Thread (25 messages) 25 messages, 3 authors, 2019-11-26

[PATCH v3 12/15] powerpc/8xx: split breakpoint exception

From: Christophe Leroy <hidden>
Date: 2019-09-10 09:17:47
Also in: linux-mm, lkml
Subsystem: linux for powerpc (32-bit and 64-bit), the rest · Maintainers: Madhavan Srinivasan, Michael Ellerman, Linus Torvalds

Breakpoint exception is big.

Split it to support future growth on exception prolog.

Signed-off-by: Christophe Leroy <redacted>
---
 arch/powerpc/kernel/head_8xx.S | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 1e718e47fe3c..225e242ce1c5 100644
--- 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
-- 
2.13.3
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