1 files changed, 19 insertions, 8 deletions

diff --git a/arch/powerpc/kernel/align.c b/arch/powerpc/kernel/align.c
index cbc7c42cdb74..ec7a8b099dd9 100644
--- a/arch/powerpc/kernel/align.c
+++ b/arch/powerpc/kernel/align.c
@@ -807,14 +807,25 @@ int fix_alignment(struct pt_regs *regs)
         nb = aligninfo[instr].len;
         flags = aligninfo[instr].flags;
 
-        /* ldbrx/stdbrx overlap lfs/stfs in the DSISR unfortunately */
-        if (IS_XFORM(instruction) && ((instruction >> 1) & 0x3ff) == 532) {
-                nb = 8;
-                flags = LD+SW;
-        } else if (IS_XFORM(instruction) &&
-                   ((instruction >> 1) & 0x3ff) == 660) {
-                nb = 8;
-                flags = ST+SW;
+        /*
+         * Handle some cases which give overlaps in the DSISR values.
+         */
+        if (IS_XFORM(instruction)) {
+                switch (get_xop(instruction)) {
+                case 532:       /* ldbrx */
+                        nb = 8;
+                        flags = LD+SW;
+                        break;
+                case 660:       /* stdbrx */
+                        nb = 8;
+                        flags = ST+SW;
+                        break;
+                case 20:        /* lwarx */
+                case 84:        /* ldarx */
+                case 116:       /* lharx */
+                case 276:       /* lqarx */
+                        return 0;       /* not emulated ever */
+                }
         }
 
         /* Byteswap little endian loads and stores */