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| author |   Joel Stanley <joel@jms.id.au> | 2021-10-14 08:04:38 +1030 |
|---|---|---|
| committer |   Michael Ellerman <mpe@ellerman.id.au> | 2021-10-22 15:22:02 +1100 |
| commit | 4f703e7faa67a116016c4678fc88b507c12670c9 (patch) | |
| tree | 29b21d3ba6945f30efd81ef52076fc1708774ba4 /arch/powerpc/mm/book3s64/radix_pgtable.c | |
| parent | powerpc: Mark .opd section read-only (diff) | |
| download | linux-dev-4f703e7faa67a116016c4678fc88b507c12670c9.tar.xz linux-dev-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 '')
| -rw-r--r-- | arch/powerpc/mm/book3s64/radix_pgtable.c | 7 |
1 files changed, 7 insertions, 0 deletions
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, |