From 907722917002ed06b8f75e119b83842d5f63b15e Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Mon, 16 Oct 2023 11:24:34 +0100 Subject: [PATCH] arm64: Use build-time assertions for cpucap ordering 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 Cc: Mark Brown Cc: Suzuki K Poulose Cc: Will Deacon Signed-off-by: Catalin Marinas --- arch/arm64/kernel/fpsimd.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index 601b973f90ad..48338cf8f90b 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -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);