Re: [PATCH] acpi/prmt: find block with specific type

[Koba Ko <kobak@nvidia.com>]

On 8/21/24 11:20, Zhang, Rui wrote:
> External email: Use caution opening links or attachments
>
>
> On Thu, 2024-08-01 at 09:48 +0800, KobaK wrote:
>> 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.
>>
> Too many characters in one line.
> https://docs.kernel.org/process/submitting-patches.html#the-canonical-patch-format
will fix this in the description.
>
>
>>      [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:
>>        __efi_queue_work+0x11c/0x170
>>        efi_call_acpi_prm_handler+0x68/0xd0
>>        acpi_platformrt_space_handler+0x198/0x258
>>        acpi_ev_address_space_dispatch+0x144/0x388
>>        acpi_ex_access_region+0x9c/0x118
>>        acpi_ex_write_serial_bus+0xc4/0x218
>>        acpi_ex_write_data_to_field+0x168/0x218
>>        acpi_ex_store_object_to_node+0x1a8/0x258
>>        acpi_ex_store+0xec/0x330
>>        acpi_ex_opcode_1A_1T_1R+0x15c/0x618
>>        acpi_ds_exec_end_op+0x274/0x548
>>        acpi_ps_parse_loop+0x10c/0x6b8
>>        acpi_ps_parse_aml+0x140/0x3b0
>>        acpi_ps_execute_method+0x12c/0x2a0
>>        acpi_ns_evaluate+0x210/0x310
>>        acpi_evaluate_object+0x178/0x358
>>        acpi_proc_write+0x1a8/0x8a0 [acpi_call]
>>        proc_reg_write+0xcc/0x150
>>        vfs_write+0xd8/0x380
>>        ksys_write+0x70/0x120
>>        __arm64_sys_write+0x24/0x48
>>        invoke_syscall.constprop.0+0x80/0xf8
>>        do_el0_svc+0x50/0x110
>>        el0_svc+0x48/0x1d0
>>        el0t_64_sync_handler+0x15c/0x178
>>        el0t_64_sync+0x1a8/0x1b0
>>
>> Find a block with specific type to fix this.
>> prmt find a block with EFI_RUNTIME_SERVICES_DATA for prm handler.
>> prmt find a block with EFI_RUNTIME_SERVICES_CODE for prm context.
>> By using the correct memory types for runtime services,
>> we can ensure that the PRM handler and
>> its context are properly mapped in the virtual address space during
>> runtime,
>> preventing the paging request error.
> some general rules to follow when writing a changelog
> https://docs.kernel.org/process/maintainer-tip.html 4.2.3. Changelog
will decorate this.
>
>> [1]
>> https://uefi.org/sites/default/files/resources/UEFI_Spec_2_10_Aug29.pdf
>>
>> Fixes: cefc7ca46235 ("ACPI: PRM: implement OperationRegion handler
>> for the PlatformRtMechanism subtype")
>> Signed-off-by: KobaK <kobak@nvidia.com>
>> Reviewed-by: Matthew R. Ochs <mochs@nvidia.com>
>> ---
>>   drivers/acpi/prmt.c | 46 ++++++++++++++++++++++++++++++-------------
>> --
>>   1 file changed, 31 insertions(+), 15 deletions(-)
>>
>> diff --git a/drivers/acpi/prmt.c b/drivers/acpi/prmt.c
>> index c78453c74ef5..e2f0bdd81013 100644
>> --- a/drivers/acpi/prmt.c
>> +++ b/drivers/acpi/prmt.c
>> @@ -72,17 +72,21 @@ struct prm_module_info {
>>          struct prm_handler_info handlers[]
>> __counted_by(handler_count);
>>   };
>>
>> -static u64 efi_pa_va_lookup(u64 pa)
>> +static u64 efi_pa_va_lookup(u64 pa, u32 type)
>>   {
>>          efi_memory_desc_t *md;
>>          u64 pa_offset = pa & ~PAGE_MASK;
>>          u64 page = pa & PAGE_MASK;
>>
>>          for_each_efi_memory_desc(md) {
>> -               if (md->phys_addr < pa && pa < md->phys_addr +
>> PAGE_SIZE * md->num_pages)
>> +               if ((md->type == type) &&
>> +                       (md->phys_addr < pa && pa < md->phys_addr +
>> PAGE_SIZE * md->num_pages)) {
>>                          return pa_offset + md->virt_addr + page - md-
>>> phys_addr;
>> +               }
>>          }
>>
>> +       pr_err("PRM: Failed to find a block for pa: %lx type %u\n",
>> pa, type);
>> +
> If it is a pr_err, why not error out?
> or what is the proper handling for such failures?
>
>>          return 0;
>>   }
>>
>> @@ -148,9 +152,12 @@ acpi_parse_prmt(union acpi_subtable_headers
>> *header, const unsigned long end)
>>                  th = &tm->handlers[cur_handler];
>>
>>                  guid_copy(&th->guid, (guid_t *)handler_info-
>>> handler_guid);
>> -               th->handler_addr = (void
>> *)efi_pa_va_lookup(handler_info->handler_address);
>> -               th->static_data_buffer_addr =
>> efi_pa_va_lookup(handler_info->static_data_buffer_address);
>> -               th->acpi_param_buffer_addr =
>> efi_pa_va_lookup(handler_info->acpi_param_buffer_address);
>> +               th->handler_addr =
>> +                       (void *)efi_pa_va_lookup(handler_info-
>>> handler_address, EFI_RUNTIME_SERVICES_CODE);
>> +               th->static_data_buffer_addr =
>> +                       efi_pa_va_lookup(handler_info-
>>> static_data_buffer_address, EFI_RUNTIME_SERVICES_DATA);
>> +               th->acpi_param_buffer_addr =
>> +                       efi_pa_va_lookup(handler_info-
>>> acpi_param_buffer_address, EFI_RUNTIME_SERVICES_DATA);
>>          } while (++cur_handler < tm->handler_count && (handler_info =
>> get_next_handler(handler_info)));
>>
>>          return 0;
>> @@ -250,8 +257,16 @@ static acpi_status
>> acpi_platformrt_space_handler(u32 function,
>>
>>                  handler = find_prm_handler(&buffer->handler_guid);
>>                  module = find_prm_module(&buffer->handler_guid);
>> -               if (!handler || !module)
>> -                       goto invalid_guid;
>> +               if (!handler || !module) {
>> +                       buffer->prm_status =
>> PRM_HANDLER_GUID_NOT_FOUND;
>> +                       goto error;
> I think it is okay to return AE_OK directly, right?
>
> thanks,
> rui

I'm also good for this.
I followed the convention in this block.
If change to "return", i will change all "goto error".
How do you think?

>> +               }
>> +
>> +               if (!handler->handler_addr || !handler-
>>> static_data_buffer_addr ||
>> +                       !handler->acpi_param_buffer_addr) {
>> +                       buffer->prm_status = PRM_HANDLER_ERROR;
>> +                       goto error;
>> +               }
>>
>>                  ACPI_COPY_NAMESEG(context.signature, "PRMC");
>>                  context.revision = 0x0;
>> @@ -274,8 +289,10 @@ static acpi_status
>> acpi_platformrt_space_handler(u32 function,
>>          case PRM_CMD_START_TRANSACTION:
>>
>>                  module = find_prm_module(&buffer->handler_guid);
>> -               if (!module)
>> -                       goto invalid_guid;
>> +               if (!module) {
>> +                       buffer->prm_status =
>> PRM_HANDLER_GUID_NOT_FOUND;
>> +                       goto error;
>> +               }
>>
>>                  if (module->updatable)
>>                          module->updatable = false;
>> @@ -286,8 +303,10 @@ static acpi_status
>> acpi_platformrt_space_handler(u32 function,
>>          case PRM_CMD_END_TRANSACTION:
>>
>>                  module = find_prm_module(&buffer->handler_guid);
>> -               if (!module)
>> -                       goto invalid_guid;
>> +               if (!module) {
>> +                       buffer->prm_status =
>> PRM_HANDLER_GUID_NOT_FOUND;
>> +                       goto error;
>> +               }
>>
>>                  if (module->updatable)
>>                          buffer->prm_status =
>> UPDATE_UNLOCK_WITHOUT_LOCK;
>> @@ -301,10 +320,7 @@ static acpi_status
>> acpi_platformrt_space_handler(u32 function,
>>                  break;
>>          }
>>
>> -       return AE_OK;
>> -
>> -invalid_guid:
>> -       buffer->prm_status = PRM_HANDLER_GUID_NOT_FOUND;
>> +error:
>>          return AE_OK;
>>   }
>>