MIPS: Move & rename fpu_emulator_{save,restore}_context

These functions aren't directly related to the FPU emulator at all, they
simply copy between a thread's saved context & a sigcontext. Thus move
them to the appropriate signal files & rename them accordingly. This
makes it clearer that the functions don't require the FPU emulator in
any way.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Reviewed-by: Qais Yousef <qais.yousef@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/6422/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

2 files changed, 76 insertions, 12 deletions

diff --git a/arch/mips/kernel/signal.c b/arch/mips/kernel/signal.c
index 5199563c4403..b7e4614d41b5 100644
--- a/arch/mips/kernel/signal.c
+++ b/arch/mips/kernel/signal.c
@@ -46,9 +46,6 @@ static int (*restore_fp_context)(struct sigcontext __user *sc);
 extern asmlinkage int _save_fp_context(struct sigcontext __user *sc);
 extern asmlinkage int _restore_fp_context(struct sigcontext __user *sc);
 
-extern asmlinkage int fpu_emulator_save_context(struct sigcontext __user *sc);
-extern asmlinkage int fpu_emulator_restore_context(struct sigcontext __user *sc);
-
 struct sigframe {
 	u32 sf_ass[4];		/* argument save space for o32 */
 	u32 sf_pad[2];		/* Was: signal trampoline */
@@ -64,6 +61,40 @@ struct rt_sigframe {
 };
 
 /*
+ * Thread saved context copy to/from a signal context presumed to be on the
+ * user stack, and therefore accessed with appropriate macros from uaccess.h.
+ */
+static int copy_fp_to_sigcontext(struct sigcontext __user *sc)
+{
+	int i;
+	int err = 0;
+
+	for (i = 0; i < 32; i++) {
+		err |=
+		    __put_user(get_fpr64(&current->thread.fpu.fpr[i], 0),
+			       &sc->sc_fpregs[i]);
+	}
+	err |= __put_user(current->thread.fpu.fcr31, &sc->sc_fpc_csr);
+
+	return err;
+}
+
+static int copy_fp_from_sigcontext(struct sigcontext __user *sc)
+{
+	int i;
+	int err = 0;
+	u64 fpr_val;
+
+	for (i = 0; i < 32; i++) {
+		err |= __get_user(fpr_val, &sc->sc_fpregs[i]);
+		set_fpr64(&current->thread.fpu.fpr[i], 0, fpr_val);
+	}
+	err |= __get_user(current->thread.fpu.fcr31, &sc->sc_fpc_csr);
+
+	return err;
+}
+
+/*
  * Helper routines
  */
 static int protected_save_fp_context(struct sigcontext __user *sc)
@@ -595,14 +626,14 @@ static int smp_save_fp_context(struct sigcontext __user *sc)
 {
 	return raw_cpu_has_fpu
 	       ? _save_fp_context(sc)
-	       : fpu_emulator_save_context(sc);
+	       : copy_fp_to_sigcontext(sc);
 }
 
 static int smp_restore_fp_context(struct sigcontext __user *sc)
 {
 	return raw_cpu_has_fpu
 	       ? _restore_fp_context(sc)
-	       : fpu_emulator_restore_context(sc);
+	       : copy_fp_from_sigcontext(sc);
 }
 #endif
 
@@ -617,8 +648,8 @@ static int signal_setup(void)
 		save_fp_context = _save_fp_context;
 		restore_fp_context = _restore_fp_context;
 	} else {
-		save_fp_context = fpu_emulator_save_context;
-		restore_fp_context = fpu_emulator_restore_context;
+		save_fp_context = copy_fp_from_sigcontext;
+		restore_fp_context = copy_fp_to_sigcontext;
 	}
 #endif
 
diff --git a/arch/mips/kernel/signal32.c b/arch/mips/kernel/signal32.c
index 3d60f7750fa8..dc09206d8c7b 100644
--- a/arch/mips/kernel/signal32.c
+++ b/arch/mips/kernel/signal32.c
@@ -42,9 +42,6 @@ static int (*restore_fp_context32)(struct sigcontext32 __user *sc);
 extern asmlinkage int _save_fp_context32(struct sigcontext32 __user *sc);
 extern asmlinkage int _restore_fp_context32(struct sigcontext32 __user *sc);
 
-extern asmlinkage int fpu_emulator_save_context32(struct sigcontext32 __user *sc);
-extern asmlinkage int fpu_emulator_restore_context32(struct sigcontext32 __user *sc);
-
 /*
  * Including <asm/unistd.h> would give use the 64-bit syscall numbers ...
  */
@@ -78,6 +75,42 @@ struct rt_sigframe32 {
 };
 
 /*
+ * Thread saved context copy to/from a signal context presumed to be on the
+ * user stack, and therefore accessed with appropriate macros from uaccess.h.
+ */
+static int copy_fp_to_sigcontext32(struct sigcontext32 __user *sc)
+{
+	int i;
+	int err = 0;
+	int inc = test_thread_flag(TIF_32BIT_FPREGS) ? 2 : 1;
+
+	for (i = 0; i < 32; i += inc) {
+		err |=
+		    __put_user(get_fpr64(&current->thread.fpu.fpr[i], 0),
+			       &sc->sc_fpregs[i]);
+	}
+	err |= __put_user(current->thread.fpu.fcr31, &sc->sc_fpc_csr);
+
+	return err;
+}
+
+static int copy_fp_from_sigcontext32(struct sigcontext32 __user *sc)
+{
+	int i;
+	int err = 0;
+	int inc = test_thread_flag(TIF_32BIT_FPREGS) ? 2 : 1;
+	u64 fpr_val;
+
+	for (i = 0; i < 32; i += inc) {
+		err |= __get_user(fpr_val, &sc->sc_fpregs[i]);
+		set_fpr64(&current->thread.fpu.fpr[i], 0, fpr_val);
+	}
+	err |= __get_user(current->thread.fpu.fcr31, &sc->sc_fpc_csr);
+
+	return err;
+}
+
+/*
  * sigcontext handlers
  */
 static int protected_save_fp_context32(struct sigcontext32 __user *sc)
@@ -566,8 +599,8 @@ static int signal32_init(void)
 		save_fp_context32 = _save_fp_context32;
 		restore_fp_context32 = _restore_fp_context32;
 	} else {
-		save_fp_context32 = fpu_emulator_save_context32;
-		restore_fp_context32 = fpu_emulator_restore_context32;
+		save_fp_context32 = copy_fp_to_sigcontext32;
+		restore_fp_context32 = copy_fp_from_sigcontext32;
 	}
 
 	return 0;