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>

1 files changed, 11 insertions, 3 deletions

diff --git a/arch/powerpc/kernel/ptrace32.c b/arch/powerpc/kernel/ptrace32.c
index 4c1de6af4c09..67bf1a1e7e14 100644
--- a/arch/powerpc/kernel/ptrace32.c
+++ b/arch/powerpc/kernel/ptrace32.c
@@ -64,6 +64,11 @@ static long compat_ptrace_old(struct task_struct *child, long request,
         return -EPERM;
 }
 
+/* Macros to workout the correct index for the FPR in the thread struct */
+#define FPRNUMBER(i) (((i) - PT_FPR0) >> 1)
+#define FPRHALF(i) (((i) - PT_FPR0) & 1)
+#define FPRINDEX(i) TS_FPRWIDTH * FPRNUMBER(i) + FPRHALF(i)
+
 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
                         compat_ulong_t caddr, compat_ulong_t cdata)
 {
@@ -122,7 +127,8 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
                          * to be an array of unsigned int (32 bits) - the
                          * index passed in is based on this assumption.
                          */
-                        tmp = ((unsigned int *)child->thread.fpr)[index - PT_FPR0];
+                        tmp = ((unsigned int *)child->thread.fpr)
+                                [FPRINDEX(index)];
                 }
                 ret = put_user((unsigned int)tmp, (u32 __user *)data);
                 break;
@@ -162,7 +168,8 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
                 CHECK_FULL_REGS(child->thread.regs);
                 if (numReg >= PT_FPR0) {
                         flush_fp_to_thread(child);
-                        tmp = ((unsigned long int *)child->thread.fpr)[numReg - PT_FPR0];
+                        tmp = ((unsigned long int *)child->thread.fpr)
+                                [FPRINDEX(numReg)];
                 } else { /* register within PT_REGS struct */
                         tmp = ptrace_get_reg(child, numReg);
                 } 
@@ -217,7 +224,8 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
                          * to be an array of unsigned int (32 bits) - the
                          * index passed in is based on this assumption.
                          */
-                        ((unsigned int *)child->thread.fpr)[index - PT_FPR0] = data;
+                        ((unsigned int *)child->thread.fpr)
+                                [FPRINDEX(index)] = data;
                         ret = 0;
                 }
                 break;