[v2, 4/5] riscv: vector: do not pass task_struct into riscv_v_vstate_{save,restore}()

Andy Chiu
2023-07-21T11:29:51Z

riscv_v_vstate_{save,restore}() can operate only on the knowlege of
struct __riscv_v_ext_state, and struct pt_regs. Let the caller decides
which should be passed into the function. Meanwhile, the kernel-mode
Vector is going to introduce another vstate, so this also makes functions
potentially able to be reused.

Signed-off-by: Andy Chiu <andy.chiu@sifive.com>
---
Changelog v2:
- fix build fail that get caught on this patch (Conor)
---
arch/riscv/include/asm/entry-common.h | 2 +-
arch/riscv/include/asm/vector.h | 14 +++++---------
arch/riscv/kernel/kernel_mode_vector.c | 2 +-
arch/riscv/kernel/ptrace.c | 2 +-
arch/riscv/kernel/signal.c | 2 +-
5 files changed, 9 insertions(+), 13 deletions(-)

diff --git a/arch/riscv/include/asm/entry-common.h b/arch/riscv/include/asm/entry-common.h
index 52926f4d8d7c..aa1b9e50d6c8 100644
--- a/arch/riscv/include/asm/entry-common.h
+++ b/arch/riscv/include/asm/entry-common.h
@@ -12,7 +12,7 @@ static inline void arch_exit_to_user_mode_prepare(struct pt_regs *regs,
{
if (ti_work & _TIF_RISCV_V_DEFER_RESTORE) {
clear_thread_flag(TIF_RISCV_V_DEFER_RESTORE);
- riscv_v_vstate_restore(current, regs);
+ riscv_v_vstate_restore(&current->thread.vstate, regs);
}
}

diff --git a/arch/riscv/include/asm/vector.h b/arch/riscv/include/asm/vector.h
index b46b8f3261fa..3b783b317112 100644
--- a/arch/riscv/include/asm/vector.h
+++ b/arch/riscv/include/asm/vector.h
@@ -163,23 +163,19 @@ static inline void riscv_v_vstate_discard(struct pt_regs *regs)
__riscv_v_vstate_dirty(regs);
}

-static inline void riscv_v_vstate_save(struct task_struct *task,
+static inline void riscv_v_vstate_save(struct __riscv_v_ext_state *vstate,
struct pt_regs *regs)
{
if ((regs->status & SR_VS) == SR_VS_DIRTY) {
- struct __riscv_v_ext_state *vstate = &task->thread.vstate;
-
__riscv_v_vstate_save(vstate, vstate->datap);
__riscv_v_vstate_clean(regs);
}
}

-static inline void riscv_v_vstate_restore(struct task_struct *task,
+static inline void riscv_v_vstate_restore(struct __riscv_v_ext_state *vstate,
struct pt_regs *regs)
{
if ((regs->status & SR_VS) != SR_VS_OFF) {
- struct __riscv_v_ext_state *vstate = &task->thread.vstate;
-
__riscv_v_vstate_restore(vstate, vstate->datap);
__riscv_v_vstate_clean(regs);
}
@@ -200,7 +196,7 @@ static inline void __switch_to_vector(struct task_struct *prev,
struct pt_regs *regs;

regs = task_pt_regs(prev);
- riscv_v_vstate_save(prev, regs);
+ riscv_v_vstate_save(&prev->thread.vstate, regs);
riscv_v_vstate_set_restore(next, task_pt_regs(next));
}

@@ -218,8 +214,8 @@ static inline bool riscv_v_vstate_query(struct pt_regs *regs) { return false; }
static inline bool riscv_v_vstate_ctrl_user_allowed(void) { return false; }
#define riscv_v_vsize (0)
#define riscv_v_vstate_discard(regs) do {} while (0)
-#define riscv_v_vstate_save(task, regs) do {} while (0)
-#define riscv_v_vstate_restore(task, regs) do {} while (0)
+#define riscv_v_vstate_save(vstate, regs) do {} while (0)
+#define riscv_v_vstate_restore(vstate, regs) do {} while (0)
#define __switch_to_vector(__prev, __next) do {} while (0)
#define riscv_v_vstate_off(regs) do {} while (0)
#define riscv_v_vstate_on(regs) do {} while (0)
diff --git a/arch/riscv/kernel/kernel_mode_vector.c b/arch/riscv/kernel/kernel_mode_vector.c
index 1c3b32d2b340..d9e097e68937 100644
--- a/arch/riscv/kernel/kernel_mode_vector.c
+++ b/arch/riscv/kernel/kernel_mode_vector.c
@@ -68,7 +68,7 @@ void kernel_vector_begin(void)

BUG_ON(!may_use_simd());

- riscv_v_vstate_save(current, task_pt_regs(current));
+ riscv_v_vstate_save(&current->thread.vstate, task_pt_regs(current));

get_cpu_vector_context();

diff --git a/arch/riscv/kernel/ptrace.c b/arch/riscv/kernel/ptrace.c
index 1d572cf3140f..85e7167245cc 100644
--- a/arch/riscv/kernel/ptrace.c
+++ b/arch/riscv/kernel/ptrace.c
@@ -99,7 +99,7 @@ static int riscv_vr_get(struct task_struct *target,
* copying them to membuf.
*/
if (target == current)
- riscv_v_vstate_save(current, task_pt_regs(current));
+ riscv_v_vstate_save(&current->thread.vstate, task_pt_regs(current));

/* Copy vector header from vstate. */
membuf_write(&to, vstate, offsetof(struct __riscv_v_ext_state, datap));
diff --git a/arch/riscv/kernel/signal.c b/arch/riscv/kernel/signal.c
index 0fca2c128b5f..75fd8cc05e10 100644
--- a/arch/riscv/kernel/signal.c
+++ b/arch/riscv/kernel/signal.c
@@ -86,7 +86,7 @@ static long save_v_state(struct pt_regs *regs, void __user **sc_vec)
/* datap is designed to be 16 byte aligned for better performance */
WARN_ON(unlikely(!IS_ALIGNED((unsigned long)datap, 16)));

- riscv_v_vstate_save(current, regs);
+ riscv_v_vstate_save(&current->thread.vstate, regs);
/* Copy everything of vstate but datap. */
err = __copy_to_user(&state->v_state, &current->thread.vstate,
offsetof(struct __riscv_v_ext_state, datap));
--
2.17.1