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UPSTREAM: arm64/sme: Fix EFI save/restore

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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 <lkp@intel.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220602124132.3528951-1-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 2e990e63220bb01e2755b55b93878ce7c8cbe747)
Signed-off-by: Lee Jones <joneslee@google.com>
Change-Id: I44a1e104216728816cc443dc029de8d8e644744e
This commit is contained in:
Mark Brown
2022-06-02 14:41:32 +02:00
committed by Treehugger Robot
parent d2d5e7f1cb
commit 925d10e1cb
1 changed files with 14 additions and 4 deletions
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18
arch/arm64/kernel/fpsimd.c
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@@ -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;
}
}