1 files changed, 148 insertions, 22 deletions

diff --git a/arch/mips/kernel/signal.c b/arch/mips/kernel/signal.c
index 5199563c4403..33133d3df3e5 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>
@@ -30,6 +31,7 @@
 #include <linux/bitops.h>
 #include <asm/cacheflush.h>
 #include <asm/fpu.h>
+#include <asm/msa.h>
 #include <asm/sim.h>
 #include <asm/ucontext.h>
 #include <asm/cpu-features.h>
@@ -46,8 +48,8 @@ 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);
+extern asmlinkage int _save_msa_context(struct sigcontext __user *sc);
+extern asmlinkage int _restore_msa_context(struct sigcontext __user *sc);
 
 struct sigframe {
         u32 sf_ass[4];          /* argument save space for o32 */
@@ -64,17 +66,95 @@ 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;
+}
+
+/*
+ * These functions will save only the upper 64 bits of the vector registers,
+ * since the lower 64 bits have already been saved as the scalar FP context.
+ */
+static int copy_msa_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], 1),
+                               &sc->sc_msaregs[i]);
+        }
+        err |= __put_user(current->thread.fpu.msacsr, &sc->sc_msa_csr);
+
+        return err;
+}
+
+static int copy_msa_from_sigcontext(struct sigcontext __user *sc)
+{
+        int i;
+        int err = 0;
+        u64 val;
+
+        for (i = 0; i < NUM_FPU_REGS; i++) {
+                err |= __get_user(val, &sc->sc_msaregs[i]);
+                set_fpr64(&current->thread.fpu.fpr[i], 1, val);
+        }
+        err |= __get_user(current->thread.fpu.msacsr, &sc->sc_msa_csr);
+
+        return err;
+}
+
+/*
  * Helper routines
  */
-static int protected_save_fp_context(struct sigcontext __user *sc)
+static int protected_save_fp_context(struct sigcontext __user *sc,
+                                     unsigned used_math)
 {
         int err;
+        bool save_msa = cpu_has_msa && (used_math & USEDMATH_MSA);
+#ifndef CONFIG_EVA
         while (1) {
                 lock_fpu_owner();
-                err = own_fpu_inatomic(1);
-                if (!err)
-                        err = save_fp_context(sc); /* this might fail */
-                unlock_fpu_owner();
+                if (is_fpu_owner()) {
+                        err = save_fp_context(sc);
+                        if (save_msa && !err)
+                                err = _save_msa_context(sc);
+                        unlock_fpu_owner();
+                } else {
+                        unlock_fpu_owner();
+                        err = copy_fp_to_sigcontext(sc);
+                        if (save_msa && !err)
+                                err = copy_msa_to_sigcontext(sc);
+                }
                 if (likely(!err))
                         break;
                 /* touch the sigcontext and try again */
@@ -84,18 +164,44 @@ 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.
+         */
+        disable_msa();
+        lose_fpu(1);
+        err = save_fp_context(sc); /* this might fail */
+        if (save_msa && !err)
+                err = copy_msa_to_sigcontext(sc);
+#endif
         return err;
 }
 
-static int protected_restore_fp_context(struct sigcontext __user *sc)
+static int protected_restore_fp_context(struct sigcontext __user *sc,
+                                        unsigned used_math)
 {
         int err, tmp __maybe_unused;
+        bool restore_msa = cpu_has_msa && (used_math & USEDMATH_MSA);
+#ifndef CONFIG_EVA
         while (1) {
                 lock_fpu_owner();
-                err = own_fpu_inatomic(0);
-                if (!err)
-                        err = restore_fp_context(sc); /* this might fail */
-                unlock_fpu_owner();
+                if (is_fpu_owner()) {
+                        err = restore_fp_context(sc);
+                        if (restore_msa && !err) {
+                                enable_msa();
+                                err = _restore_msa_context(sc);
+                        } else {
+                                /* signal handler may have used MSA */
+                                disable_msa();
+                        }
+                        unlock_fpu_owner();
+                } else {
+                        unlock_fpu_owner();
+                        err = copy_fp_from_sigcontext(sc);
+                        if (!err && (used_math & USEDMATH_MSA))
+                                err = copy_msa_from_sigcontext(sc);
+                }
                 if (likely(!err))
                         break;
                 /* touch the sigcontext and try again */
@@ -105,6 +211,17 @@ 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.
+         */
+        enable_msa();
+        lose_fpu(0);
+        err = restore_fp_context(sc); /* this might fail */
+        if (restore_msa && !err)
+                err = copy_msa_from_sigcontext(sc);
+#endif
         return err;
 }
 
@@ -135,7 +252,8 @@ int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
                 err |= __put_user(rddsp(DSP_MASK), &sc->sc_dsp);
         }
 
-        used_math = !!used_math();
+        used_math = used_math() ? USEDMATH_FP : 0;
+        used_math |= thread_msa_context_live() ? USEDMATH_MSA : 0;
         err |= __put_user(used_math, &sc->sc_used_math);
 
         if (used_math) {
@@ -143,7 +261,7 @@ int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
                  * Save FPU state to signal context. Signal handler
                  * will "inherit" current FPU state.
                  */
-                err |= protected_save_fp_context(sc);
+                err |= protected_save_fp_context(sc, used_math);
         }
         return err;
 }
@@ -168,14 +286,14 @@ int fpcsr_pending(unsigned int __user *fpcsr)
 }
 
 static int
-check_and_restore_fp_context(struct sigcontext __user *sc)
+check_and_restore_fp_context(struct sigcontext __user *sc, unsigned used_math)
 {
         int err, sig;
 
         err = sig = fpcsr_pending(&sc->sc_fpc_csr);
         if (err > 0)
                 err = 0;
-        err |= protected_restore_fp_context(sc);
+        err |= protected_restore_fp_context(sc, used_math);
         return err ?: sig;
 }
 
@@ -215,9 +333,10 @@ int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
         if (used_math) {
                 /* restore fpu context if we have used it before */
                 if (!err)
-                        err = check_and_restore_fp_context(sc);
+                        err = check_and_restore_fp_context(sc, used_math);
         } else {
-                /* signal handler may have used FPU.  Give it up. */
+                /* signal handler may have used FPU or MSA. Disable them. */
+                disable_msa();
                 lose_fpu(0);
         }
 
@@ -591,23 +710,26 @@ 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;
@@ -617,9 +739,13 @@ 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;