| From 1268870be30e4571b0e007c986231c434c3b4912 Mon Sep 17 00:00:00 2001 |
| From: Kevin Hao <kexin.hao@windriver.com> |
| Date: Tue, 2 Mar 2010 16:51:57 -0500 |
| Subject: [PATCH] powerpc: Replace kmap_atomic with kmap in pte_offset_map |
| |
| commit 1268870be30e4571b0e007c986231c434c3b4912 in tip. |
| |
| 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> |
| |
| diff --git a/arch/powerpc/include/asm/pgtable-ppc32.h b/arch/powerpc/include/asm/pgtable-ppc32.h |
| index 55646ad..a838099 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. |
| -- |
| 1.7.1.1 |
| |
