From: Marc Zyngier <marc.zyngier@xxxxxxx> commit 0064030c6fd4ca6cfab42de037b2a89445beeead upstream. Should we ever have a workaround for an erratum that is detected using a capability and affecting a particular CPU, it'd be nice to have a way to probe them directly. Acked-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx> Signed-off-by: James Morse <james.morse@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/arm64/include/asm/arch_timer.h | 1 + drivers/clocksource/arm_arch_timer.c | 28 ++++++++++++++++++++++++---- 2 files changed, 25 insertions(+), 4 deletions(-) --- a/arch/arm64/include/asm/arch_timer.h +++ b/arch/arm64/include/asm/arch_timer.h @@ -39,6 +39,7 @@ extern struct static_key_false arch_time enum arch_timer_erratum_match_type { ate_match_dt, + ate_match_local_cap_id, }; struct arch_timer_erratum_workaround { --- a/drivers/clocksource/arm_arch_timer.c +++ b/drivers/clocksource/arm_arch_timer.c @@ -162,6 +162,13 @@ bool arch_timer_check_dt_erratum(const s return of_property_read_bool(np, wa->id); } +static +bool arch_timer_check_local_cap_erratum(const struct arch_timer_erratum_workaround *wa, + const void *arg) +{ + return this_cpu_has_cap((uintptr_t)wa->id); +} + static const struct arch_timer_erratum_workaround * arch_timer_iterate_errata(enum arch_timer_erratum_match_type type, ate_match_fn_t match_fn, @@ -192,14 +199,16 @@ static void arch_timer_check_ool_workaro { const struct arch_timer_erratum_workaround *wa; ate_match_fn_t match_fn = NULL; - - if (static_branch_unlikely(&arch_timer_read_ool_enabled)) - return; + bool local = false; switch (type) { case ate_match_dt: match_fn = arch_timer_check_dt_erratum; break; + case ate_match_local_cap_id: + match_fn = arch_timer_check_local_cap_erratum; + local = true; + break; default: WARN_ON(1); return; @@ -209,8 +218,17 @@ static void arch_timer_check_ool_workaro if (!wa) return; + if (needs_unstable_timer_counter_workaround()) { + if (wa != timer_unstable_counter_workaround) + pr_warn("Can't enable workaround for %s (clashes with %s\n)", + wa->desc, + timer_unstable_counter_workaround->desc); + return; + } + arch_timer_enable_workaround(wa); - pr_info("Enabling global workaround for %s\n", wa->desc); + pr_info("Enabling %s workaround for %s\n", + local ? "local" : "global", wa->desc); } #else @@ -470,6 +488,8 @@ static void __arch_timer_setup(unsigned BUG(); } + arch_timer_check_ool_workaround(ate_match_local_cap_id, NULL); + erratum_workaround_set_sne(clk); } else { clk->features |= CLOCK_EVT_FEAT_DYNIRQ; Patches currently in stable-queue which might be from james.morse@xxxxxxx are queue-4.9/clocksource-drivers-arm_arch_timer-remove-fsl-a008585-parameter.patch queue-4.9/arm64-capabilities-clean-up-midr-range-helpers.patch queue-4.9/arm64-entry-add-macro-for-reading-symbol-addresses-from-the-trampoline.patch queue-4.9/arm64-use-the-clearbhb-instruction-in-mitigations.patch queue-4.9/arm64-add-percpu-vectors-for-el1.patch queue-4.9/arm64-arch_timer-add-workaround-for-arm-erratum-1188873.patch queue-4.9/arm64-capabilities-add-support-for-checks-based-on-a-list-of-midrs.patch queue-4.9/arm64-arch_timer-add-infrastructure-for-multiple-erratum-detection-methods.patch queue-4.9/arm64-entry-free-up-another-register-on-kpti-s-tramp_exit-path.patch queue-4.9/arm64-entry-don-t-assume-tramp_vectors-is-the-start-of-the-vectors.patch queue-4.9/arm64-entry-make-the-trampoline-cleanup-optional.patch queue-4.9/arm64-add-silicon-errata.txt-entry-for-arm-erratum-1188873.patch queue-4.9/clocksource-drivers-arm_arch_timer-introduce-generic-errata-handling-infrastructure.patch queue-4.9/kvm-arm64-add-templates-for-bhb-mitigation-sequences.patch queue-4.9/arm64-entry-add-non-kpti-__bp_harden_el1_vectors-for-mitigations.patch queue-4.9/arm64-add-id_aa64isar2_el1-sys-register.patch queue-4.9/kvm-arm64-allow-smccc_arch_workaround_3-to-be-discovered-and-migrated.patch queue-4.9/arm64-capabilities-update-prototype-for-enable-call-back.patch queue-4.9/arm64-add-neoverse-n2-cortex-a710-cpu-part-definition.patch queue-4.9/arm64-add-midr-encoding-for-arm-cortex-a55-and-cortex-a35.patch queue-4.9/arm64-capabilities-move-errata-processing-code.patch queue-4.9/arm64-arch_timer-add-erratum-handler-for-cpu-specific-capability.patch queue-4.9/arm64-errata-provide-macro-for-major-and-minor-cpu-revisions.patch queue-4.9/arm64-arch_timer-avoid-unused-function-warning.patch queue-4.9/arm64-capabilities-move-errata-work-around-check-on-boot-cpu.patch queue-4.9/arm64-add-helpers-for-checking-cpu-midr-against-a-range.patch queue-4.9/arm64-entry-move-trampoline-macros-out-of-ifdef-d-section.patch queue-4.9/arm64-entry-allow-tramp_alias-to-access-symbols-after-the-4k-boundary.patch queue-4.9/arm64-add-part-number-for-arm-cortex-a77.patch queue-4.9/arm64-capabilities-add-flags-to-handle-the-conflicts-on-late-cpu.patch queue-4.9/arm64-entry-move-the-trampoline-data-page-before-the-text-page.patch queue-4.9/arm64-entry.s-add-ventry-overflow-sanity-checks.patch queue-4.9/arm64-add-part-number-for-neoverse-n1.patch queue-4.9/arm64-entry-add-vectors-that-have-the-bhb-mitigation-sequences.patch queue-4.9/arm64-make-arm64_erratum_1188873-depend-on-compat.patch queue-4.9/arm64-mitigate-spectre-style-branch-history-side-channels.patch queue-4.9/arm64-move-arm64_update_smccc_conduit-out-of-ssbd-ifdef.patch queue-4.9/arm64-entry-allow-the-trampoline-text-to-occupy-multiple-pages.patch queue-4.9/arm64-add-cortex-x2-cpu-part-definition.patch queue-4.9/arm64-add-helper-to-decode-register-from-instruction.patch queue-4.9/arm64-capabilities-prepare-for-fine-grained-capabilities.patch queue-4.9/arm64-remove-useless-uao-ipi-and-describe-how-this-gets-enabled.patch queue-4.9/arm64-entry-make-the-kpti-trampoline-s-kpti-sequence-optional.patch