kernel/linux.git/drivers/acpi/prmt.c, branch v6.12.80

ACPI: PRM: Skip handlers with NULL handler_address or NULL VA

2025-11-13T20:34:03+00:00

[ Upstream commit 311942ce763e21dacef7e53996d5a1e19b8adab1 ] If handler_address or mapped VA is NULL, the related buffer address and VA can be ignored, so make acpi_parse_prmt() skip the current handler in those cases. Signed-off-by: Shang song (Lenovo) Link: https://patch.msgid.link/20250826030229.834901-1-shangsong2@foxmail.com [ rjw: Subject and changelog edits ] Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin

ACPI: PRM: Reduce unnecessary printing to avoid user confusion

2025-08-20T16:30:24+00:00

[ Upstream commit 3db5648c4d608b5483470efc1da9780b081242dd ] Commit 088984c8d54c ("ACPI: PRM: Find EFI_MEMORY_RUNTIME block for PRM handler and context") introduced non-essential printing "Failed to find VA for GUID: xxxx, PA: 0x0" which may confuse users to think that something wrong is going on while it is not the case. According to the PRM Spec Section 4.1.2 [1], both static data buffer address and ACPI parameter buffer address may be NULL if they are not needed, so there is no need to print out the "Failed to find VA ... " in those cases. Link: https://uefi.org/sites/default/files/resources/Platform%20Runtime%20Mechanism%20-%20with%20legal%20notice.pdf # [1] Signed-off-by: Zhu Qiyu Link: https://patch.msgid.link/20250704014104.82524-1-qiyuzhu2@amd.com [ rjw: Edits in new comments, subject and changelog ] Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin

ACPI: PRM: Remove unnecessary strict handler address checks

2025-02-17T09:05:30+00:00

commit 7f5704b6a143b8eca640cba820968e798d065e91 upstream. Commit 088984c8d54c ("ACPI: PRM: Find EFI_MEMORY_RUNTIME block for PRM handler and context") added unnecessary strict handler address checks, causing the PRM module to fail in translating memory error addresses. Both static data buffer address and ACPI parameter buffer address may be NULL if they are not needed, as described in section 4.1.2 PRM Handler Information Structure of Platform Runtime Mechanism specification [1]. Here are two examples from real hardware: ----PRMT.dsl---- - staic data address is not used [10Ch 0268 2] Revision : 0000 [10Eh 0270 2] Length : 002C [110h 0272 16] Handler GUID : F6A58D47-E04F-4F5A-86B8-2A50D4AA109B [120h 0288 8] Handler address : 0000000065CE51F4 [128h 0296 8] Satic Data Address : 0000000000000000 [130h 0304 8] ACPI Parameter Address : 000000006522A718 - ACPI parameter address is not used [1B0h 0432 2] Revision : 0000 [1B2h 0434 2] Length : 002C [1B4h 0436 16] Handler GUID : 657E8AE6-A8FC-4877-BB28-42E7DE1899A5 [1C4h 0452 8] Handler address : 0000000065C567C8 [1CCh 0460 8] Satic Data Address : 000000006113FB98 [1D4h 0468 8] ACPI Parameter Address : 0000000000000000 Fixes: 088984c8d54c ("ACPI: PRM: Find EFI_MEMORY_RUNTIME block for PRM handler and context") Reported-and-tested-by: Shi Liu Cc: All applicable Signed-off-by: Aubrey Li Link: https://uefi.org/sites/default/files/resources/Platform%20Runtime%20Mechanism%20-%20with%20legal%20notice.pdf # [1] Reviewed-by: Koba Ko Acked-by: Ard Biesheuvel Link: https://patch.msgid.link/20250126022250.3014210-1-aubrey.li@linux.intel.com [ rjw: Minor changelog edits ] Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

ACPI: PRM: Clean up guid type in struct prm_handler_info

2024-10-24T15:31:41+00:00

Clang 19 prints a warning when we pass &th->guid to efi_pa_va_lookup(): drivers/acpi/prmt.c:156:29: error: passing 1-byte aligned argument to 4-byte aligned parameter 1 of 'efi_pa_va_lookup' may result in an unaligned pointer access [-Werror,-Walign-mismatch] 156 | (void *)efi_pa_va_lookup(&th->guid, handler_info->handler_address); | ^ The problem is that efi_pa_va_lookup() takes a efi_guid_t and &th->guid is a regular guid_t. The difference between the two types is the alignment. efi_guid_t is a typedef. typedef guid_t efi_guid_t __aligned(__alignof__(u32)); It's possible that this a bug in Clang 19. Even though the alignment of &th->guid is not explicitly specified, it will still end up being aligned at 4 or 8 bytes. Anyway, as Ard points out, it's cleaner to change guid to efi_guid_t type and that also makes the warning go away. Fixes: 088984c8d54c ("ACPI: PRM: Find EFI_MEMORY_RUNTIME block for PRM handler and context") Reported-by: Linux Kernel Functional Testing Suggested-by: Ard Biesheuvel Signed-off-by: Dan Carpenter Tested-by: Paul E. McKenney Acked-by: Ard Biesheuvel Link: https://patch.msgid.link/3777d71b-9e19-45f4-be4e-17bf4fa7a834@stanley.mountain [ rjw: Subject edit ] Signed-off-by: Rafael J. Wysocki

ACPI: PRM: Find EFI_MEMORY_RUNTIME block for PRM handler and context

2024-10-21T11:46:50+00:00

PRMT needs to find the correct type of block to translate the PA-VA mapping for EFI runtime services. The issue arises because the PRMT is finding a block of type EFI_CONVENTIONAL_MEMORY, which is not appropriate for runtime services as described in Section 2.2.2 (Runtime Services) of the UEFI Specification [1]. Since the PRM handler is a type of runtime service, this causes an exception when the PRM handler is called. [Firmware Bug]: Unable to handle paging request in EFI runtime service WARNING: CPU: 22 PID: 4330 at drivers/firmware/efi/runtime-wrappers.c:341 __efi_queue_work+0x11c/0x170 Call trace: Let PRMT find a block with EFI_MEMORY_RUNTIME for PRM handler and PRM context. If no suitable block is found, a warning message will be printed, but the procedure continues to manage the next PRM handler. However, if the PRM handler is actually called without proper allocation, it would result in a failure during error handling. By using the correct memory types for runtime services, ensure that the PRM handler and the context are properly mapped in the virtual address space during runtime, preventing the paging request error. The issue is really that only memory that has been remapped for runtime by the firmware can be used by the PRM handler, and so the region needs to have the EFI_MEMORY_RUNTIME attribute. Link: https://uefi.org/sites/default/files/resources/UEFI_Spec_2_10_Aug29.pdf # [1] Fixes: cefc7ca46235 ("ACPI: PRM: implement OperationRegion handler for the PlatformRtMechanism subtype") Cc: All applicable Signed-off-by: Koba Ko Reviewed-by: Matthew R. Ochs Reviewed-by: Zhang Rui Reviewed-by: Ard Biesheuvel Link: https://patch.msgid.link/20241012205010.4165798-1-kobak@nvidia.com [ rjw: Subject and changelog edits ] Signed-off-by: Rafael J. Wysocki

ACPI: PRM: Add PRM handler direct call support

2024-08-01T12:23:39+00:00

Platform Runtime Mechanism (PRM) handlers can be invoked from either the AML interpreter or directly by an OS driver. Implement the latter. [ bp: Massage commit message. ] Signed-off-by: John Allen Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Yazen Ghannam Reviewed-by: Ard Biesheuvel Acked-by: Rafael J. Wysocki Link: https://lore.kernel.org/r/20240730151731.15363-2-john.allen@amd.com

ACPI: PRM: Annotate struct prm_module_info with __counted_by

2023-10-03T19:24:10+00:00

Prepare for the coming implementation by GCC and Clang of the __counted_by attribute. Flexible array members annotated with __counted_by can have their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family functions). As found with Coccinelle[1], add __counted_by for struct prm_module_info. Link: https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci # [1] Signed-off-by: Kees Cook Reviewed-by: Gustavo A. R. Silva Signed-off-by: Rafael J. Wysocki

acpi/prmt: Use EFI runtime sandbox to invoke PRM handlers

2023-08-22T08:39:26+00:00

Instead of bypassing the kernel's adaptation layer for performing EFI runtime calls, wire up ACPI PRM handling into it. This means these calls can no longer occur concurrently with EFI runtime calls, and will be made from the EFI runtime workqueue. It also means any page faults occurring during PRM handling will be identified correctly as originating in firmware code. Acked-by: Rafael J. Wysocki Signed-off-by: Ard Biesheuvel

efi/runtime-wrappers: Remove duplicated macro for service returning void

2023-08-22T08:39:26+00:00

__efi_call_virt() exists as an alternative for efi_call_virt() for the sole reason that ResetSystem() returns void, and so we cannot use a call to it in the RHS of an assignment. Given that there is only a single user, let's drop the macro, and expand it into the caller. That way, the remaining macro can be tightened somewhat in terms of type safety too. Note that the use of typeof() on the runtime service invocation does not result in an actual call being made, but it does require a few pointer types to be fixed up and converted into the proper function pointer prototypes. Signed-off-by: Ard Biesheuvel

ACPI: PRM: Check whether EFI runtime is available

2023-01-18T18:58:15+00:00

The ACPI PRM address space handler calls efi_call_virt_pointer() to execute PRM firmware code, but doing so is only permitted when the EFI runtime environment is available. Otherwise, such calls are guaranteed to result in a crash, and must therefore be avoided. Given that the EFI runtime services may become unavailable after a crash occurring in the firmware, we need to check this each time the PRM address space handler is invoked. If the EFI runtime services were not available at registration time to being with, don't install the address space handler at all. Fixes: cefc7ca46235 ("ACPI: PRM: implement OperationRegion handler for the PlatformRtMechanism subtype") Signed-off-by: Ard Biesheuvel Cc: All applicable Signed-off-by: Rafael J. Wysocki