| .. | .. |
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| 17 | 17 | #include <asm/setup.h> |
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| 18 | 18 | #include <asm/segment.h> |
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| 19 | 19 | #include <asm/page.h> |
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| 20 | | -#include <asm/pgalloc.h> |
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| 21 | 20 | #include <asm/traps.h> |
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| 22 | 21 | #include <asm/machdep.h> |
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| 23 | 22 | |
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| 24 | | - |
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| 25 | | -/* ++andreas: {get,free}_pointer_table rewritten to use unused fields from |
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| 26 | | - struct page instead of separately kmalloced struct. Stolen from |
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| 27 | | - arch/sparc/mm/srmmu.c ... */ |
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| 28 | | - |
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| 29 | | -typedef struct list_head ptable_desc; |
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| 30 | | -static LIST_HEAD(ptable_list); |
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| 31 | | - |
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| 32 | | -#define PD_PTABLE(page) ((ptable_desc *)&(virt_to_page(page)->lru)) |
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| 33 | | -#define PD_PAGE(ptable) (list_entry(ptable, struct page, lru)) |
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| 34 | | -#define PD_MARKBITS(dp) (*(unsigned char *)&PD_PAGE(dp)->index) |
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| 35 | | - |
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| 36 | | -#define PTABLE_SIZE (PTRS_PER_PMD * sizeof(pmd_t)) |
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| 37 | | - |
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| 38 | | -void __init init_pointer_table(unsigned long ptable) |
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| 39 | | -{ |
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| 40 | | - ptable_desc *dp; |
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| 41 | | - unsigned long page = ptable & PAGE_MASK; |
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| 42 | | - unsigned char mask = 1 << ((ptable - page)/PTABLE_SIZE); |
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| 43 | | - |
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| 44 | | - dp = PD_PTABLE(page); |
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| 45 | | - if (!(PD_MARKBITS(dp) & mask)) { |
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| 46 | | - PD_MARKBITS(dp) = 0xff; |
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| 47 | | - list_add(dp, &ptable_list); |
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| 48 | | - } |
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| 49 | | - |
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| 50 | | - PD_MARKBITS(dp) &= ~mask; |
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| 51 | | - pr_debug("init_pointer_table: %lx, %x\n", ptable, PD_MARKBITS(dp)); |
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| 52 | | - |
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| 53 | | - /* unreserve the page so it's possible to free that page */ |
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| 54 | | - PD_PAGE(dp)->flags &= ~(1 << PG_reserved); |
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| 55 | | - init_page_count(PD_PAGE(dp)); |
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| 56 | | - |
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| 57 | | - return; |
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| 58 | | -} |
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| 59 | | - |
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| 60 | | -pmd_t *get_pointer_table (void) |
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| 61 | | -{ |
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| 62 | | - ptable_desc *dp = ptable_list.next; |
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| 63 | | - unsigned char mask = PD_MARKBITS (dp); |
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| 64 | | - unsigned char tmp; |
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| 65 | | - unsigned int off; |
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| 66 | | - |
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| 67 | | - /* |
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| 68 | | - * For a pointer table for a user process address space, a |
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| 69 | | - * table is taken from a page allocated for the purpose. Each |
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| 70 | | - * page can hold 8 pointer tables. The page is remapped in |
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| 71 | | - * virtual address space to be noncacheable. |
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| 72 | | - */ |
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| 73 | | - if (mask == 0) { |
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| 74 | | - void *page; |
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| 75 | | - ptable_desc *new; |
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| 76 | | - |
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| 77 | | - if (!(page = (void *)get_zeroed_page(GFP_KERNEL))) |
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| 78 | | - return NULL; |
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| 79 | | - |
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| 80 | | - flush_tlb_kernel_page(page); |
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| 81 | | - nocache_page(page); |
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| 82 | | - |
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| 83 | | - new = PD_PTABLE(page); |
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| 84 | | - PD_MARKBITS(new) = 0xfe; |
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| 85 | | - list_add_tail(new, dp); |
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| 86 | | - |
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| 87 | | - return (pmd_t *)page; |
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| 88 | | - } |
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| 89 | | - |
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| 90 | | - for (tmp = 1, off = 0; (mask & tmp) == 0; tmp <<= 1, off += PTABLE_SIZE) |
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| 91 | | - ; |
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| 92 | | - PD_MARKBITS(dp) = mask & ~tmp; |
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| 93 | | - if (!PD_MARKBITS(dp)) { |
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| 94 | | - /* move to end of list */ |
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| 95 | | - list_move_tail(dp, &ptable_list); |
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| 96 | | - } |
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| 97 | | - return (pmd_t *) (page_address(PD_PAGE(dp)) + off); |
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| 98 | | -} |
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| 99 | | - |
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| 100 | | -int free_pointer_table (pmd_t *ptable) |
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| 101 | | -{ |
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| 102 | | - ptable_desc *dp; |
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| 103 | | - unsigned long page = (unsigned long)ptable & PAGE_MASK; |
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| 104 | | - unsigned char mask = 1 << (((unsigned long)ptable - page)/PTABLE_SIZE); |
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| 105 | | - |
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| 106 | | - dp = PD_PTABLE(page); |
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| 107 | | - if (PD_MARKBITS (dp) & mask) |
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| 108 | | - panic ("table already free!"); |
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| 109 | | - |
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| 110 | | - PD_MARKBITS (dp) |= mask; |
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| 111 | | - |
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| 112 | | - if (PD_MARKBITS(dp) == 0xff) { |
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| 113 | | - /* all tables in page are free, free page */ |
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| 114 | | - list_del(dp); |
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| 115 | | - cache_page((void *)page); |
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| 116 | | - free_page (page); |
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| 117 | | - return 1; |
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| 118 | | - } else if (ptable_list.next != dp) { |
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| 119 | | - /* |
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| 120 | | - * move this descriptor to the front of the list, since |
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| 121 | | - * it has one or more free tables. |
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| 122 | | - */ |
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| 123 | | - list_move(dp, &ptable_list); |
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| 124 | | - } |
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| 125 | | - return 0; |
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| 126 | | -} |
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| 127 | 23 | |
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| 128 | 24 | /* invalidate page in both caches */ |
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| 129 | 25 | static inline void clear040(unsigned long paddr) |
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