powerpc: Add VSX context save/restore, ptrace and signal support

[linux-2.6-omap-h63xx.git] / arch / powerpc / kernel / signal_32.c

diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index f7fa395b9fb5da1d18446895d6bb111f7a17de73..349d3487d92014709f8f142c383e117180f42583 100644 (file)
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -378,6 +378,21 @@ static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
        memcpy(&buf[i], &current->thread.fpscr, sizeof(double));
        if (__copy_to_user(&frame->mc_fregs, buf, ELF_NFPREG * sizeof(double)))
                return 1;
+       /*
+        * Copy VSR 0-31 upper half from thread_struct to local
+        * buffer, then write that to userspace.  Also set MSR_VSX in
+        * the saved MSR value to indicate that frame->mc_vregs
+        * contains valid data
+        */
+       if (current->thread.used_vsr) {
+               flush_vsx_to_thread(current);
+               for (i = 0; i < 32 ; i++)
+                       buf[i] = current->thread.fpr[i][TS_VSRLOWOFFSET];
+               if (__copy_to_user(&frame->mc_vsregs, buf,
+                                  ELF_NVSRHALFREG  * sizeof(double)))
+                       return 1;
+               msr |= MSR_VSX;
+       }
 #else
        /* save floating-point registers */
        if (__copy_to_user(&frame->mc_fregs, current->thread.fpr,
@@ -482,6 +497,24 @@ static long restore_user_regs(struct pt_regs *regs,
        for (i = 0; i < 32 ; i++)
                current->thread.TS_FPR(i) = buf[i];
        memcpy(&current->thread.fpscr, &buf[i], sizeof(double));
+       /*
+        * Force the process to reload the VSX registers from
+        * current->thread when it next does VSX instruction.
+        */
+       regs->msr &= ~MSR_VSX;
+       if (msr & MSR_VSX) {
+               /*
+                * Restore altivec registers from the stack to a local
+                * buffer, then write this out to the thread_struct
+                */
+               if (__copy_from_user(buf, &sr->mc_vsregs,
+                                    sizeof(sr->mc_vsregs)))
+                       return 1;
+               for (i = 0; i < 32 ; i++)
+                       current->thread.fpr[i][TS_VSRLOWOFFSET] = buf[i];
+       } else if (current->thread.used_vsr)
+               for (i = 0; i < 32 ; i++)
+                       current->thread.fpr[i][TS_VSRLOWOFFSET] = 0;
 #else
        if (__copy_from_user(current->thread.fpr, &sr->mc_fregs,
                             sizeof(sr->mc_fregs)))