Subject: [PATCH 4/6] powerpc: Fix comment, use clear and restore macros

From: Rohan McLure <[email-masked]>
Date: Wed, 1 Jun 2022 15:48:48 +1000

Only r10 is saved to the PACA. Reflect this in the inline comment.

Replace instructions for restoring gprs from the stack and clearing them
with the REST_GPRS and ZERO_GPRS convenience macros.

Signed-off-by: Rohan McLure <[email-masked]>
---
 arch/powerpc/kernel/exceptions-64s.S |  2 +-
 arch/powerpc/kernel/interrupt_64.S   | 13 +++----------
 2 files changed, 4 insertions(+), 11 deletions(-)

diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index b66dd6f775a4..102896fc6a86 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -281,7 +281,7 @@ BEGIN_FTR_SECTION
 	mfspr	r9,SPRN_PPR
 END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
 	HMT_MEDIUM
-	std	r10,IAREA+EX_R10(r13)		/* save r10 - r12 */
+	std	r10,IAREA+EX_R10(r13)		/* save r10 */
 	.if ICFAR
 BEGIN_FTR_SECTION
 	mfspr	r10,SPRN_CFAR
diff --git a/arch/powerpc/kernel/interrupt_64.S b/arch/powerpc/kernel/interrupt_64.S
index e601ed999798..92740d9889a3 100644
--- a/arch/powerpc/kernel/interrupt_64.S
+++ b/arch/powerpc/kernel/interrupt_64.S
@@ -152,17 +152,10 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
 	/* Could zero these as per ABI, but we may consider a stricter ABI
 	 * which preserves these if libc implementations can benefit, so
 	 * restore them for now until further measurement is done. */
-	ld	r0,GPR0(r1)
-	ld	r4,GPR4(r1)
-	ld	r5,GPR5(r1)
-	ld	r6,GPR6(r1)
-	ld	r7,GPR7(r1)
-	ld	r8,GPR8(r1)
+	REST_GPR(0, r1)
+	REST_GPRS(4, 8, r1)
 	/* Zero volatile regs that may contain sensitive kernel data */
-	li	r9,0
-	li	r10,0
-	li	r11,0
-	li	r12,0
+	ZERO_GPRS(9, 12)
 	mtspr	SPRN_XER,r0
 
 	/*
-- 
2.34.1