Re: [PATCH 7/8] efi: Decode IA32/X64 MS Check structure

From: Ard Biesheuvel
Date: Sat Feb 24 2018 - 11:44:06 EST


On 23 February 2018 at 20:03, Yazen Ghannam <Yazen.Ghannam@xxxxxxx> wrote:
> From: Yazen Ghannam <yazen.ghannam@xxxxxxx>
>
> The IA32/X64 MS Check structure varies from the other Check structures
> in the the bit positions of its fields, and it includes an additional
> "Error Type" field.
>
> Decode the MS Check structure in a separate function.
>
> Based on UEFI 2.7 Table 260. IA32/X64 MS Check Field Description.
>
> Cc: <stable@xxxxxxxxxxxxxxx> # 4.16.x
> Signed-off-by: Yazen Ghannam <yazen.ghannam@xxxxxxx>
> ---
> drivers/firmware/efi/cper-x86.c | 55 ++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 54 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/firmware/efi/cper-x86.c b/drivers/firmware/efi/cper-x86.c
> index df4cf6221d8e..02b1b424f537 100644
> --- a/drivers/firmware/efi/cper-x86.c
> +++ b/drivers/firmware/efi/cper-x86.c
> @@ -60,6 +60,20 @@
> #define CHECK_BUS_TIME_OUT BIT_ULL(32)
> #define CHECK_BUS_ADDR_SPACE(check) ((check & GENMASK_ULL(34, 33)) >> 33)
>
> +#define CHECK_VALID_MS_ERR_TYPE BIT_ULL(0)
> +#define CHECK_VALID_MS_PCC BIT_ULL(1)
> +#define CHECK_VALID_MS_UNCORRECTED BIT_ULL(2)
> +#define CHECK_VALID_MS_PRECISE_IP BIT_ULL(3)
> +#define CHECK_VALID_MS_RESTARTABLE_IP BIT_ULL(4)
> +#define CHECK_VALID_MS_OVERFLOW BIT_ULL(5)
> +
> +#define CHECK_MS_ERR_TYPE(check) ((check & GENMASK_ULL(18, 16)) >> 16)

Parens

> +#define CHECK_MS_PCC BIT_ULL(19)
> +#define CHECK_MS_UNCORRECTED BIT_ULL(20)
> +#define CHECK_MS_PRECISE_IP BIT_ULL(21)
> +#define CHECK_MS_RESTARTABLE_IP BIT_ULL(22)
> +#define CHECK_MS_OVERFLOW BIT_ULL(23)
> +
> enum err_types {
> ERR_TYPE_CACHE = 0,
> ERR_TYPE_TLB,
> @@ -114,19 +128,58 @@ static const char * const ia_check_bus_addr_space_strs[] = {
> "Other Transaction",
> };
>
> +static const char * const ia_check_ms_error_type_strs[] = {
> + "No Error",
> + "Unclassified",
> + "Microcode ROM Parity Error",
> + "External Error",
> + "FRC Error",
> + "Internal Unclassified",
> +};
> +
> static inline void print_bool(char *str, const char *pfx, u64 check, u64 bit)
> {
> printk("%s%s: %s\n", pfx, str, (check & bit) ? "true" : "false");
> }
>
> +static void print_err_info_ms(const char *pfx, u16 validation_bits, u64 check)
> +{
> + if (validation_bits & CHECK_VALID_MS_ERR_TYPE) {
> + u8 err_type = CHECK_MS_ERR_TYPE(check);
> +
> + printk("%sError Type: %u, %s\n", pfx, err_type,
> + err_type < ARRAY_SIZE(ia_check_ms_error_type_strs) ?
> + ia_check_ms_error_type_strs[err_type] : "unknown");
> + }
> +
> + if (validation_bits & CHECK_VALID_MS_PCC)
> + print_bool("Processor Context Corrupt", pfx, check, CHECK_MS_PCC);
> +
> + if (validation_bits & CHECK_VALID_MS_UNCORRECTED)
> + print_bool("Uncorrected", pfx, check, CHECK_MS_UNCORRECTED);
> +
> + if (validation_bits & CHECK_VALID_MS_PRECISE_IP)
> + print_bool("Precise IP", pfx, check, CHECK_MS_PRECISE_IP);
> +
> + if (validation_bits & CHECK_VALID_MS_RESTARTABLE_IP)
> + print_bool("Restartable IP", pfx, check, CHECK_MS_RESTARTABLE_IP);
> +
> + if (validation_bits & CHECK_VALID_MS_OVERFLOW)
> + print_bool("Overflow", pfx, check, CHECK_MS_OVERFLOW);
> +}
> +
> static void print_err_info(const char *pfx, enum err_types err_type, u64 check)
> {
> u16 validation_bits = CHECK_VALID_BITS(check);
>
> printk("%sValidation Bits: 0x%04x\n", pfx, validation_bits);
>
> + /*
> + * The MS Check structure varies a lot from the others, so use a
> + * separate function for decoding.
> + */
> if (err_type == ERR_TYPE_MS)
> - return;
> + return print_err_info_ms(pfx, validation_bits, check);
>
> if (validation_bits & CHECK_VALID_TRANS_TYPE) {
> u8 trans_type = CHECK_TRANS_TYPE(check);
> --
> 2.14.1
>