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

This patch extends the floating point save and restore code to use the
VSX load/stores when VSX is available.  This will make FP context
save/restore marginally slower on FP only code, when VSX is available,
as it has to load/store 128bits rather than just 64bits.

Mixing FP, VMX and VSX code will get constant architected state.

The signals interface is extended to enable access to VSR 0-31
doubleword 1 after discussions with tool chain maintainers.  Backward
compatibility is maintained.

The ptrace interface is also extended to allow access to VSR 0-31 full
registers.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 29 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index b463d48145a..878fbddb6ae 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -967,6 +967,20 @@ void altivec_unavailable_exception(struct pt_regs *regs)
         die("Unrecoverable VMX/Altivec Unavailable Exception", regs, SIGABRT);
 }
 
+void vsx_unavailable_exception(struct pt_regs *regs)
+{
+        if (user_mode(regs)) {
+                /* A user program has executed an vsx instruction,
+                   but this kernel doesn't support vsx. */
+                _exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
+                return;
+        }
+
+        printk(KERN_EMERG "Unrecoverable VSX Unavailable Exception "
+                        "%lx at %lx\n", regs->trap, regs->nip);
+        die("Unrecoverable VSX Unavailable Exception", regs, SIGABRT);
+}
+
 void performance_monitor_exception(struct pt_regs *regs)
 {
         perf_irq(regs);
@@ -1099,6 +1113,21 @@ void altivec_assist_exception(struct pt_regs *regs)
 }
 #endif /* CONFIG_ALTIVEC */
 
+#ifdef CONFIG_VSX
+void vsx_assist_exception(struct pt_regs *regs)
+{
+        if (!user_mode(regs)) {
+                printk(KERN_EMERG "VSX assist exception in kernel mode"
+                       " at %lx\n", regs->nip);
+                die("Kernel VSX assist exception", regs, SIGILL);
+        }
+
+        flush_vsx_to_thread(current);
+        printk(KERN_INFO "VSX assist not supported at %lx\n", regs->nip);
+        _exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
+}
+#endif /* CONFIG_VSX */
+
 #ifdef CONFIG_FSL_BOOKE
 void CacheLockingException(struct pt_regs *regs, unsigned long address,
                            unsigned long error_code)