[PATCH v3 0/6] Exynos-pmu: Generalise cpu{hotplug,idle},PMU intr gen and add Exynos850 CPU hotplug

[PATCH v3 0/6] Exynos-pmu: Generalise cpu{hotplug,idle},PMU intr gen and add Exynos850 CPU hotplug

[Alexey Klimov]

Series generalises the GS101-specific cpuhotplug, cpuidle and PMU interrupt
generation block support, which is currently implemented specifically for
the google GS101 SoC, to make it reusable by other Samsung Exynos SoCs.

The PMU interrupt generation IP block introduced for google GS101 is a
standard Samsung Exynos block found in other SoCs, including Exynos850,
and it is not strictly exclusive to google Exynos-based platforms.
Access to this block is required to implement and enable cpuhotplug
on Exynos850-based boards.

As a next steps it will be possible to enable idle states on top of it.

First patches work on DT bindings to reflect that Exynos850 SoC predates
gs101 one and adding mandatory property 'google,pmu-intr-gen-syscon'
for exynos850-pmu.
Then series generalises ("Exynosizes") cpuhotplug/cpuidle routines by
deferring platform-specific PMU and PMU-intr-gen updates to platform-
specific callbacks and then finally introduces new file exynos850-pmu.c
where such callbacks are implemented for Exynos850. Last commit adds
pmu_intr_gen DT node to exynos850.dtsi.

This series was tested on Exynos850 WinLink E850-96 board:
-- by spinning "chcpu -d 1-7; chcpu -e 1-7" in a loop for a few hours;
-- by running script [1] that randomly offlines or onlines random cpus
   for a few hours.

I tried to implement it in way to not break anything for gs101, but
testing from others is highly appreciated.

Thanks,
Alexey

[1]: https://github.com/laklimov/xlam/blob/main/e850_cpuhotplug_random.sh

Signed-off-by: Alexey Klimov <alexey.klimov@linaro.org>
---
Changes in v3:
- dropped two commits where samsung,pmu-intr-gen phandle is introduced and
  where google,pmu-intr-gen-syscon is deprecated (as suggested by Rob Herring);
- addtion to maintainers file was moved to separate entry, change commit message;
- commit message in "generalise gs101-specific cpu{idle,hotplug} for Exynos SoCs"
  was updated since it no longer touches samsung,pmu-intr-gen-syscon;
- added missing asm/cputype.h header to exynos850-pmu.h
  (reported by Henrik Grimler);
- new commit "dt-bindings: soc: samsung: exynos-pmu: Require
  pmu-intr-gen-syscon for Exynos850";
- Link to v2: https://lore.kernel.org/r/20260401-exynos850-cpuhotplug-v2-0-c5a760a3e259@linaro.org

Changes in v2:
- moved gs101 cpu {offline,online} callbacks to gs101-pmu.c, updated MAINTAINERS;
- added new file exynos850-pmu.c with cpu {offline,online} callbacks and
  exynos850 pmu data;
- new patch that adds exynos850-pmu.c to MAINTAINERS;
- moved pmu_intr_gen to right after pmu_system_controller@11860000;
- merged two patches that update google,gs101-pmu-intr-gen.yaml together,
  now rename and adding exynos850 entry goes in a single patch;
- commits 5 and 6 from RFC series are merged together and reworked,
  cpu_pmu_{offline,online} callbacks are moved into pmu_data struct, and
  callbacks now need pmu_context as an argument, exynos_pmu_context and
  CPU_INFORM defines are moved to exynos-pmu.h, gs101 callbacks
  renamed. It is really better to check commit description.
- Link to RFC (v1 from b4 point of view):
  https://lore.kernel.org/r/20260226-exynos850-cpuhotplug-v1-0-71d7c4063382@linaro.org

---
Alexey Klimov (6):
      dt-bindings: soc: move,rename google,gs101-pmu-intr-gen and add exynos850
      dt-bindings: soc: samsung: exynos-pmu: Require pmu-intr-gen-syscon for Exynos850
      soc: samsung: exynos-pmu: generalise gs101-specific cpu{idle,hotplug} for Exynos SoCs
      soc: samsung: exynos-pmu: add Exynos850 CPU hotplug support
      MAINTAINERS: add Exynos850 PMU entry
      arm64: dts: exynos850: add PMU interrupt generation node

 .../bindings/soc/samsung/exynos-pmu.yaml           |   1 +
 .../samsung,exynos850-pmu-intr-gen.yaml}           |   8 +-
 MAINTAINERS                                        |   9 +-
 arch/arm64/boot/dts/exynos/exynos850.dtsi          |   6 ++
 drivers/soc/samsung/Makefile                       |   2 +-
 drivers/soc/samsung/exynos-pmu.c                   | 119 ++++-----------------
 drivers/soc/samsung/exynos-pmu.h                   |  32 ++++++
 drivers/soc/samsung/exynos850-pmu.c                |  79 ++++++++++++++
 drivers/soc/samsung/gs101-pmu.c                    |  57 ++++++++++
 include/linux/soc/samsung/exynos-regs-pmu.h        |  15 ++-
 10 files changed, 222 insertions(+), 106 deletions(-)
---
base-commit: 0787c45ea08a13b5482e701fabc741877cf681f6
change-id: 20260226-exynos850-cpuhotplug-69f1976eefa8

Best regards,
-- 
Alexey Klimov <alexey.klimov@linaro.org>

[PATCH v3 1/6] dt-bindings: soc: move,rename google,gs101-pmu-intr-gen and add exynos850

[Alexey Klimov]

The PMU interrupt generation block introduced for the Google GS101 is
actually a standard Samsung Exynos IP block found in older SoCs, such
as the Exynos850, and is not exclusive to Google SoCs. To accurately
reflect its origin, move the schema file to under soc/samsung/
directory and rename it.
Concurrently, add the new "samsung,exynos850-pmu-intr-gen" compatible
string to the bindings. Support for this block is required to enable
power management features like CPU hotplug and idle states on Exynos850
platforms.
Also, move this file under Exynos850 SoC in MAINTAINERS entry.

Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Alexey Klimov <alexey.klimov@linaro.org>
---
 .../samsung,exynos850-pmu-intr-gen.yaml}                          | 8 +++++---
 MAINTAINERS                                                       | 2 +-
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/Documentation/devicetree/bindings/soc/google/google,gs101-pmu-intr-gen.yaml b/Documentation/devicetree/bindings/soc/samsung/samsung,exynos850-pmu-intr-gen.yaml
similarity index 70%
rename from Documentation/devicetree/bindings/soc/google/google,gs101-pmu-intr-gen.yaml
rename to Documentation/devicetree/bindings/soc/samsung/samsung,exynos850-pmu-intr-gen.yaml
index 2be022ca6a7d..df23467d0e0e 100644
--- a/Documentation/devicetree/bindings/soc/google/google,gs101-pmu-intr-gen.yaml
+++ b/Documentation/devicetree/bindings/soc/samsung/samsung,exynos850-pmu-intr-gen.yaml
@@ -1,10 +1,10 @@
 # SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
 %YAML 1.2
 ---
-$id: http://devicetree.org/schemas/soc/google/google,gs101-pmu-intr-gen.yaml#
+$id: http://devicetree.org/schemas/soc/samsung/samsung,exynos850-pmu-intr-gen.yaml#
 $schema: http://devicetree.org/meta-schemas/core.yaml#
 
-title: Google Power Management Unit (PMU) Interrupt Generation
+title: Samsung Power Management Unit (PMU) Interrupt Generation
 
 description: |
   PMU interrupt generator for handshaking between PMU through interrupts.
@@ -15,7 +15,9 @@ maintainers:
 properties:
   compatible:
     items:
-      - const: google,gs101-pmu-intr-gen
+      - enum:
+          - google,gs101-pmu-intr-gen
+          - samsung,exynos850-pmu-intr-gen
       - const: syscon
 
   reg:
diff --git a/MAINTAINERS b/MAINTAINERS
index 86ca9297edab..498ca30a00c5 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -10952,7 +10952,6 @@ P:	Documentation/process/maintainer-soc-clean-dts.rst
 C:	irc://irc.oftc.net/pixel6-kernel-dev
 F:	Documentation/devicetree/bindings/clock/google,gs101-clock.yaml
 F:	Documentation/devicetree/bindings/phy/google,lga-usb-phy.yaml
-F:	Documentation/devicetree/bindings/soc/google/google,gs101-pmu-intr-gen.yaml
 F:	Documentation/devicetree/bindings/usb/google,lga-dwc3.yaml
 F:	arch/arm64/boot/dts/exynos/google/
 F:	drivers/clk/samsung/clk-gs101.c
@@ -23652,6 +23651,7 @@ L:	linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)
 L:	linux-samsung-soc@vger.kernel.org
 S:	Maintained
 F:	Documentation/devicetree/bindings/clock/samsung,exynos850-clock.yaml
+F:	Documentation/devicetree/bindings/soc/samsung/samsung,exynos850-pmu-intr-gen.yaml
 F:	arch/arm64/boot/dts/exynos/exynos850*
 F:	drivers/clk/samsung/clk-exynos850.c
 F:	include/dt-bindings/clock/exynos850.h

-- 
2.51.0

[PATCH v3 2/6] dt-bindings: soc: samsung: exynos-pmu: Require pmu-intr-gen-syscon for Exynos850

[Alexey Klimov]

Update the Exynos PMU schema to mandate the 'google,pmu-intr-gen-syscon'
property for the 'samsung,exynos850-pmu' compatible so the driver can
obtain the necessary syscon regmap.

The Exynos850 PMU relies on a separate system controller block to handle
interrupts generation, similar to the hardware design of the GS101
SoC. To ensure the hardware is correctly described, this syscon phandle
must be explicitly provided.

Signed-off-by: Alexey Klimov <alexey.klimov@linaro.org>
---
 Documentation/devicetree/bindings/soc/samsung/exynos-pmu.yaml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Documentation/devicetree/bindings/soc/samsung/exynos-pmu.yaml b/Documentation/devicetree/bindings/soc/samsung/exynos-pmu.yaml
index 76ce7e98c10f..6550c3736a3b 100644
--- a/Documentation/devicetree/bindings/soc/samsung/exynos-pmu.yaml
+++ b/Documentation/devicetree/bindings/soc/samsung/exynos-pmu.yaml
@@ -182,6 +182,7 @@ allOf:
           contains:
             enum:
               - google,gs101-pmu
+              - samsung,exynos850-pmu
     then:
       required:
         - google,pmu-intr-gen-syscon

-- 
2.51.0

[PATCH v3 3/6] soc: samsung: exynos-pmu: generalise gs101-specific cpu{idle,hotplug} for Exynos SoCs

[Alexey Klimov]

The cpuhotplug and cpuidle support for GS101-based SoCs which
utilizes GS101 PMU interrupts generation block can be generalised
to be (re)used for other Exynos-based SoCs. Also, the GS101 PMU
interrupts generation block is not exclusive to Google GS101 SoCs
and should be made more Exynos-generic.

Specifically, apply the following changes:
- rename gs101-specific calls, structs, names to be exynos-prefixed;
- move exynos_pmu_context and CPU_INFORM_* defines into exynos-pmu.h;
- introduce cpu_pmu_{offline,online} callbacks in driver-specific
  exynos_pmu_data which can be used to hold PMU and PMU intr gen
  update routines for different platforms and update cpuidle and cpuhotplug
  support to use them;
- add checks for the presense of cpu_pmu_{offline,online} callbacks;
- move and rename gs101-specific cpu{offline,online} PMU updates
  routines into gs101-pmu.c file, also removing underscore prefix;
- update gs101_pmu_data to use newly introduced callbacks;
- rename PMU interrupts generation GS101_INTR_* regs to EXYNOS_INTR_*.

This allows other platforms to add cpuhotplug and cpuidle support in
a similar manner, using their own platform-specific PMU and
PMU intr gen update routines.

Signed-off-by: Alexey Klimov <alexey.klimov@linaro.org>
---
 drivers/soc/samsung/exynos-pmu.c            | 118 ++++++----------------------
 drivers/soc/samsung/exynos-pmu.h            |  31 ++++++++
 drivers/soc/samsung/gs101-pmu.c             |  57 ++++++++++++++
 include/linux/soc/samsung/exynos-regs-pmu.h |  10 +--
 4 files changed, 115 insertions(+), 101 deletions(-)

diff --git a/drivers/soc/samsung/exynos-pmu.c b/drivers/soc/samsung/exynos-pmu.c
index d58376c38179..660416c0db43 100644
--- a/drivers/soc/samsung/exynos-pmu.c
+++ b/drivers/soc/samsung/exynos-pmu.c
@@ -24,22 +24,6 @@
 
 #include "exynos-pmu.h"
 
-struct exynos_pmu_context {
-	struct device *dev;
-	const struct exynos_pmu_data *pmu_data;
-	struct regmap *pmureg;
-	struct regmap *pmuintrgen;
-	/*
-	 * Serialization lock for CPU hot plug and cpuidle ACPM hint
-	 * programming. Also protects in_cpuhp, sys_insuspend & sys_inreboot
-	 * flags.
-	 */
-	raw_spinlock_t cpupm_lock;
-	unsigned long *in_cpuhp;
-	bool sys_insuspend;
-	bool sys_inreboot;
-};
-
 void __iomem *pmu_base_addr;
 static struct exynos_pmu_context *pmu_context;
 /* forward declaration */
@@ -219,44 +203,8 @@ struct regmap *exynos_get_pmu_regmap_by_phandle(struct device_node *np,
 }
 EXPORT_SYMBOL_GPL(exynos_get_pmu_regmap_by_phandle);
 
-/*
- * CPU_INFORM register "hint" values are required to be programmed in addition to
- * the standard PSCI calls to have functional CPU hotplug and CPU idle states.
- * This is required to workaround limitations in the el3mon/ACPM firmware.
- */
-#define CPU_INFORM_CLEAR	0
-#define CPU_INFORM_C2		1
-
-/*
- * __gs101_cpu_pmu_ prefix functions are common code shared by CPU PM notifiers
- * (CPUIdle) and CPU hotplug callbacks. Functions should be called with IRQs
- * disabled and cpupm_lock held.
- */
-static int __gs101_cpu_pmu_online(unsigned int cpu)
-	__must_hold(&pmu_context->cpupm_lock)
-{
-	unsigned int cpuhint = smp_processor_id();
-	u32 reg, mask;
-
-	/* clear cpu inform hint */
-	regmap_write(pmu_context->pmureg, GS101_CPU_INFORM(cpuhint),
-		     CPU_INFORM_CLEAR);
-
-	mask = BIT(cpu);
-
-	regmap_update_bits(pmu_context->pmuintrgen, GS101_GRP2_INTR_BID_ENABLE,
-			   mask, (0 << cpu));
-
-	regmap_read(pmu_context->pmuintrgen, GS101_GRP2_INTR_BID_UPEND, &reg);
-
-	regmap_write(pmu_context->pmuintrgen, GS101_GRP2_INTR_BID_CLEAR,
-		     reg & mask);
-
-	return 0;
-}
-
 /* Called from CPU PM notifier (CPUIdle code path) with IRQs disabled */
-static int gs101_cpu_pmu_online(void)
+static int exynos_cpu_pmu_online(void)
 {
 	int cpu;
 
@@ -268,20 +216,20 @@ static int gs101_cpu_pmu_online(void)
 	}
 
 	cpu = smp_processor_id();
-	__gs101_cpu_pmu_online(cpu);
+	pmu_context->pmu_data->cpu_pmu_online(pmu_context, cpu);
 	raw_spin_unlock(&pmu_context->cpupm_lock);
 
 	return NOTIFY_OK;
 }
 
 /* Called from CPU hot plug callback with IRQs enabled */
-static int gs101_cpuhp_pmu_online(unsigned int cpu)
+static int exynos_cpuhp_pmu_online(unsigned int cpu)
 {
 	unsigned long flags;
 
 	raw_spin_lock_irqsave(&pmu_context->cpupm_lock, flags);
 
-	__gs101_cpu_pmu_online(cpu);
+	pmu_context->pmu_data->cpu_pmu_online(pmu_context, cpu);
 	/*
 	 * Mark this CPU as having finished the hotplug.
 	 * This means this CPU can now enter C2 idle state.
@@ -292,35 +240,8 @@ static int gs101_cpuhp_pmu_online(unsigned int cpu)
 	return 0;
 }
 
-/* Common function shared by both CPU hot plug and CPUIdle */
-static int __gs101_cpu_pmu_offline(unsigned int cpu)
-	__must_hold(&pmu_context->cpupm_lock)
-{
-	unsigned int cpuhint = smp_processor_id();
-	u32 reg, mask;
-
-	/* set cpu inform hint */
-	regmap_write(pmu_context->pmureg, GS101_CPU_INFORM(cpuhint),
-		     CPU_INFORM_C2);
-
-	mask = BIT(cpu);
-	regmap_update_bits(pmu_context->pmuintrgen, GS101_GRP2_INTR_BID_ENABLE,
-			   mask, BIT(cpu));
-
-	regmap_read(pmu_context->pmuintrgen, GS101_GRP1_INTR_BID_UPEND, &reg);
-	regmap_write(pmu_context->pmuintrgen, GS101_GRP1_INTR_BID_CLEAR,
-		     reg & mask);
-
-	mask = (BIT(cpu + 8));
-	regmap_read(pmu_context->pmuintrgen, GS101_GRP1_INTR_BID_UPEND, &reg);
-	regmap_write(pmu_context->pmuintrgen, GS101_GRP1_INTR_BID_CLEAR,
-		     reg & mask);
-
-	return 0;
-}
-
 /* Called from CPU PM notifier (CPUIdle code path) with IRQs disabled */
-static int gs101_cpu_pmu_offline(void)
+static int exynos_cpu_pmu_offline(void)
 {
 	int cpu;
 
@@ -338,14 +259,14 @@ static int gs101_cpu_pmu_offline(void)
 		return NOTIFY_OK;
 	}
 
-	__gs101_cpu_pmu_offline(cpu);
+	pmu_context->pmu_data->cpu_pmu_offline(pmu_context, cpu);
 	raw_spin_unlock(&pmu_context->cpupm_lock);
 
 	return NOTIFY_OK;
 }
 
 /* Called from CPU hot plug callback with IRQs enabled */
-static int gs101_cpuhp_pmu_offline(unsigned int cpu)
+static int exynos_cpuhp_pmu_offline(unsigned int cpu)
 {
 	unsigned long flags;
 
@@ -355,29 +276,29 @@ static int gs101_cpuhp_pmu_offline(unsigned int cpu)
 	 * ACPM the CPU entering hotplug should not enter C2 idle state.
 	 */
 	set_bit(cpu, pmu_context->in_cpuhp);
-	__gs101_cpu_pmu_offline(cpu);
+	pmu_context->pmu_data->cpu_pmu_offline(pmu_context, cpu);
 
 	raw_spin_unlock_irqrestore(&pmu_context->cpupm_lock, flags);
 
 	return 0;
 }
 
-static int gs101_cpu_pm_notify_callback(struct notifier_block *self,
+static int exynos_cpu_pm_notify_callback(struct notifier_block *self,
 					unsigned long action, void *v)
 {
 	switch (action) {
 	case CPU_PM_ENTER:
-		return gs101_cpu_pmu_offline();
+		return exynos_cpu_pmu_offline();
 
 	case CPU_PM_EXIT:
-		return gs101_cpu_pmu_online();
+		return exynos_cpu_pmu_online();
 	}
 
 	return NOTIFY_OK;
 }
 
-static struct notifier_block gs101_cpu_pm_notifier = {
-	.notifier_call = gs101_cpu_pm_notify_callback,
+static struct notifier_block exynos_cpu_pm_notifier = {
+	.notifier_call = exynos_cpu_pm_notify_callback,
 	/*
 	 * We want to be called first, as the ACPM hint and handshake is what
 	 * puts the CPU into C2.
@@ -425,6 +346,11 @@ static int setup_cpuhp_and_cpuidle(struct device *dev)
 		return 0;
 	}
 
+	if (!pmu_context->pmu_data->cpu_pmu_offline || !pmu_context->pmu_data->cpu_pmu_online) {
+		dev_err(dev, "PMU write/read sequence is not present for cpuhotplug and cpuidle\n");
+		return -ENODEV;
+	}
+
 	/*
 	 * To avoid lockdep issues (CPU PM notifiers use raw spinlocks) create
 	 * a mmio regmap for pmu-intr-gen that uses raw spinlocks instead of
@@ -458,17 +384,17 @@ static int setup_cpuhp_and_cpuidle(struct device *dev)
 
 	/* set PMU to power on */
 	for_each_online_cpu(cpu)
-		gs101_cpuhp_pmu_online(cpu);
+		exynos_cpuhp_pmu_online(cpu);
 
 	/* register CPU hotplug callbacks */
 	cpuhp_setup_state(CPUHP_BP_PREPARE_DYN,	"soc/exynos-pmu:prepare",
-			  gs101_cpuhp_pmu_online, NULL);
+			  exynos_cpuhp_pmu_online, NULL);
 
 	cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "soc/exynos-pmu:online",
-			  NULL, gs101_cpuhp_pmu_offline);
+			  NULL, exynos_cpuhp_pmu_offline);
 
 	/* register CPU PM notifiers for cpuidle */
-	cpu_pm_register_notifier(&gs101_cpu_pm_notifier);
+	cpu_pm_register_notifier(&exynos_cpu_pm_notifier);
 	register_reboot_notifier(&exynos_cpupm_reboot_nb);
 	return 0;
 }
diff --git a/drivers/soc/samsung/exynos-pmu.h b/drivers/soc/samsung/exynos-pmu.h
index fbe381e2a2e1..186299a049a8 100644
--- a/drivers/soc/samsung/exynos-pmu.h
+++ b/drivers/soc/samsung/exynos-pmu.h
@@ -13,6 +13,14 @@
 
 #define PMU_TABLE_END	(-1U)
 
+/*
+ * CPU_INFORM register "hint" values are required to be programmed in addition to
+ * the standard PSCI calls to have functional CPU hotplug and CPU idle states.
+ * This is required to workaround limitations in the el3mon/ACPM firmware.
+ */
+#define CPU_INFORM_CLEAR	0
+#define CPU_INFORM_C2		1
+
 struct regmap_access_table;
 
 struct exynos_pmu_conf {
@@ -20,6 +28,22 @@ struct exynos_pmu_conf {
 	u8 val[NUM_SYS_POWERDOWN];
 };
 
+struct exynos_pmu_context {
+	struct device *dev;
+	const struct exynos_pmu_data *pmu_data;
+	struct regmap *pmureg;
+	struct regmap *pmuintrgen;
+	/*
+	 * Serialization lock for CPU hot plug and cpuidle ACPM hint
+	 * programming. Also protects in_cpuhp, sys_insuspend & sys_inreboot
+	 * flags.
+	 */
+	raw_spinlock_t cpupm_lock;
+	unsigned long *in_cpuhp;
+	bool sys_insuspend;
+	bool sys_inreboot;
+};
+
 /**
  * struct exynos_pmu_data - of_device_id (match) data
  *
@@ -44,6 +68,10 @@ struct exynos_pmu_conf {
  *            used (i.e. when @pmu_secure is @true).
  * @wr_table: A table of writable register ranges in case a custom regmap is
  *            used (i.e. when @pmu_secure is @true).
+ * @cpu_pmu_offline: Optional callback to be called before entering CPU offline
+ *                   or idle state. Only valid when pmu_cpuhp set to true.
+ * @cpu_pmu_online: Optional callback to be called after CPU onlined or after
+ *                  exiting idle state. Only valid when pmu_cpuhp set to true.
  */
 struct exynos_pmu_data {
 	const struct exynos_pmu_conf *pmu_config;
@@ -57,6 +85,9 @@ struct exynos_pmu_data {
 
 	const struct regmap_access_table *rd_table;
 	const struct regmap_access_table *wr_table;
+
+	int (*cpu_pmu_offline)(struct exynos_pmu_context *pmu_context, unsigned int cpu);
+	int (*cpu_pmu_online)(struct exynos_pmu_context *pmu_context, unsigned int cpu);
 };
 
 extern void __iomem *pmu_base_addr;
diff --git a/drivers/soc/samsung/gs101-pmu.c b/drivers/soc/samsung/gs101-pmu.c
index 17dadc1b9c6e..5f2a59924144 100644
--- a/drivers/soc/samsung/gs101-pmu.c
+++ b/drivers/soc/samsung/gs101-pmu.c
@@ -322,11 +322,68 @@ static const struct regmap_access_table gs101_pmu_wr_table = {
 	.n_no_ranges = ARRAY_SIZE(gs101_pmu_ro_registers),
 };
 
+/*
+ * gs101_cpu_pmu_ prefix functions are common code shared by CPU PM notifiers
+ * (CPUIdle) and CPU hotplug callbacks. Functions should be called with IRQs
+ * disabled and cpupm_lock held.
+ */
+static int gs101_cpu_pmu_online(struct exynos_pmu_context *pmu_context, unsigned int cpu)
+	__must_hold(&pmu_context->cpupm_lock)
+{
+	unsigned int cpuhint = smp_processor_id();
+	u32 reg, mask;
+
+	/* clear cpu inform hint */
+	regmap_write(pmu_context->pmureg, GS101_CPU_INFORM(cpuhint),
+		     CPU_INFORM_CLEAR);
+
+	mask = BIT(cpu);
+
+	regmap_update_bits(pmu_context->pmuintrgen, EXYNOS_GRP2_INTR_BID_ENABLE,
+			   mask, (0 << cpu));
+
+	regmap_read(pmu_context->pmuintrgen, EXYNOS_GRP2_INTR_BID_UPEND, &reg);
+
+	regmap_write(pmu_context->pmuintrgen, EXYNOS_GRP2_INTR_BID_CLEAR,
+		     reg & mask);
+
+	return 0;
+}
+
+/* Common function shared by both CPU hot plug and CPUIdle */
+static int gs101_cpu_pmu_offline(struct exynos_pmu_context *pmu_context, unsigned int cpu)
+	__must_hold(&pmu_context->cpupm_lock)
+{
+	unsigned int cpuhint = smp_processor_id();
+	u32 reg, mask;
+
+	/* set cpu inform hint */
+	regmap_write(pmu_context->pmureg, GS101_CPU_INFORM(cpuhint),
+		     CPU_INFORM_C2);
+
+	mask = BIT(cpu);
+	regmap_update_bits(pmu_context->pmuintrgen, EXYNOS_GRP2_INTR_BID_ENABLE,
+			   mask, BIT(cpu));
+
+	regmap_read(pmu_context->pmuintrgen, EXYNOS_GRP1_INTR_BID_UPEND, &reg);
+	regmap_write(pmu_context->pmuintrgen, EXYNOS_GRP1_INTR_BID_CLEAR,
+		     reg & mask);
+
+	mask = (BIT(cpu + 8));
+	regmap_read(pmu_context->pmuintrgen, EXYNOS_GRP1_INTR_BID_UPEND, &reg);
+	regmap_write(pmu_context->pmuintrgen, EXYNOS_GRP1_INTR_BID_CLEAR,
+		     reg & mask);
+
+	return 0;
+}
+
 const struct exynos_pmu_data gs101_pmu_data = {
 	.pmu_secure = true,
 	.pmu_cpuhp = true,
 	.rd_table = &gs101_pmu_rd_table,
 	.wr_table = &gs101_pmu_wr_table,
+	.cpu_pmu_offline = gs101_cpu_pmu_offline,
+	.cpu_pmu_online = gs101_cpu_pmu_online,
 };
 
 /*
diff --git a/include/linux/soc/samsung/exynos-regs-pmu.h b/include/linux/soc/samsung/exynos-regs-pmu.h
index db8a7ca81080..9c4d3da41dbf 100644
--- a/include/linux/soc/samsung/exynos-regs-pmu.h
+++ b/include/linux/soc/samsung/exynos-regs-pmu.h
@@ -1009,11 +1009,11 @@
 #define GS101_PHY_CTRL_UFS                      0x3ec8
 
 /* PMU INTR GEN */
-#define GS101_GRP1_INTR_BID_UPEND				(0x0108)
-#define GS101_GRP1_INTR_BID_CLEAR				(0x010c)
-#define GS101_GRP2_INTR_BID_ENABLE				(0x0200)
-#define GS101_GRP2_INTR_BID_UPEND				(0x0208)
-#define GS101_GRP2_INTR_BID_CLEAR				(0x020c)
+#define EXYNOS_GRP1_INTR_BID_UPEND				(0x0108)
+#define EXYNOS_GRP1_INTR_BID_CLEAR				(0x010c)
+#define EXYNOS_GRP2_INTR_BID_ENABLE				(0x0200)
+#define EXYNOS_GRP2_INTR_BID_UPEND				(0x0208)
+#define EXYNOS_GRP2_INTR_BID_CLEAR				(0x020c)
 
 /* exynosautov920 */
 #define EXYNOSAUTOV920_PHY_CTRL_USB20				(0x0710)

-- 
2.51.0

[PATCH v3 4/6] soc: samsung: exynos-pmu: add Exynos850 CPU hotplug support

[Alexey Klimov]

Add cpuhotplug support for Exynos850 platforms. This SoC requires
its own specific set of writes/updates to PMU and PMU interrupts
generation block in order to put a CPU or a group of CPUs into
a different sleep states or prepare these entities for a CPU_OFF
or wake-up out of idle state or after CPU online.
Without these writes/updates the CPU(s) wake-up or online fails.
While at this, also add description of Exynos850 PMU registers.

Signed-off-by: Alexey Klimov <alexey.klimov@linaro.org>
---
 drivers/soc/samsung/Makefile                |  2 +-
 drivers/soc/samsung/exynos-pmu.c            |  1 +
 drivers/soc/samsung/exynos-pmu.h            |  1 +
 drivers/soc/samsung/exynos850-pmu.c         | 79 +++++++++++++++++++++++++++++
 include/linux/soc/samsung/exynos-regs-pmu.h |  5 ++
 5 files changed, 87 insertions(+), 1 deletion(-)

diff --git a/drivers/soc/samsung/Makefile b/drivers/soc/samsung/Makefile
index 636a762608c9..7f544e3c1fcc 100644
--- a/drivers/soc/samsung/Makefile
+++ b/drivers/soc/samsung/Makefile
@@ -7,7 +7,7 @@ exynos_chipid-y			+= exynos-chipid.o exynos-asv.o
 obj-$(CONFIG_EXYNOS_USI)	+= exynos-usi.o
 
 obj-$(CONFIG_EXYNOS_PMU)	+= exynos_pmu.o
-exynos_pmu-y			+= exynos-pmu.o gs101-pmu.o
+exynos_pmu-y			+= exynos-pmu.o gs101-pmu.o exynos850-pmu.o
 
 obj-$(CONFIG_EXYNOS_PMU_ARM_DRIVERS)	+= exynos3250-pmu.o exynos4-pmu.o \
 					exynos5250-pmu.o exynos5420-pmu.o
diff --git a/drivers/soc/samsung/exynos-pmu.c b/drivers/soc/samsung/exynos-pmu.c
index 660416c0db43..9dddf4759ab5 100644
--- a/drivers/soc/samsung/exynos-pmu.c
+++ b/drivers/soc/samsung/exynos-pmu.c
@@ -133,6 +133,7 @@ static const struct of_device_id exynos_pmu_of_device_ids[] = {
 		.compatible = "samsung,exynos7-pmu",
 	}, {
 		.compatible = "samsung,exynos850-pmu",
+		.data = &exynos850_pmu_data,
 	},
 	{ /*sentinel*/ },
 };
diff --git a/drivers/soc/samsung/exynos-pmu.h b/drivers/soc/samsung/exynos-pmu.h
index 186299a049a8..4202d3cd94c9 100644
--- a/drivers/soc/samsung/exynos-pmu.h
+++ b/drivers/soc/samsung/exynos-pmu.h
@@ -102,6 +102,7 @@ extern const struct exynos_pmu_data exynos5250_pmu_data;
 extern const struct exynos_pmu_data exynos5420_pmu_data;
 #endif
 extern const struct exynos_pmu_data gs101_pmu_data;
+extern const struct exynos_pmu_data exynos850_pmu_data;
 
 extern void pmu_raw_writel(u32 val, u32 offset);
 extern u32 pmu_raw_readl(u32 offset);
diff --git a/drivers/soc/samsung/exynos850-pmu.c b/drivers/soc/samsung/exynos850-pmu.c
new file mode 100644
index 000000000000..7a1ea45810bd
--- /dev/null
+++ b/drivers/soc/samsung/exynos850-pmu.c
@@ -0,0 +1,79 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2026 Linaro Ltd.
+ *
+ * Exynos850 PMU support
+ */
+
+#include <linux/soc/samsung/exynos-pmu.h>
+#include <linux/soc/samsung/exynos-regs-pmu.h>
+#include <linux/regmap.h>
+#include <asm/cputype.h>
+
+#include "exynos-pmu.h"
+
+static int exynos850_cpu_pmu_offline(struct exynos_pmu_context *pmu_context, unsigned int cpu)
+	__must_hold(&pmu_context->cpupm_lock)
+{
+	u32 this_cluster = MPIDR_AFFINITY_LEVEL(read_cpuid_mpidr(), 2);
+	u32 cluster_cpu = MPIDR_AFFINITY_LEVEL(read_cpuid_mpidr(), 1);
+	unsigned int cpuhint = smp_processor_id();
+	u32 reg, mask;
+
+	/* set cpu inform hint */
+	regmap_write(pmu_context->pmureg, EXYNOS850_CPU_INFORM(cpuhint),
+		     CPU_INFORM_C2);
+
+	mask = BIT(cpu);
+	regmap_update_bits(pmu_context->pmuintrgen, EXYNOS_GRP2_INTR_BID_ENABLE,
+			   mask, BIT(cpu));
+
+	regmap_read(pmu_context->pmuintrgen, EXYNOS_GRP1_INTR_BID_UPEND, &reg);
+	regmap_write(pmu_context->pmuintrgen, EXYNOS_GRP1_INTR_BID_CLEAR,
+		     reg & mask);
+
+	mask = (BIT(cpu + 8));
+	regmap_read(pmu_context->pmuintrgen, EXYNOS_GRP1_INTR_BID_UPEND, &reg);
+	regmap_write(pmu_context->pmuintrgen, EXYNOS_GRP1_INTR_BID_CLEAR,
+		     reg & mask);
+
+	regmap_update_bits(pmu_context->pmureg,
+			   EXYNOS850_CLUSTER_CPU_INT_EN(this_cluster, cluster_cpu),
+			   1 << 3, 1 << 3);
+	return 0;
+}
+
+static int exynos850_cpu_pmu_online(struct exynos_pmu_context *pmu_context, unsigned int cpu)
+	__must_hold(&pmu_context->cpupm_lock)
+{
+	u32 this_cluster = MPIDR_AFFINITY_LEVEL(read_cpuid_mpidr(), 2);
+	u32 cluster_cpu = MPIDR_AFFINITY_LEVEL(read_cpuid_mpidr(), 1);
+	unsigned int cpuhint = smp_processor_id();
+	u32 reg, mask;
+
+	/* clear cpu inform hint */
+	regmap_write(pmu_context->pmureg, EXYNOS850_CPU_INFORM(cpuhint),
+		     CPU_INFORM_CLEAR);
+
+	mask = BIT(cpu);
+
+	regmap_update_bits(pmu_context->pmuintrgen, EXYNOS_GRP2_INTR_BID_ENABLE,
+			   mask, (0 << cpu));
+
+	regmap_read(pmu_context->pmuintrgen, EXYNOS_GRP2_INTR_BID_UPEND, &reg);
+
+	regmap_write(pmu_context->pmuintrgen, EXYNOS_GRP2_INTR_BID_CLEAR,
+		     reg & mask);
+
+	regmap_update_bits(pmu_context->pmureg,
+			   EXYNOS850_CLUSTER_CPU_INT_EN(this_cluster, cluster_cpu),
+			   1 << 3, 0 << 3);
+	return 0;
+}
+
+const struct exynos_pmu_data exynos850_pmu_data = {
+	.pmu_cpuhp = true,
+	.cpu_pmu_offline = exynos850_cpu_pmu_offline,
+	.cpu_pmu_online = exynos850_cpu_pmu_online,
+};
+
diff --git a/include/linux/soc/samsung/exynos-regs-pmu.h b/include/linux/soc/samsung/exynos-regs-pmu.h
index 9c4d3da41dbf..93c4d724c8ea 100644
--- a/include/linux/soc/samsung/exynos-regs-pmu.h
+++ b/include/linux/soc/samsung/exynos-regs-pmu.h
@@ -1015,6 +1015,11 @@
 #define EXYNOS_GRP2_INTR_BID_UPEND				(0x0208)
 #define EXYNOS_GRP2_INTR_BID_CLEAR				(0x020c)
 
+/* Exynos850 PMU Alive */
+#define EXYNOS850_CPU_INFORM(cpu)		(0x0860 + ((cpu) & 7) * 4)
+#define EXYNOS850_CLUSTER_CPU_OFFSET(cl, cpu)	(0x1000 + ((cl * 0x400) + ((cpu) * 0x80)))
+#define EXYNOS850_CLUSTER_CPU_INT_EN(cl, cpu)	(EXYNOS850_CLUSTER_CPU_OFFSET(cl, cpu) + 0x44)
+
 /* exynosautov920 */
 #define EXYNOSAUTOV920_PHY_CTRL_USB20				(0x0710)
 #define EXYNOSAUTOV920_PHY_CTRL_USB31				(0x0714)

-- 
2.51.0

[PATCH v3 5/6] MAINTAINERS: add Exynos850 PMU entry

[Alexey Klimov]

Add Exynos850 PMU entry describing new file
drivers/soc/samsung/exynos850-pmu.c.
Add myself as M there since I contributed Exynos850
PMU support and intend to maintain that.

Signed-off-by: Alexey Klimov <alexey.klimov@linaro.org>
---
 MAINTAINERS | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 498ca30a00c5..60c25fed8ffa 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -23645,6 +23645,13 @@ F:	arch/arm64/boot/dts/exynos/exynos2200*
 F:	drivers/clk/samsung/clk-exynos2200.c
 F:	include/dt-bindings/clock/samsung,exynos2200-cmu.h
 
+SAMSUNG EXYNOS850 PMU SUPPORT
+M:	Alexey Klimov <alexey.klimov@linaro.org>
+L:	linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)
+L:	linux-samsung-soc@vger.kernel.org
+S:	Maintained
+F:	drivers/soc/samsung/exynos850-pmu.c
+
 SAMSUNG EXYNOS850 SoC SUPPORT
 M:	Sam Protsenko <semen.protsenko@linaro.org>
 L:	linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)

-- 
2.51.0

[PATCH v3 6/6] arm64: dts: exynos850: add PMU interrupt generation node

[Alexey Klimov]

Add pmu_intr_gen node for Exynos850. This hw block is required
for different power management routines like CPU hotplug and
different sleep and idle states.
Also reference this node from main PMU node.

Signed-off-by: Alexey Klimov <alexey.klimov@linaro.org>
---
 arch/arm64/boot/dts/exynos/exynos850.dtsi | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/arm64/boot/dts/exynos/exynos850.dtsi b/arch/arm64/boot/dts/exynos/exynos850.dtsi
index 3881f573ec08..04662b1c5458 100644
--- a/arch/arm64/boot/dts/exynos/exynos850.dtsi
+++ b/arch/arm64/boot/dts/exynos/exynos850.dtsi
@@ -214,6 +214,7 @@ gic: interrupt-controller@12a01000 {
 		pmu_system_controller: system-controller@11860000 {
 			compatible = "samsung,exynos850-pmu", "syscon";
 			reg = <0x11860000 0x10000>;
+			google,pmu-intr-gen-syscon = <&pmu_intr_gen>;
 
 			poweroff: syscon-poweroff {
 				compatible = "syscon-poweroff";
@@ -231,6 +232,11 @@ reboot: syscon-reboot {
 			};
 		};
 
+		pmu_intr_gen: syscon@11870000 {
+			compatible = "samsung,exynos850-pmu-intr-gen", "syscon";
+			reg = <0x11870000 0x10000>;
+		};
+
 		watchdog_cl0: watchdog@10050000 {
 			compatible = "samsung,exynos850-wdt";
 			reg = <0x10050000 0x100>;

-- 
2.51.0

Re: [PATCH v3 4/6] soc: samsung: exynos-pmu: add Exynos850 CPU hotplug support

[Alexey Klimov]

On Thu Apr 30, 2026 at 2:56 AM BST, Alexey Klimov wrote:
> Add cpuhotplug support for Exynos850 platforms. This SoC requires
> its own specific set of writes/updates to PMU and PMU interrupts
> generation block in order to put a CPU or a group of CPUs into
> a different sleep states or prepare these entities for a CPU_OFF
> or wake-up out of idle state or after CPU online.
> Without these writes/updates the CPU(s) wake-up or online fails.
> While at this, also add description of Exynos850 PMU registers.
>
> Signed-off-by: Alexey Klimov <alexey.klimov@linaro.org>
> ---
>  drivers/soc/samsung/Makefile                |  2 +-
>  drivers/soc/samsung/exynos-pmu.c            |  1 +
>  drivers/soc/samsung/exynos-pmu.h            |  1 +
>  drivers/soc/samsung/exynos850-pmu.c         | 79 +++++++++++++++++++++++++++++

[..]

> +const struct exynos_pmu_data exynos850_pmu_data = {
> +	.pmu_cpuhp = true,
> +	.cpu_pmu_offline = exynos850_cpu_pmu_offline,
> +	.cpu_pmu_online = exynos850_cpu_pmu_online,
> +};
> +

Ah, sorry, I forgot to remove blank line here. Will do in the next
update.

BR,
Alexey