[RFC PATCH V3 11/11] riscv: Add sigcontext save/restore

[guoren@xxxxxxxxxx]

From: Guo Ren <guoren@xxxxxxxxxxxxxxxxx>

This patch add sigcontext save/restore and it's very similar to
fpu.

Signed-off-by: Guo Ren <guoren@xxxxxxxxxxxxxxxxx>
---
 arch/riscv/include/uapi/asm/sigcontext.h |  1 +
 arch/riscv/kernel/signal.c               | 40 ++++++++++++++++++++++++
 2 files changed, 41 insertions(+)

diff --git a/arch/riscv/include/uapi/asm/sigcontext.h b/arch/riscv/include/uapi/asm/sigcontext.h
index 84f2dfcfdbce..f74b3c814423 100644
--- a/arch/riscv/include/uapi/asm/sigcontext.h
+++ b/arch/riscv/include/uapi/asm/sigcontext.h
@@ -17,6 +17,7 @@
 struct sigcontext {
 	struct user_regs_struct sc_regs;
 	union __riscv_fp_state sc_fpregs;
+	struct __riscv_v_state sc_vregs;
 };
 
 #endif /* _UAPI_ASM_RISCV_SIGCONTEXT_H */
diff --git a/arch/riscv/kernel/signal.c b/arch/riscv/kernel/signal.c
index 17ba190e84a5..4295c00e8934 100644
--- a/arch/riscv/kernel/signal.c
+++ b/arch/riscv/kernel/signal.c
@@ -83,6 +83,40 @@ static long save_fp_state(struct pt_regs *regs,
 #define restore_fp_state(task, regs) (0)
 #endif
 
+#ifdef CONFIG_VECTOR
+static long restore_v_state(struct pt_regs *regs,
+			    struct __riscv_v_state *sc_vregs)
+{
+	long err;
+	struct __riscv_v_state __user *state = sc_vregs;
+
+	err = __copy_from_user(&current->thread.vstate, state, sizeof(*state));
+	if (unlikely(err))
+		return err;
+
+	vstate_restore(current, regs);
+
+	return err;
+}
+
+static long save_v_state(struct pt_regs *regs,
+			 struct __riscv_v_state *sc_vregs)
+{
+	long err;
+	struct __riscv_v_state __user *state = sc_vregs;
+
+	vstate_save(current, regs);
+	err = __copy_to_user(state, &current->thread.vstate, sizeof(*state));
+	if (unlikely(err))
+		return err;
+
+	return err;
+}
+#else
+#define save_v_state(task, regs) (0)
+#define restore_v_state(task, regs) (0)
+#endif
+
 static long restore_sigcontext(struct pt_regs *regs,
 	struct sigcontext __user *sc)
 {
@@ -92,6 +126,9 @@ static long restore_sigcontext(struct pt_regs *regs,
 	/* Restore the floating-point state. */
 	if (has_fpu)
 		err |= restore_fp_state(regs, &sc->sc_fpregs);
+	/* Restore the vector state. */
+	if (has_vector)
+		err |= restore_v_state(regs, &sc->sc_vregs);
 	return err;
 }
 
@@ -145,6 +182,9 @@ static long setup_sigcontext(struct rt_sigframe __user *frame,
 	/* Save the floating-point state. */
 	if (has_fpu)
 		err |= save_fp_state(regs, &sc->sc_fpregs);
+	/* Save the vector state. */
+	if (has_vector)
+		err |= save_v_state(regs, &sc->sc_vregs);
 	return err;
 }
 
-- 
2.17.0