Originally, I was convinced that we needed to use tmpalias flushes everwhere, for both user and kernel flushes. However, when I modified flush_kernel_dcache_page_addr, to use a tmpalias flush, my c8000 would crash quite early when booting. The PDC returns alias values of 0 for the icache and dcache. This indicates that either the alias boundary is greater than 16MB or equivalent aliasing doesn't work. I modified the tmpalias code to make it easy to try alternate boundaries. I tried boundaries up to 128MB but still kernel tmpalias flushes didn't work on c8000. This led me to conclude that tmpalias flushes don't work on PA8800 and PA8900 machines, and that we needed to flush directly using the virtual address of user and kernel pages. This is likely the major cause of instability on the c8000 and rp34xx machines. Flushing user pages requires doing a temporary context switch as we have to flush pages that don't belong to the current context. Further, we have to deal with pages that aren't present. If a page isn't present, the flush instructions fault on every line. Other code has been rearranged and simplified based on testing. For example, I introduced a flush_cache_dup_mm routine. flush_cache_mm and flush_cache_dup_mm differ in that flush_cache_mm calls purge_cache_pages and flush_cache_dup_mm calls flush_cache_pages. In some implementations, pdc is more efficient than fdc. Based on my testing, I don't believe there's any performance benefit on the c8000.
Showing the changes to arch/parisc/include (2 of 3 files). Show all
Unified · Split
| @@ -59,20 +59,12 @@ void flush_dcache_page(struct page *page); · 58 unmodified lines | |||
| 59 | flush_kernel_icache_range_asm(s,e); \ | 59 | flush_kernel_icache_range_asm(s,e); \ |
| 60 | } while (0) | 60 | } while (0) |
| 61 | 61 | ||
| 62 | #define copy_to_user_page(vma, page, vaddr, dst, src, len) \ | 62 | void copy_to_user_page(struct vm_area_struct *vma, struct page *page, |
| 63 | do { \ | 63 | unsigned long user_vaddr, void *dst, void *src, int len); |
| 64 | flush_cache_page(vma, vaddr, page_to_pfn(page)); \ | 64 | void copy_from_user_page(struct vm_area_struct *vma, struct page *page, |
| 65 | memcpy(dst, src, len); \ | 65 | unsigned long user_vaddr, void *dst, void *src, int len); |
| 66 | flush_kernel_dcache_range_asm((unsigned long)dst, (unsigned long)dst + len); \ | 66 | void flush_cache_page(struct vm_area_struct *vma, unsigned long vmaddr, |
| 67 | } while (0) | 67 | unsigned long pfn); |
| 68 | |||
| 69 | #define copy_from_user_page(vma, page, vaddr, dst, src, len) \ | ||
| 70 | do { \ | ||
| 71 | flush_cache_page(vma, vaddr, page_to_pfn(page)); \ | ||
| 72 | memcpy(dst, src, len); \ | ||
| 73 | } while (0) | ||
| 74 | |||
| 75 | void flush_cache_page(struct vm_area_struct *vma, unsigned long vmaddr, unsigned long pfn); | ||
| 76 | void flush_cache_range(struct vm_area_struct *vma, | 68 | void flush_cache_range(struct vm_area_struct *vma, |
| 77 | unsigned long start, unsigned long end); | 69 | unsigned long start, unsigned long end); |
| 78 | 70 | ||
| @@ -80,16 +72,7 @@ void flush_cache_range(struct vm_area_struct *vma, · 1 unmodified line | |||
| 80 | void flush_dcache_page_asm(unsigned long phys_addr, unsigned long vaddr); | 72 | void flush_dcache_page_asm(unsigned long phys_addr, unsigned long vaddr); |
| 81 | 73 | ||
| 82 | #define ARCH_HAS_FLUSH_ANON_PAGE | 74 | #define ARCH_HAS_FLUSH_ANON_PAGE |
| 83 | static inline void | 75 | void flush_anon_page(struct vm_area_struct *vma, struct page *page, unsigned long vmaddr); |
| 84 | flush_anon_page(struct vm_area_struct *vma, struct page *page, unsigned long vmaddr) | ||
| 85 | { | ||
| 86 | if (PageAnon(page)) { | ||
| 87 | flush_tlb_page(vma, vmaddr); | ||
| 88 | preempt_disable(); | ||
| 89 | flush_dcache_page_asm(page_to_phys(page), vmaddr); | ||
| 90 | preempt_enable(); | ||
| 91 | } | ||
| 92 | } | ||
| 93 | 76 | ||
| 94 | #define ARCH_HAS_FLUSH_ON_KUNMAP | 77 | #define ARCH_HAS_FLUSH_ON_KUNMAP |
| 95 | static inline void kunmap_flush_on_unmap(void *addr) | 78 | static inline void kunmap_flush_on_unmap(void *addr) |
| @@ -26,12 +26,14 @@ · 25 unmodified lines | |||
| 26 | #define copy_page(to, from) copy_page_asm((void *)(to), (void *)(from)) | 26 | #define copy_page(to, from) copy_page_asm((void *)(to), (void *)(from)) |
| 27 | 27 | ||
| 28 | struct page; | 28 | struct page; |
| 29 | struct vm_area_struct; | ||
| 29 | 30 | ||
| 30 | void clear_page_asm(void *page); | 31 | void clear_page_asm(void *page); |
| 31 | void copy_page_asm(void *to, void *from); | 32 | void copy_page_asm(void *to, void *from); |
| 32 | #define clear_user_page(vto, vaddr, page) clear_page_asm(vto) | 33 | #define clear_user_page(vto, vaddr, page) clear_page_asm(vto) |
| 33 | void copy_user_page(void *vto, void *vfrom, unsigned long vaddr, | 34 | void copy_user_highpage(struct page *to, struct page *from, unsigned long vaddr, |
| 34 | struct page *pg); | 35 | struct vm_area_struct *vma); |
| 36 | #define __HAVE_ARCH_COPY_USER_HIGHPAGE | ||
| 35 | 37 | ||
| 36 | /* | 38 | /* |
| 37 | * These are used to make use of C type-checking.. | 39 | * These are used to make use of C type-checking.. |