Commit eaac4d83 authored by Suzuki K Poulose's avatar Suzuki K Poulose Committed by Will Deacon
Browse files

arm64: capabilities: Unify the verification 



Now that each capability describes how to treat the conflicts
of CPU cap state vs System wide cap state, we can unify the
verification logic to a single place.

Reviewed-by: default avatarDave Martin <dave.martin@arm.com>
Signed-off-by: default avatarSuzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
parent 5b4747c5

arch/arm64/kernel/cpufeature.c

+58 −33
Original line number Diff line number Diff line
@@ -1305,6 +1305,58 @@ enable_cpu_capabilities(const struct arm64_cpu_capabilities *caps) 
	}

}



/*

 * Run through the list of capabilities to check for conflicts.

 * If the system has already detected a capability, take necessary

 * action on this CPU.

 *

 * Returns "false" on conflicts.

 */

static bool

__verify_local_cpu_caps(const struct arm64_cpu_capabilities *caps_list)

{

	bool cpu_has_cap, system_has_cap;

	const struct arm64_cpu_capabilities *caps;



	for (caps = caps_list; caps->matches; caps++) {

		cpu_has_cap = __this_cpu_has_cap(caps_list, caps->capability);

		system_has_cap = cpus_have_cap(caps->capability);



		if (system_has_cap) {

			/*

			 * Check if the new CPU misses an advertised feature,

			 * which is not safe to miss.

			 */

			if (!cpu_has_cap && !cpucap_late_cpu_optional(caps))

				break;

			/*

			 * We have to issue cpu_enable() irrespective of

			 * whether the CPU has it or not, as it is enabeld

			 * system wide. It is upto the call back to take

			 * appropriate action on this CPU.

			 */

			if (caps->cpu_enable)

				caps->cpu_enable(caps);

		} else {

			/*

			 * Check if the CPU has this capability if it isn't

			 * safe to have when the system doesn't.

			 */

			if (cpu_has_cap && !cpucap_late_cpu_permitted(caps))

				break;

		}

	}



	if (caps->matches) {

		pr_crit("CPU%d: Detected conflict for capability %d (%s), System: %d, CPU: %d\n",

			smp_processor_id(), caps->capability,

			caps->desc, system_has_cap, cpu_has_cap);

		return false;

	}



	return true;

}



/*

 * Check for CPU features that are used in early boot

 * based on the Boot CPU value.
@@ -1327,26 +1379,11 @@ verify_local_elf_hwcaps(const struct arm64_cpu_capabilities *caps) 
		}

}



static void

verify_local_cpu_features(const struct arm64_cpu_capabilities *caps_list)

static void verify_local_cpu_features(void)

{

	const struct arm64_cpu_capabilities *caps = caps_list;

	for (; caps->matches; caps++) {

		if (!cpus_have_cap(caps->capability))

			continue;

		/*

		 * If the new CPU misses an advertised feature, we cannot proceed

		 * further, park the cpu.

		 */

		if (!__this_cpu_has_cap(caps_list, caps->capability)) {

			pr_crit("CPU%d: missing feature: %s\n",

					smp_processor_id(), caps->desc);

	if (!__verify_local_cpu_caps(arm64_features))

		cpu_die_early();

}

		if (caps->cpu_enable)

			caps->cpu_enable(caps);

	}

}



static void verify_sve_features(void)

{
@@ -1372,21 +1409,9 @@ static void verify_sve_features(void) 
 */

static void verify_local_cpu_errata_workarounds(void)

{

	const struct arm64_cpu_capabilities *caps = arm64_errata;



	for (; caps->matches; caps++) {

		if (cpus_have_cap(caps->capability)) {

			if (caps->cpu_enable)

				caps->cpu_enable(caps);

		} else if (caps->matches(caps, SCOPE_LOCAL_CPU)) {

			pr_crit("CPU%d: Requires work around for %s, not detected"

					" at boot time\n",

				smp_processor_id(),

				caps->desc ? : "an erratum");

	if (!__verify_local_cpu_caps(arm64_errata))

		cpu_die_early();

}

	}

}



static void update_cpu_errata_workarounds(void)

{
@@ -1409,7 +1434,7 @@ static void __init enable_errata_workarounds(void) 
static void verify_local_cpu_capabilities(void)

{

	verify_local_cpu_errata_workarounds();

	verify_local_cpu_features(arm64_features);

	verify_local_cpu_features();

	verify_local_elf_hwcaps(arm64_elf_hwcaps);



	if (system_supports_32bit_el0())