2024-02-22 05:32:48

by Michael Ellerman

[permalink] [raw]
Subject: Re: [PATCH 1/2] powerpc: Refactor __kernel_map_pages()

Christophe Leroy <[email protected]> writes:
> __kernel_map_pages() is almost identical for PPC32 and RADIX.
>
> Refactor it.
>
> On PPC32 it is not needed for KFENCE, but to keep it simple
> just make it similar to PPC64.
>
> Signed-off-by: Christophe Leroy <[email protected]>
> ---
> arch/powerpc/include/asm/book3s/64/pgtable.h | 10 ----------
> arch/powerpc/include/asm/book3s/64/radix.h | 2 --
> arch/powerpc/mm/book3s64/radix_pgtable.c | 14 --------------
> arch/powerpc/mm/pageattr.c | 19 +++++++++++++++++++
> arch/powerpc/mm/pgtable_32.c | 15 ---------------
> 5 files changed, 19 insertions(+), 41 deletions(-)
>
> diff --git a/arch/powerpc/mm/pageattr.c b/arch/powerpc/mm/pageattr.c
> index 421db7c4f2a4..16b8d20d6ca8 100644
> --- a/arch/powerpc/mm/pageattr.c
> +++ b/arch/powerpc/mm/pageattr.c
> @@ -101,3 +101,22 @@ int change_memory_attr(unsigned long addr, int numpages, long action)
> return apply_to_existing_page_range(&init_mm, start, size,
> change_page_attr, (void *)action);
> }
> +
> +#if defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_KFENCE)
> +#ifdef CONFIG_ARCH_SUPPORTS_DEBUG_PAGEALLOC
> +void __kernel_map_pages(struct page *page, int numpages, int enable)
> +{
> + unsigned long addr = (unsigned long)page_address(page);
> +
> + if (PageHighMem(page))
> + return;
> +
> + if (IS_ENABLED(CONFIG_PPC_BOOK3S_64) && !radix_enabled())
> + hash__kernel_map_pages(page, numpages, enable);
> + else if (enable)
> + set_memory_p(addr, numpages);
> + else
> + set_memory_np(addr, numpages);
> +}

This doesn't build on 32-bit, eg. ppc32_allmodconfig:

./arch/powerpc/mm/pageattr.c: In function '__kernel_map_pages':
./arch/powerpc/mm/pageattr.c:116:23: error: implicit declaration of function 'hash__kernel_map_pages' [-Werror=implicit-function-declaration]
116 | err = hash__kernel_map_pages(page, numpages, enable);
| ^~~~~~~~~~~~~~~~~~~~~~

I couldn't see a nice way to get around it, so ended up with:

void __kernel_map_pages(struct page *page, int numpages, int enable)
{
int err;
unsigned long addr = (unsigned long)page_address(page);

if (PageHighMem(page))
return;

#ifdef CONFIG_PPC_BOOK3S_64
if (!radix_enabled())
err = hash__kernel_map_pages(page, numpages, enable);
else
#endif
if (enable)
err = set_memory_p(addr, numpages);
else
err = set_memory_np(addr, numpages);



cheers