linux-kernel - [PATCH 5.16 074/203] riscv: Fix XIP_FIXUP_FLASH

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Date:   Mon, 14 Feb 2022 10:25:18 +0100
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Myrtle Shah <gatecat@....me>,
        Palmer Dabbelt <palmer@...osinc.com>
Subject: [PATCH 5.16 074/203] riscv: Fix XIP_FIXUP_FLASH_OFFSET

From: Myrtle Shah <gatecat@....me>

commit 3c04d84508b54fcf524093b0d4a718680ed67f0f upstream.

There were several problems with the calculation. Not only was an 'and'
being computed into t1 but thrown away; but the 'and' itself would
cause problems if the granularity of the XIP physical address was less
than XIP_OFFSET - in my case I had the kernel image at 2MB in SPI flash.

Fixes: f9ace4ede49b ("riscv: remove .text section size limitation for XIP")
Cc: stable@...r.kernel.org
Signed-off-by: Myrtle Shah <gatecat@....me>
Signed-off-by: Palmer Dabbelt <palmer@...osinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
 arch/riscv/kernel/head.S |   11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

--- a/arch/riscv/kernel/head.S
+++ b/arch/riscv/kernel/head.S
@@ -21,14 +21,13 @@
 	add \reg, \reg, t0
 .endm
 .macro XIP_FIXUP_FLASH_OFFSET reg
-	la t1, __data_loc
-	li t0, XIP_OFFSET_MASK
-	and t1, t1, t0
-	li t1, XIP_OFFSET
-	sub t0, t0, t1
-	sub \reg, \reg, t0
+	la t0, __data_loc
+	REG_L t1, _xip_phys_offset
+	sub \reg, \reg, t1
+	add \reg, \reg, t0
 .endm
 _xip_fixup: .dword CONFIG_PHYS_RAM_BASE - CONFIG_XIP_PHYS_ADDR - XIP_OFFSET
+_xip_phys_offset: .dword CONFIG_XIP_PHYS_ADDR + XIP_OFFSET
 #else
 .macro XIP_FIXUP_OFFSET reg
 .endm