Refactor FPU code in signal setup/return procedures

FPU-related logic is separated from normal signal handling path in
this patch.  Kernel can easily be configured to exclude those procedures
for no-FPU systems.

Signed-off-by: Alan Kao <alankao@andestech.com>
Cc: Greentime Hu <greentime@andestech.com>
Cc: Vincent Chen <vincentc@andestech.com>
Cc: Zong Li <zong@andestech.com>
Cc: Nick Hu <nickhu@andestech.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

1 files changed, 41 insertions, 27 deletions

diff --git a/arch/riscv/kernel/signal.c b/arch/riscv/kernel/signal.c
index 718d0c984ef0..6a18b9819ead 100644
--- a/arch/riscv/kernel/signal.c
+++ b/arch/riscv/kernel/signal.c
@@ -37,45 +37,63 @@ struct rt_sigframe {
         struct ucontext uc;
 };
 
-static long restore_d_state(struct pt_regs *regs,
-        struct __riscv_d_ext_state __user *state)
+static long restore_fp_state(struct pt_regs *regs,
+                             union __riscv_fp_state *sc_fpregs)
 {
         long err;
+        struct __riscv_d_ext_state __user *state = &sc_fpregs->d;
+        size_t i;
+
         err = __copy_from_user(&current->thread.fstate, state, sizeof(*state));
-        if (likely(!err))
-                fstate_restore(current, regs);
+        if (unlikely(err))
+                return err;
+
+        fstate_restore(current, regs);
+
+        /* We support no other extension state at this time. */
+        for (i = 0; i < ARRAY_SIZE(sc_fpregs->q.reserved); i++) {
+                u32 value;
+
+                err = __get_user(value, &sc_fpregs->q.reserved[i]);
+                if (unlikely(err))
+                        break;
+                if (value != 0)
+                        return -EINVAL;
+        }
+
         return err;
 }
 
-static long save_d_state(struct pt_regs *regs,
-        struct __riscv_d_ext_state __user *state)
+static long save_fp_state(struct pt_regs *regs,
+                          union __riscv_fp_state *sc_fpregs)
 {
+        long err;
+        struct __riscv_d_ext_state __user *state = &sc_fpregs->d;
+        size_t i;
+
         fstate_save(current, regs);
-        return __copy_to_user(state, &current->thread.fstate, sizeof(*state));
+        err = __copy_to_user(state, &current->thread.fstate, sizeof(*state));
+        if (unlikely(err))
+                return err;
+
+        /* We support no other extension state at this time. */
+        for (i = 0; i < ARRAY_SIZE(sc_fpregs->q.reserved); i++) {
+                err = __put_user(0, &sc_fpregs->q.reserved[i]);
+                if (unlikely(err))
+                        break;
+        }
+
+        return err;
 }
 
 static long restore_sigcontext(struct pt_regs *regs,
         struct sigcontext __user *sc)
 {
         long err;
-        size_t i;
         /* sc_regs is structured the same as the start of pt_regs */
         err = __copy_from_user(regs, &sc->sc_regs, sizeof(sc->sc_regs));
-        if (unlikely(err))
-                return err;
         /* Restore the floating-point state. */
-        err = restore_d_state(regs, &sc->sc_fpregs.d);
-        if (unlikely(err))
-                return err;
-        /* We support no other extension state at this time. */
-        for (i = 0; i < ARRAY_SIZE(sc->sc_fpregs.q.reserved); i++) {
-                u32 value;
-                err = __get_user(value, &sc->sc_fpregs.q.reserved[i]);
-                if (unlikely(err))
-                        break;
-                if (value != 0)
-                        return -EINVAL;
-        }
+        err |= restore_fp_state(regs, &sc->sc_fpregs);
         return err;
 }
 
@@ -124,14 +142,10 @@ static long setup_sigcontext(struct rt_sigframe __user *frame,
 {
         struct sigcontext __user *sc = &frame->uc.uc_mcontext;
         long err;
-        size_t i;
         /* sc_regs is structured the same as the start of pt_regs */
         err = __copy_to_user(&sc->sc_regs, regs, sizeof(sc->sc_regs));
         /* Save the floating-point state. */
-        err |= save_d_state(regs, &sc->sc_fpregs.d);
-        /* We support no other extension state at this time. */
-        for (i = 0; i < ARRAY_SIZE(sc->sc_fpregs.q.reserved); i++)
-                err |= __put_user(0, &sc->sc_fpregs.q.reserved[i]);
+        err |= save_fp_state(regs, &sc->sc_fpregs);
         return err;
 }