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Message-ID: <20180209182522.GI5862@e103592.cambridge.arm.com>
Date: Fri, 9 Feb 2018 18:25:22 +0000
From: Dave Martin <Dave.Martin@....com>
To: Suzuki K Poulose <suzuki.poulose@....com>
Cc: linux-arm-kernel@...ts.infradead.org, mark.rutland@....com,
ckadabi@...eaurora.org, ard.biesheuvel@...aro.org,
marc.zyngier@....com, catalin.marinas@....com, will.deacon@....com,
linux-kernel@...r.kernel.org, jnair@...iumnetworks.com,
robin.murphy@....com
Subject: Re: [PATCH v3 11/22] arm64: capabilities: Group handling of features
and errata workarounds
On Fri, Feb 09, 2018 at 05:54:51PM +0000, Suzuki K Poulose wrote:
> Now that the features and errata workarounds have the same
> rules and flow, group the handling of the tables.
>
> Cc: Dave Martin <dave.martin@....com>
> Signed-off-by: Suzuki K Poulose <suzuki.poulose@....com>
The naming gets a bit confusing, particularly with
setup_system_capabilities() which enables for SCOPE_ALL, but I can't
think of an obviously better name.
Otherwise the refactoring looks sensible, so FWIW,
Reviewed-by: Dave Martin <Dave.Martin@....com>
> ---
> arch/arm64/kernel/cpufeature.c | 72 ++++++++++++++++++++++++------------------
> 1 file changed, 41 insertions(+), 31 deletions(-)
>
> diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
> index 45bac0c4ae91..9b111d560b30 100644
> --- a/arch/arm64/kernel/cpufeature.c
> +++ b/arch/arm64/kernel/cpufeature.c
> @@ -504,8 +504,7 @@ static void __init init_cpu_ftr_reg(u32 sys_reg, u64 new)
> }
>
> extern const struct arm64_cpu_capabilities arm64_errata[];
> -static void update_cpu_capabilities(const struct arm64_cpu_capabilities *caps,
> - u16 scope_mask, const char *info);
> +static void update_cpu_capabilities(u16 scope_mask);
>
> void __init init_cpu_features(struct cpuinfo_arm64 *info)
> {
> @@ -554,10 +553,7 @@ void __init init_cpu_features(struct cpuinfo_arm64 *info)
> * Run the errata work around and local feature checks on the
> * boot CPU, once we have initialised the cpu feature infrastructure.
> */
> - update_cpu_capabilities(arm64_errata, SCOPE_LOCAL_CPU,
> - "enabling workaround for");
> - update_cpu_capabilities(arm64_features, SCOPE_LOCAL_CPU,
> - "detected feature:");
> + update_cpu_capabilities(SCOPE_LOCAL_CPU);
> }
>
> static void update_cpu_ftr_reg(struct arm64_ftr_reg *reg, u64 new)
> @@ -1225,7 +1221,7 @@ static bool __this_cpu_has_cap(const struct arm64_cpu_capabilities *cap_array,
> return false;
> }
>
> -static void update_cpu_capabilities(const struct arm64_cpu_capabilities *caps,
> +static void __update_cpu_capabilities(const struct arm64_cpu_capabilities *caps,
> u16 scope_mask, const char *info)
> {
> scope_mask &= ARM64_CPUCAP_SCOPE_MASK;
> @@ -1240,6 +1236,14 @@ static void update_cpu_capabilities(const struct arm64_cpu_capabilities *caps,
> }
> }
>
> +static void update_cpu_capabilities(u16 scope_mask)
> +{
> + __update_cpu_capabilities(arm64_features, scope_mask,
> + "detected feature:");
> + __update_cpu_capabilities(arm64_errata, scope_mask,
> + "enabling workaround for");
> +}
> +
> static int __enable_cpu_capability(void *arg)
> {
> const struct arm64_cpu_capabilities *cap = arg;
> @@ -1253,7 +1257,7 @@ static int __enable_cpu_capability(void *arg)
> * CPUs
> */
> static void __init
> -enable_cpu_capabilities(const struct arm64_cpu_capabilities *caps, u16 scope_mask)
> +__enable_cpu_capabilities(const struct arm64_cpu_capabilities *caps, u16 scope_mask)
> {
> scope_mask &= ARM64_CPUCAP_SCOPE_MASK;
> for (; caps->matches; caps++) {
> @@ -1277,6 +1281,12 @@ enable_cpu_capabilities(const struct arm64_cpu_capabilities *caps, u16 scope_mas
> }
> }
>
> +static void __init enable_cpu_capabilities(u16 scope_mask)
> +{
> + __enable_cpu_capabilities(arm64_features, scope_mask);
> + __enable_cpu_capabilities(arm64_errata, scope_mask);
> +}
> +
> /*
> * Run through the list of capabilities to check for conflicts.
> * If the system has already detected a capability, take necessary
> @@ -1332,6 +1342,12 @@ static bool __verify_local_cpu_caps(const struct arm64_cpu_capabilities *caps_li
> return true;
> }
>
> +static bool verify_local_cpu_caps(u16 scope_mask)
> +{
> + return __verify_local_cpu_caps(arm64_errata, scope_mask) &&
> + __verify_local_cpu_caps(arm64_features, scope_mask);
> +}
> +
> /*
> * Check for CPU features that are used in early boot
> * based on the Boot CPU value.
> @@ -1371,7 +1387,6 @@ static void verify_sve_features(void)
> /* Add checks on other ZCR bits here if necessary */
> }
>
> -
> /*
> * Run through the enabled system capabilities and enable() it on this CPU.
> * The capabilities were decided based on the available CPUs at the boot time.
> @@ -1382,15 +1397,9 @@ static void verify_sve_features(void)
> */
> static void verify_local_cpu_capabilities(void)
> {
> - /*
> - * The CPU Errata work arounds are detected and applied at boot time
> - * and the related information is freed soon after. If the new CPU
> - * requires an errata not detected at boot, fail this CPU.
> - */
> - if (!__verify_local_cpu_caps(arm64_errata, SCOPE_ALL))
> - cpu_die_early();
> - if (!__verify_local_cpu_caps(arm64_features, SCOPE_ALL))
> + if (!verify_local_cpu_caps(SCOPE_ALL))
> cpu_die_early();
> +
> verify_local_elf_hwcaps(arm64_elf_hwcaps);
>
> if (system_supports_32bit_el0())
> @@ -1417,14 +1426,10 @@ void check_local_cpu_capabilities(void)
> * Otherwise, this CPU should verify that it has all the system
> * advertised capabilities.
> */
> - if (!sys_caps_initialised) {
> - update_cpu_capabilities(arm64_errata, SCOPE_LOCAL_CPU,
> - "enabling workaround for");
> - update_cpu_capabilities(arm64_features, SCOPE_LOCAL_CPU,
> - "detected feature:");
> - } else {
> + if (!sys_caps_initialised)
> + update_cpu_capabilities(SCOPE_LOCAL_CPU);
> + else
> verify_local_cpu_capabilities();
> - }
> }
>
> DEFINE_STATIC_KEY_FALSE(arm64_const_caps_ready);
> @@ -1443,18 +1448,23 @@ bool this_cpu_has_cap(unsigned int cap)
> __this_cpu_has_cap(arm64_errata, cap));
> }
>
> +static void __init setup_system_capabilities(void)
> +{
> + /*
> + * We have finalised the system-wide safe feature
> + * registers, finalise the capabilities that depend
> + * on it. Also enable all the available capabilities.
> + */
> + update_cpu_capabilities(SCOPE_SYSTEM);
> + enable_cpu_capabilities(SCOPE_ALL);
> +}
> +
> void __init setup_cpu_features(void)
> {
> u32 cwg;
> int cls;
>
> - /* Set the CPU feature capabilies */
> - update_cpu_capabilities(arm64_features, SCOPE_SYSTEM,
> - "detected feature:");
> - update_cpu_capabilities(arm64_errata, SCOPE_SYSTEM,
> - "enabling workaround for");
> - enable_cpu_capabilities(arm64_features, SCOPE_ALL);
> - enable_cpu_capabilities(arm64_errata, SCOPE_ALL);
> + setup_system_capabilities();
> mark_const_caps_ready();
> setup_elf_hwcaps(arm64_elf_hwcaps);
>
> --
> 2.14.3
>
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@...ts.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
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