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Diffstat (limited to 'arch/arm64/kernel/fpsimd.c')
-rw-r--r--arch/arm64/kernel/fpsimd.c36
1 files changed, 22 insertions, 14 deletions
diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c
index f38d22dac140..8854bce5cfe2 100644
--- a/arch/arm64/kernel/fpsimd.c
+++ b/arch/arm64/kernel/fpsimd.c
@@ -119,7 +119,7 @@
* whatever is in the FPSIMD registers is not saved to memory, but discarded.
*/
-static DEFINE_PER_CPU(struct cpu_fp_state, fpsimd_last_state);
+DEFINE_PER_CPU(struct cpu_fp_state, fpsimd_last_state);
__ro_after_init struct vl_info vl_info[ARM64_VEC_MAX] = {
#ifdef CONFIG_ARM64_SVE
@@ -359,9 +359,6 @@ static void task_fpsimd_load(void)
WARN_ON(preemptible());
WARN_ON(test_thread_flag(TIF_KERNEL_FPSTATE));
- if (system_supports_fpmr())
- write_sysreg_s(current->thread.uw.fpmr, SYS_FPMR);
-
if (system_supports_sve() || system_supports_sme()) {
switch (current->thread.fp_type) {
case FP_STATE_FPSIMD:
@@ -413,6 +410,9 @@ static void task_fpsimd_load(void)
restore_ffr = system_supports_fa64();
}
+ if (system_supports_fpmr())
+ write_sysreg_s(current->thread.uw.fpmr, SYS_FPMR);
+
if (restore_sve_regs) {
WARN_ON_ONCE(current->thread.fp_type != FP_STATE_SVE);
sve_load_state(sve_pffr(&current->thread),
@@ -453,12 +453,15 @@ static void fpsimd_save_user_state(void)
*(last->fpmr) = read_sysreg_s(SYS_FPMR);
/*
- * If a task is in a syscall the ABI allows us to only
- * preserve the state shared with FPSIMD so don't bother
- * saving the full SVE state in that case.
+ * Save SVE state if it is live.
+ *
+ * The syscall ABI discards live SVE state at syscall entry. When
+ * entering a syscall, fpsimd_syscall_enter() sets to_save to
+ * FP_STATE_FPSIMD to allow the SVE state to be lazily discarded until
+ * either new SVE state is loaded+bound or fpsimd_syscall_exit() is
+ * called prior to a return to userspace.
*/
- if ((last->to_save == FP_STATE_CURRENT && test_thread_flag(TIF_SVE) &&
- !in_syscall(current_pt_regs())) ||
+ if ((last->to_save == FP_STATE_CURRENT && test_thread_flag(TIF_SVE)) ||
last->to_save == FP_STATE_SVE) {
save_sve_regs = true;
save_ffr = true;
@@ -651,7 +654,7 @@ static void __fpsimd_to_sve(void *sst, struct user_fpsimd_state const *fst,
* task->thread.uw.fpsimd_state must be up to date before calling this
* function.
*/
-static void fpsimd_to_sve(struct task_struct *task)
+static inline void fpsimd_to_sve(struct task_struct *task)
{
unsigned int vq;
void *sst = task->thread.sve_state;
@@ -675,7 +678,7 @@ static void fpsimd_to_sve(struct task_struct *task)
* bytes of allocated kernel memory.
* task->thread.sve_state must be up to date before calling this function.
*/
-static void sve_to_fpsimd(struct task_struct *task)
+static inline void sve_to_fpsimd(struct task_struct *task)
{
unsigned int vq, vl;
void const *sst = task->thread.sve_state;
@@ -1436,7 +1439,7 @@ void do_sme_acc(unsigned long esr, struct pt_regs *regs)
* If this not a trap due to SME being disabled then something
* is being used in the wrong mode, report as SIGILL.
*/
- if (ESR_ELx_ISS(esr) != ESR_ELx_SME_ISS_SME_DISABLED) {
+ if (ESR_ELx_SME_ISS_SMTC(esr) != ESR_ELx_SME_ISS_SMTC_SME_DISABLED) {
force_signal_inject(SIGILL, ILL_ILLOPC, regs->pc, 0);
return;
}
@@ -1460,6 +1463,8 @@ void do_sme_acc(unsigned long esr, struct pt_regs *regs)
sme_set_vq(vq_minus_one);
fpsimd_bind_task_to_cpu();
+ } else {
+ fpsimd_flush_task_state(current);
}
put_cpu_fpsimd_context();
@@ -1573,8 +1578,8 @@ void fpsimd_thread_switch(struct task_struct *next)
fpsimd_save_user_state();
if (test_tsk_thread_flag(next, TIF_KERNEL_FPSTATE)) {
- fpsimd_load_kernel_state(next);
fpsimd_flush_cpu_state();
+ fpsimd_load_kernel_state(next);
} else {
/*
* Fix up TIF_FOREIGN_FPSTATE to correctly describe next's
@@ -1661,6 +1666,9 @@ void fpsimd_flush_thread(void)
current->thread.svcr = 0;
}
+ if (system_supports_fpmr())
+ current->thread.uw.fpmr = 0;
+
current->thread.fp_type = FP_STATE_FPSIMD;
put_cpu_fpsimd_context();
@@ -1801,7 +1809,7 @@ void fpsimd_update_current_state(struct user_fpsimd_state const *state)
get_cpu_fpsimd_context();
current->thread.uw.fpsimd_state = *state;
- if (test_thread_flag(TIF_SVE))
+ if (current->thread.fp_type == FP_STATE_SVE)
fpsimd_to_sve(current);
task_fpsimd_load();