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arm64: fpsimd: Fold sve_init_regs() into do_sve_acc()

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For historical reasons, do_sve_acc() is structurally different from
do_sme_acc(), and the logic to convert the task from FPSIMD to SVE is
out-of-line in sve_init_regs(). We only use sve_init_regs() within
do_sve_acc(), so it's not necessary for this to be a separate function.

Fold sve_init_regs() into do_sve_acc(), and simplify the associated
comments. This makes do_sve_acc() structurally similar to do_sme_acc(),
making it easier to see similarities and differences.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Vladimir Murzin <vladimir.murzin@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Fuad Tabba <tabba@google.com>
Cc: James Morse <james.morse@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Oliver Upton <oupton@kernel.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
This commit is contained in:
Mark Rutland authored and Will Deacon committed 2026-06-03 16:50:48 +01:00
1 parent afd7af2b56
commit 3efb6c7f22
1 file changed
+17 -31
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arch/arm64/kernel/fpsimd.c
+17 -31
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@@ -1293,31 +1293,6 @@ void sme_suspend_exit(void)
#endif /* CONFIG_ARM64_SME */
static void sve_init_regs(void)
{
/*
* Convert the FPSIMD state to SVE, zeroing all the state that
* is not shared with FPSIMD. If (as is likely) the current
* state is live in the registers then do this there and
* update our metadata for the current task including
* disabling the trap, otherwise update our in-memory copy.
* We are guaranteed to not be in streaming mode, we can only
* take a SVE trap when not in streaming mode and we can't be
* in streaming mode when taking a SME trap.
*/
if (!test_thread_flag(TIF_FOREIGN_FPSTATE)) {
unsigned long vq_minus_one =
sve_vq_from_vl(task_get_sve_vl(current)) - 1;
sve_set_vq(vq_minus_one);
sve_flush_live(true, vq_minus_one);
fpsimd_bind_task_to_cpu();
} else {
fpsimd_to_sve(current);
current->thread.fp_type = FP_STATE_SVE;
fpsimd_flush_task_state(current);
}
}
/*
* Trapped SVE access
*
@@ -1349,13 +1324,24 @@ void do_sve_acc(unsigned long esr, struct pt_regs *regs)
WARN_ON(1); /* SVE access shouldn't have trapped */
/*
* Even if the task can have used streaming mode we can only
* generate SVE access traps in normal SVE mode and
* transitioning out of streaming mode may discard any
* streaming mode state. Always clear the high bits to avoid
* any potential errors tracking what is properly initialised.
* Convert the FPSIMD state to SVE. Stale SVE state can be present in
* registers or memory, so we must zero all state that is not shared
* with FPSIMD.
*
* SVE traps cannot be taken from streaming mode, so there cannot be
* any effective streaming mode SVE state.
*/
sve_init_regs();
if (!test_thread_flag(TIF_FOREIGN_FPSTATE)) {
unsigned long vq_minus_one =
sve_vq_from_vl(task_get_sve_vl(current)) - 1;
sve_set_vq(vq_minus_one);
sve_flush_live(true, vq_minus_one);
fpsimd_bind_task_to_cpu();
} else {
fpsimd_to_sve(current);
current->thread.fp_type = FP_STATE_SVE;
fpsimd_flush_task_state(current);
}
put_cpu_fpsimd_context();
}