On Thu, 20 Jun 2024 20:01:46 +0200 Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx> wrote: > Up to UEFI spec, the type byte of CPER struct for ARM processor was > defined simply as: > > Type at byte offset 4: > > - Cache error > - TLB Error > - Bus Error > - Micro-architectural Error > All other values are reserved > > Yet, there was no information about how this would be encoded. > > Spec 2.9A errata corrected it by defining: > > - Bit 1 - Cache Error > - Bit 2 - TLB Error > - Bit 3 - Bus Error > - Bit 4 - Micro-architectural Error > All other values are reserved > > That actually aligns with the values already defined on older > versions at N.2.4.1. Generic Processor Error Section. > > Spec 2.10 also preserve the same encoding as 2.9A > > See: https://uefi.org/specs/UEFI/2.10/Apx_N_Common_Platform_Error_Record.html#arm-processor-error-information > > Adjust CPER and GHES handling code for both generic and ARM > processors to properly handle UEFI 2.9A and 2.10 encoding. > > Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx> I think you can avoid complexity of your masking solution. Cost is we don't have that function print that there were reserved bits set, but that could be easily handled at the caller including notifying on bits above the defined range which might be helpful. > diff --git a/drivers/firmware/efi/cper-arm.c b/drivers/firmware/efi/cper-arm.c > index d9bbcea0adf4..4c101a09fd80 100644 > --- a/drivers/firmware/efi/cper-arm.c > +++ b/drivers/firmware/efi/cper-arm.c ... > if (error_info & CPER_ARM_ERR_VALID_PROC_CONTEXT_CORRUPT) { > @@ -241,6 +232,7 @@ void cper_print_proc_arm(const char *pfx, > struct cper_arm_err_info *err_info; > struct cper_arm_ctx_info *ctx_info; > char newpfx[64], infopfx[65]; > + char error_type[120]; > > printk("%sMIDR: 0x%016llx\n", pfx, proc->midr); > > @@ -289,9 +281,11 @@ void cper_print_proc_arm(const char *pfx, > newpfx); > } > > - printk("%serror_type: %d, %s\n", newpfx, err_info->type, > - err_info->type < ARRAY_SIZE(cper_proc_error_type_strs) ? > - cper_proc_error_type_strs[err_info->type] : "unknown"); > + cper_bits_to_str(error_type, sizeof(error_type), err_info->type, > + cper_proc_error_type_strs, > + ARRAY_SIZE(cper_proc_error_type_strs), > + CPER_ARM_ERR_TYPE_MASK); Maybe drop this mask complexity and just use FIELD_GET() to extract the relevant field with no shift from 0. > + printk("%serror_type: %s\n", newpfx, error_type); > if (err_info->validation_bits & CPER_ARM_INFO_VALID_ERR_INFO) { > printk("%serror_info: 0x%016llx\n", newpfx, > err_info->error_info);