[v3, 4/5] riscv: vector: do not pass task_struct into riscv_v_vstate_{save,restore}()

[Andy Chiu]

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 at sifive.com>
---
Changelog v3:
 - save V context after get_cpu_vector_context
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 8d64f1c18169..fd78361bf301 100644
--- a/arch/riscv/include/asm/entry-common.h
+++ b/arch/riscv/include/asm/entry-common.h
@@ -16,7 +16,7 @@ static inline void arch_exit_to_user_mode_prepare(struct pt_regs *regs,
 		 * We are already called with irq disabled, so go without
 		 * keepping track of vector_context_busy.
 		 */
-		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 2f11c6f3ad96..d356eac8c0b4 100644
--- a/arch/riscv/include/asm/vector.h
+++ b/arch/riscv/include/asm/vector.h
@@ -166,23 +166,19 @@ 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);
 	}
@@ -203,7 +199,7 @@ 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));
 }
 
@@ -221,8 +217,8 @@ 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 fa01dc62256f..2344817f8640 100644
--- a/arch/riscv/kernel/kernel_mode_vector.c
+++ b/arch/riscv/kernel/kernel_mode_vector.c
@@ -70,7 +70,7 @@ void kernel_vector_begin(void)
 
 	get_cpu_vector_context();
 
-	riscv_v_vstate_save(current, task_pt_regs(current));
+	riscv_v_vstate_save(&current->thread.vstate, task_pt_regs(current));
 
 	riscv_v_enable();
 }
diff --git a/arch/riscv/kernel/ptrace.c b/arch/riscv/kernel/ptrace.c
index 7b93bcbdf9fa..e8515aa9d80b 100644
--- a/arch/riscv/kernel/ptrace.c
+++ b/arch/riscv/kernel/ptrace.c
@@ -101,7 +101,7 @@ static int riscv_vr_get(struct task_struct *target,
 	 */
 	if (target == current) {
 		get_cpu_vector_context();
-		riscv_v_vstate_save(current, task_pt_regs(current));
+		riscv_v_vstate_save(&current->thread.vstate, task_pt_regs(current));
 		put_cpu_vector_context();
 	}
 
diff --git a/arch/riscv/kernel/signal.c b/arch/riscv/kernel/signal.c
index d31d2c74d31f..13cb00cbcd58 100644
--- a/arch/riscv/kernel/signal.c
+++ b/arch/riscv/kernel/signal.c
@@ -87,7 +87,7 @@ static long save_v_state(struct pt_regs *regs, void __user **sc_vec)
 	WARN_ON(unlikely(!IS_ALIGNED((unsigned long)datap, 16)));
 
 	get_cpu_vector_context();
-	riscv_v_vstate_save(current, regs);
+	riscv_v_vstate_save(&current->thread.vstate, regs);
 	put_cpu_vector_context();
 
 	/* Copy everything of vstate but datap. */
-- 
2.17.1