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From: Jiaxun Yang <jiaxun.yang@flygoat.com>
Date: Tue, 21 May 2024 21:12:14 +0100
Subject: [PATCH 3/4] LoongArch: Fix entry point in image header
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Message-Id: <20240521-loongarch-booting-fixes-v1-3-659c201c0370@flygoat.com>
References: <20240521-loongarch-booting-fixes-v1-0-659c201c0370@flygoat.com>
In-Reply-To: <20240521-loongarch-booting-fixes-v1-0-659c201c0370@flygoat.com>
To: Huacai Chen <chenhuacai@kernel.org>, 
 Binbin Zhou <zhoubinbin@loongson.cn>
Cc: loongarch@lists.linux.dev, linux-kernel@vger.kernel.org, 
 Jiaxun Yang <jiaxun.yang@flygoat.com>, stable@vger.kernel.org

Currently kernel entry in head.S is in DMW address range,
firmware is instructed to jump to this address after loading
the image.

However kernel should not make any assumption on firmware's
DMW setting, thus the entry point should be a physical address
falls into direct translation region.

Fix by applying a calculation to the entry. Note that due
to relocation restriction TO_PHYS can't be used, we can
only do plus and minus here.

Cc: stable@vger.kernel.org
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
---
 arch/loongarch/kernel/head.S | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/loongarch/kernel/head.S b/arch/loongarch/kernel/head.S
index c4f7de2e2805..1a83564023e1 100644
--- a/arch/loongarch/kernel/head.S
+++ b/arch/loongarch/kernel/head.S
@@ -22,7 +22,7 @@
 _head:
 	.word	MZ_MAGIC		/* "MZ", MS-DOS header */
 	.org	0x8
-	.dword	kernel_entry		/* Kernel entry point */
+	.dword	PHYS_LINK_KADDR + (kernel_entry	- _head)	/* Kernel entry point */
 	.dword	_kernel_asize		/* Kernel image effective size */
 	.quad	PHYS_LINK_KADDR		/* Kernel image load offset from start of RAM */
 	.org	0x38			/* 0x20 ~ 0x37 reserved */

-- 
2.43.0