| Message ID | 20250404174435.3288106-5-mark.rutland@arm.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | arm64: Preparatory FPSIMD/SVE/SME fixes | expand |
On Fri, Apr 04, 2025 at 06:44:25PM +0100, Mark Rutland wrote: > All calls to task_fpsimd_load() are followed by a call to > fpsimd_bind_task_to_cpu(), where the latter configures traps for SVE and > SME dependent upon the current values of TIF_SVE and TIF_SME, overriding > any trap configuration performed by task_fpsimd_load(). > The calls to sve_user_{enable,disable}() calls in task_fpsimd_load() > have been redundant (though benign) since they were introduced in > commit: > a0136be443d51803 ("arm64/fpsimd: Load FP state based on recorded data type") > Remove the unnecessary and confusing SVE trap manipulation. Reviewed-by: Mark Brown <broonie@kernel.org>
diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index 1391a491f2226..757445d72e5b7 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -366,13 +366,11 @@ static void task_fpsimd_load(void) switch (current->thread.fp_type) { case FP_STATE_FPSIMD: /* Stop tracking SVE for this task until next use. */ - if (test_and_clear_thread_flag(TIF_SVE)) - sve_user_disable(); + clear_thread_flag(TIF_SVE); break; case FP_STATE_SVE: - if (!thread_sm_enabled(¤t->thread) && - !WARN_ON_ONCE(!test_and_set_thread_flag(TIF_SVE))) - sve_user_enable(); + if (!thread_sm_enabled(¤t->thread)) + WARN_ON_ONCE(!test_and_set_thread_flag(TIF_SVE)); if (test_thread_flag(TIF_SVE)) sve_set_vq(sve_vq_from_vl(task_get_sve_vl(current)) - 1);
When task_fpsimd_load() loads the saved FPSIMD/SVE/SME state, it configures EL0 SVE traps by calling sve_user_{enable,disable}(). This is unnecessary, and this is suspicious/confusing as task_fpsimd_load() does not configure EL0 SME traps. All calls to task_fpsimd_load() are followed by a call to fpsimd_bind_task_to_cpu(), where the latter configures traps for SVE and SME dependent upon the current values of TIF_SVE and TIF_SME, overriding any trap configuration performed by task_fpsimd_load(). The calls to sve_user_{enable,disable}() calls in task_fpsimd_load() have been redundant (though benign) since they were introduced in commit: a0136be443d51803 ("arm64/fpsimd: Load FP state based on recorded data type") Remove the unnecessary and confusing SVE trap manipulation. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Mark Brown <broonie@kernel.org> Cc: Will Deacon <will@kernel.org> --- arch/arm64/kernel/fpsimd.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-)