arch/xtensa/include/asm/page.h

   1 /*
   2  * include/asm-xtensa/page.h
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version2 as
   6  * published by the Free Software Foundation.
   7  *
   8  * Copyright (C) 2001 - 2007 Tensilica Inc.
   9  */
  10
  11 #ifndef _XTENSA_PAGE_H
  12 #define _XTENSA_PAGE_H
  13
  14 #include <asm/processor.h>
  15 #include <asm/types.h>
  16 #include <asm/cache.h>
  17 #include <platform/hardware.h>
  18 #include <asm/kmem_layout.h>
  19
  20 /*
  21  * PAGE_SHIFT determines the page size
  22  */
  23
  24 #define PAGE_SHIFT      12
  25 #define PAGE_SIZE       (__XTENSA_UL_CONST(1) << PAGE_SHIFT)
  26 #define PAGE_MASK       (~(PAGE_SIZE-1))
  27
  28 #ifdef CONFIG_MMU
  29 #define PAGE_OFFSET     XCHAL_KSEG_CACHED_VADDR
  30 #define PHYS_OFFSET     XCHAL_KSEG_PADDR
  31 #define MAX_LOW_PFN     (PHYS_PFN(XCHAL_KSEG_PADDR) + \
  32                          PHYS_PFN(XCHAL_KSEG_SIZE))
  33 #else
  34 #define PAGE_OFFSET     PLATFORM_DEFAULT_MEM_START
  35 #define PHYS_OFFSET     PLATFORM_DEFAULT_MEM_START
  36 #define MAX_LOW_PFN     PHYS_PFN(0xfffffffful)
  37 #endif
  38
  39 #define PGTABLE_START   0x80000000
  40
  41 /*
  42  * Cache aliasing:
  43  *
  44  * If the cache size for one way is greater than the page size, we have to
  45  * deal with cache aliasing. The cache index is wider than the page size:
  46  *
  47  * |    |cache| cache index
  48  * | pfn  |off| virtual address
  49  * |xxxx:X|zzz|
  50  * |    : |   |
  51  * | \  / |   |
  52  * |trans.|   |
  53  * | /  \ |   |
  54  * |yyyy:Y|zzz| physical address
  55  *
  56  * When the page number is translated to the physical page address, the lowest
  57  * bit(s) (X) that are part of the cache index are also translated (Y).
  58  * If this translation changes bit(s) (X), the cache index is also afected,
  59  * thus resulting in a different cache line than before.
  60  * The kernel does not provide a mechanism to ensure that the page color
  61  * (represented by this bit) remains the same when allocated or when pages
  62  * are remapped. When user pages are mapped into kernel space, the color of
  63  * the page might also change.
  64  *
  65  * We use the address space VMALLOC_END ... VMALLOC_END + DCACHE_WAY_SIZE * 2
  66  * to temporarily map a patch so we can match the color.
  67  */
  68
  69 #if DCACHE_WAY_SIZE > PAGE_SIZE
  70 # define DCACHE_ALIAS_ORDER     (DCACHE_WAY_SHIFT - PAGE_SHIFT)
  71 # define DCACHE_ALIAS_MASK      (PAGE_MASK & (DCACHE_WAY_SIZE - 1))
  72 # define DCACHE_ALIAS(a)        (((a) & DCACHE_ALIAS_MASK) >> PAGE_SHIFT)
  73 # define DCACHE_ALIAS_EQ(a,b)   ((((a) ^ (b)) & DCACHE_ALIAS_MASK) == 0)
  74 #else
  75 # define DCACHE_ALIAS_ORDER     0
  76 # define DCACHE_ALIAS(a)        ((void)(a), 0)
  77 #endif
  78 #define DCACHE_N_COLORS         (1 << DCACHE_ALIAS_ORDER)
  79
  80 #if ICACHE_WAY_SIZE > PAGE_SIZE
  81 # define ICACHE_ALIAS_ORDER     (ICACHE_WAY_SHIFT - PAGE_SHIFT)
  82 # define ICACHE_ALIAS_MASK      (PAGE_MASK & (ICACHE_WAY_SIZE - 1))
  83 # define ICACHE_ALIAS(a)        (((a) & ICACHE_ALIAS_MASK) >> PAGE_SHIFT)
  84 # define ICACHE_ALIAS_EQ(a,b)   ((((a) ^ (b)) & ICACHE_ALIAS_MASK) == 0)
  85 #else
  86 # define ICACHE_ALIAS_ORDER     0
  87 #endif
  88
  89
  90 #ifdef __ASSEMBLY__
  91
  92 #define __pgprot(x)     (x)
  93
  94 #else
  95
  96 /*
  97  * These are used to make use of C type-checking..
  98  */
  99
 100 typedef struct { unsigned long pte; } pte_t;            /* page table entry */
 101 typedef struct { unsigned long pgd; } pgd_t;            /* PGD table entry */
 102 typedef struct { unsigned long pgprot; } pgprot_t;
 103 typedef struct page *pgtable_t;
 104
 105 #define pte_val(x)      ((x).pte)
 106 #define pgd_val(x)      ((x).pgd)
 107 #define pgprot_val(x)   ((x).pgprot)
 108
 109 #define __pte(x)        ((pte_t) { (x) } )
 110 #define __pgd(x)        ((pgd_t) { (x) } )
 111 #define __pgprot(x)     ((pgprot_t) { (x) } )
 112
 113 /*
 114  * Pure 2^n version of get_order
 115  * Use 'nsau' instructions if supported by the processor or the generic version.
 116  */
 117
 118 #if XCHAL_HAVE_NSA
 119
 120 static inline __attribute_const__ int get_order(unsigned long size)
 121 {
 122         int lz;
 123         asm ("nsau %0, %1" : "=r" (lz) : "r" ((size - 1) >> PAGE_SHIFT));
 124         return 32 - lz;
 125 }
 126
 127 #else
 128
 129 # include <asm-generic/getorder.h>
 130
 131 #endif
 132
 133 struct page;
 134 struct vm_area_struct;
 135 extern void clear_page(void *page);
 136 extern void copy_page(void *to, void *from);
 137
 138 /*
 139  * If we have cache aliasing and writeback caches, we might have to do
 140  * some extra work
 141  */
 142
 143 #if defined(CONFIG_MMU) && DCACHE_WAY_SIZE > PAGE_SIZE
 144 extern void clear_page_alias(void *vaddr, unsigned long paddr);
 145 extern void copy_page_alias(void *to, void *from,
 146                             unsigned long to_paddr, unsigned long from_paddr);
 147
 148 #define clear_user_highpage clear_user_highpage
 149 void clear_user_highpage(struct page *page, unsigned long vaddr);
 150 #define __HAVE_ARCH_COPY_USER_HIGHPAGE
 151 void copy_user_highpage(struct page *to, struct page *from,
 152                         unsigned long vaddr, struct vm_area_struct *vma);
 153 #else
 154 # define clear_user_page(page, vaddr, pg)       clear_page(page)
 155 # define copy_user_page(to, from, vaddr, pg)    copy_page(to, from)
 156 #endif
 157
 158 /*
 159  * This handles the memory map.  We handle pages at
 160  * XCHAL_KSEG_CACHED_VADDR for kernels with 32 bit address space.
 161  * These macros are for conversion of kernel address, not user
 162  * addresses.
 163  */
 164
 165 #define ARCH_PFN_OFFSET         (PHYS_OFFSET >> PAGE_SHIFT)
 166
 167 #define __pa(x) \
 168         ((unsigned long) (x) - PAGE_OFFSET + PHYS_OFFSET)
 169 #define __va(x) \
 170         ((void *)((unsigned long) (x) - PHYS_OFFSET + PAGE_OFFSET))
 171 #define pfn_valid(pfn) \
 172         ((pfn) >= ARCH_PFN_OFFSET && ((pfn) - ARCH_PFN_OFFSET) < max_mapnr)
 173
 174 #ifdef CONFIG_DISCONTIGMEM
 175 # error CONFIG_DISCONTIGMEM not supported
 176 #endif
 177
 178 #define virt_to_page(kaddr)     pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
 179 #define page_to_virt(page)      __va(page_to_pfn(page) << PAGE_SHIFT)
 180 #define virt_addr_valid(kaddr)  pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
 181 #define page_to_phys(page)      (page_to_pfn(page) << PAGE_SHIFT)
 182
 183 #endif /* __ASSEMBLY__ */
 184
 185 #define VM_DATA_DEFAULT_FLAGS   (VM_READ | VM_WRITE | VM_EXEC | \
 186                                  VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
 187
 188 #include <asm-generic/memory_model.h>
 189 #endif /* _XTENSA_PAGE_H */