[PATCH v7 02/37] arm64/sve: Generalise vector length configuration prctl() for SME
Mark Brown
broonie at kernel.org
Fri Dec 10 10:40:58 PST 2021
In preparation for adding SME support update the bulk of the implementation
for the vector length configuration prctl() calls to be independent of
vector type.
Signed-off-by: Mark Brown <broonie at kernel.org>
---
arch/arm64/include/asm/fpsimd.h | 6 ++---
arch/arm64/kernel/fpsimd.c | 47 ++++++++++++++++++---------------
arch/arm64/kernel/ptrace.c | 4 +--
arch/arm64/kvm/reset.c | 8 +++---
4 files changed, 34 insertions(+), 31 deletions(-)
diff --git a/arch/arm64/include/asm/fpsimd.h b/arch/arm64/include/asm/fpsimd.h
index dbb4b30a5648..cb24385e3632 100644
--- a/arch/arm64/include/asm/fpsimd.h
+++ b/arch/arm64/include/asm/fpsimd.h
@@ -51,8 +51,8 @@ extern void fpsimd_bind_state_to_cpu(struct user_fpsimd_state *state,
extern void fpsimd_flush_task_state(struct task_struct *target);
extern void fpsimd_save_and_flush_cpu_state(void);
-/* Maximum VL that SVE VL-agnostic software can transparently support */
-#define SVE_VL_ARCH_MAX 0x100
+/* Maximum VL that SVE/SME VL-agnostic software can transparently support */
+#define VL_ARCH_MAX 0x100
/* Offset of FFR in the SVE register dump */
static inline size_t sve_ffr_offset(int vl)
@@ -122,7 +122,7 @@ extern void fpsimd_sync_to_sve(struct task_struct *task);
extern void sve_sync_to_fpsimd(struct task_struct *task);
extern void sve_sync_from_fpsimd_zeropad(struct task_struct *task);
-extern int sve_set_vector_length(struct task_struct *task,
+extern int vec_set_vector_length(struct task_struct *task, enum vec_type type,
unsigned long vl, unsigned long flags);
extern int sve_set_current_vl(unsigned long arg);
diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c
index 23e575c4e580..4a98cc3b1df1 100644
--- a/arch/arm64/kernel/fpsimd.c
+++ b/arch/arm64/kernel/fpsimd.c
@@ -632,7 +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 |
@@ -643,33 +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();
@@ -690,10 +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;
@@ -701,20 +703,21 @@ int sve_set_vector_length(struct task_struct *task,
/*
* 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;
@@ -732,11 +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 */
@@ -745,7 +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,
diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c
index 88a9034fb9b5..716dde289446 100644
--- a/arch/arm64/kernel/ptrace.c
+++ b/arch/arm64/kernel/ptrace.c
@@ -812,9 +812,9 @@ static int sve_set(struct task_struct *target,
/*
* Apart from SVE_PT_REGS_MASK, all SVE_PT_* flags are consumed by
- * sve_set_vector_length(), which will also validate them for us:
+ * vec_set_vector_length(), which will also validate them for us:
*/
- ret = sve_set_vector_length(target, header.vl,
+ ret = vec_set_vector_length(target, ARM64_VEC_SVE, header.vl,
((unsigned long)header.flags & ~SVE_PT_REGS_MASK) << 16);
if (ret)
goto out;
diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c
index 426bd7fbc3fd..27386f0d81e4 100644
--- a/arch/arm64/kvm/reset.c
+++ b/arch/arm64/kvm/reset.c
@@ -52,10 +52,10 @@ int kvm_arm_init_sve(void)
* The get_sve_reg()/set_sve_reg() ioctl interface will need
* to be extended with multiple register slice support in
* order to support vector lengths greater than
- * SVE_VL_ARCH_MAX:
+ * VL_ARCH_MAX:
*/
- if (WARN_ON(kvm_sve_max_vl > SVE_VL_ARCH_MAX))
- kvm_sve_max_vl = SVE_VL_ARCH_MAX;
+ if (WARN_ON(kvm_sve_max_vl > VL_ARCH_MAX))
+ kvm_sve_max_vl = VL_ARCH_MAX;
/*
* Don't even try to make use of vector lengths that
@@ -103,7 +103,7 @@ static int kvm_vcpu_finalize_sve(struct kvm_vcpu *vcpu)
* set_sve_vls(). Double-check here just to be sure:
*/
if (WARN_ON(!sve_vl_valid(vl) || vl > sve_max_virtualisable_vl() ||
- vl > SVE_VL_ARCH_MAX))
+ vl > VL_ARCH_MAX))
return -EIO;
buf = kzalloc(SVE_SIG_REGS_SIZE(sve_vq_from_vl(vl)), GFP_KERNEL_ACCOUNT);
--
2.30.2
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