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| author | Kevin Hao <kexin.hao@windriver.com> | 2010-03-02 16:51:57 -0500 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2010-04-27 17:24:39 +0200 |
| commit | 1268870be30e4571b0e007c986231c434c3b4912 (patch) | |
| tree | 84f3128f89dbf0b58c054c4fd3e25c6ed0f9ea15 | |
| parent | b6589c1199dea2d26358808b65666c49495f735e (diff) | |
| download | lwn-1268870be30e4571b0e007c986231c434c3b4912.tar.gz lwn-1268870be30e4571b0e007c986231c434c3b4912.zip | |
powerpc: Replace kmap_atomic with kmap in pte_offset_map
The pte_offset_map/pte_offset_map_nested use kmap_atomic to get the
virtual address for the pte table, but kmap_atomic will disable preempt.
Hence there will be call trace if we acquire a spin lock after invoking
pte_offset_map/pte_offset_map_nested in preempt-rt. To fix it, I've
replaced kmap_atomic with kmap in these macros.
Signed-off-by: Kevin Hao <kexin.hao@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
LKML-Reference: <ffaf532c138188b526a8c623ed3c7f5067da6d68.1267566249.git.paul.gortmaker@windriver.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| -rw-r--r-- | arch/powerpc/include/asm/pgtable-ppc32.h | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/pgtable-ppc32.h b/arch/powerpc/include/asm/pgtable-ppc32.h index 55646adfa843..a83809916f28 100644 --- a/arch/powerpc/include/asm/pgtable-ppc32.h +++ b/arch/powerpc/include/asm/pgtable-ppc32.h @@ -307,6 +307,17 @@ static inline void __ptep_set_access_flags(pte_t *ptep, pte_t entry) (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)) #define pte_offset_kernel(dir, addr) \ ((pte_t *) pmd_page_vaddr(*(dir)) + pte_index(addr)) +#ifdef CONFIG_PREEMPT_RT +#define pte_offset_map(dir, addr) \ + ((pte_t *) kmap(pmd_page(*(dir))) + pte_index(addr)) +#define pte_offset_map_nested(dir, addr) \ + ((pte_t *) kmap(pmd_page(*(dir))) + pte_index(addr)) + +#define pte_unmap(pte) \ + kunmap((struct page *)_ALIGN_DOWN((unsigned int)pte, PAGE_SIZE)) +#define pte_unmap_nested(pte) \ + kunmap((struct page *)_ALIGN_DOWN((unsigned int)pte, PAGE_SIZE)) +#else #define pte_offset_map(dir, addr) \ ((pte_t *) kmap_atomic(pmd_page(*(dir)), KM_PTE0) + pte_index(addr)) #define pte_offset_map_nested(dir, addr) \ @@ -314,6 +325,7 @@ static inline void __ptep_set_access_flags(pte_t *ptep, pte_t entry) #define pte_unmap(pte) kunmap_atomic(pte, KM_PTE0) #define pte_unmap_nested(pte) kunmap_atomic(pte, KM_PTE1) +#endif /* * Encode and decode a swap entry. |