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| author |   Mark Rutland <mark.rutland@arm.com> | 2022-09-12 17:22:08 +0100 |
|---|---|---|
| committer |   Catalin Marinas <catalin.marinas@arm.com> | 2022-09-16 17:15:03 +0100 |
| commit | 4c0bd995d73ed8897650095c7892b132a0bd66a4 (patch) | |
| tree | 554558e8ad1ab0797b279f93875bd490b84ccd7f /arch/arm64/kernel/cpufeature.c | |
| parent | arm64: alternatives: make alt_region const (diff) | |
| download | linux-dev-4c0bd995d73ed8897650095c7892b132a0bd66a4.tar.xz linux-dev-4c0bd995d73ed8897650095c7892b132a0bd66a4.zip | |
arm64: alternatives: have callbacks take a cap
Today, callback alternatives are special-cased within
__apply_alternatives(), and are applied alongside patching for system
capabilities as ARM64_NCAPS is not part of the boot_capabilities feature
mask.
This special-casing is less than ideal. Giving special meaning to
ARM64_NCAPS for this requires some structures and loops to use
ARM64_NCAPS + 1 (AKA ARM64_NPATCHABLE), while others use ARM64_NCAPS.
It's also not immediately clear callback alternatives are only applied
when applying alternatives for system-wide features.
To make this a bit clearer, changes the way that callback alternatives
are identified to remove the special-casing of ARM64_NCAPS, and to allow
callback alternatives to be associated with a cpucap as with all other
alternatives.
New cpucaps, ARM64_ALWAYS_BOOT and ARM64_ALWAYS_SYSTEM are added which
are always detected alongside boot cpu capabilities and system
capabilities respectively. All existing callback alternatives are made
to use ARM64_ALWAYS_SYSTEM, and so will be patched at the same point
during the boot flow as before.
Subsequent patches will make more use of these new cpucaps.
There should be no functional change as a result of this patch.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: Joey Gouly <joey.gouly@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20220912162210.3626215-7-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/kernel/cpufeature.c')
| -rw-r--r-- | arch/arm64/kernel/cpufeature.c | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index af4de817d712..68a0545285a1 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -108,8 +108,7 @@ DECLARE_BITMAP(cpu_hwcaps, ARM64_NCAPS); EXPORT_SYMBOL(cpu_hwcaps); static struct arm64_cpu_capabilities const __ro_after_init *cpu_hwcaps_ptrs[ARM64_NCAPS]; -/* Need also bit for ARM64_CB_PATCH */ -DECLARE_BITMAP(boot_capabilities, ARM64_NPATCHABLE); +DECLARE_BITMAP(boot_capabilities, ARM64_NCAPS); bool arm64_use_ng_mappings = false; EXPORT_SYMBOL(arm64_use_ng_mappings); @@ -1392,6 +1391,12 @@ u64 __read_sysreg_by_encoding(u32 sys_id) #include <linux/irqchip/arm-gic-v3.h> static bool +has_always(const struct arm64_cpu_capabilities *entry, int scope) +{ + return true; +} + +static bool feature_matches(u64 reg, const struct arm64_cpu_capabilities *entry) { int val = cpuid_feature_extract_field_width(reg, entry->field_pos, @@ -2088,6 +2093,16 @@ cpucap_panic_on_conflict(const struct arm64_cpu_capabilities *cap) static const struct arm64_cpu_capabilities arm64_features[] = { { + .capability = ARM64_ALWAYS_BOOT, + .type = ARM64_CPUCAP_BOOT_CPU_FEATURE, + .matches = has_always, + }, + { + .capability = ARM64_ALWAYS_SYSTEM, + .type = ARM64_CPUCAP_SYSTEM_FEATURE, + .matches = has_always, + }, + { .desc = "GIC system register CPU interface", .capability = ARM64_HAS_SYSREG_GIC_CPUIF, .type = ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE, |