Here is a summary of the changes in this patch series:
1. Fix for race condition in updating of the chan_in_use flag
Ensures correct updating of the chan_in_use flag to avoid potential race
conditions.
2. Interrupt handling fix
Ensures platform acknowledgment interrupts are always cleared to avoid
leaving the interrupt asserted forever.
3. Endian conversion cleanup
Removes unnecessary endianness conversion in the PCC mailbox driver.
4. Memory mapping improvements
Uses acpi_os_ioremap() instead of direct mapping methods for better ACPI
compatibility.
5. Return early if the command complete register is absent
Ensures that if no GAS (Generic Address Structure) register is available,
the function exits early.
6. Refactor IRQ handler and move error handling to a separate function
Improves readability of error handling in the PCC mailbox driver’s
interrupt handler.
7. Shared memory mapping refactoring/enhancements
Ensures the shared memory is always mapped and unmapped in the PCC
mailbox driver when the PCC channel is requested and release.
8. Refactored check_and_ack() Function
Simplifies and improves the logic for handling type4 platform notification
acknowledgments.
09-13. Shared memory handling simplifications across multiple drivers
Simplifies shared memory handling in:
Kunpeng HCCS driver (soc: hisilicon)
Apm X-Gene Slimpro I2C driver
X-Gene hardware monitoring driver (hwmon)
ACPI PCC driver
ACPI CPPC driver
The X-gene related changes now change the mapping attributes to align
with ACPI specification. There are possibilities for more cleanups on
top of these changes around how the shmem is accessed within these
driver.
Also, my main aim is to get 1-8 merged first and target 9-13 for
following merge window through respective tree.
Overall, the patch series focuses on improving correctness, efficiency, and
maintainability of the PCC mailbox driver and related components by fixing
race conditions, optimizing memory handling, simplifying shared memory
interactions, and refactoring code for clarity.
Signed-off-by: Sudeep Holla <sudeep.holla@xxxxxxx>
---
Jassi,
Please take patch [1-8]/13 through the mailbox tree if and when you are
happy with the changes. I haven't got Ack from I2C still, but if you are
happy to take [9-13]/13, I can check with I2C maintainer. Or else I am
happy to take it individually later once the PCC changes are merged. I
am still keeping it together if anyone is interested in testing.
Changes in v3:
- Updated the comment around updation of chan_in_use flag to keep it
appropriate even after acknowledging the interrupt as first action
in the irq handler
- Added all the review/ack/tested-by tags from Huisong Li, Adam Young
and Robbie King
- Added a note that double mapping introduced temporarily will not
impact any existing mbox client drivers as all the drivers move to
using new and only mapping after all the changes
- s/pcc_chan_check_and_ack/pcc_chan_acknowledge/ which was originally
check_and_ack()
- Link to v2: https://lore.kernel.org/r/20250305-pcc_fixes_updates-v2-0-1b1822bc8746@xxxxxxx
Changes in v2:
- Improved time vs flow graph for the platform ack interrupt
acknowledgment issue in patch 2
- Replaced PCC_ACK_FLAG_MASK with PCC_CMD_COMPLETION_NOTIFY in patch 3
- Fixed return value check from pcc_mbox_error_check_and_clear() in patch 6
- Dropped the change moving the function pcc_mbox_ioremap()
- Adjusted error message in kunpeng_hccs driver after the change
- Added the received ack/review tags
- Link to v1: https://lore.kernel.org/r/20250303-pcc_fixes_updates-v1-0-3b44f3d134b1@xxxxxxx
---
Huisong Li (1):
mailbox: pcc: Fix the possible race in updation of chan_in_use flag
Sudeep Holla (12):
mailbox: pcc: Always clear the platform ack interrupt first
mailbox: pcc: Drop unnecessary endianness conversion of pcc_hdr.flags
mailbox: pcc: Return early if no GAS register from pcc_mbox_cmd_complete_check
mailbox: pcc: Use acpi_os_ioremap() instead of ioremap()
mailbox: pcc: Refactor error handling in irq handler into separate function
mailbox: pcc: Always map the shared memory communication address
mailbox: pcc: Refactor and simplify check_and_ack()
soc: hisilicon: kunpeng_hccs: Simplify PCC shared memory region handling
i2c: xgene-slimpro: Simplify PCC shared memory region handling
hwmon: (xgene-hwmon) Simplify PCC shared memory region handling
ACPI: PCC: Simplify PCC shared memory region handling
ACPI: CPPC: Simplify PCC shared memory region handling
drivers/acpi/acpi_pcc.c | 13 +---
drivers/acpi/cppc_acpi.c | 16 +----
drivers/hwmon/xgene-hwmon.c | 40 ++----------
drivers/i2c/busses/i2c-xgene-slimpro.c | 39 ++----------
drivers/mailbox/pcc.c | 113 ++++++++++++++++-----------------
drivers/soc/hisilicon/kunpeng_hccs.c | 42 +++++-------
drivers/soc/hisilicon/kunpeng_hccs.h | 2 -
include/acpi/pcc.h | 6 --
8 files changed, 84 insertions(+), 187 deletions(-)
---
base-commit: 4d872d51bc9d7b899c1f61534e3dbde72613f627
change-id: 20250303-pcc_fixes_updates-55a17fd28e76
--
Regards,
Sudeep
