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arm64: Use build-time assertions for cpucap ordering

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Both sme2_kernel_enable() and fa64_kernel_enable() need to run after
sme_kernel_enable(). This happens to be true today as ARM64_SME has a
lower index than either ARM64_SME2 or ARM64_SME_FA64, and both functions
have a comment to this effect.

It would be nicer to have a build-time assertion like we for for
can_use_gic_priorities() and has_gic_prio_relaxed_sync(), as that way
it will be harder to miss any potential breakage.

This patch replaces the comments with build-time assertions.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This commit is contained in:
Mark Rutland 2023-10-16 11:24:34 +01:00 committed by Catalin Marinas
parent bc9bbb7880
commit 9077229170
1 changed files with 6 additions and 8 deletions
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14
arch/arm64/kernel/fpsimd.c
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@ -1310,23 +1310,21 @@ void sme_kernel_enable(const struct arm64_cpu_capabilities *__always_unused p)
isb();
}
/*
* This must be called after sme_kernel_enable(), we rely on the
* feature table being sorted to ensure this.
*/
void sme2_kernel_enable(const struct arm64_cpu_capabilities *__always_unused p)
{
/* This must be enabled after SME */
BUILD_BUG_ON(ARM64_SME2 <= ARM64_SME);
/* Allow use of ZT0 */
write_sysreg_s(read_sysreg_s(SYS_SMCR_EL1) | SMCR_ELx_EZT0_MASK,
SYS_SMCR_EL1);
}
/*
* This must be called after sme_kernel_enable(), we rely on the
* feature table being sorted to ensure this.
*/
void fa64_kernel_enable(const struct arm64_cpu_capabilities *__always_unused p)
{
/* This must be enabled after SME */
BUILD_BUG_ON(ARM64_SME_FA64 <= ARM64_SME);
/* Allow use of FA64 */
write_sysreg_s(read_sysreg_s(SYS_SMCR_EL1) | SMCR_ELx_FA64_MASK,
SYS_SMCR_EL1);