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Diffstat (limited to 'arch/arm64/kernel/fpsimd.c')
-rw-r--r--arch/arm64/kernel/fpsimd.c69
1 files changed, 39 insertions, 30 deletions
diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c
index fa244c426f61..f2307d6631eb 100644
--- a/arch/arm64/kernel/fpsimd.c
+++ b/arch/arm64/kernel/fpsimd.c
@@ -15,6 +15,7 @@
#include <linux/compiler.h>
#include <linux/cpu.h>
#include <linux/cpu_pm.h>
+#include <linux/ctype.h>
#include <linux/kernel.h>
#include <linux/linkage.h>
#include <linux/irqflags.h>
@@ -406,12 +407,13 @@ static unsigned int find_supported_vector_length(enum vec_type type,
#if defined(CONFIG_ARM64_SVE) && defined(CONFIG_SYSCTL)
-static int sve_proc_do_default_vl(struct ctl_table *table, int write,
+static int vec_proc_do_default_vl(struct ctl_table *table, int write,
void *buffer, size_t *lenp, loff_t *ppos)
{
- struct vl_info *info = &vl_info[ARM64_VEC_SVE];
+ struct vl_info *info = table->extra1;
+ enum vec_type type = info->type;
int ret;
- int vl = get_sve_default_vl();
+ int vl = get_default_vl(type);
struct ctl_table tmp_table = {
.data = &vl,
.maxlen = sizeof(vl),
@@ -428,7 +430,7 @@ static int sve_proc_do_default_vl(struct ctl_table *table, int write,
if (!sve_vl_valid(vl))
return -EINVAL;
- set_sve_default_vl(find_supported_vector_length(ARM64_VEC_SVE, vl));
+ set_default_vl(type, find_supported_vector_length(type, vl));
return 0;
}
@@ -436,7 +438,8 @@ static struct ctl_table sve_default_vl_table[] = {
{
.procname = "sve_default_vector_length",
.mode = 0644,
- .proc_handler = sve_proc_do_default_vl,
+ .proc_handler = vec_proc_do_default_vl,
+ .extra1 = &vl_info[ARM64_VEC_SVE],
},
{ }
};
@@ -629,7 +632,7 @@ void sve_sync_from_fpsimd_zeropad(struct task_struct *task)
__fpsimd_to_sve(sst, fst, vq);
}
-int sve_set_vector_length(struct task_struct *task,
+int vec_set_vector_length(struct task_struct *task, enum vec_type type,
unsigned long vl, unsigned long flags)
{
if (flags & ~(unsigned long)(PR_SVE_VL_INHERIT |
@@ -640,33 +643,35 @@ int sve_set_vector_length(struct task_struct *task,
return -EINVAL;
/*
- * Clamp to the maximum vector length that VL-agnostic SVE code can
- * work with. A flag may be assigned in the future to allow setting
- * of larger vector lengths without confusing older software.
+ * Clamp to the maximum vector length that VL-agnostic code
+ * can work with. A flag may be assigned in the future to
+ * allow setting of larger vector lengths without confusing
+ * older software.
*/
- if (vl > SVE_VL_ARCH_MAX)
- vl = SVE_VL_ARCH_MAX;
+ if (vl > VL_ARCH_MAX)
+ vl = VL_ARCH_MAX;
- vl = find_supported_vector_length(ARM64_VEC_SVE, vl);
+ vl = find_supported_vector_length(type, vl);
if (flags & (PR_SVE_VL_INHERIT |
PR_SVE_SET_VL_ONEXEC))
- task_set_sve_vl_onexec(task, vl);
+ task_set_vl_onexec(task, type, vl);
else
/* Reset VL to system default on next exec: */
- task_set_sve_vl_onexec(task, 0);
+ task_set_vl_onexec(task, type, 0);
/* Only actually set the VL if not deferred: */
if (flags & PR_SVE_SET_VL_ONEXEC)
goto out;
- if (vl == task_get_sve_vl(task))
+ if (vl == task_get_vl(task, type))
goto out;
/*
* To ensure the FPSIMD bits of the SVE vector registers are preserved,
* write any live register state back to task_struct, and convert to a
- * non-SVE thread.
+ * regular FPSIMD thread. Since the vector length can only be changed
+ * with a syscall we can't be in streaming mode while reconfiguring.
*/
if (task == current) {
get_cpu_fpsimd_context();
@@ -687,10 +692,10 @@ int sve_set_vector_length(struct task_struct *task,
*/
sve_free(task);
- task_set_sve_vl(task, vl);
+ task_set_vl(task, type, vl);
out:
- update_tsk_thread_flag(task, TIF_SVE_VL_INHERIT,
+ update_tsk_thread_flag(task, vec_vl_inherit_flag(type),
flags & PR_SVE_VL_INHERIT);
return 0;
@@ -698,20 +703,21 @@ out:
/*
* Encode the current vector length and flags for return.
- * This is only required for prctl(): ptrace has separate fields
+ * This is only required for prctl(): ptrace has separate fields.
+ * SVE and SME use the same bits for _ONEXEC and _INHERIT.
*
- * flags are as for sve_set_vector_length().
+ * flags are as for vec_set_vector_length().
*/
-static int sve_prctl_status(unsigned long flags)
+static int vec_prctl_status(enum vec_type type, unsigned long flags)
{
int ret;
if (flags & PR_SVE_SET_VL_ONEXEC)
- ret = task_get_sve_vl_onexec(current);
+ ret = task_get_vl_onexec(current, type);
else
- ret = task_get_sve_vl(current);
+ ret = task_get_vl(current, type);
- if (test_thread_flag(TIF_SVE_VL_INHERIT))
+ if (test_thread_flag(vec_vl_inherit_flag(type)))
ret |= PR_SVE_VL_INHERIT;
return ret;
@@ -729,11 +735,11 @@ int sve_set_current_vl(unsigned long arg)
if (!system_supports_sve() || is_compat_task())
return -EINVAL;
- ret = sve_set_vector_length(current, vl, flags);
+ ret = vec_set_vector_length(current, ARM64_VEC_SVE, vl, flags);
if (ret)
return ret;
- return sve_prctl_status(flags);
+ return vec_prctl_status(ARM64_VEC_SVE, flags);
}
/* PR_SVE_GET_VL */
@@ -742,7 +748,7 @@ int sve_get_current_vl(void)
if (!system_supports_sve() || is_compat_task())
return -EINVAL;
- return sve_prctl_status(0);
+ return vec_prctl_status(ARM64_VEC_SVE, 0);
}
static void vec_probe_vqs(struct vl_info *info,
@@ -1107,7 +1113,7 @@ static void fpsimd_flush_thread_vl(enum vec_type type)
vl = get_default_vl(type);
if (WARN_ON(!sve_vl_valid(vl)))
- vl = SVE_VL_MIN;
+ vl = vl_info[type].min_vl;
supported_vl = find_supported_vector_length(type, vl);
if (WARN_ON(supported_vl != vl))
@@ -1213,7 +1219,8 @@ void fpsimd_bind_state_to_cpu(struct user_fpsimd_state *st, void *sve_state,
/*
* 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'
+ * state of 'current'. This is called when we are preparing to return to
+ * userspace to ensure that userspace sees a good register state.
*/
void fpsimd_restore_current_state(void)
{
@@ -1244,7 +1251,9 @@ void fpsimd_restore_current_state(void)
/*
* Load an updated userland FPSIMD state for 'current' from memory and set the
* flag that indicates that the FPSIMD register contents are the most recent
- * FPSIMD state of 'current'
+ * FPSIMD state of 'current'. This is used by the signal code to restore the
+ * register state when returning from a signal handler in FPSIMD only cases,
+ * any SVE context will be discarded.
*/
void fpsimd_update_current_state(struct user_fpsimd_state const *state)
{
generated by cgit v1.2.3 (git 2.39.0) at 2024-12-27 15:44:01 +0300