From: Yazen Ghannam <yazen.ghannam@xxxxxxx> ACPI Boot Error Record Table (BERT) is being used by the kernel to report errors that occurred in a previous boot. On some modern AMD systems, these very errors within the BERT are reported through the x86 Common Platform Error Record (CPER) format which consists of one or more Processor Context Information Structures. These context structures provide a starting address and represent an x86 MSR range in which the data constitutes a contiguous set of MSRs starting from, and including the starting address. It's common, for AMD systems that implement this behavior, that the MSR range represents the MCAX register space used for the Scalable MCA feature. The apei_smca_report_x86_error() function decodes and passes this information through the MCE notifier chain. However, this function assumes a fixed register size based on the original HW/FW implementation. This assumption breaks with the addition of two new MCAX registers viz. MCA_SYND1 and MCA_SYND2. These registers are added at the end of the MCAX register space, so they won't be included when decoding the CPER data. Rework apei_smca_report_x86_error() to support a variable register array size. This covers any case where the MSR context information starts at the MCAX address for MCA_STATUS and ends at any other register within the MCAX register space. Add code comments indicating the MCAX register at each offset. [Yazen: Add Avadhut as co-developer for wrapper changes.] Co-developed-by: Avadhut Naik <avadhut.naik@xxxxxxx> Signed-off-by: Avadhut Naik <avadhut.naik@xxxxxxx> Signed-off-by: Yazen Ghannam <yazen.ghannam@xxxxxxx> Signed-off-by: Avadhut Naik <avadhut.naik@xxxxxxx> --- Changes in v2: [1] https://lore.kernel.org/linux-edac/20240521125434.1555845-1-yazen.ghannam@xxxxxxx/ [2] https://lore.kernel.org/linux-edac/20240523155641.2805411-1-yazen.ghannam@xxxxxxx/ 1. Drop dependencies on sets [1] and [2] above and rebase on top of tip/master. Changes in v3: 1. Incorporate suggested touchup. 2. Fix SoB chain to properly reflect the patch path. --- arch/x86/kernel/cpu/mce/apei.c | 72 +++++++++++++++++++++++++++------- 1 file changed, 58 insertions(+), 14 deletions(-) diff --git a/arch/x86/kernel/cpu/mce/apei.c b/arch/x86/kernel/cpu/mce/apei.c index b8f4e75fb8a7..5949fc103be4 100644 --- a/arch/x86/kernel/cpu/mce/apei.c +++ b/arch/x86/kernel/cpu/mce/apei.c @@ -69,9 +69,9 @@ EXPORT_SYMBOL_GPL(apei_mce_report_mem_error); int apei_smca_report_x86_error(struct cper_ia_proc_ctx *ctx_info, u64 lapic_id) { const u64 *i_mce = ((const u64 *) (ctx_info + 1)); + unsigned int cpu, num_regs; struct mce_hw_err err; struct mce *m = &err.m; - unsigned int cpu; memset(&err, 0, sizeof(struct mce_hw_err)); @@ -91,16 +91,12 @@ int apei_smca_report_x86_error(struct cper_ia_proc_ctx *ctx_info, u64 lapic_id) return -EINVAL; /* - * The register array size must be large enough to include all the - * SMCA registers which need to be extracted. - * * The number of registers in the register array is determined by * Register Array Size/8 as defined in UEFI spec v2.8, sec N.2.4.2.2. - * The register layout is fixed and currently the raw data in the - * register array includes 6 SMCA registers which the kernel can - * extract. + * Sanity-check registers array size. */ - if (ctx_info->reg_arr_size < 48) + num_regs = ctx_info->reg_arr_size >> 3; + if (!num_regs) return -EINVAL; mce_setup(m); @@ -118,12 +114,60 @@ int apei_smca_report_x86_error(struct cper_ia_proc_ctx *ctx_info, u64 lapic_id) m->apicid = lapic_id; m->bank = (ctx_info->msr_addr >> 4) & 0xFF; - m->status = *i_mce; - m->addr = *(i_mce + 1); - m->misc = *(i_mce + 2); - /* Skipping MCA_CONFIG */ - m->ipid = *(i_mce + 4); - m->synd = *(i_mce + 5); + + /* + * The SMCA register layout is fixed and includes 16 registers. + * The end of the array may be variable, but the beginning is known. + * Cap the number of registers to expected max (15). + */ + if (num_regs > 15) + num_regs = 15; + + switch (num_regs) { + /* MCA_SYND2 */ + case 15: + err.vendor.amd.synd2 = *(i_mce + 14); + fallthrough; + /* MCA_SYND1 */ + case 14: + err.vendor.amd.synd1 = *(i_mce + 13); + fallthrough; + /* MCA_MISC4 */ + case 13: + /* MCA_MISC3 */ + case 12: + /* MCA_MISC2 */ + case 11: + /* MCA_MISC1 */ + case 10: + /* MCA_DEADDR */ + case 9: + /* MCA_DESTAT */ + case 8: + /* reserved */ + case 7: + /* MCA_SYND */ + case 6: + m->synd = *(i_mce + 5); + fallthrough; + /* MCA_IPID */ + case 5: + m->ipid = *(i_mce + 4); + fallthrough; + /* MCA_CONFIG */ + case 4: + /* MCA_MISC0 */ + case 3: + m->misc = *(i_mce + 2); + fallthrough; + /* MCA_ADDR */ + case 2: + m->addr = *(i_mce + 1); + fallthrough; + /* MCA_STATUS */ + case 1: + m->status = *i_mce; + } mce_log(&err); -- 2.34.1
