From 925d10e1cbf5490a49d667524591995ce2e99e6f Mon Sep 17 00:00:00 2001 From: Mark Brown Date: Thu, 2 Jun 2022 14:41:32 +0200 Subject: [PATCH] UPSTREAM: arm64/sme: Fix EFI save/restore The EFI save/restore code is confused. When saving the check for saving FFR is inverted due to confusion with the streaming mode check, and when restoring we check if we need to restore FFR by checking the percpu efi_sm_state without the required wrapper rather than based on the combination of FA64 support and streaming mode. Bug: 254441685 Fixes: e0838f6373e5 ("arm64/sme: Save and restore streaming mode over EFI runtime calls") Reported-by: kernel test robot Reviewed-by: Catalin Marinas Signed-off-by: Mark Brown Link: https://lore.kernel.org/r/20220602124132.3528951-1-broonie@kernel.org Signed-off-by: Catalin Marinas (cherry picked from commit 2e990e63220bb01e2755b55b93878ce7c8cbe747) Signed-off-by: Lee Jones Change-Id: I44a1e104216728816cc443dc029de8d8e644744e --- arch/arm64/kernel/fpsimd.c | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-) diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index a46be5787a1b..968c545d397e 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -1889,10 +1889,15 @@ void __efi_fpsimd_begin(void) if (system_supports_sme()) { svcr = read_sysreg_s(SYS_SVCR); - if (!system_supports_fa64()) - ffr = svcr & SVCR_SM_MASK; + __this_cpu_write(efi_sm_state, + svcr & SVCR_SM_MASK); - __this_cpu_write(efi_sm_state, ffr); + /* + * Unless we have FA64 FFR does not + * exist in streaming mode. + */ + if (!system_supports_fa64()) + ffr = !(svcr & SVCR_SM_MASK); } sve_save_state(sve_state + sve_ffr_offset(sve_max_vl()), @@ -1937,8 +1942,13 @@ void __efi_fpsimd_end(void) sysreg_clear_set_s(SYS_SVCR, 0, SVCR_SM_MASK); + + /* + * Unless we have FA64 FFR does not + * exist in streaming mode. + */ if (!system_supports_fa64()) - ffr = efi_sm_state; + ffr = false; } }