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| author |   Mark Brown <broonie@kernel.org> | 2021-05-12 16:11:31 +0100 |
|---|---|---|
| committer |   Will Deacon <will@kernel.org> | 2021-05-26 20:04:28 +0100 |
| commit | ad4711f962e08eff8d6e9b03f9670b1af6ea9395 (patch) | |
| tree | bb1979f64369118ce873375598f7f0bfc3115b86 /arch/arm64/kernel/fpsimd.c | |
| parent | arm64/sve: Use the sve_flush macros in sve_load_from_fpsimd_state() (diff) | |
| download | linux-dev-ad4711f962e08eff8d6e9b03f9670b1af6ea9395.tar.xz linux-dev-ad4711f962e08eff8d6e9b03f9670b1af6ea9395.zip | |
arm64/sve: Skip flushing Z registers with 128 bit vectors
When the SVE vector length is 128 bits then there are no bits in the Z
registers which are not shared with the V registers so we can skip them
when zeroing state not shared with FPSIMD, this results in a minor
performance improvement.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210512151131.27877-4-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'arch/arm64/kernel/fpsimd.c')
| -rw-r--r-- | arch/arm64/kernel/fpsimd.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index ad3dd34a83cf..e57b23f95284 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -957,8 +957,10 @@ void do_sve_acc(unsigned int esr, struct pt_regs *regs) * disabling the trap, otherwise update our in-memory copy. */ if (!test_thread_flag(TIF_FOREIGN_FPSTATE)) { - sve_set_vq(sve_vq_from_vl(current->thread.sve_vl) - 1); - sve_flush_live(); + unsigned long vq_minus_one = + sve_vq_from_vl(current->thread.sve_vl) - 1; + sve_set_vq(vq_minus_one); + sve_flush_live(vq_minus_one); fpsimd_bind_task_to_cpu(); } else { fpsimd_to_sve(current); |