[PATCH v1 08/38] arm64/sve: Track vector lengths for tasks in an array
Mark Brown
broonie at kernel.org
Thu Sep 30 11:11:14 PDT 2021
As for SVE we will track a per task SME vector length for tasks. Convert
the existing storage for the vector length into an array and update
fpsimd_flush_task() to initialise this in a function.
Signed-off-by: Mark Brown <broonie at kernel.org>
---
arch/arm64/include/asm/processor.h | 44 +++++++++++--
arch/arm64/include/asm/thread_info.h | 2 +-
arch/arm64/kernel/fpsimd.c | 97 ++++++++++++++++------------
3 files changed, 95 insertions(+), 48 deletions(-)
diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h
index fb0608fe9ded..9b854e8196df 100644
--- a/arch/arm64/include/asm/processor.h
+++ b/arch/arm64/include/asm/processor.h
@@ -152,8 +152,8 @@ struct thread_struct {
unsigned int fpsimd_cpu;
void *sve_state; /* SVE registers, if any */
- unsigned int sve_vl; /* SVE vector length */
- unsigned int sve_vl_onexec; /* SVE vl after next exec */
+ unsigned int vl[ARM64_VEC_MAX]; /* vector length */
+ unsigned int vl_onexec[ARM64_VEC_MAX]; /* vl after next exec */
unsigned long fault_address; /* fault info */
unsigned long fault_code; /* ESR_EL1 value */
struct debug_info debug; /* debugging */
@@ -169,15 +169,45 @@ struct thread_struct {
u64 sctlr_user;
};
+static inline unsigned int thread_get_vl(struct thread_struct *thread,
+ enum vec_type type)
+{
+ return thread->vl[type];
+}
+
static inline unsigned int thread_get_sve_vl(struct thread_struct *thread)
{
- return thread->sve_vl;
+ return thread_get_vl(thread, ARM64_VEC_SVE);
+}
+
+unsigned int task_get_vl(const struct task_struct *task, enum vec_type type);
+void task_set_vl(struct task_struct *task, enum vec_type type,
+ unsigned long vl);
+void task_set_vl_onexec(struct task_struct *task, enum vec_type type,
+ unsigned long vl);
+unsigned int task_get_vl_onexec(const struct task_struct *task,
+ enum vec_type type);
+
+static inline unsigned int task_get_sve_vl(const struct task_struct *task)
+{
+ return task_get_vl(task, ARM64_VEC_SVE);
}
-unsigned int task_get_sve_vl(const struct task_struct *task);
-void task_set_sve_vl(struct task_struct *task, unsigned long vl);
-unsigned int task_get_sve_vl_onexec(const struct task_struct *task);
-void task_set_sve_vl_onexec(struct task_struct *task, unsigned long vl);
+static inline void task_set_sve_vl(struct task_struct *task, unsigned long vl)
+{
+ task_set_vl(task, ARM64_VEC_SVE, vl);
+}
+
+static inline unsigned int task_get_sve_vl_onexec(const struct task_struct *task)
+{
+ return task_get_vl_onexec(task, ARM64_VEC_SVE);
+}
+
+static inline void task_set_sve_vl_onexec(struct task_struct *task,
+ unsigned long vl)
+{
+ task_set_vl_onexec(task, ARM64_VEC_SVE, vl);
+}
#define SCTLR_USER_MASK \
(SCTLR_ELx_ENIA | SCTLR_ELx_ENIB | SCTLR_ELx_ENDA | SCTLR_ELx_ENDB | \
diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h
index 6623c99f0984..d5c8ac81ce11 100644
--- a/arch/arm64/include/asm/thread_info.h
+++ b/arch/arm64/include/asm/thread_info.h
@@ -78,7 +78,7 @@ int arch_dup_task_struct(struct task_struct *dst,
#define TIF_SINGLESTEP 21
#define TIF_32BIT 22 /* 32bit process */
#define TIF_SVE 23 /* Scalable Vector Extension in use */
-#define TIF_SVE_VL_INHERIT 24 /* Inherit sve_vl_onexec across exec */
+#define TIF_SVE_VL_INHERIT 24 /* Inherit SVE vl_onexec across exec */
#define TIF_SSBD 25 /* Wants SSB mitigation */
#define TIF_TAGGED_ADDR 26 /* Allow tagged user addresses */
diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c
index 44bb3203c9d1..814080209093 100644
--- a/arch/arm64/kernel/fpsimd.c
+++ b/arch/arm64/kernel/fpsimd.c
@@ -133,6 +133,17 @@ __ro_after_init struct vl_info vl_info[ARM64_VEC_MAX] = {
#endif
};
+static unsigned int vec_vl_inherit_flag(enum vec_type type)
+{
+ switch (type) {
+ case ARM64_VEC_SVE:
+ return TIF_SVE_VL_INHERIT;
+ default:
+ WARN_ON_ONCE(1);
+ return 0;
+ }
+}
+
struct vl_config {
int __default_vl; /* Default VL for tasks */
};
@@ -239,24 +250,27 @@ static void sve_free(struct task_struct *task)
__sve_free(task);
}
-unsigned int task_get_sve_vl(const struct task_struct *task)
+unsigned int task_get_vl(const struct task_struct *task, enum vec_type type)
{
- return task->thread.sve_vl;
+ return task->thread.vl[type];
}
-void task_set_sve_vl(struct task_struct *task, unsigned long vl)
+void task_set_vl(struct task_struct *task, enum vec_type type,
+ unsigned long vl)
{
- task->thread.sve_vl = vl;
+ task->thread.vl[type] = vl;
}
-unsigned int task_get_sve_vl_onexec(const struct task_struct *task)
+unsigned int task_get_vl_onexec(const struct task_struct *task,
+ enum vec_type type)
{
- return task->thread.sve_vl_onexec;
+ return task->thread.vl_onexec[type];
}
-void task_set_sve_vl_onexec(struct task_struct *task, unsigned long vl)
+void task_set_vl_onexec(struct task_struct *task, enum vec_type type,
+ unsigned long vl)
{
- task->thread.sve_vl_onexec = vl;
+ task->thread.vl_onexec[type] = vl;
}
/*
@@ -1074,10 +1088,43 @@ void fpsimd_thread_switch(struct task_struct *next)
__put_cpu_fpsimd_context();
}
-void fpsimd_flush_thread(void)
+static void fpsimd_flush_thread_vl(enum vec_type type)
{
int vl, supported_vl;
+ /*
+ * Reset the task vector length as required. This is where we
+ * ensure that all user tasks have a valid vector length
+ * configured: no kernel task can become a user task without
+ * an exec and hence a call to this function. By the time the
+ * first call to this function is made, all early hardware
+ * probing is complete, so __sve_default_vl should be valid.
+ * If a bug causes this to go wrong, we make some noise and
+ * try to fudge thread.sve_vl to a safe value here.
+ */
+ vl = task_get_vl_onexec(current, type);
+ if (!vl)
+ vl = get_default_vl(type);
+
+ if (WARN_ON(!sve_vl_valid(vl)))
+ vl = SVE_VL_MIN;
+
+ supported_vl = find_supported_vector_length(type, vl);
+ if (WARN_ON(supported_vl != vl))
+ vl = supported_vl;
+
+ task_set_vl(current, type, vl);
+
+ /*
+ * If the task is not set to inherit, ensure that the vector
+ * length will be reset by a subsequent exec:
+ */
+ if (!test_thread_flag(vec_vl_inherit_flag(type)))
+ task_set_vl_onexec(current, type, 0);
+}
+
+void fpsimd_flush_thread(void)
+{
if (!system_supports_fpsimd())
return;
@@ -1090,37 +1137,7 @@ void fpsimd_flush_thread(void)
if (system_supports_sve()) {
clear_thread_flag(TIF_SVE);
sve_free(current);
-
- /*
- * Reset the task vector length as required.
- * This is where we ensure that all user tasks have a valid
- * vector length configured: no kernel task can become a user
- * task without an exec and hence a call to this function.
- * By the time the first call to this function is made, all
- * early hardware probing is complete, so __sve_default_vl
- * should be valid.
- * If a bug causes this to go wrong, we make some noise and
- * try to fudge thread.sve_vl to a safe value here.
- */
- vl = task_get_sve_vl_onexec(current);
- if (!vl)
- vl = get_sve_default_vl();
-
- if (WARN_ON(!sve_vl_valid(vl)))
- vl = SVE_VL_MIN;
-
- supported_vl = find_supported_vector_length(ARM64_VEC_SVE, vl);
- if (WARN_ON(supported_vl != vl))
- vl = supported_vl;
-
- task_set_sve_vl(current, vl);
-
- /*
- * If the task is not set to inherit, ensure that the vector
- * length will be reset by a subsequent exec:
- */
- if (!test_thread_flag(TIF_SVE_VL_INHERIT))
- task_set_sve_vl_onexec(current, 0);
+ fpsimd_flush_thread_vl(ARM64_VEC_SVE);
}
put_cpu_fpsimd_context();
--
2.20.1
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