Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc

[linux-2.6-omap-h63xx.git] / arch / powerpc / kernel / entry_32.S

diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 7ecc0d1855c3342d341a8b00ea9cdbd9f51d1b42..6f7eb7e00c79eb3df9c6eba5ad61087e36427015 100644 (file)
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -1162,39 +1162,17 @@ machine_check_in_rtas:
 #ifdef CONFIG_DYNAMIC_FTRACE
 _GLOBAL(mcount)
 _GLOBAL(_mcount)
-       stwu    r1,-48(r1)
-       stw     r3, 12(r1)
-       stw     r4, 16(r1)
-       stw     r5, 20(r1)
-       stw     r6, 24(r1)
-       mflr    r3
-       stw     r7, 28(r1)
-       mfcr    r5
-       stw     r8, 32(r1)
-       stw     r9, 36(r1)
-       stw     r10,40(r1)
-       stw     r3, 44(r1)
-       stw     r5, 8(r1)
-       subi    r3, r3, MCOUNT_INSN_SIZE
-       .globl mcount_call
-mcount_call:
-       bl      ftrace_stub
-       nop
-       lwz     r6, 8(r1)
-       lwz     r0, 44(r1)
-       lwz     r3, 12(r1)
+       /*
+        * It is required that _mcount on PPC32 must preserve the
+        * link register. But we have r0 to play with. We use r0
+        * to push the return address back to the caller of mcount
+        * into the ctr register, restore the link register and
+        * then jump back using the ctr register.
+        */
+       mflr    r0
        mtctr   r0
-       lwz     r4, 16(r1)
-       mtcr    r6
-       lwz     r5, 20(r1)
-       lwz     r6, 24(r1)
-       lwz     r0, 52(r1)
-       lwz     r7, 28(r1)
-       lwz     r8, 32(r1)
+       lwz     r0, 4(r1)
        mtlr    r0
-       lwz     r9, 36(r1)
-       lwz     r10,40(r1)
-       addi    r1, r1, 48
        bctr
 
 _GLOBAL(ftrace_caller)