diff options
| author | Mark Brown <broonie@kernel.org> | 2022-11-15 09:46:34 +0000 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2022-11-29 15:01:56 +0000 |
| commit | baa8515281b30861cff3da7db70662d2a25c6440 (patch) | |
| tree | be859459aad5a241687f5836db0479759ab6d3f4 /arch/arm64/kernel/signal.c | |
| parent | 93ae6b01bafee8fa385aa25ee7ebdb40057f6abe (diff) | |
| download | linux-baa8515281b30861cff3da7db70662d2a25c6440.tar.bz2 | |
arm64/fpsimd: Track the saved FPSIMD state type separately to TIF_SVE
When we save the state for the floating point registers this can be done
in the form visible through either the FPSIMD V registers or the SVE Z and
P registers. At present we track which format is currently used based on
TIF_SVE and the SME streaming mode state but particularly in the SVE case
this limits our options for optimising things, especially around syscalls.
Introduce a new enum which we place together with saved floating point
state in both thread_struct and the KVM guest state which explicitly
states which format is active and keep it up to date when we change it.
At present we do not use this state except to verify that it has the
expected value when loading the state, future patches will introduce
functional changes.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221115094640.112848-3-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'arch/arm64/kernel/signal.c')
| -rw-r--r-- | arch/arm64/kernel/signal.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c index 9ad911f1647c..e0d09bf5b01b 100644 --- a/arch/arm64/kernel/signal.c +++ b/arch/arm64/kernel/signal.c @@ -207,6 +207,7 @@ static int restore_fpsimd_context(struct fpsimd_context __user *ctx) __get_user_error(fpsimd.fpcr, &ctx->fpcr, err); clear_thread_flag(TIF_SVE); + current->thread.fp_type = FP_STATE_FPSIMD; /* load the hardware registers from the fpsimd_state structure */ if (!err) @@ -292,6 +293,7 @@ static int restore_sve_fpsimd_context(struct user_ctxs *user) if (sve.head.size <= sizeof(*user->sve)) { clear_thread_flag(TIF_SVE); current->thread.svcr &= ~SVCR_SM_MASK; + current->thread.fp_type = FP_STATE_FPSIMD; goto fpsimd_only; } @@ -327,6 +329,7 @@ static int restore_sve_fpsimd_context(struct user_ctxs *user) current->thread.svcr |= SVCR_SM_MASK; else set_thread_flag(TIF_SVE); + current->thread.fp_type = FP_STATE_SVE; fpsimd_only: /* copy the FP and status/control registers */ @@ -932,9 +935,11 @@ static void setup_return(struct pt_regs *regs, struct k_sigaction *ka, * FPSIMD register state - flush the saved FPSIMD * register state in case it gets loaded. */ - if (current->thread.svcr & SVCR_SM_MASK) + if (current->thread.svcr & SVCR_SM_MASK) { memset(¤t->thread.uw.fpsimd_state, 0, sizeof(current->thread.uw.fpsimd_state)); + current->thread.fp_type = FP_STATE_FPSIMD; + } current->thread.svcr &= ~(SVCR_ZA_MASK | SVCR_SM_MASK); |