[PATCH] powerpc: Fix load/store float double alignment handler

[Michael Neuling]

When we introduced VSX, we changed the way FPRs are stored in the
thread_struct.  Unfortunately we missed the load/store float double
alignment handler code when updating how we access FPRs in the
thread_struct. 

Below fixes this and merges the little/big endian case.  

Signed-off-by: Michael Neuling <mi...@neuling.org>
---
benh: this needs to go into 27,28 and 29.  Sorry :-)

 arch/powerpc/kernel/align.c |   29 +++++++++++++----------------
 1 file changed, 13 insertions(+), 16 deletions(-)

Index: linux-bml/arch/powerpc/kernel/align.c
===================================================================
--- linux-bml.orig/arch/powerpc/kernel/align.c
+++ linux-bml/arch/powerpc/kernel/align.c
@@ -367,27 +367,24 @@ static int emulate_multiple(struct pt_re
 static int emulate_fp_pair(unsigned char __user *addr, unsigned int reg,
                           unsigned int flags)
 {
-       char *ptr = (char *) &current->thread.TS_FPR(reg);
-       int i, ret;
+       char *ptr0 = (char *) &current->thread.TS_FPR(reg);
+       char *ptr1 = (char *) &current->thread.TS_FPR(reg+1);
+       int i, ret, sw = 0;
 
        if (!(flags & F))
                return 0;
        if (reg & 1)
                return 0;       /* invalid form: FRS/FRT must be even */
-       if (!(flags & SW)) {
-               /* not byte-swapped - easy */
-               if (!(flags & ST))
-                       ret = __copy_from_user(ptr, addr, 16);
-               else
-                       ret = __copy_to_user(addr, ptr, 16);
-       } else {
-               /* each FPR value is byte-swapped separately */
-               ret = 0;
-               for (i = 0; i < 16; ++i) {
-                       if (!(flags & ST))
-                               ret |= __get_user(ptr[i^7], addr + i);
-                       else
-                               ret |= __put_user(ptr[i^7], addr + i);
+       if (flags & SW)
+               sw = 7;
+       ret = 0;
+       for (i = 0; i < 8; ++i) {
+               if (!(flags & ST)) {
+                       ret |= __get_user(ptr0[i^sw], addr + i);
+                       ret |= __get_user(ptr1[i^sw], addr + i + 8);
+               } else {
+                       ret |= __put_user(ptr0[i^sw], addr + i);
+                       ret |= __put_user(ptr1[i^sw], addr + i + 8);
                }
        }
        if (ret)

_______________________________________________
Linuxppc-dev mailing list
Linuxppc-dev@ozlabs.org
https://ozlabs.org/mailman/listinfo/linuxppc-dev