[PATCH v3 0/5] platform: generic: spacemit: add K3 platform support

[Troy Mitchell <troy.mitchell@linux.spacemit.com>]

SpacemiT K3 combines eight X100 harts and eight A100 harts in four
clusters. The two core types expose different ISA capabilities: X100
implements H and has a 256-bit VLEN, while A100 does not implement H and
has a 1024-bit VLEN. OpenSBI currently selects one expected-trap handler
from the cold-boot hart, so an X100 boot hart would make A100 access H-only
CSRs. Select that handler per hart; the remaining extension and vector
state used by OpenSBI is already maintained or queried per hart.

Only hart 0 is powered at reset. Add a start-only HSM backend which removes
the requested hart's core and cluster power-down votes and wakes it on
demand. Before common warm-boot code runs, each hart restores the PMA
attributes expected by later firmware, enables cache snooping and prefetch,
and enables H on X100. The cold-boot hart also programs the cluster reset
vectors and enables CCI-550 snoop and DVM requests before secondary harts
can start.

K1 shares the vendor cache CSRs, PMU fields, cluster sizing, and CCI-550
helper with K3. Factor only those definitions and helpers into common
SpacemiT files; K1 keeps its topology, boot flow, and HSM behavior. Two
independent K1 fixes clarify the cache operation name and move per-hart
setup out of cold_boot_allowed().

The K3 SDK still loads ESOS for RPMI reset, suspend, and MPXY services.
Secondary-hart startup does not depend on the ESOS HSM service: the K3 HSM
driver matches the root node first and uses the SoC PMU directly, following
the SDK firmware's direct wakeup path.

Runtime validation on a SpacemiT K3 COM260 used the SDK's split NOR
firmware layout. OpenSBI was flashed as fw_dynamic.itb, then loaded from
NOR by the SDK FSBL. OpenSBI built from this series selected the
spacemit-k3-hsm device and reported 16 harts. U-Boot and Linux 6.18.3
started, Linux detected SBI v3.0 and the HSM extension, and all 16 CPUs
came online.

The series has been build-tested with:

  - the RV64 generic default configuration
  - RV64 K1-only and K3-only configurations
  - the RV32 generic configuration, where SpacemiT platform objects are
    intentionally omitted
  - the K3 SDK split OpenSBI and U-Boot packaging flow

The public K3 SDK v1.0.7 components needed to reproduce the firmware build
are pinned at:

  manifests:
    https://github.com/spacemit-com/manifests
    6d767b42fdbd759dc9511b8a13523c3de42aaa5a
  scripts:
    https://github.com/spacemit-com/scripts
    96418825a37a1cf07d3275c13d9d3329934224f0
  U-Boot:
    https://github.com/spacemit-com/uboot-2022.10
    676971d3a61f2583dfd53d8f7dfbc9607cea74b7
  ESOS and esos-lite:
    https://github.com/spacemit-com/esos
    eaf9afd83b27583b9bcafe0153028b32219518f5
    https://github.com/spacemit-com/esos-lite
    df4b2665cd4f3af563538cb41ba85c85dd39de7c

The kernel and root filesystem are independent of this firmware build.
Any board-compatible kernel and root filesystem may be used, so neither is
pinned here. EDK II is not used in this fastboot path.

Before building U-Boot, update UART0 in
bsp-src/uboot-2022.10/arch/riscv/dts/k3.dtsi. This DT is passed to OpenSBI:

  uart0: uart@d4017000 {
          ...
          compatible = "spacemit,k1-uart", "intel,xscale-uart",
                       "ns16550";
          ...
  };

The compatible order makes OpenSBI select UART_CAP_UUE and preserve
UART_IER_UUE (bit 6); matching only "ns16550" writes 0x00 to UART_IER and
stops serial output. Build U-Boot and use the FSBL, bootinfo, and U-Boot
FIT produced by the same SDK build:

  K3_SDK_DIR=/path/to/k3-sdk
  make -C "$K3_SDK_DIR" uboot

This produces the following files under output/k3/images:

  FSBL.bin
  bootinfo_spinor.bin
  u-boot.itb

Build OpenSBI at the address used by the SDK, then wrap fw_dynamic.bin in
the SDK's standalone OpenSBI FIT:

  make O=build-k3 CROSS_COMPILE=riscv64-linux-gnu- PLATFORM=generic \
       PLATFORM_RISCV_ISA=rv64gc FW_TEXT_START=0x100000000
  FW_DIR="$PWD/build-k3/platform/generic/firmware"
  cp "$K3_SDK_DIR/bsp-src/opensbi/platform/generic/spacemit/fw_dynamic.its" \
     "$FW_DIR/"
  (cd "$FW_DIR" && \
   "$K3_SDK_DIR/output/k3/build/uboot-custom/tools/mkimage" \
     -f fw_dynamic.its fw_dynamic.itb)

There are two ways to enter U-Boot fastboot. On a provisioned board, hold
`s` during U-Boot startup and run:

  => fastboot 0

Alternatively, extract factory/FSBL.bin and u-boot.itb from
Bianbu-Minimal-K3-20260728010729.tar.gz. Hold FEL while resetting the
board to enter BROM fastboot, then run on the host:

  fastboot stage factory/FSBL.bin
  fastboot continue
  sleep 8
  fastboot stage u-boot.itb
  fastboot continue

COM260 boots from SPI NOR and uses partition_4M.json from the Bianbu image
for its firmware layout. Select that MTD layout before writing a firmware
partition:

  fastboot flash mtd partition_4M.json

If the installed FSBL and U-Boot already match the prerequisites above,
only the OpenSBI partition needs updating:

  fastboot flash opensbi "$FW_DIR/fw_dynamic.itb"
  fastboot reboot

For an older boot firmware, update the boot-chain components from the
pinned SDK build in the same fastboot session before rebooting:

  SDK_IMAGES="$K3_SDK_DIR/output/k3/images"
  fastboot flash bootinfo "$SDK_IMAGES/bootinfo_spinor.bin"
  fastboot flash fsbl "$SDK_IMAGES/FSBL.bin"
  fastboot flash uboot "$SDK_IMAGES/u-boot.itb"
  fastboot flash opensbi "$FW_DIR/fw_dynamic.itb"
  fastboot reboot

The full Bianbu Minimal image is only needed to initialize a board without
a usable system; this OpenSBI test does not otherwise depend on its Linux
or root filesystem images.

Signed-off-by: Troy Mitchell <troy.mitchell@linux.spacemit.com>
---
Changes in v3:
  - select the HSM backend from the root compatible while preserving K1's
    existing start and stop behavior
  - start secondary harts on demand from the K3 HSM callback; remove the
    cold-boot wake-all loop, WFI tables, and timeout
  - perform PMA, cache, and H-extension setup before the common warm entry;
    use the OpenSBI VMA and guest-translation fence helpers
  - use assembler-safe constants shared by the C and assembly paths
  - omit the 64-bit-only SpacemiT platform objects from RV32 builds
  - clarify the boundary between the K3 HSM backend and ESOS services
  - update the cover letter with the public SDK build and split NOR
    validation procedure
  - add Reviewed-by trailers from Bo Gan
  - Link to v2: https://patch.msgid.link/20260818-spacemit-k3-v2-0-84cb7773a481@linux.spacemit.com

Changes in v2:
  - correct the K3 PMACFG0 CSR number from 0xbc0 to 0x7de
  - select the expected-trap handler per hart for heterogeneous H support
  - move K1 and K3 per-hart setup out of cold_boot_allowed()
  - split the generic and K1 fixes into standalone patches, growing the
    series from three patches to five
  - document X100/A100 ISA and VLEN differences and the homogeneous-core
    audit
  - document OpenSBI/U-Boot packaging, the UART compatible adjustment,
    and the USB fastboot test procedure
  - Link to v1: https://lore.kernel.org/r/20260724-spacemit-k3-v1-0-f0e49329feb8@linux.spacemit.com

---
Troy Mitchell (2):
      lib: sbi: select expected trap handler per hart
      platform: generic: spacemit: k1: move hart init to nascent hook

Xianbin Zhu (3):
      platform: generic: spacemit: k1: rename cache flush operation
      platform: generic: spacemit: k1: refactor platform support
      platform: generic: spacemit: k3: add platform support

 include/sbi/sbi_csr_detect.h                 |   4 +-
 include/sbi/sbi_hart.h                       |   2 +-
 lib/sbi/sbi_hart.c                           |   9 +-
 lib/sbi/sbi_illegal_atomic.c                 |   4 +-
 lib/sbi/sbi_unpriv.c                         |   6 +-
 lib/utils/hsm/fdt_hsm_spacemit.c             | 125 ++++++++++++++++++++------
 platform/generic/Kconfig                     |  11 +++
 platform/generic/configs/defconfig           |   1 +
 platform/generic/include/spacemit/common.h   |  90 +++++++++++++++++++
 platform/generic/include/spacemit/k1.h       |  96 ++++----------------
 platform/generic/include/spacemit/k3.h       | 127 +++++++++++++++++++++++++++
 platform/generic/include/spacemit/k3_asm.h   |  16 ++++
 platform/generic/include/spacemit/spacemit.h |  14 +++
 platform/generic/spacemit/k1.c               |  45 ++++------
 platform/generic/spacemit/k3.c               | 122 +++++++++++++++++++++++++
 platform/generic/spacemit/k3_asm.S           |  52 +++++++++++
 platform/generic/spacemit/objects.mk         |   5 ++
 platform/generic/spacemit/spacemit.c         |  36 ++++++++
 18 files changed, 617 insertions(+), 148 deletions(-)
---
base-commit: c0f87f10d1bfb9e72a84ddfafb5604ee1bfe9d04
change-id: 20260723-spacemit-k3-84720a7be53d

Best regards,
--  
Troy Mitchell <troy.mitchell@linux.spacemit.com>


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