Messages in this thread Patch in this message | | | From | Marc Zyngier <> | Subject | [PATCH v2 17/18] arm64: arch_timer: Allow erratum matching with ACPI OEM information | Date | Mon, 20 Mar 2017 17:48:28 +0000 |
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Just as we're able to identify a broken platform using some DT information, let's enable a way to spot the offenders with ACPI.
The difference is that we can only match on some OEM info instead of implementation-specific properties. So in order to avoid the insane multiplication of errata structures, we allow an array of OEM descriptions to be attached to an erratum structure.
Tested-by: dann frazier <dann.frazier@canonical.com> Tested-by: Hanjun Guo <hanjun.guo@linaro.org> Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> --- arch/arm64/include/asm/arch_timer.h | 1 + drivers/clocksource/arm_arch_timer.c | 32 ++++++++++++++++++++++++++++++++ 2 files changed, 33 insertions(+)
diff --git a/arch/arm64/include/asm/arch_timer.h b/arch/arm64/include/asm/arch_timer.h index 3cba3a5e4ba1..a79c6932bf3f 100644 --- a/arch/arm64/include/asm/arch_timer.h +++ b/arch/arm64/include/asm/arch_timer.h @@ -42,6 +42,7 @@ enum arch_timer_erratum_match_type { ate_match_dt, ate_match_global_cap_id, ate_match_local_cap_id, + ate_match_acpi_oem_info, }; struct clock_event_device; diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c index ba4be5859aa4..9e8cef63e59e 100644 --- a/drivers/clocksource/arm_arch_timer.c +++ b/drivers/clocksource/arm_arch_timer.c @@ -190,6 +190,12 @@ static struct cyclecounter cyclecounter __ro_after_init = { .mask = CLOCKSOURCE_MASK(56), }; +struct ate_acpi_oem_info { + char oem_id[ACPI_OEM_ID_SIZE + 1]; + char oem_table_id[ACPI_OEM_TABLE_ID_SIZE + 1]; + u32 oem_revision; +}; + #ifdef CONFIG_FSL_ERRATUM_A008585 /* * The number of retries is an arbitrary value well beyond the highest number @@ -378,6 +384,28 @@ bool arch_timer_check_local_cap_erratum(const struct arch_timer_erratum_workarou return this_cpu_has_cap((uintptr_t)wa->id); } + +static +bool arch_timer_check_acpi_oem_erratum(const struct arch_timer_erratum_workaround *wa, + const void *arg) +{ + static const struct ate_acpi_oem_info empty_oem_info = {}; + const struct ate_acpi_oem_info *info = wa->id; + const struct acpi_table_header *table = arg; + + /* Iterate over the ACPI OEM info array, looking for a match */ + while (memcmp(info, &empty_oem_info, sizeof(*info))) { + if (!memcmp(info->oem_id, table->oem_id, ACPI_OEM_ID_SIZE) && + !memcmp(info->oem_table_id, table->oem_table_id, ACPI_OEM_TABLE_ID_SIZE) && + info->oem_revision == table->oem_revision) + return true; + + info++; + } + + return false; +} + static const struct arch_timer_erratum_workaround * arch_timer_iterate_errata(enum arch_timer_erratum_match_type type, ate_match_fn_t match_fn, @@ -441,6 +469,9 @@ static void arch_timer_check_ool_workaround(enum arch_timer_erratum_match_type t match_fn = arch_timer_check_local_cap_erratum; local = true; break; + case ate_match_acpi_oem_info: + match_fn = arch_timer_check_acpi_oem_erratum; + break; } wa = arch_timer_iterate_errata(type, match_fn, arg); @@ -1286,6 +1317,7 @@ static int __init arch_timer_acpi_init(struct acpi_table_header *table) /* Check for globally applicable workarounds */ arch_timer_check_ool_workaround(ate_match_global_cap_id, NULL); + arch_timer_check_ool_workaround(ate_match_acpi_oem_info, table); arch_timer_init(); return 0; -- 2.11.0
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