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| author |   Christophe Leroy <christophe.leroy@c-s.fr> | 2020-02-17 09:41:35 +0000 |
|---|---|---|
| committer |   Michael Ellerman <mpe@ellerman.id.au> | 2020-03-04 22:44:27 +1100 |
| commit | 6453f9ed9d4e4b4cdf201bf34bf460c436bf50ea (patch) | |
| tree | 32e12fddda6e9dcaf3da8900ec572bd9780a13d0 /arch/powerpc/include/asm/nohash/32/pgtable.h | |
| parent | powerpc/book3s64: Fix error handling in mm_iommu_do_alloc() (diff) | |
| download | wireguard-linux-6453f9ed9d4e4b4cdf201bf34bf460c436bf50ea.tar.xz wireguard-linux-6453f9ed9d4e4b4cdf201bf34bf460c436bf50ea.zip | |
powerpc/mm: Don't kmap_atomic() in pte_offset_map() on PPC32
On PPC32, pte_offset_map() does a kmap_atomic() in order to support
page tables allocated in high memory, just like ARM and x86/32.
But since at least 2008 and commit 8054a3428fbe ("powerpc: Remove dead
CONFIG_HIGHPTE"), page tables are never allocated in high memory.
When the page is in low mem, kmap_atomic() just returns the page
address but still disable preemption and pagefault. And it is
not an inlined function, so we suffer function call for no reason.
Make pte_offset_map() the same as pte_offset_kernel() and make
pte_unmap() void, in the same way as PPC64 which doesn't have HIGHMEM.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/03c97f0f6b3790d164822563be80f2fd4713a955.1581932480.git.christophe.leroy@c-s.fr
Diffstat (limited to 'arch/powerpc/include/asm/nohash/32/pgtable.h')
| -rw-r--r-- | arch/powerpc/include/asm/nohash/32/pgtable.h | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/arch/powerpc/include/asm/nohash/32/pgtable.h b/arch/powerpc/include/asm/nohash/32/pgtable.h index 60c4d829152e..b04ba257fddb 100644 --- a/arch/powerpc/include/asm/nohash/32/pgtable.h +++ b/arch/powerpc/include/asm/nohash/32/pgtable.h @@ -372,10 +372,8 @@ static inline int pte_young(pte_t pte) #define pte_offset_kernel(dir, addr) \ (pmd_bad(*(dir)) ? NULL : (pte_t *)pmd_page_vaddr(*(dir)) + \ pte_index(addr)) -#define pte_offset_map(dir, addr) \ - ((pte_t *)(kmap_atomic(pmd_page(*(dir))) + \ - (pmd_page_vaddr(*(dir)) & ~PAGE_MASK)) + pte_index(addr)) -#define pte_unmap(pte) kunmap_atomic(pte) +#define pte_offset_map(dir, addr) pte_offset_kernel((dir), (addr)) +static inline void pte_unmap(pte_t *pte) { } /* * Encode and decode a swap entry. |