2022-07-05 22:48:40

by Max Filippov

Subject: [PATCH] xtensa: noMMU: fix vm_get_page_prot definition

Don't define protection_map and don't use DECLARE_VM_GET_PAGE_PROT in
noMMU configs, because in that case the definition for vm_get_page_prot
is provided by the include/linux/mm.h

Fixes: 61ab8053710f ("xtensa/mm: enable ARCH_HAS_VM_GET_PAGE_PROT")
Signed-off-by: Max Filippov <[email protected]>
---
arch/xtensa/mm/init.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/arch/xtensa/mm/init.c b/arch/xtensa/mm/init.c
index fb830ec8183c..b2587a1a7c46 100644
--- a/arch/xtensa/mm/init.c
+++ b/arch/xtensa/mm/init.c
@@ -217,6 +217,7 @@ static int __init parse_memmap_opt(char *str)
}
early_param("memmap", parse_memmap_opt);

+#ifdef CONFIG_MMU
static const pgprot_t protection_map[16] = {
[VM_NONE] = PAGE_NONE,
[VM_READ] = PAGE_READONLY,
@@ -236,3 +237,4 @@ static const pgprot_t protection_map[16] = {
[VM_SHARED | VM_EXEC | VM_WRITE | VM_READ] = PAGE_SHARED_EXEC
};
DECLARE_VM_GET_PAGE_PROT
+#endif
--
2.30.2

2022-07-06 05:04:44

by Anshuman Khandual

Subject: Re: [PATCH] xtensa: noMMU: fix vm_get_page_prot definition

Hello Max,

I could reproduce the build failure with nommu_kc705_defconfig.

On 7/6/22 03:44, Max Filippov wrote:
> Don't define protection_map and don't use DECLARE_VM_GET_PAGE_PROT in
> noMMU configs, because in that case the definition for vm_get_page_prot
> is provided by the include/linux/mm.h

Right, a fallback (!CONFIG_MMU) stub definition is provided there.

>
> Fixes: 61ab8053710f ("xtensa/mm: enable ARCH_HAS_VM_GET_PAGE_PROT")
> Signed-off-by: Max Filippov <[email protected]>
> ---
> arch/xtensa/mm/init.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/arch/xtensa/mm/init.c b/arch/xtensa/mm/init.c
> index fb830ec8183c..b2587a1a7c46 100644
> --- a/arch/xtensa/mm/init.c
> +++ b/arch/xtensa/mm/init.c
> @@ -217,6 +217,7 @@ static int __init parse_memmap_opt(char *str)
> }
> early_param("memmap", parse_memmap_opt);
>
> +#ifdef CONFIG_MMU
> static const pgprot_t protection_map[16] = {
> [VM_NONE] = PAGE_NONE,
> [VM_READ] = PAGE_READONLY,
> @@ -236,3 +237,4 @@ static const pgprot_t protection_map[16] = {
> [VM_SHARED | VM_EXEC | VM_WRITE | VM_READ] = PAGE_SHARED_EXEC
> };
> DECLARE_VM_GET_PAGE_PROT
> +#endif

LGTM and fixes the build problem.

Reviewed-by: Anshuman Khandual <[email protected]>

Reviewing CONFIG_MMU dependency for other platforms ....

* powerpc - No CONFIG_MMU found - config MMU - bool default y
* sparc - No CONFIG_MMU found - config MMU - bool default y
* arm64 - No CONFIG_MMU found - config MMU - bool default y
* x86 - No CONFIG_MMU found - config MMU - bool default y
* microblaze - No CONFIG_MMU found - config MMU - bool default y
* loongarch - No CONFIG_MMU found - config MMU - bool default y
* openrisc - No CONFIG_MMU found - config MMU - bool default y
* xtensa - This fix here
* hexagon - No CONFIG_MMU found - config MMU - bool default y
* parisc - No CONFIG_MMU found - config MMU - bool default y
* alpha - No CONFIG_MMU found - config MMU - bool default y
* nios2 - No CONFIG_MMU found - config MMU - bool default y
* riscv - Both protection_map[] and DECLARE_VM_GET_PAGE_PROT
are inside CONFIG_MMU
* csky - No CONFIG_MMU found - config MMU - bool default y
* s390 - No CONFIG_MMU found - config MMU - bool default y
* ia64 - No CONFIG_MMU found - config MMU - bool default y
* mips - No CONFIG_MMU found - config MMU - bool default y
* m68k - Both protection_map[] and DECLARE_VM_GET_PAGE_PROT
are inside CONFIG_MMU (SUN3, MOTOROLA, COLDFIRE)
* arc - No CONFIG_MMU found - config MMU - bool default y
* arm - Both protection_map[] and DECLARE_VM_GET_PAGE_PROT
are inside CONFIG_MMU
* um - No CONFIG_MMU found - config MMU - bool default y
* sh - Both protection_map[] and DECLARE_VM_GET_PAGE_PROT
needs to be moved inside CONFIG_MMU, will send a
patch soon.

So apart from xtensa and sh, no other platform seems to have this
CONFIG_MMU related build problem. But please do let me know if I
might have missed something.

- Anshuman