XIP_OFFSET is the hard-coded offset of writable data section within the
kernel.

By hard-coding this value, the read-only section of the kernel (which is
placed before the writable data section) is restricted in size.

As a preparation to remove this hard-coded macro XIP_OFFSET entirely,
remove the use of XIP_OFFSET in kernel_mapping_va_to_pa(). The macro
XIP_OFFSET is used in this case to check if the virtual address is mapped
to Flash or to RAM. The same check can be done with kernel_map.xiprom_sz.

Signed-off-by: Nam Cao <namcao@linutronix.de>
---
 arch/riscv/include/asm/page.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/riscv/include/asm/page.h b/arch/riscv/include/asm/page.h
index 14d0de928f9b..bcd77df15835 100644
--- a/arch/riscv/include/asm/page.h
+++ b/arch/riscv/include/asm/page.h
@@ -159,7 +159,7 @@ phys_addr_t linear_mapping_va_to_pa(unsigned long x);
 #ifdef CONFIG_XIP_KERNEL
 #define kernel_mapping_va_to_pa(y) ({						\
 	unsigned long _y = (unsigned long)(y);					\
-	(_y < kernel_map.virt_addr + XIP_OFFSET) ?				\
+	(_y < kernel_map.virt_addr + kernel_map.xiprom_sz) ?			\
 		(_y - kernel_map.va_kernel_xip_pa_offset) :			\
 		(_y - kernel_map.va_kernel_data_pa_offset);			\
 	})
-- 
2.39.2

On 10/05/2024 08:28, Nam Cao wrote:
> XIP_OFFSET is the hard-coded offset of writable data section within the
> kernel.
>
> By hard-coding this value, the read-only section of the kernel (which is
> placed before the writable data section) is restricted in size.
>
> As a preparation to remove this hard-coded macro XIP_OFFSET entirely,
> remove the use of XIP_OFFSET in kernel_mapping_va_to_pa(). The macro
> XIP_OFFSET is used in this case to check if the virtual address is mapped
> to Flash or to RAM. The same check can be done with kernel_map.xiprom_sz.
>
> Signed-off-by: Nam Cao <namcao@linutronix.de>
> ---
>   arch/riscv/include/asm/page.h | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/riscv/include/asm/page.h b/arch/riscv/include/asm/page.h
> index 14d0de928f9b..bcd77df15835 100644
> --- a/arch/riscv/include/asm/page.h
> +++ b/arch/riscv/include/asm/page.h
> @@ -159,7 +159,7 @@ phys_addr_t linear_mapping_va_to_pa(unsigned long x);
>   #ifdef CONFIG_XIP_KERNEL
>   #define kernel_mapping_va_to_pa(y) ({						\
>   	unsigned long _y = (unsigned long)(y);					\
> -	(_y < kernel_map.virt_addr + XIP_OFFSET) ?				\
> +	(_y < kernel_map.virt_addr + kernel_map.xiprom_sz) ?			\
>   		(_y - kernel_map.va_kernel_xip_pa_offset) :			\
>   		(_y - kernel_map.va_kernel_data_pa_offset);			\
>   	})


Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>

Thanks,

Alex