powerpc: Fix reading and writing SPRs from xmon on 32-bit

When we created the instructions to read/write SPRs in xmon, we were
setting up a ppc64-style procedure descriptor and calling that, which
doesn't work in 32-bit.  For 32-bit a function pointer just points
to the instructions of the function.  This fixes it to do the right
thing for both 32-bit and 64-bit.

Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 18 insertions, 7 deletions

diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index cfcb2a56d662..ef4356b29a97 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -1467,17 +1467,23 @@ read_spr(int n)
 {
         unsigned int instrs[2];
         unsigned long (*code)(void);
-        unsigned long opd[3];
         unsigned long ret = -1UL;
+#ifdef CONFIG_PPC64
+        unsigned long opd[3];
 
-        instrs[0] = 0x7c6002a6 + ((n & 0x1F) << 16) + ((n & 0x3e0) << 6);
-        instrs[1] = 0x4e800020;
         opd[0] = (unsigned long)instrs;
         opd[1] = 0;
         opd[2] = 0;
+        code = (unsigned long (*)(void)) opd;
+#else
+        code = (unsigned long (*)(void)) instrs;
+#endif
+
+        /* mfspr r3,n; blr */
+        instrs[0] = 0x7c6002a6 + ((n & 0x1F) << 16) + ((n & 0x3e0) << 6);
+        instrs[1] = 0x4e800020;
         store_inst(instrs);
         store_inst(instrs+1);
-        code = (unsigned long (*)(void)) opd;
 
         if (setjmp(bus_error_jmp) == 0) {
                 catch_memory_errors = 1;
@@ -1499,16 +1505,21 @@ write_spr(int n, unsigned long val)
 {
         unsigned int instrs[2];
         unsigned long (*code)(unsigned long);
+#ifdef CONFIG_PPC64
         unsigned long opd[3];
 
-        instrs[0] = 0x7c6003a6 + ((n & 0x1F) << 16) + ((n & 0x3e0) << 6);
-        instrs[1] = 0x4e800020;
         opd[0] = (unsigned long)instrs;
         opd[1] = 0;
         opd[2] = 0;
+        code = (unsigned long (*)(unsigned long)) opd;
+#else
+        code = (unsigned long (*)(unsigned long)) instrs;
+#endif
+
+        instrs[0] = 0x7c6003a6 + ((n & 0x1F) << 16) + ((n & 0x3e0) << 6);
+        instrs[1] = 0x4e800020;
         store_inst(instrs);
         store_inst(instrs+1);
-        code = (unsigned long (*)(unsigned long)) opd;
 
         if (setjmp(bus_error_jmp) == 0) {
                 catch_memory_errors = 1;