1 files changed, 78 insertions, 13 deletions

diff --git a/arch/mips/kernel/signal.c b/arch/mips/kernel/signal.c
index 2f285abc76d..9e60d117e41 100644
--- a/arch/mips/kernel/signal.c
+++ b/arch/mips/kernel/signal.c
@@ -6,6 +6,7 @@
  * Copyright (C) 1991, 1992  Linus Torvalds
  * Copyright (C) 1994 - 2000  Ralf Baechle
  * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
+ * Copyright (C) 2014, Imagination Technologies Ltd.
  */
 #include <linux/cache.h>
 #include <linux/context_tracking.h>
@@ -46,9 +47,6 @@ 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 */
@@ -64,16 +62,55 @@ 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 < NUM_FPU_REGS; 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 < NUM_FPU_REGS; 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)
 {
 	int err;
+#ifndef CONFIG_EVA
 	while (1) {
 		lock_fpu_owner();
-		own_fpu_inatomic(1);
-		err = save_fp_context(sc); /* this might fail */
-		unlock_fpu_owner();
+		if (is_fpu_owner()) {
+			err = save_fp_context(sc);
+			unlock_fpu_owner();
+		} else {
+			unlock_fpu_owner();
+			err = copy_fp_to_sigcontext(sc);
+		}
 		if (likely(!err))
 			break;
 		/* touch the sigcontext and try again */
@@ -83,17 +120,30 @@ static int protected_save_fp_context(struct sigcontext __user *sc)
 		if (err)
 			break;	/* really bad sigcontext */
 	}
+#else
+	/*
+	 * EVA does not have FPU EVA instructions so saving fpu context directly
+	 * does not work.
+	 */
+	lose_fpu(1);
+	err = save_fp_context(sc); /* this might fail */
+#endif
 	return err;
 }
 
 static int protected_restore_fp_context(struct sigcontext __user *sc)
 {
 	int err, tmp __maybe_unused;
+#ifndef CONFIG_EVA
 	while (1) {
 		lock_fpu_owner();
-		own_fpu_inatomic(0);
-		err = restore_fp_context(sc); /* this might fail */
-		unlock_fpu_owner();
+		if (is_fpu_owner()) {
+			err = restore_fp_context(sc);
+			unlock_fpu_owner();
+		} else {
+			unlock_fpu_owner();
+			err = copy_fp_from_sigcontext(sc);
+		}
 		if (likely(!err))
 			break;
 		/* touch the sigcontext and try again */
@@ -103,6 +153,14 @@ static int protected_restore_fp_context(struct sigcontext __user *sc)
 		if (err)
 			break;	/* really bad sigcontext */
 	}
+#else
+	/*
+	 * EVA does not have FPU EVA instructions so restoring fpu context
+	 * directly does not work.
+	 */
+	lose_fpu(0);
+	err = restore_fp_context(sc); /* this might fail */
+#endif
 	return err;
 }
 
@@ -589,23 +647,26 @@ asmlinkage void do_notify_resume(struct pt_regs *regs, void *unused,
 }
 
 #ifdef CONFIG_SMP
+#ifndef CONFIG_EVA
 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 /* CONFIG_EVA */
 #endif
 
 static int signal_setup(void)
 {
+#ifndef CONFIG_EVA
 #ifdef CONFIG_SMP
 	/* For now just do the cpu_has_fpu check when the functions are invoked */
 	save_fp_context = smp_save_fp_context;
@@ -615,9 +676,13 @@ 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 /* CONFIG_SMP */
+#else
+	save_fp_context = copy_fp_from_sigcontext;;
+	restore_fp_context = copy_fp_to_sigcontext;
 #endif
 
 	return 0;