powerpc: Add macros to access floating point registers in thread_struct.

We are going to change where the floating point registers are stored
in the thread_struct, so in preparation add some macros to access the
floating point registers.  Update all code to use these new macros.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c
index 2a9fe97..59ff087 100644
--- a/arch/powerpc/kernel/ptrace.c
+++ b/arch/powerpc/kernel/ptrace.c
@@ -218,7 +218,7 @@
 	flush_fp_to_thread(target);
 
 	BUILD_BUG_ON(offsetof(struct thread_struct, fpscr) !=
-		     offsetof(struct thread_struct, fpr[32]));
+		     offsetof(struct thread_struct, TS_FPR(32)));
 
 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 				   &target->thread.fpr, 0, -1);
@@ -231,7 +231,7 @@
 	flush_fp_to_thread(target);
 
 	BUILD_BUG_ON(offsetof(struct thread_struct, fpscr) !=
-		     offsetof(struct thread_struct, fpr[32]));
+		     offsetof(struct thread_struct, TS_FPR(32)));
 
 	return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 				  &target->thread.fpr, 0, -1);
@@ -728,7 +728,8 @@
 			tmp = ptrace_get_reg(child, (int) index);
 		} else {
 			flush_fp_to_thread(child);
-			tmp = ((unsigned long *)child->thread.fpr)[index - PT_FPR0];
+			tmp = ((unsigned long *)child->thread.fpr)
+				[TS_FPRWIDTH * (index - PT_FPR0)];
 		}
 		ret = put_user(tmp,(unsigned long __user *) data);
 		break;
@@ -755,7 +756,8 @@
 			ret = ptrace_put_reg(child, index, data);
 		} else {
 			flush_fp_to_thread(child);
-			((unsigned long *)child->thread.fpr)[index - PT_FPR0] = data;
+			((unsigned long *)child->thread.fpr)
+				[TS_FPRWIDTH * (index - PT_FPR0)] = data;
 			ret = 0;
 		}
 		break;