doc, linux-kernel,
	rust-for-linux, Alice Ryhl
In-Reply-To: <20260529-remove-task-euid-v4-0-07cbdf3af980@google.com>

task_euid() is a very weird operation. You can see how weird it is by
grepping for task_euid() - binder is its only user. task_euid() obtains
the objective effective UID - it looks at the credentials of the task
for purposes of acting on it as an object, but then accesses the
effective UID (which the credentials.7 man page describes as "[...] used
by the kernel to determine the permissions that the process will have
when accessing shared resources [...]").

Since usage in Binder has now been removed, get rid of the resulting
dead code.

Changes to the zh_CN translation was carried out with the help of
Gemini and Google Translate, and since adjusted as per Alex Shi's
feedback.

Suggested-by: Jann Horn <jannh@google.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
---
 Documentation/security/credentials.rst                    |  6 ++----
 Documentation/translations/zh_CN/security/credentials.rst |  4 +---
 include/linux/cred.h                                      |  1 -
 rust/helpers/task.c                                       |  5 -----
 rust/kernel/task.rs                                       | 10 ----------
 5 files changed, 3 insertions(+), 23 deletions(-)

diff --git a/Documentation/security/credentials.rst b/Documentation/security/credentials.rst
index d0191c8b8060..81d3b5737d85 100644
--- a/Documentation/security/credentials.rst
+++ b/Documentation/security/credentials.rst
@@ -393,16 +393,14 @@ the credentials so obtained when they're finished with.
    The result of ``__task_cred()`` should not be passed directly to
    ``get_cred()`` as this may race with ``commit_cred()``.
 
-There are a couple of convenience functions to access bits of another task's
-credentials, hiding the RCU magic from the caller::
+There is a convenience function to access bits of another task's credentials,
+hiding the RCU magic from the caller::
 
 	uid_t task_uid(task)		Task's real UID
-	uid_t task_euid(task)		Task's effective UID
 
 If the caller is holding the RCU read lock at the time anyway, then::
 
 	__task_cred(task)->uid
-	__task_cred(task)->euid
 
 should be used instead.  Similarly, if multiple aspects of a task's credentials
 need to be accessed, RCU read lock should be used, ``__task_cred()`` called,
diff --git a/Documentation/translations/zh_CN/security/credentials.rst b/Documentation/translations/zh_CN/security/credentials.rst
index 88fcd9152ffe..20c8696f8198 100644
--- a/Documentation/translations/zh_CN/security/credentials.rst
+++ b/Documentation/translations/zh_CN/security/credentials.rst
@@ -337,15 +337,13 @@ const指针上操作,因此不需要进行类型转换,但需要临时放弃
    ``__task_cred()`` 的结果不应直接传递给 ``get_cred()`` ,
    因为这可能与 ``commit_cred()`` 发生竞争条件。
 
-还有一些方便的函数可以访问另一个任务凭据的特定部分,将RCU操作对调用方隐藏起来::
+有一个方便的函数可用于访问另一个任务凭据的特定部分,从而对调用方隐藏RCU机制::
 
 	uid_t task_uid(task)		Task's real UID
-	uid_t task_euid(task)		Task's effective UID
 
 如果调用方在此时已经持有RCU读锁,则应使用::
 
 	__task_cred(task)->uid
-	__task_cred(task)->euid
 
 类似地,如果需要访问任务凭据的多个方面,应使用RCU读锁,调用 ``__task_cred()``
 函数,将结果存储在临时指针中,然后从临时指针中调用凭据的各个方面,最后释放锁。
diff --git a/include/linux/cred.h b/include/linux/cred.h
index c6676265a985..6ef1750c93e2 100644
--- a/include/linux/cred.h
+++ b/include/linux/cred.h
@@ -371,7 +371,6 @@ DEFINE_FREE(put_cred, struct cred *, if (!IS_ERR_OR_NULL(_T)) put_cred(_T))
 })
 
 #define task_uid(task)		(task_cred_xxx((task), uid))
-#define task_euid(task)		(task_cred_xxx((task), euid))
 #define task_ucounts(task)	(task_cred_xxx((task), ucounts))
 
 #define current_cred_xxx(xxx)			\
diff --git a/rust/helpers/task.c b/rust/helpers/task.c
index c0e1a06ede78..b46b1433a67e 100644
--- a/rust/helpers/task.c
+++ b/rust/helpers/task.c
@@ -28,11 +28,6 @@ __rust_helper kuid_t rust_helper_task_uid(struct task_struct *task)
 	return task_uid(task);
 }
 
-__rust_helper kuid_t rust_helper_task_euid(struct task_struct *task)
-{
-	return task_euid(task);
-}
-
 #ifndef CONFIG_USER_NS
 __rust_helper uid_t rust_helper_from_kuid(struct user_namespace *to, kuid_t uid)
 {
diff --git a/rust/kernel/task.rs b/rust/kernel/task.rs
index eabd65bfde12..c2b3457b700c 100644
--- a/rust/kernel/task.rs
+++ b/rust/kernel/task.rs
@@ -217,16 +217,6 @@ pub fn uid(&self) -> Kuid {
         Kuid::from_raw(unsafe { bindings::task_uid(self.as_ptr()) })
     }
 
-    /// Returns the objective effective UID of the given task.
-    ///
-    /// You should probably not be using this; the effective UID is normally
-    /// only relevant in subjective credentials.
-    #[inline]
-    pub fn euid(&self) -> Kuid {
-        // SAFETY: It's always safe to call `task_euid` on a valid task.
-        Kuid::from_raw(unsafe { bindings::task_euid(self.as_ptr()) })
-    }
-
     /// Determines whether the given task has pending signals.
     #[inline]
     pub fn signal_pending(&self) -> bool {

-- 
2.54.0.823.g6e5bcc1fc9-goog


^ permalink raw reply related

* [PATCH v4 1/2] rust: task: clarify comments on task UID accessors
From: Alice Ryhl @ 2026-05-29  9:33 UTC (permalink / raw)
  To: Paul Moore, Serge Hallyn, Jonathan Corbet, Greg Kroah-Hartman,
	Shuah Khan, Alex Shi, Yanteng Si, Dongliang Mu
  Cc: Miguel Ojeda, Boqun Feng, Gary Guo, Björn Roy Baron,
	Benno Lossin, Andreas Hindborg, Trevor Gross, Danilo Krummrich,
	Jann Horn, linux-security-module, linux-doc, linux-kernel,
	rust-for-linux, Alice Ryhl
In-Reply-To: <20260529-remove-task-euid-v4-0-07cbdf3af980@google.com>

From: Jann Horn <jannh@google.com>

Linux has separate subjective and objective task credentials, see the
comment above `struct cred`. Clarify which accessor functions operate on
which set of credentials.

Also document that Task::euid() is a very weird operation. You can see how
weird it is by grepping for task_euid() - binder is its only user.
Task::euid() obtains the objective effective UID - it looks at the
credentials of the task for purposes of acting on it as an object, but then
accesses the effective UID (which the credentials.7 man page describes as
"[...] used by the kernel to determine the permissions that the process
will have when accessing shared resources [...]").

For context:
Arguably, binder's use of task_euid() is a theoretical security problem,
which only has no impact on Android because Android has no setuid binaries
executable by apps.
commit 29bc22ac5e5b ("binder: use euid from cred instead of using task")
fixed that by removing that only user of task_euid(), but the fix got
reverted in commit c21a80ca0684 ("binder: fix test regression due to
sender_euid change") because some Android test started failing.

Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
---
Originally sent as:
https://lore.kernel.org/r/20260212-rust-uid-v1-1-deff4214c766@google.com
---
 rust/kernel/task.rs | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/rust/kernel/task.rs b/rust/kernel/task.rs
index 38273f4eedb5..eabd65bfde12 100644
--- a/rust/kernel/task.rs
+++ b/rust/kernel/task.rs
@@ -210,14 +210,17 @@ pub fn pid(&self) -> Pid {
         unsafe { *ptr::addr_of!((*self.as_ptr()).pid) }
     }
 
-    /// Returns the UID of the given task.
+    /// Returns the objective real UID of the given task.
     #[inline]
     pub fn uid(&self) -> Kuid {
         // SAFETY: It's always safe to call `task_uid` on a valid task.
         Kuid::from_raw(unsafe { bindings::task_uid(self.as_ptr()) })
     }
 
-    /// Returns the effective UID of the given task.
+    /// Returns the objective effective UID of the given task.
+    ///
+    /// You should probably not be using this; the effective UID is normally
+    /// only relevant in subjective credentials.
     #[inline]
     pub fn euid(&self) -> Kuid {
         // SAFETY: It's always safe to call `task_euid` on a valid task.
@@ -371,7 +374,7 @@ fn eq(&self, other: &Self) -> bool {
 impl Eq for Task {}
 
 impl Kuid {
-    /// Get the current euid.
+    /// Get the current subjective effective UID.
     #[inline]
     pub fn current_euid() -> Kuid {
         // SAFETY: Just an FFI call.

-- 
2.54.0.823.g6e5bcc1fc9-goog


^ permalink raw reply related

* [PATCH v4 0/2] Delete task_euid()
From: Alice Ryhl @ 2026-05-29  9:33 UTC (permalink / raw)
  To: Paul Moore, Serge Hallyn, Jonathan Corbet, Greg Kroah-Hartman,
	Shuah Khan, Alex Shi, Yanteng Si, Dongliang Mu
  Cc: Miguel Ojeda, Boqun Feng, Gary Guo, Björn Roy Baron,
	Benno Lossin, Andreas Hindborg, Trevor Gross, Danilo Krummrich,
	Jann Horn, linux-security-module, linux-doc, linux-kernel,
	rust-for-linux, Alice Ryhl

The task_euid() method is a very weird method, and Binder was the only
user. As of commit 65b672152289 ("binder: use current_euid() for
transaction sender identity") Binder doesn't use task_euid() anymore,
so we can delete this method.

My suggestion would be to merge this through the LSM tree.

Signed-off-by: Alice Ryhl <aliceryhl@google.com>
---
Changes in v4:
- Reword 'euid' -> 'effective UID' in 'Kuid::current_euid()' docs.
- Link to v3: https://lore.kernel.org/r/20260507-remove-task-euid-v3-0-27f22f335c2c@google.com

Changes in v3:
- Include 'task' clarification commit in series.
- Rebase and resend.
- Link to v2: https://lore.kernel.org/r/20260227-remove-task-euid-v2-1-9a9c80a82eb6@google.com

Changes in v2:
- Update translation as per Alex Shi.
- Pick up Reviewed-by Gary.
- Update commit title to use cred: prefix.
- Link to v1: https://lore.kernel.org/r/20260219-remove-task-euid-v1-1-904060826e07@google.com

---
Alice Ryhl (1):
      cred: delete task_euid()

Jann Horn (1):
      rust: task: clarify comments on task UID accessors

 Documentation/security/credentials.rst                    |  6 ++----
 Documentation/translations/zh_CN/security/credentials.rst |  4 +---
 include/linux/cred.h                                      |  1 -
 rust/helpers/task.c                                       |  5 -----
 rust/kernel/task.rs                                       | 11 ++---------
 5 files changed, 5 insertions(+), 22 deletions(-)
---
base-commit: 7fd2df204f342fc17d1a0bfcd474b24232fb0f32
change-id: 20260219-remove-task-euid-19e4b00beebe

Best regards,
-- 
Alice Ryhl <aliceryhl@google.com>


^ permalink raw reply

* Re: [PATCH v3 2/2] hwmon: (pmbus/max20860a) Add driver for Analog Devices MAX20860A
From: Nuno Sá @ 2026-05-29  9:31 UTC (permalink / raw)
  To: Pradhan, Sanman
  Cc: linux-hwmon@vger.kernel.org, linux@roeck-us.net, robh@kernel.org,
	krzk+dt@kernel.org, conor+dt@kernel.org, corbet@lwn.net,
	skhan@linuxfoundation.org, devicetree@vger.kernel.org,
	linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
	Syed, Arif, Sanman Pradhan
In-Reply-To: <20260529001903.625737-3-sanman.pradhan@hpe.com>

On Fri, May 29, 2026 at 12:19:21AM +0000, Pradhan, Sanman wrote:
> From: Syed Arif <arif.syed@hpe.com>
> 
> Add a PMBus driver for the Analog Devices MAX20860A step-down DC-DC
> switching regulator. The MAX20860A provides monitoring of input/output
> voltage, output current, and temperature via the PMBus interface using
> linear data format.
> 
> Signed-off-by: Syed Arif <arif.syed@hpe.com>
> Signed-off-by: Sanman Pradhan <psanman@juniper.net>
> ---
> v3:
>   - Removed "maxim,max20860a" from of_device_id
> v2:
>   - Removed WRITE_PROTECT write from probe
> 
>  Documentation/hwmon/index.rst     |  1 +
>  Documentation/hwmon/max20860a.rst | 57 +++++++++++++++++++++++++++++++
>  MAINTAINERS                       |  8 +++++
>  drivers/hwmon/pmbus/Kconfig       |  9 +++++
>  drivers/hwmon/pmbus/Makefile      |  1 +
>  drivers/hwmon/pmbus/max20860a.c   | 57 +++++++++++++++++++++++++++++++
>  6 files changed, 133 insertions(+)
>  create mode 100644 Documentation/hwmon/max20860a.rst
>  create mode 100644 drivers/hwmon/pmbus/max20860a.c
> 
> diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst
> index e880c6ca84f0..ffaacda416e7 100644
> --- a/Documentation/hwmon/index.rst
> +++ b/Documentation/hwmon/index.rst
> @@ -163,6 +163,7 @@ Hardware Monitoring Kernel Drivers
>     max20730
>     max20751
>     max20830
> +   max20860a
>     max31722
>     max31730
>     max31760
> diff --git a/Documentation/hwmon/max20860a.rst b/Documentation/hwmon/max20860a.rst
> new file mode 100644
> index 000000000000..ea6d2228fafc
> --- /dev/null
> +++ b/Documentation/hwmon/max20860a.rst
> @@ -0,0 +1,57 @@
> +.. SPDX-License-Identifier: GPL-2.0
> +
> +Kernel driver max20860a
> +=======================
> +
> +Supported chips:
> +
> +  * Analog Devices MAX20860A
> +
> +    Prefix: 'max20860a'
> +
> +    Addresses scanned: -
> +
> +    Datasheet: https://www.analog.com/en/products/max20860a.html
> +
> +Author:
> +
> +  - Syed Arif <arif.syed@hpe.com>
> +  - Sanman Pradhan <psanman@juniper.net>
> +
> +
> +Description
> +-----------
> +
> +This driver supports hardware monitoring for Analog Devices MAX20860A
> +Step-Down Switching Regulator with PMBus Interface.
> +
> +The MAX20860A is a fully integrated step-down DC-DC switching regulator.
> +Through the PMBus interface, the device can monitor input/output voltages,
> +output current and temperature.
> +
> +The driver is a client driver to the core PMBus driver. Please see
> +Documentation/hwmon/pmbus.rst for details on PMBus client drivers.
> +
> +Usage Notes
> +-----------
> +
> +This driver does not auto-detect devices. You will have to instantiate
> +the devices explicitly.
> +
> +Sysfs entries
> +-------------
> +
> +================= ========================================
> +in1_label         "vin"
> +in1_input         Measured input voltage
> +in1_alarm         Input voltage alarm
> +in2_label         "vout1"
> +in2_input         Measured output voltage
> +in2_alarm         Output voltage alarm
> +curr1_label       "iout1"
> +curr1_input       Measured output current
> +curr1_alarm       Output current alarm
> +temp1_input       Measured temperature
> +temp1_alarm       Chip temperature alarm
> +temp2_input       Measured temperature (secondary)
> +================= ========================================
> diff --git a/MAINTAINERS b/MAINTAINERS
> index b71acb130395..1d9651947ee3 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -15688,6 +15688,14 @@ F:	Documentation/devicetree/bindings/hwmon/pmbus/adi,max20830.yaml
>  F:	Documentation/hwmon/max20830.rst
>  F:	drivers/hwmon/pmbus/max20830.c
>  
> +MAX20860A HARDWARE MONITOR DRIVER
> +M:	Sanman Pradhan <psanman@juniper.net>
> +L:	linux-hwmon@vger.kernel.org
> +S:	Maintained
> +F:	Documentation/devicetree/bindings/hwmon/pmbus/adi,max20860a.yaml
> +F:	Documentation/hwmon/max20860a.rst
> +F:	drivers/hwmon/pmbus/max20860a.c
> +
>  MAX2175 SDR TUNER DRIVER
>  M:	Ramesh Shanmugasundaram <rashanmu@gmail.com>
>  L:	linux-media@vger.kernel.org
> diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig
> index 64f38654f4e7..5825dda75f2c 100644
> --- a/drivers/hwmon/pmbus/Kconfig
> +++ b/drivers/hwmon/pmbus/Kconfig
> @@ -402,6 +402,15 @@ config SENSORS_MAX20830
>  	  This driver can also be built as a module. If so, the module will
>  	  be called max20830.
>  
> +config SENSORS_MAX20860A
> +	tristate "Analog Devices MAX20860A"
> +	help
> +	  If you say yes here you get hardware monitoring support for Analog
> +	  Devices MAX20860A step-down converter.
> +
> +	  This driver can also be built as a module. If so, the module will
> +	  be called max20860a.
> +
>  config SENSORS_MAX31785
>  	tristate "Maxim MAX31785 and compatibles"
>  	help
> diff --git a/drivers/hwmon/pmbus/Makefile b/drivers/hwmon/pmbus/Makefile
> index 1f2c73b71953..ffc05f493213 100644
> --- a/drivers/hwmon/pmbus/Makefile
> +++ b/drivers/hwmon/pmbus/Makefile
> @@ -39,6 +39,7 @@ obj-$(CONFIG_SENSORS_MAX17616)	+= max17616.o
>  obj-$(CONFIG_SENSORS_MAX20730)	+= max20730.o
>  obj-$(CONFIG_SENSORS_MAX20751)	+= max20751.o
>  obj-$(CONFIG_SENSORS_MAX20830)	+= max20830.o
> +obj-$(CONFIG_SENSORS_MAX20860A)	+= max20860a.o
>  obj-$(CONFIG_SENSORS_MAX31785)	+= max31785.o
>  obj-$(CONFIG_SENSORS_MAX34440)	+= max34440.o
>  obj-$(CONFIG_SENSORS_MAX8688)	+= max8688.o
> diff --git a/drivers/hwmon/pmbus/max20860a.c b/drivers/hwmon/pmbus/max20860a.c
> new file mode 100644
> index 000000000000..f5feefcbe407
> --- /dev/null
> +++ b/drivers/hwmon/pmbus/max20860a.c
> @@ -0,0 +1,57 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Hardware monitoring driver for Analog Devices MAX20860A
> + *
> + * SPDX-FileCopyrightText: Copyright Hewlett Packard Enterprise Development LP
> + */
> +
> +#include <linux/i2c.h>
> +#include <linux/module.h>
> +#include "pmbus.h"
> +
> +static struct pmbus_driver_info max20860a_info = {
> +	.pages = 1,
> +	.format[PSC_VOLTAGE_IN] = linear,
> +	.format[PSC_VOLTAGE_OUT] = linear,
> +	.format[PSC_CURRENT_OUT] = linear,
> +	.format[PSC_TEMPERATURE] = linear,
> +	.func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT |
> +		PMBUS_HAVE_STATUS_VOUT |
> +		PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |
> +		PMBUS_HAVE_TEMP | PMBUS_HAVE_TEMP2 |
> +		PMBUS_HAVE_STATUS_TEMP | PMBUS_HAVE_STATUS_INPUT,
> +};

Any reason not to add regulator support? Given that the device seems to
be a regulator...

- Nuno Sá

> +
> +static int max20860a_probe(struct i2c_client *client)
> +{
> +	return pmbus_do_probe(client, &max20860a_info);
> +}
> +
> +static const struct i2c_device_id max20860a_id[] = {
> +	{"max20860a"},
> +	{}
> +};
> +MODULE_DEVICE_TABLE(i2c, max20860a_id);
> +
> +static const struct of_device_id max20860a_of_match[] = {
> +	{ .compatible = "adi,max20860a" },
> +	{}
> +};
> +MODULE_DEVICE_TABLE(of, max20860a_of_match);
> +
> +static struct i2c_driver max20860a_driver = {
> +	.driver = {
> +		.name = "max20860a",
> +		.of_match_table = max20860a_of_match,
> +	},
> +	.probe = max20860a_probe,
> +	.id_table = max20860a_id,
> +};
> +
> +module_i2c_driver(max20860a_driver);
> +
> +MODULE_AUTHOR("Syed Arif <arif.syed@hpe.com>");
> +MODULE_AUTHOR("Sanman Pradhan <psanman@juniper.net>");
> +MODULE_DESCRIPTION("PMBus driver for Analog Devices MAX20860A");
> +MODULE_LICENSE("GPL");
> +MODULE_IMPORT_NS("PMBUS");
> -- 
> 2.34.1
> 

^ permalink raw reply

* Re: [PATCH v2 1/2] dt-bindings: hwmon: pmbus: Add Analog Devices MAX20860A
From: Nuno Sá @ 2026-05-29  9:23 UTC (permalink / raw)
  To: Conor Dooley
  Cc: Pradhan, Sanman, linux-hwmon@vger.kernel.org, linux@roeck-us.net,
	robh@kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org,
	corbet@lwn.net, skhan@linuxfoundation.org,
	devicetree@vger.kernel.org, linux-doc@vger.kernel.org,
	linux-kernel@vger.kernel.org, Syed, Arif, Sanman Pradhan
In-Reply-To: <20260528-paging-alfalfa-9c3837635192@spud>

On Thu, May 28, 2026 at 06:41:31PM +0100, Conor Dooley wrote:
> On Thu, May 28, 2026 at 05:34:36PM +0000, Pradhan, Sanman wrote:
> > From: Sanman Pradhan <psanman@juniper.net>
> > 
> > Add devicetree binding documentation for the Analog Devices MAX20860A
> > step-down DC-DC switching regulator with PMBus interface.
> > 
> > Both "adi,max20860a" and "maxim,max20860a" compatible strings are
> > supported. The MAX20860A was originally manufactured by Maxim Integrated,
> > now part of Analog Devices.
> > 
> > Signed-off-by: Sanman Pradhan <psanman@juniper.net>
> > ---
> > v2:
> >   - Added allOf regulator.yaml reference and unevaluatedProperties
> 
> >   - Added "maxim,max20860a" as alternative compatible
> 
> No, please delete this.
> I don't remember what the policy that ADI use for things that used to be
> maxim products, but just pick one compatible for this device. I have a
> feeling they want adi to always be used in these cases.

Yes, adi should be the prefix.

- Nuno Sá

> 
> pw-bot: changes-requested
> 
> > 
> >  .../bindings/hwmon/pmbus/adi,max20860a.yaml   | 47 ++++++++++++++++++++
> >  1 file changed, 47 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/hwmon/pmbus/adi,max20860a.yaml
> > 
> > diff --git a/Documentation/devicetree/bindings/hwmon/pmbus/adi,max20860a.yaml b/Documentation/devicetree/bindings/hwmon/pmbus/adi,max20860a.yaml
> > new file mode 100644
> > index 000000000000..f7eeb30f11b3
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/hwmon/pmbus/adi,max20860a.yaml
> > @@ -0,0 +1,47 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/hwmon/pmbus/adi,max20860a.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Analog Devices MAX20860A Step-Down Converter
> > +
> > +maintainers:
> > +  - Sanman Pradhan <psanman@juniper.net>
> > +
> > +description: |
> > +  The MAX20860A is a fully integrated step-down DC-DC switching regulator
> > +  with PMBus interface for monitoring input/output voltage, output current
> > +  and temperature.
> > +
> > +  Datasheet: https://www.analog.com/en/products/max20860a.html
> > +
> > +allOf:
> > +  - $ref: /schemas/regulator/regulator.yaml#
> > +
> > +properties:
> > +  compatible:
> > +    enum:
> > +      - adi,max20860a
> > +      - maxim,max20860a
> 
> And for future reference, please use fallback compatibles when dealing
> with devices that have the same programming mode.
> 
> Cheers,
> Conor.



^ permalink raw reply

* Re: [PATCH net-next v2 10/10] net: ethernet: adi: Add a driver for the ADIN1140 MACPHY
From: Nuno Sá @ 2026-05-29  9:21 UTC (permalink / raw)
  To: ciprian.regus
  Cc: Parthiban Veerasooran, Andrew Lunn, David S. Miller, Eric Dumazet,
	Jakub Kicinski, Paolo Abeni, Simon Horman, Jonathan Corbet,
	Shuah Khan, Andrew Lunn, Heiner Kallweit, Russell King,
	Rob Herring, Krzysztof Kozlowski, Conor Dooley, netdev,
	linux-kernel, linux-doc, devicetree
In-Reply-To: <20260527-adin1140-driver-v2-10-37e5c8d4e0a0@analog.com>

On Wed, May 27, 2026 at 12:51:55AM +0300, Ciprian Regus via B4 Relay wrote:
> From: Ciprian Regus <ciprian.regus@analog.com>
> 
> Add a driver for ADIN1140. The device is a 10BASE-T1S MAC-PHY
> (integrated in the same package) that connects to a CPU over an SPI bus,
> and implements the Open Alliance TC6 protocol for control and frame
> transfers. As such, this driver relies on oa_tc6 for the communication
> with the device. The device has an alternative name (AD3306), so the
> driver can be probed using one of the two compatible strings.
> 
> For control transactions, ADIN1140 only implements the protected mode.
> The driver has a custom implementation for the mii_bus access methods as a
> workaround for hardware issues:
> 
> 1. The OA TC6 standard defines the direct and indirect access modes for
>    MDIO transactions. The ADIN1140 incorrectly advertises indirect mode
>    only (supported capabilities register - 0x2, bit 9), while actually
>    implementing just the direct mode. We cannot rely on the CAP register
>    to choose an access method (which oa_tc6 does by default, even though
>    it only implements the direct mode), so the driver has to use its
>    own.
> 2. The ADIN1140 cannot access the C22 register space of the internal
>    PHY, while the PHY is busy receiving frames. If that happens, the
>    CONFIG0 and CONFIG2 registers of the MAC will get corrupted and the
>    data transfer will stop. Those two registers configure settings for
>    the transfer protocol between the MAC and host, so the value for some
>    of their subfields shouldn't be changed while the netdev is up.
>    Since we know the PHY is internal, the MAC driver can implement a
>    custom mii_bus, which can intercept C22 accesses. Most of the
>    registers mapped in the 0x0 - 0x3 range (the only ones the PHY offers)
>    are read only, and their value can be read from somewhere else (e.g
>    the PHYID 1 & 2 have the same value as 0x1 in the MAC memory map).
>    For the fields that are R/W (loopback and AN/reset) in the control
>    register, the PHY driver already implements the set_loopback() and
>    config_aneg() functions. The C22 write function of the driver is a
>    no-op and is used to protect against the ioctl MDIO access path.
>    C45 accesses do not cause this issue, so we can properly implement
>    them.
> 
> Update the oa_tc6 header file to include definitions for the standard
> registers used by the adin1140 driver.
> 
> Signed-off-by: Ciprian Regus <ciprian.regus@analog.com>
> 
> ---
> v2 changelog:
>  - Exported statistics that match the ethtool_stats entries as such and
>    kept the other ones custom, using ethtool strings.
>  - Used phy_do_ioctl_running() for ndo_eth_ioctl.
>  - Adapted the mii_bus and PHY handling to the newly added
>    OA_TC6_BROKEN_PHY flag for oa_tc6.
>  - Used the oa_tc6_mdiobus_read_c45/oa_tc6_mdiobus_write_c45 functions
>    for the C45 read/write mii_bus operations.
>  - Removed OA TC6 register definitions (e.g CONFIG2) from the adin1140
>    driver and instead used the ones exported from oa_tc6.h
>  - Used OA_TC6_MMS_REG to define MMS registers instead of
>    ADIN1140_MMS_REG.
>  - Returned default values for the MII_PHYSID1/MII_PHYSID2.
>  - Set the mii_bus->phy_mask, since the the same PHY will be registered
>    32 times otherwise.
>  - Updated the MAINTAINERS entry to include the dt-bindings.
> ---
>  MAINTAINERS                         |   8 +
>  drivers/net/ethernet/adi/Kconfig    |  12 +
>  drivers/net/ethernet/adi/Makefile   |   1 +
>  drivers/net/ethernet/adi/adin1140.c | 811 ++++++++++++++++++++++++++++++++++++
>  4 files changed, 832 insertions(+)
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index eda74f3154dc..3d6da16c4312 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -1857,6 +1857,14 @@ S:	Supported
>  W:	https://ez.analog.com/linux-software-drivers
>  F:	drivers/dma/dma-axi-dmac.c
>  
> +ANALOG DEVICES INC ETHERNET DRIVERS
> +M:	Ciprian Regus <ciprian.regus@analog.com>
> +L:	netdev@vger.kernel.org
> +S:	Maintained
> +W:	https://ez.analog.com/linux-software-drivers
> +F:	Documentation/devicetree/bindings/net/adi,adin1140.yaml
> +F:	drivers/net/ethernet/adi/adin1140.c
> +
>  ANALOG DEVICES INC ETHERNET PHY DRIVERS
>  M:	Ciprian Regus <ciprian.regus@analog.com>
>  L:	netdev@vger.kernel.org
> diff --git a/drivers/net/ethernet/adi/Kconfig b/drivers/net/ethernet/adi/Kconfig
> index 760a9a60bc15..bdb8ff7d15da 100644
> --- a/drivers/net/ethernet/adi/Kconfig
> +++ b/drivers/net/ethernet/adi/Kconfig
> @@ -26,4 +26,16 @@ config ADIN1110
>  	  Say yes here to build support for Analog Devices ADIN1110
>  	  Low Power 10BASE-T1L Ethernet MAC-PHY.
>  
> +config ADIN1140
> +	tristate "Analog Devices ADIN1140 MAC-PHY"
> +	depends on SPI
> +	select ADIN1140_PHY
> +	select OA_TC6
> +	help
> +	  Say yes here to build support for Analog Devices, Inc. ADIN1140
> +	  10BASE-T1S Ethernet MAC-PHY.
> +
> +	  To compile this driver as a module, choose M here. The module will be
> +	  called adin1140.
> +
>  endif # NET_VENDOR_ADI
> diff --git a/drivers/net/ethernet/adi/Makefile b/drivers/net/ethernet/adi/Makefile
> index d0383d94303c..0390ca8ccc49 100644
> --- a/drivers/net/ethernet/adi/Makefile
> +++ b/drivers/net/ethernet/adi/Makefile
> @@ -4,3 +4,4 @@
>  #
>  
>  obj-$(CONFIG_ADIN1110) += adin1110.o
> +obj-$(CONFIG_ADIN1140) += adin1140.o
> diff --git a/drivers/net/ethernet/adi/adin1140.c b/drivers/net/ethernet/adi/adin1140.c
> new file mode 100644
> index 000000000000..671bfc08ce38
> --- /dev/null
> +++ b/drivers/net/ethernet/adi/adin1140.c
> @@ -0,0 +1,811 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Driver for Analog Devices, Inc. ADIN1140 10BASE-T1S MAC-PHY
> + *
> + * Copyright 2026 Analog Devices Inc.
> + */
> +
> +#include <linux/etherdevice.h>
> +#include <linux/kernel.h>
> +#include <linux/mdio.h>
> +#include <linux/module.h>
> +#include <linux/oa_tc6.h>
> +#include <linux/phy.h>

...

> +}
> +
> +static void adin1140_rx_mode(struct net_device *netdev)
> +{
> +	struct adin1140_priv *priv = netdev_priv(netdev);
> +
> +	schedule_work(&priv->rx_mode_work);
> +}
> +
> +static void adin1140_stats_work(struct work_struct *work)
> +{
> +	struct delayed_work *dwork = to_delayed_work(work);
> +	u64 stat_buff[ADIN1140_STATS_CNT] = {};
> +	struct adin1140_priv *priv;
> +	u32 reg_val;
> +	int ret;
> +	u32 i;
> +
> +	priv = container_of(dwork, struct adin1140_priv, stats_work);
> +
> +	for (i = 0; i < ARRAY_SIZE(adin1140_stat_regs); i++) {
> +		ret = oa_tc6_read_register(priv->tc6, adin1140_stat_regs[i],
> +					   &reg_val);
> +		if (ret)
> +			break;
> +
> +		stat_buff[i] = reg_val;
> +	}
> +
> +	spin_lock(&priv->stat_lock);

Maybe consider using scoped_guard() and similar for other places?
Marginal win though so up to you.

> +	memcpy(&priv->stats, stat_buff, sizeof(priv->stats));
> +	spin_unlock(&priv->stat_lock);
> +
> +	schedule_delayed_work(dwork, ADIN1140_STATS_CHECK_DELAY);
> +}
> +
> +static int adin1140_configure(struct adin1140_priv *priv)
> +{
> +	int ret;
> +
> +	ret = oa_tc6_zero_align_receive_frame_enable(priv->tc6);
> +	if (ret)
> +		return ret;
> +
> +	/* Disable MAC loopback */
> +	ret = oa_tc6_write_register(priv->tc6, ADIN1140_MAC_P1_LOOP_ADDR_REG,
> +				    0x0);
> +	if (ret)
> +		return ret;
> +
> +	return adin1140_default_filter_config(priv);
> +}
> +
> +static int adin1140_open(struct net_device *netdev)
> +{
> +	struct adin1140_priv *priv = netdev_priv(netdev);
> +
> +	schedule_delayed_work(&priv->stats_work, ADIN1140_STATS_CHECK_DELAY);
> +
> +	phy_start(netdev->phydev);
> +	netif_start_queue(netdev);
> +
> +	return 0;
> +}
> +
> +static int adin1140_close(struct net_device *netdev)
> +{
> +	struct adin1140_priv *priv = netdev_priv(netdev);
> +
> +	cancel_delayed_work_sync(&priv->stats_work);
> +
> +	netif_stop_queue(netdev);
> +	phy_stop(netdev->phydev);
> +
> +	return 0;
> +}
> +
> +static netdev_tx_t adin1140_start_xmit(struct sk_buff *skb,
> +				       struct net_device *netdev)
> +{
> +	struct adin1140_priv *priv = netdev_priv(netdev);
> +
> +	/* Pad frames to minimum Ethernet frame size (60 bytes without FCS).
> +	 * The MAC will append the FCS, but we need to ensure the frame is
> +	 * at least ETH_ZLEN bytes.
> +	 */
> +	if (skb_put_padto(skb, ETH_ZLEN))
> +		return NETDEV_TX_OK;
> +
> +	return oa_tc6_start_xmit(priv->tc6, skb);
> +}
> +
> +static int adin1140_set_mac_address(struct net_device *netdev, void *addr)
> +{
> +	struct adin1140_priv *priv = netdev_priv(netdev);
> +	struct sockaddr *address = addr;
> +	u8 mask[ETH_ALEN];
> +	int ret;
> +
> +	ret = eth_prepare_mac_addr_change(netdev, addr);
> +	if (ret < 0)
> +		return ret;
> +
> +	if (ether_addr_equal(address->sa_data, netdev->dev_addr))
> +		return 0;
> +
> +	memset(mask, 0xFF, ETH_ALEN);
> +	ret = adin1140_mac_filter_set(priv, address->sa_data, mask,
> +				      ADIN1140_MAC_FILT_UC_SLOT);
> +	if (ret)
> +		return ret;
> +
> +	eth_commit_mac_addr_change(netdev, addr);
> +
> +	return 0;
> +}
> +
> +static void adin1140_ndo_get_stats64(struct net_device *dev,
> +				     struct rtnl_link_stats64 *storage)
> +{
> +	struct adin1140_priv *priv = netdev_priv(dev);
> +
> +	storage->rx_packets = priv->netdev->stats.rx_packets;
> +	storage->tx_packets = priv->netdev->stats.tx_packets;
> +
> +	storage->rx_bytes = priv->netdev->stats.rx_bytes;
> +	storage->tx_bytes = priv->netdev->stats.tx_bytes;
> +
> +	spin_lock(&priv->stat_lock);
> +
> +	storage->rx_errors = priv->stats[rx_crc_errors] +
> +			     priv->stats[rx_align_errors] +
> +			     priv->stats[rx_preamble_errors] +
> +			     priv->stats[rx_short_frame_errors] +
> +			     priv->stats[rx_long_frame_errors] +
> +			     priv->stats[rx_phy_errors] +
> +			     priv->stats[rx_ifg_errors];
> +
> +	storage->tx_errors = priv->stats[tx_excess_collision] +
> +			     priv->stats[tx_underrun];
> +
> +	storage->rx_dropped = priv->stats[rx_fifo_full_dropped] +
> +			      priv->stats[rx_addr_filter_dropped];
> +
> +	storage->multicast = priv->stats[rx_mc_frames];
> +
> +	storage->collisions = priv->stats[tx_single_collision] +
> +			      priv->stats[tx_multi_collision];
> +
> +	storage->rx_length_errors = priv->stats[rx_short_frame_errors] +
> +				    priv->stats[rx_long_frame_errors];
> +	storage->rx_over_errors = priv->stats[rx_fifo_full_dropped];
> +	storage->rx_crc_errors = priv->stats[rx_crc_errors];
> +	storage->rx_frame_errors = priv->stats[rx_align_errors];
> +	storage->rx_missed_errors = priv->stats[rx_fifo_full_dropped];
> +
> +	storage->tx_aborted_errors = priv->stats[tx_excess_collision];
> +	storage->tx_fifo_errors = priv->stats[tx_underrun];
> +	storage->tx_window_errors = priv->stats[tx_late_collision];
> +
> +	spin_unlock(&priv->stat_lock);
> +}
> +
> +static void adin1140_get_drvinfo(struct net_device *netdev,
> +				 struct ethtool_drvinfo *info)
> +{
> +	strscpy(info->driver, "ADIN1140", sizeof(info->driver));
> +	strscpy(info->bus_info, dev_name(netdev->dev.parent),
> +		sizeof(info->bus_info));
> +}
> +
> +static void adin1140_get_ethtool_stats(struct net_device *netdev,
> +				       struct ethtool_stats *stats, u64 *data)
> +{
> +	struct adin1140_priv *priv = netdev_priv(netdev);
> +	u32 i;
> +
> +	spin_lock(&priv->stat_lock);
> +	for (i = 0; i < ARRAY_SIZE(adin1140_stats); i++)
> +		data[i] = priv->stats[adin1140_stats[i].idx];
> +	spin_unlock(&priv->stat_lock);
> +}
> +
> +static void adin1140_get_ethtool_strings(struct net_device *netdev, u32 sset,
> +					 u8 *p)
> +{
> +	u32 i;
> +
> +	switch (sset) {
> +	case ETH_SS_STATS:
> +		for (i = 0; i < ARRAY_SIZE(adin1140_stats); i++)
> +			ethtool_puts(&p, adin1140_stats[i].name);
> +
> +		break;
> +	}
> +}
> +
> +static int adin1140_get_sset_count(struct net_device *netdev, int sset)
> +{
> +	switch (sset) {
> +	case ETH_SS_STATS:
> +		return ARRAY_SIZE(adin1140_stats);
> +	default:
> +		return -EOPNOTSUPP;
> +	}
> +}
> +
> +static void adin1140_get_eth_mac_stats(struct net_device *netdev,
> +				       struct ethtool_eth_mac_stats *mac_stats)
> +{
> +	struct adin1140_priv *priv = netdev_priv(netdev);
> +
> +	spin_lock(&priv->stat_lock);
> +
> +	mac_stats->FramesReceivedOK = priv->stats[rx_frames];
> +	mac_stats->BroadcastFramesReceivedOK = priv->stats[rx_bc_frames];
> +	mac_stats->MulticastFramesReceivedOK = priv->stats[rx_mc_frames];
> +	mac_stats->FrameCheckSequenceErrors = priv->stats[rx_crc_errors];
> +	mac_stats->AlignmentErrors = priv->stats[rx_align_errors];
> +	mac_stats->FrameTooLongErrors = priv->stats[rx_long_frame_errors];
> +	mac_stats->FramesLostDueToIntMACRcvError =
> +					priv->stats[rx_fifo_full_dropped];
> +	mac_stats->FramesTransmittedOK = priv->stats[tx_frames];
> +	mac_stats->BroadcastFramesXmittedOK = priv->stats[tx_bc_frames];
> +	mac_stats->MulticastFramesXmittedOK = priv->stats[tx_mc_frames];
> +	mac_stats->SingleCollisionFrames = priv->stats[tx_single_collision];
> +	mac_stats->MultipleCollisionFrames = priv->stats[tx_multi_collision];
> +	mac_stats->FramesWithDeferredXmissions = priv->stats[tx_deferred];
> +	mac_stats->LateCollisions = priv->stats[tx_late_collision];
> +	mac_stats->FramesAbortedDueToXSColls = priv->stats[tx_excess_collision];
> +	mac_stats->FramesLostDueToIntMACXmitError = priv->stats[tx_underrun];
> +
> +	spin_unlock(&priv->stat_lock);
> +}
> +
> +static int adin1140_mdiobus_read(struct mii_bus *bus, int addr, int regnum)
> +{
> +	/* The ADIN1140's standard PHY C22 register map (OA TC6 0xFF00 -
> +	 * 0xFF1F), of which only 0xFF00 - 0xFF03 are implemented) cannot be
> +	 * accessed while frames are being received by the PHY. In case this
> +	 * happens the CONFIG0 and CONFIG2 register values will get corrupted,
> +	 * getting a random value. Both reads and writes cause the same
> +	 * behavior. This is a workaround that avoids MDIO accesses all
> +	 * together. Since this is a 10BASE-T1S PHY, only the loopback and
> +	 * reset (AN) bits in the control register (0x0) can be written.
> +	 * These functionalities have custom implementations in the PHY
> +	 * driver. C45 accesses do not cause this issue.
> +	 */
> +
> +	switch (regnum) {
> +	case MII_BMCR:
> +		return ADIN1140_PHY_CTRL_DEFAULT;
> +	case MII_BMSR:
> +		return ADIN1140_PHY_STATUS_DEFAULT;
> +	case MII_PHYSID1:
> +		return ADIN1140_PHY_ID1;
> +	case MII_PHYSID2:
> +		return ADIN1140_PHY_ID2;
> +	default:
> +		return 0xFFFF;
> +	}
> +}
> +
> +static int adin1140_mdiobus_write(struct mii_bus *bus, int addr, int regnum,
> +				  u16 val)
> +{
> +	return -EIO;
> +}
> +
> +static int adin1140_mdio_register(struct adin1140_priv *priv,
> +				  struct spi_device *spidev)
> +{
> +	int ret;
> +
> +	priv->mdiobus = mdiobus_alloc();
> +	if (!priv->mdiobus) {
> +		netdev_err(priv->netdev, "MDIO bus alloc failed\n");
> +		return -ENOMEM;
> +	}
> +
> +	priv->mdiobus->name = "adin1140-mdiobus";
> +	priv->mdiobus->priv = priv->tc6;
> +	priv->mdiobus->parent = &spidev->dev;
> +	priv->mdiobus->phy_mask = ~BIT(0);
> +	priv->mdiobus->read = adin1140_mdiobus_read;
> +	priv->mdiobus->write = adin1140_mdiobus_write;
> +	priv->mdiobus->read_c45 = oa_tc6_mdiobus_read_c45;
> +	priv->mdiobus->write_c45 = oa_tc6_mdiobus_write_c45;
> +
> +	snprintf(priv->mdiobus->id, MII_BUS_ID_SIZE, "adin1140-%s.%u",
> +		 dev_name(&spidev->dev), spi_get_chipselect(spidev, 0));
> +
> +	ret = mdiobus_register(priv->mdiobus);
> +	if (ret) {
> +		netdev_err(priv->netdev, "Could not register MDIO bus\n");
> +		mdiobus_free(priv->mdiobus);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static void adin1140_handle_link_change(struct net_device *netdev)
> +{
> +	phy_print_status(netdev->phydev);
> +}
> +
> +static int adin1140_phy_init(struct adin1140_priv *priv,
> +			     struct spi_device *spidev)
> +{
> +	int ret;
> +
> +	ret = adin1140_mdio_register(priv, spidev);
> +	if (ret)
> +		return ret;
> +
> +	priv->phydev = phy_find_first(priv->mdiobus);
> +	if (!priv->phydev) {
> +		netdev_err(priv->netdev, "No PHY found\n");
> +		ret = -ENODEV;
> +		goto free_mdio;
> +	}
> +
> +	priv->phydev->is_internal = true;
> +	ret = phy_connect_direct(priv->netdev, priv->phydev,
> +				 &adin1140_handle_link_change,
> +				 PHY_INTERFACE_MODE_INTERNAL);
> +	if (ret) {
> +		netdev_err(priv->netdev, "Can't attach PHY to %s\n",
> +			   priv->mdiobus->id);
> +		goto unregister_mdio;
> +	}
> +
> +	phy_attached_info(priv->phydev);
> +
> +	return 0;
> +
> +unregister_mdio:
> +	mdiobus_unregister(priv->mdiobus);
> +free_mdio:
> +	mdiobus_free(priv->mdiobus);
> +
> +	return ret;
> +}
> +
> +static void adin1140_phy_remove(struct adin1140_priv *priv)
> +{
> +	phy_disconnect(priv->phydev);
> +	mdiobus_unregister(priv->mdiobus);
> +	mdiobus_free(priv->mdiobus);
> +}
> +
> +static const struct ethtool_ops adin1140_ethtool_ops = {
> +	.get_drvinfo = adin1140_get_drvinfo,
> +	.get_link = ethtool_op_get_link,
> +	.get_ethtool_stats = adin1140_get_ethtool_stats,
> +	.get_sset_count = adin1140_get_sset_count,
> +	.get_strings = adin1140_get_ethtool_strings,
> +	.get_link_ksettings = phy_ethtool_get_link_ksettings,
> +	.set_link_ksettings = phy_ethtool_set_link_ksettings,
> +	.get_eth_mac_stats = adin1140_get_eth_mac_stats,
> +};
> +
> +static const struct net_device_ops adin1140_netdev_ops = {
> +	.ndo_open = adin1140_open,
> +	.ndo_stop = adin1140_close,
> +	.ndo_start_xmit	= adin1140_start_xmit,
> +	.ndo_set_mac_address = adin1140_set_mac_address,
> +	.ndo_validate_addr = eth_validate_addr,
> +	.ndo_set_rx_mode = adin1140_rx_mode,
> +	.ndo_eth_ioctl = phy_do_ioctl_running,
> +	.ndo_get_stats64 = adin1140_ndo_get_stats64,
> +};
> +
> +static int adin1140_probe(struct spi_device *spi)
> +{
> +	struct oa_tc6_config tc6_config = {};
> +	struct net_device *netdev;
> +	struct adin1140_priv *priv;
> +	int ret;
> +
> +	netdev = alloc_etherdev(sizeof(struct adin1140_priv));
> +	if (!netdev)
> +		return -ENOMEM;

devm_alloc_etherdev() and similar so that we can make error handling
easier? Any strong reason to not use device managed allocations?

> +
> +	priv = netdev_priv(netdev);
> +	priv->netdev = netdev;
> +	spi_set_drvdata(spi, priv);
> +	spin_lock_init(&priv->stat_lock);
> +
> +	tc6_config.spi = spi;
> +	tc6_config.netdev = netdev;
> +	tc6_config.quirk_flags = OA_TC6_BROKEN_PHY;
> +
> +	priv->tc6 = oa_tc6_init(&tc6_config);
> +	if (!priv->tc6) {
> +		ret = -ENODEV;
> +		goto netdev_free;
> +	}
> +
> +	ret = adin1140_phy_init(priv, spi);
> +	if (ret)
> +		goto oa_tc6_exit;
> +
> +	if (device_get_ethdev_address(&spi->dev, netdev))
> +		eth_hw_addr_random(netdev);
> +
> +	ret = adin1140_configure(priv);
> +	if (ret)
> +		goto phy_exit;
> +
> +	INIT_WORK(&priv->rx_mode_work, adin1140_rx_mode_work);
> +	INIT_DELAYED_WORK(&priv->stats_work, adin1140_stats_work);
> +
> +	netdev->if_port = IF_PORT_10BASET;
> +	netdev->irq = spi->irq;
> +	netdev->netdev_ops = &adin1140_netdev_ops;
> +	netdev->ethtool_ops = &adin1140_ethtool_ops;
> +	netdev->netns_immutable = true;
> +	netdev->priv_flags |= IFF_LIVE_ADDR_CHANGE |
> +			      IFF_UNICAST_FLT;
> +
> +	ret = register_netdev(netdev);
> +	if (ret) {
> +		dev_err(&spi->dev, "Failed to register netdev (%d)", ret);

If we go to devm, this could be return dev_err_probe().

- Nuno Sá


^ permalink raw reply

* Re: [PATCH v2] arm64: kernel: Unify CNP disable workaround into ARM64_WORKAROUND_DISABLE_CNP
From: Vladimir Murzin @ 2026-05-29  9:17 UTC (permalink / raw)
  To: Zeng Heng, xuwei5, wangyushan12, maz, skhan, miko.lenczewski,
	lucaswei, broonie, thuth, ryan.roberts, tongtiangen, oupton,
	kuninori.morimoto.gx, mark.rutland, will, corbet, catalin.marinas,
	kevin.brodsky, lpieralisi, yangyicong, james.clark, yeoreum.yun
  Cc: linux-doc, wangkefeng.wang, linux-arm-kernel, linux-kernel
In-Reply-To: <20260529063132.766491-1-zengheng@huaweicloud.com>

Hi,

On 5/29/26 07:31, Zeng Heng wrote:
> From: Zeng Heng <zengheng4@huawei.com>
> 
> HiSilicon HIP09 implements TLB entry matching behavior that deviates
> from the ARM architecture specification when the CnP (Common not Private)
> bit is set in TTBRx_ELx.
> 
> When TTBRx.CNP=1, TLB entries may be incorrectly shared between CPU
> cores, leading to TLB conflicts and stale mappings. This breaks
> coherency and can result in incorrect translations.
> 
> Add the hardware erratum workaround (Hisilicon erratum 162100125) to
> disable CNP on affected HIP09 cores.
> 
> Merge the existing NVIDIA Carmel and the HiSilicon HIP09 CNP errata
> workarounds into a single generic capability ARM64_WORKAROUND_DISABLE_CNP.
> 
> Both NVIDIA Carmel and HiSilicon HIP09 have hardware errata where
> CNP (Common Not Private) behavior differs from the ARM specification,
> causing incorrect TLB entry sharing between cores. The existing
> NVIDIA_CARMEL_CNP_ERRATUM and the newly added HISILICON_ERRATUM_162100125
> are now both handled by the unified ARM64_WORKAROUND_DISABLE_CNP.
> 
> Co-developed-by: Tong Tiangen <tongtiangen@huawei.com>
> Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
> Signed-off-by: Zeng Heng <zengheng4@huawei.com>
> ---
> v1: https://lore.kernel.org/all/20260526015720.206854-1-zengheng@huaweicloud.com/
> 
> Changes in v2:
>   - Unify CNP disable workaround into ARM64_WORKAROUND_DISABLE_CNP
> ---
> 
>  Documentation/arch/arm64/silicon-errata.rst |  4 +++-
>  arch/arm64/Kconfig                          | 17 ++++++++++++-----
>  arch/arm64/include/asm/cpucaps.h            |  4 ++--
>  arch/arm64/kernel/cpu_errata.c              | 17 ++++++++++++-----
>  arch/arm64/kernel/cpufeature.c              |  2 +-
>  arch/arm64/tools/cpucaps                    |  2 +-
>  6 files changed, 31 insertions(+), 15 deletions(-)
> 
> diff --git a/Documentation/arch/arm64/silicon-errata.rst b/Documentation/arch/arm64/silicon-errata.rst
> index 211119ce7adc..b4565e1a726d 100644
> --- a/Documentation/arch/arm64/silicon-errata.rst
> +++ b/Documentation/arch/arm64/silicon-errata.rst
> @@ -254,7 +254,7 @@ stable kernels.
>  | Marvell        | ARM-MMU-500     | #582743         | N/A                         |
>  +----------------+-----------------+-----------------+-----------------------------+
>  +----------------+-----------------+-----------------+-----------------------------+
> -| NVIDIA         | Carmel Core     | N/A             | NVIDIA_CARMEL_CNP_ERRATUM   |
> +| NVIDIA         | Carmel Core     | N/A             | ARM64_WORKAROUND_DISABLE_CNP|
>  +----------------+-----------------+-----------------+-----------------------------+
>  | NVIDIA         | T241 GICv3/4.x  | T241-FABRIC-4   | N/A                         |
>  +----------------+-----------------+-----------------+-----------------------------+
> @@ -284,6 +284,8 @@ stable kernels.
>  +----------------+-----------------+-----------------+-----------------------------+
>  | Hisilicon      | Hip09           | #162100801      | HISILICON_ERRATUM_162100801 |
>  +----------------+-----------------+-----------------+-----------------------------+
> +| Hisilicon      | Hip09           | #162100125      | ARM64_WORKAROUND_DISABLE_CNP|
> ++----------------+-----------------+-----------------+-----------------------------+
>  +----------------+-----------------+-----------------+-----------------------------+
>  | Qualcomm Tech. | Kryo/Falkor v1  | E1003           | QCOM_FALKOR_ERRATUM_1003    |
>  +----------------+-----------------+-----------------+-----------------------------+
> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> index fe60738e5943..dc0bd32ea2d1 100644
> --- a/arch/arm64/Kconfig
> +++ b/arch/arm64/Kconfig
> @@ -1315,13 +1315,20 @@ config QCOM_FALKOR_ERRATUM_E1041
> 
>  	  If unsure, say Y.
> 
> -config NVIDIA_CARMEL_CNP_ERRATUM
> -	bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores"
> +config ARM64_WORKAROUND_DISABLE_CNP
> +	bool "Disable CNP on affected CPUs"
>  	default y
>  	help
> -	  If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not
> -	  invalidate shared TLB entries installed by a different core, as it would
> -	  on standard ARM cores.
> +	  This option disables the CNP (Common Not Private) feature on CPUs
> +	  that have hardware errata affecting CNP behavior.
> +
> +	  On NVIDIA Carmel cores, CNP behaves differently than on standard ARM
> +	  cores: non-shareable TLBIs on a core may not invalidate shared TLB
> +	  entries installed by a different core.
> +
> +	  On Hisilicon HIP09 cores, TLB entries may be incorrectly shared
> +	  between cores when TTBRx.CNP=1, leading to TLB conflicts and
> +	  stale mappings.
> 
>  	  If unsure, say Y.
>

I'm afraid we cannot swap one config with another. Instead, we need to follow
established pattern for sharing workaround, something like

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 378e50fef247..68eb2993cfd3 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -1315,9 +1315,13 @@ config QCOM_FALKOR_ERRATUM_E1041
 
          If unsure, say Y.
 
+config ARM64_WORKAROUND_DISABLE_CNP
+       bool
+
 config NVIDIA_CARMEL_CNP_ERRATUM
        bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores"
        default y
+       select ARM64_WORKAROUND_DISABLE_CNP
        help
          If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not
          invalidate shared TLB entries installed by a different core, as it would


and related changes for generalisation of the workaround - that would to be patch 1/2.

Then we can easily wire-up your errata with something like

+config HISILICON_ERRATUM_162100125
+       bool "Hisilicon erratum 162100125"
+       default y
+       select ARM64_WORKAROUND_DISABLE_CNP
+       help
+         On HiSilicon HIP09, TLB entry matching behavior when CNP
+         (TTBRx.CNP=1) is enabled differs from the ARM architecture
+         specification.
+
+         TLB entries may be incorrectly shared between CPUs, potentially
+         causing TLB conflicts and stale mappings.
+
+         Disable CNP support for affected HiSilicon HIP09 cores.
+
+         If unsure, say Y.

and related update in documentation and MIDR list - that would be patch 2/2

Thanks
Vladimir
 
> diff --git a/arch/arm64/include/asm/cpucaps.h b/arch/arm64/include/asm/cpucaps.h
> index d0d3cdd5763c..25c61cda901c 100644
> --- a/arch/arm64/include/asm/cpucaps.h
> +++ b/arch/arm64/include/asm/cpucaps.h
> @@ -58,8 +58,8 @@ cpucap_is_possible(const unsigned int cap)
>  		return IS_ENABLED(CONFIG_ARM64_ERRATUM_2658417);
>  	case ARM64_WORKAROUND_CAVIUM_23154:
>  		return IS_ENABLED(CONFIG_CAVIUM_ERRATUM_23154);
> -	case ARM64_WORKAROUND_NVIDIA_CARMEL_CNP:
> -		return IS_ENABLED(CONFIG_NVIDIA_CARMEL_CNP_ERRATUM);
> +	case ARM64_WORKAROUND_DISABLE_CNP:
> +		return IS_ENABLED(CONFIG_ARM64_WORKAROUND_DISABLE_CNP);
>  	case ARM64_WORKAROUND_REPEAT_TLBI:
>  		return IS_ENABLED(CONFIG_ARM64_WORKAROUND_REPEAT_TLBI);
>  	case ARM64_WORKAROUND_SPECULATIVE_SSBS:
> diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
> index 5377e4c2eba2..675cd059165c 100644
> --- a/arch/arm64/kernel/cpu_errata.c
> +++ b/arch/arm64/kernel/cpu_errata.c
> @@ -394,6 +394,14 @@ static const struct arm64_cpu_capabilities qcom_erratum_1003_list[] = {
>  };
>  #endif
> 
> +#ifdef CONFIG_ARM64_WORKAROUND_DISABLE_CNP
> +static const struct midr_range cnp_erratum_cpus[] = {
> +	MIDR_ALL_VERSIONS(MIDR_NVIDIA_CARMEL),
> +	MIDR_ALL_VERSIONS(MIDR_HISI_HIP09),
> +	{},
> +};
> +#endif
> +
>  #ifdef CONFIG_ARM64_WORKAROUND_CLEAN_CACHE
>  static const struct midr_range workaround_clean_cache[] = {
>  #if	defined(CONFIG_ARM64_ERRATUM_826319) || \
> @@ -801,12 +809,11 @@ const struct arm64_cpu_capabilities arm64_errata[] = {
>  				  1, 0),
>  	},
>  #endif
> -#ifdef CONFIG_NVIDIA_CARMEL_CNP_ERRATUM
> +#ifdef CONFIG_ARM64_WORKAROUND_DISABLE_CNP
>  	{
> -		/* NVIDIA Carmel */
> -		.desc = "NVIDIA Carmel CNP erratum",
> -		.capability = ARM64_WORKAROUND_NVIDIA_CARMEL_CNP,
> -		ERRATA_MIDR_ALL_VERSIONS(MIDR_NVIDIA_CARMEL),
> +		.desc = "NVIDIA Carmel CNP erratum, or Hisilicon erratum 162100125",
> +		.capability = ARM64_WORKAROUND_DISABLE_CNP,
> +		ERRATA_MIDR_RANGE_LIST(cnp_erratum_cpus),
>  	},
>  #endif
>  #ifdef CONFIG_ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
> diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
> index 6d53bb15cf7b..20c5f24f74a9 100644
> --- a/arch/arm64/kernel/cpufeature.c
> +++ b/arch/arm64/kernel/cpufeature.c
> @@ -1785,7 +1785,7 @@ has_useable_cnp(const struct arm64_cpu_capabilities *entry, int scope)
>  	if (is_kdump_kernel())
>  		return false;
> 
> -	if (cpus_have_cap(ARM64_WORKAROUND_NVIDIA_CARMEL_CNP))
> +	if (cpus_have_cap(ARM64_WORKAROUND_DISABLE_CNP))
>  		return false;
> 
>  	return has_cpuid_feature(entry, scope);
> diff --git a/arch/arm64/tools/cpucaps b/arch/arm64/tools/cpucaps
> index 811c2479e82d..9b85a84f6fd4 100644
> --- a/arch/arm64/tools/cpucaps
> +++ b/arch/arm64/tools/cpucaps
> @@ -120,7 +120,7 @@ WORKAROUND_CAVIUM_TX2_219_PRFM
>  WORKAROUND_CAVIUM_TX2_219_TVM
>  WORKAROUND_CLEAN_CACHE
>  WORKAROUND_DEVICE_LOAD_ACQUIRE
> -WORKAROUND_NVIDIA_CARMEL_CNP
> +WORKAROUND_DISABLE_CNP
>  WORKAROUND_PMUV3_IMPDEF_TRAPS
>  WORKAROUND_QCOM_FALKOR_E1003
>  WORKAROUND_QCOM_ORYON_CNTVOFF
> --
> 2.43.0
> 


^ permalink raw reply related

* Re: [PATCH v3 0/2] ALSA: usb-audio: Add QUIRK_FLAG_MIXER_GET_CUR_BROKEN for Sennheiser MOMENTUM 3
From: Takashi Iwai @ 2026-05-29  8:56 UTC (permalink / raw)
  To: Rong Zhang
  Cc: Jaroslav Kysela, Takashi Iwai, Jonathan Corbet, Shuah Khan,
	linux-sound, linux-doc, linux-kernel
In-Reply-To: <20260529-uac-quirk-get-cur-vol-v3-0-bde363188ca4@rong.moe>

On Thu, 28 May 2026 20:38:54 +0200,
Rong Zhang wrote:
> 
> Since commit 86aa1ea1f15c ("ALSA: usb-audio: Do not expose sticky
> mixers"), the UAC mixer core utilizes volume SET_CUR and GET_CUR to
> identify devices with sticky mixers. Unfortunately, even though most
> devices with sticky GET_CUR also have corresponding sticky SET_CUR,
> which I actually met more since the commit had been merged, there is
> also a rare case that some devices may have volume mixers that responds
> to SET_CUR properly but with its GET_CUR stubbed. This cause the sticky
> check to consider the mixer to be sticky and unnecessarily disable it.
> 
> As the sticky check can't distinguish between sticky mixers and working
> SET_CUR but broken GET_CUR, add QUIRK_FLAG_MIXER_GET_CUR_BROKEN to tell
> that the device should fall into the second category when GET_CUR
> returns a constant value. In this case, the sticky check becomes
> non-fatal and only disables GET_CUR instead of the whole mixer. The
> current volume will then be provided by the internal cache that stores
> the last set volume.
> 
> The Sennheiser MOMENTUM 3 needs the quirk flag. Though its UAC mixer
> works fine and precisely corresponds to the reported dB range, the
> mixer's volume GET_CUR method is somehow stubbed and returns a constant
> value (15dB), resulting in it being disabled by the sticky check.
> 
> Signed-off-by: Rong Zhang <i@rong.moe>

Applied to for-next branch now.  Thanks.


Takashi

^ permalink raw reply

* Re: [PATCH] Documentation: Fix syntax of kmalloc_objs example in coding style doc
From: Geert Uytterhoeven @ 2026-05-29  8:18 UTC (permalink / raw)
  To: Uwe Kleine-König
  Cc: Jonathan Corbet, Manuel Ebner, Vlastimil Babka (SUSE),
	SeongJae Park, Shuah Khan, workflows, linux-doc, linux-kernel
In-Reply-To: <20260529081006.2019687-2-ukleinek@kernel.org>

On Fri, 29 May 2026 at 10:13, Uwe Kleine-König <ukleinek@kernel.org> wrote:
> The first parameter should match the variable that the allocated memory
> is assigned to. Fix the example accordingly, the one for kmalloc_obj got
> it right already.
>
> Fixes: 7c6d969d5349 ("Documentation: adopt new coding style of type-aware kmalloc-family")
> Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

^ permalink raw reply


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