From: Mark Rutland Date: Wed, 9 Apr 2025 16:40:00 +0000 (+0100) Subject: arm64/fpsimd: Remove redundant SVE trap manipulation X-Git-Tag: v6.16-rc1~133^2~1^2~32 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=45fd86986b79c3ada56d3a14e712447e992433aa;p=thirdparty%2Fkernel%2Flinux.git arm64/fpsimd: Remove redundant SVE trap manipulation 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 Cc: Marc Zyngier Cc: Mark Brown Cc: Will Deacon Reviewed-by: Mark Brown Link: https://lore.kernel.org/r/20250409164010.3480271-4-mark.rutland@arm.com Signed-off-by: Catalin Marinas --- 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);