[PATCH 5.16 074/203] riscv: Fix XIP_FIXUP_FLASH_OFFSET

From: Greg Kroah-Hartman
Date: Mon Feb 14 2022 - 05:29:04 EST


From: Myrtle Shah <gatecat@xxxxxx>

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@xxxxxxxxxxxxxxx
Signed-off-by: Myrtle Shah <gatecat@xxxxxx>
Signed-off-by: Palmer Dabbelt <palmer@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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