powerpc/8xx: Split breakpoint exception

Breakpoint exception is big.

Split it to support future growth on exception prolog.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1dda3293d86d0f715b13b2633c95d2188a42a02c.1576916812.git.christophe.leroy@c-s.fr

diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 1e718e4..225e242 100644 (file)
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -490,14 +490,7 @@ DARFixed:/* Return from dcbx instruction bug workaround */
  * support of breakpoints and such.  Someday I will get around to
  * using them.
  */
-       . = 0x1c00
-DataBreakpoint:
-       EXCEPTION_PROLOG_0
-       mfspr   r11, SPRN_SRR0
-       cmplwi  cr1, r11, (.Ldtlbie - PAGE_OFFSET)@l
-       cmplwi  cr7, r11, (.Litlbie - PAGE_OFFSET)@l
-       beq-    cr1, 11f
-       beq-    cr7, 11f
+do_databreakpoint:
        EXCEPTION_PROLOG_1
        EXCEPTION_PROLOG_2
        addi    r3,r1,STACK_FRAME_OVERHEAD
@@ -505,7 +498,15 @@ DataBreakpoint:
        stw     r4,_DAR(r11)
        mfspr   r5,SPRN_DSISR
        EXC_XFER_STD(0x1c00, do_break)
-11:
+
+       . = 0x1c00
+DataBreakpoint:
+       EXCEPTION_PROLOG_0
+       mfspr   r11, SPRN_SRR0
+       cmplwi  cr1, r11, (.Ldtlbie - PAGE_OFFSET)@l
+       cmplwi  cr7, r11, (.Litlbie - PAGE_OFFSET)@l
+       cror    4*cr1+eq, 4*cr1+eq, 4*cr7+eq
+       bne     cr1, do_databreakpoint
        mtcr    r10
        mfspr   r10, SPRN_SPRG_SCRATCH0
        mfspr   r11, SPRN_SPRG_SCRATCH1