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Diffstat (limited to 'arch/arm64/kernel/fpsimd.c')
-rw-r--r--arch/arm64/kernel/fpsimd.c55
1 files changed, 45 insertions, 10 deletions
diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c
index c7531b85b303..e7733fb19388 100644
--- a/arch/arm64/kernel/fpsimd.c
+++ b/arch/arm64/kernel/fpsimd.c
@@ -300,6 +300,32 @@ static void fpsimd_to_sve(struct task_struct *task)
sizeof(fst->vregs[i]));
}
+/*
+ * Transfer the SVE state in task->thread.sve_state to
+ * task->thread.fpsimd_state.
+ *
+ * Task can be a non-runnable task, or current. In the latter case,
+ * softirqs (and preemption) must be disabled.
+ * task->thread.sve_state must point to at least sve_state_size(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)
+{
+ unsigned int vq;
+ void const *sst = task->thread.sve_state;
+ struct fpsimd_state *fst = &task->thread.fpsimd_state;
+ unsigned int i;
+
+ if (!system_supports_sve())
+ return;
+
+ vq = sve_vq_from_vl(task->thread.sve_vl);
+ for (i = 0; i < 32; ++i)
+ memcpy(&fst->vregs[i], ZREG(sst, vq, i),
+ sizeof(fst->vregs[i]));
+}
+
#ifdef CONFIG_ARM64_SVE
/*
@@ -501,9 +527,6 @@ void fpsimd_flush_thread(void)
/*
* Save the userland FPSIMD state of 'current' to memory, but only if the state
* currently held in the registers does in fact belong to 'current'
- *
- * Currently, SVE tasks can't exist, so just WARN in that case.
- * Subsequent patches will add full SVE support here.
*/
void fpsimd_preserve_current_state(void)
{
@@ -511,16 +534,23 @@ void fpsimd_preserve_current_state(void)
return;
local_bh_disable();
-
- if (!test_thread_flag(TIF_FOREIGN_FPSTATE))
- fpsimd_save_state(&current->thread.fpsimd_state);
-
- WARN_ON_ONCE(test_and_clear_thread_flag(TIF_SVE));
-
+ task_fpsimd_save();
local_bh_enable();
}
/*
+ * Like fpsimd_preserve_current_state(), but ensure that
+ * current->thread.fpsimd_state is updated so that it can be copied to
+ * the signal frame.
+ */
+void fpsimd_signal_preserve_current_state(void)
+{
+ fpsimd_preserve_current_state();
+ if (system_supports_sve() && test_thread_flag(TIF_SVE))
+ sve_to_fpsimd(current);
+}
+
+/*
* Load the userland FPSIMD state of 'current' from memory, but only if the
* FPSIMD state already held in the registers is /not/ the most recent FPSIMD
* state of 'current'
@@ -555,7 +585,12 @@ void fpsimd_update_current_state(struct fpsimd_state *state)
local_bh_disable();
- fpsimd_load_state(state);
+ if (system_supports_sve() && test_thread_flag(TIF_SVE)) {
+ current->thread.fpsimd_state = *state;
+ fpsimd_to_sve(current);
+ }
+ task_fpsimd_load();
+
if (test_and_clear_thread_flag(TIF_FOREIGN_FPSTATE)) {
struct fpsimd_state *st = &current->thread.fpsimd_state;