| b.liu | e958203 | 2025-04-17 19:18:16 +0800 | [diff] [blame] | 1 | From: Jeff Hansen <jhansen@cardaccess-inc.com> |
| 2 | Subject: [PATCH] kmap_coherent |
| 3 | |
| 4 | On ASUS WL-500gP there are some "Data bus error"s when executing simple |
| 5 | commands liks "ps" or "cat /proc/1/cmdline". |
| 6 | |
| 7 | This fixes OpenWrt ticket #1485: https://dev.openwrt.org/ticket/1485 |
| 8 | --- |
| 9 | --- a/arch/mips/include/asm/cpu-features.h |
| 10 | +++ b/arch/mips/include/asm/cpu-features.h |
| 11 | @@ -243,6 +243,9 @@ |
| 12 | #ifndef cpu_has_pindexed_dcache |
| 13 | #define cpu_has_pindexed_dcache (cpu_data[0].dcache.flags & MIPS_CACHE_PINDEX) |
| 14 | #endif |
| 15 | +#ifndef cpu_use_kmap_coherent |
| 16 | +#define cpu_use_kmap_coherent 1 |
| 17 | +#endif |
| 18 | |
| 19 | /* |
| 20 | * I-Cache snoops remote store. This only matters on SMP. Some multiprocessors |
| 21 | --- a/arch/mips/include/asm/mach-bcm47xx/cpu-feature-overrides.h |
| 22 | +++ b/arch/mips/include/asm/mach-bcm47xx/cpu-feature-overrides.h |
| 23 | @@ -80,4 +80,6 @@ |
| 24 | #define cpu_scache_line_size() 0 |
| 25 | #define cpu_has_vz 0 |
| 26 | |
| 27 | +#define cpu_use_kmap_coherent 0 |
| 28 | + |
| 29 | #endif /* __ASM_MACH_BCM47XX_CPU_FEATURE_OVERRIDES_H */ |
| 30 | --- a/arch/mips/mm/c-r4k.c |
| 31 | +++ b/arch/mips/mm/c-r4k.c |
| 32 | @@ -697,7 +697,7 @@ static inline void local_r4k_flush_cache |
| 33 | map_coherent = (cpu_has_dc_aliases && |
| 34 | page_mapcount(page) && |
| 35 | !Page_dcache_dirty(page)); |
| 36 | - if (map_coherent) |
| 37 | + if (map_coherent && cpu_use_kmap_coherent) |
| 38 | vaddr = kmap_coherent(page, addr); |
| 39 | else |
| 40 | vaddr = kmap_atomic(page); |
| 41 | @@ -719,7 +719,7 @@ static inline void local_r4k_flush_cache |
| 42 | } |
| 43 | |
| 44 | if (vaddr) { |
| 45 | - if (map_coherent) |
| 46 | + if (map_coherent && cpu_use_kmap_coherent) |
| 47 | kunmap_coherent(); |
| 48 | else |
| 49 | kunmap_atomic(vaddr); |
| 50 | --- a/arch/mips/mm/init.c |
| 51 | +++ b/arch/mips/mm/init.c |
| 52 | @@ -174,7 +174,7 @@ void copy_user_highpage(struct page *to, |
| 53 | void *vfrom, *vto; |
| 54 | |
| 55 | vto = kmap_atomic(to); |
| 56 | - if (cpu_has_dc_aliases && |
| 57 | + if (cpu_has_dc_aliases && cpu_use_kmap_coherent && |
| 58 | page_mapcount(from) && !Page_dcache_dirty(from)) { |
| 59 | vfrom = kmap_coherent(from, vaddr); |
| 60 | copy_page(vto, vfrom); |
| 61 | @@ -196,7 +196,7 @@ void copy_to_user_page(struct vm_area_st |
| 62 | struct page *page, unsigned long vaddr, void *dst, const void *src, |
| 63 | unsigned long len) |
| 64 | { |
| 65 | - if (cpu_has_dc_aliases && |
| 66 | + if (cpu_has_dc_aliases && cpu_use_kmap_coherent && |
| 67 | page_mapcount(page) && !Page_dcache_dirty(page)) { |
| 68 | void *vto = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK); |
| 69 | memcpy(vto, src, len); |
| 70 | @@ -214,7 +214,7 @@ void copy_from_user_page(struct vm_area_ |
| 71 | struct page *page, unsigned long vaddr, void *dst, const void *src, |
| 72 | unsigned long len) |
| 73 | { |
| 74 | - if (cpu_has_dc_aliases && |
| 75 | + if (cpu_has_dc_aliases && cpu_use_kmap_coherent && |
| 76 | page_mapcount(page) && !Page_dcache_dirty(page)) { |
| 77 | void *vfrom = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK); |
| 78 | memcpy(dst, vfrom, len); |