| From: Jeff Hansen <jhansen@cardaccess-inc.com> |
| Subject: [PATCH] kmap_coherent |
| |
| On ASUS WL-500gP there are some "Data bus error"s when executing simple |
| commands liks "ps" or "cat /proc/1/cmdline". |
| |
| This fixes OpenWrt ticket #1485: https://dev.openwrt.org/ticket/1485 |
| --- |
| --- a/arch/mips/include/asm/cpu-features.h |
| +++ b/arch/mips/include/asm/cpu-features.h |
| @@ -243,6 +243,9 @@ |
| #ifndef cpu_has_pindexed_dcache |
| #define cpu_has_pindexed_dcache (cpu_data[0].dcache.flags & MIPS_CACHE_PINDEX) |
| #endif |
| +#ifndef cpu_use_kmap_coherent |
| +#define cpu_use_kmap_coherent 1 |
| +#endif |
| |
| /* |
| * I-Cache snoops remote store. This only matters on SMP. Some multiprocessors |
| --- a/arch/mips/include/asm/mach-bcm47xx/cpu-feature-overrides.h |
| +++ b/arch/mips/include/asm/mach-bcm47xx/cpu-feature-overrides.h |
| @@ -80,4 +80,6 @@ |
| #define cpu_scache_line_size() 0 |
| #define cpu_has_vz 0 |
| |
| +#define cpu_use_kmap_coherent 0 |
| + |
| #endif /* __ASM_MACH_BCM47XX_CPU_FEATURE_OVERRIDES_H */ |
| --- a/arch/mips/mm/c-r4k.c |
| +++ b/arch/mips/mm/c-r4k.c |
| @@ -697,7 +697,7 @@ static inline void local_r4k_flush_cache |
| map_coherent = (cpu_has_dc_aliases && |
| page_mapcount(page) && |
| !Page_dcache_dirty(page)); |
| - if (map_coherent) |
| + if (map_coherent && cpu_use_kmap_coherent) |
| vaddr = kmap_coherent(page, addr); |
| else |
| vaddr = kmap_atomic(page); |
| @@ -719,7 +719,7 @@ static inline void local_r4k_flush_cache |
| } |
| |
| if (vaddr) { |
| - if (map_coherent) |
| + if (map_coherent && cpu_use_kmap_coherent) |
| kunmap_coherent(); |
| else |
| kunmap_atomic(vaddr); |
| --- a/arch/mips/mm/init.c |
| +++ b/arch/mips/mm/init.c |
| @@ -174,7 +174,7 @@ void copy_user_highpage(struct page *to, |
| void *vfrom, *vto; |
| |
| vto = kmap_atomic(to); |
| - if (cpu_has_dc_aliases && |
| + if (cpu_has_dc_aliases && cpu_use_kmap_coherent && |
| page_mapcount(from) && !Page_dcache_dirty(from)) { |
| vfrom = kmap_coherent(from, vaddr); |
| copy_page(vto, vfrom); |
| @@ -196,7 +196,7 @@ void copy_to_user_page(struct vm_area_st |
| struct page *page, unsigned long vaddr, void *dst, const void *src, |
| unsigned long len) |
| { |
| - if (cpu_has_dc_aliases && |
| + if (cpu_has_dc_aliases && cpu_use_kmap_coherent && |
| page_mapcount(page) && !Page_dcache_dirty(page)) { |
| void *vto = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK); |
| memcpy(vto, src, len); |
| @@ -214,7 +214,7 @@ void copy_from_user_page(struct vm_area_ |
| struct page *page, unsigned long vaddr, void *dst, const void *src, |
| unsigned long len) |
| { |
| - if (cpu_has_dc_aliases && |
| + if (cpu_has_dc_aliases && cpu_use_kmap_coherent && |
| page_mapcount(page) && !Page_dcache_dirty(page)) { |
| void *vfrom = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK); |
| memcpy(dst, vfrom, len); |