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author | Joel Stanley <joel@jms.id.au> | 2021-10-14 08:04:38 +1030 |
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committer | Michael Ellerman <mpe@ellerman.id.au> | 2021-10-22 15:22:02 +1100 |
commit | 4f703e7faa67a116016c4678fc88b507c12670c9 (patch) | |
tree | 29b21d3ba6945f30efd81ef52076fc1708774ba4 /arch | |
parent | 3091f5fc5f1df7741ddf326561384e0997eca2a1 (diff) | |
download | linux-stable-4f703e7faa67a116016c4678fc88b507c12670c9.tar.gz linux-stable-4f703e7faa67a116016c4678fc88b507c12670c9.tar.bz2 linux-stable-4f703e7faa67a116016c4678fc88b507c12670c9.zip |
powerpc/s64: Clarify that radix lacks DEBUG_PAGEALLOC
The page_alloc.c code will call into __kernel_map_pages() when
DEBUG_PAGEALLOC is configured and enabled.
As the implementation assumes hash, this should crash spectacularly if
not for a bit of luck in __kernel_map_pages(). In this function
linear_map_hash_count is always zero, the for loop exits without doing
any damage.
There are no other platforms that determine if they support
debug_pagealloc at runtime. Instead of adding code to mm/page_alloc.c to
do that, this change turns the map/unmap into a noop when in radix
mode and prints a warning once.
Signed-off-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
[mpe: Reformat if per Christophe's suggestion]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211013213438.675095-1-joel@jms.id.au
Diffstat (limited to 'arch')
-rw-r--r-- | arch/powerpc/include/asm/book3s/64/hash.h | 2 | ||||
-rw-r--r-- | arch/powerpc/include/asm/book3s/64/pgtable.h | 10 | ||||
-rw-r--r-- | arch/powerpc/include/asm/book3s/64/radix.h | 3 | ||||
-rw-r--r-- | arch/powerpc/mm/book3s64/hash_utils.c | 2 | ||||
-rw-r--r-- | arch/powerpc/mm/book3s64/radix_pgtable.c | 7 |
5 files changed, 23 insertions, 1 deletions
diff --git a/arch/powerpc/include/asm/book3s/64/hash.h b/arch/powerpc/include/asm/book3s/64/hash.h index d959b0195ad9..674fe0e890dc 100644 --- a/arch/powerpc/include/asm/book3s/64/hash.h +++ b/arch/powerpc/include/asm/book3s/64/hash.h @@ -255,6 +255,8 @@ int hash__create_section_mapping(unsigned long start, unsigned long end, int nid, pgprot_t prot); int hash__remove_section_mapping(unsigned long start, unsigned long end); +void hash__kernel_map_pages(struct page *page, int numpages, int enable); + #endif /* !__ASSEMBLY__ */ #endif /* __KERNEL__ */ #endif /* _ASM_POWERPC_BOOK3S_64_HASH_H */ diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h index 5d34a8646f08..33e073d6b0c4 100644 --- a/arch/powerpc/include/asm/book3s/64/pgtable.h +++ b/arch/powerpc/include/asm/book3s/64/pgtable.h @@ -1101,6 +1101,16 @@ static inline void vmemmap_remove_mapping(unsigned long start, } #endif +#ifdef CONFIG_DEBUG_PAGEALLOC +static inline void __kernel_map_pages(struct page *page, int numpages, int enable) +{ + if (radix_enabled()) + radix__kernel_map_pages(page, numpages, enable); + else + hash__kernel_map_pages(page, numpages, enable); +} +#endif + static inline pte_t pmd_pte(pmd_t pmd) { return __pte_raw(pmd_raw(pmd)); diff --git a/arch/powerpc/include/asm/book3s/64/radix.h b/arch/powerpc/include/asm/book3s/64/radix.h index 59cab558e2f0..d090d9612348 100644 --- a/arch/powerpc/include/asm/book3s/64/radix.h +++ b/arch/powerpc/include/asm/book3s/64/radix.h @@ -316,5 +316,8 @@ int radix__create_section_mapping(unsigned long start, unsigned long end, int nid, pgprot_t prot); int radix__remove_section_mapping(unsigned long start, unsigned long end); #endif /* CONFIG_MEMORY_HOTPLUG */ + +void radix__kernel_map_pages(struct page *page, int numpages, int enable); + #endif /* __ASSEMBLY__ */ #endif diff --git a/arch/powerpc/mm/book3s64/hash_utils.c b/arch/powerpc/mm/book3s64/hash_utils.c index c145776d3ae5..cfd45245d009 100644 --- a/arch/powerpc/mm/book3s64/hash_utils.c +++ b/arch/powerpc/mm/book3s64/hash_utils.c @@ -1988,7 +1988,7 @@ static void kernel_unmap_linear_page(unsigned long vaddr, unsigned long lmi) mmu_kernel_ssize, 0); } -void __kernel_map_pages(struct page *page, int numpages, int enable) +void hash__kernel_map_pages(struct page *page, int numpages, int enable) { unsigned long flags, vaddr, lmi; int i; diff --git a/arch/powerpc/mm/book3s64/radix_pgtable.c b/arch/powerpc/mm/book3s64/radix_pgtable.c index ae20add7954a..3a600bd7fbc6 100644 --- a/arch/powerpc/mm/book3s64/radix_pgtable.c +++ b/arch/powerpc/mm/book3s64/radix_pgtable.c @@ -920,6 +920,13 @@ void __meminit radix__vmemmap_remove_mapping(unsigned long start, unsigned long #endif #endif +#ifdef CONFIG_DEBUG_PAGEALLOC +void radix__kernel_map_pages(struct page *page, int numpages, int enable) +{ + pr_warn_once("DEBUG_PAGEALLOC not supported in radix mode\n"); +} +#endif + #ifdef CONFIG_TRANSPARENT_HUGEPAGE unsigned long radix__pmd_hugepage_update(struct mm_struct *mm, unsigned long addr, |