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From: Jinglin Wen <jinglin.wen@shingroup.cn>
To: npiggin@gmail.com
Cc: mpe@ellerman.id.au,
	christophe.leroy@csgroup.eu,
	naveen.n.rao@linux.ibm.com,
	jinglin.wen@shingroup.cn,
	masahiroy@kernel.org,
	linuxppc-dev@lists.ozlabs.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH] powerpc: Fixed the bug of duplicate copying
Date: Thu,  6 Jun 2024 21:21:32 +0800
Message-Id: <20240606132132.13785-1-jinglin.wen@shingroup.cn>
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Feedback-ID: bizesmtpsz:shingroup.cn:qybglogicsvrgz:qybglogicsvrgz5a-2

Fixed the issue where the kernel, when booting from address 0, had
code incorrectly duplicated to address 0.

Signed-off-by: Jinglin Wen <jinglin.wen@shingroup.cn>
---
 arch/powerpc/kernel/head_64.S | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
index 4690c219bfa4..6c73551bdc50 100644
--- a/arch/powerpc/kernel/head_64.S
+++ b/arch/powerpc/kernel/head_64.S
@@ -647,7 +647,9 @@ __after_prom_start:
  * Note: This process overwrites the OF exception vectors.
  */
 	LOAD_REG_IMMEDIATE(r3, PAGE_OFFSET)
-	mr.	r4,r26			/* In some cases the loader may  */
+	tophys(r4,r26)
+	cmplwi	cr0,r4,0	/* runtime base addr is zero */
+	mr	r4,r26			/* In some cases the loader may */
 	beq	9f			/* have already put us at zero */
 	li	r6,0x100		/* Start offset, the first 0x100 */
 					/* bytes were copied earlier.	 */
-- 
2.25.1