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 /*
  40  * Cache aliasing:
  41  *
  42  * If the cache size for one way is greater than the page size, we have to
  43  * deal with cache aliasing. The cache index is wider than the page size:
  44  *
  45  * |    |cache| cache index
  46  * | pfn  |off| virtual address
  47  * |xxxx:X|zzz|
  48  * |    : |   |
  49  * | \  / |   |
  50  * |trans.|   |
  51  * | /  \ |   |
  52  * |yyyy:Y|zzz| physical address
  53  *
  54  * When the page number is translated to the physical page address, the lowest
  55  * bit(s) (X) that are part of the cache index are also translated (Y).
  56  * If this translation changes bit(s) (X), the cache index is also afected,
  57  * thus resulting in a different cache line than before.
  58  * The kernel does not provide a mechanism to ensure that the page color
  59  * (represented by this bit) remains the same when allocated or when pages
  60  * are remapped. When user pages are mapped into kernel space, the color of
  61  * the page might also change.
  62  *
  63  * We use the address space VMALLOC_END ... VMALLOC_END + DCACHE_WAY_SIZE * 2
  64  * to temporarily map a patch so we can match the color.
  65  */
  66
  67 #if DCACHE_WAY_SIZE > PAGE_SIZE
  68 # define DCACHE_ALIAS_ORDER     (DCACHE_WAY_SHIFT - PAGE_SHIFT)
  69 # define DCACHE_ALIAS_MASK      (PAGE_MASK & (DCACHE_WAY_SIZE - 1))
  70 # define DCACHE_ALIAS(a)        (((a) & DCACHE_ALIAS_MASK) >> PAGE_SHIFT)
  71 # define DCACHE_ALIAS_EQ(a,b)   ((((a) ^ (b)) & DCACHE_ALIAS_MASK) == 0)
  72 #else
  73 # define DCACHE_ALIAS_ORDER     0
  74 # define DCACHE_ALIAS(a)        ((void)(a), 0)
  75 #endif
  76 #define DCACHE_N_COLORS         (1 << DCACHE_ALIAS_ORDER)
  77
  78 #if ICACHE_WAY_SIZE > PAGE_SIZE
  79 # define ICACHE_ALIAS_ORDER     (ICACHE_WAY_SHIFT - PAGE_SHIFT)
  80 # define ICACHE_ALIAS_MASK      (PAGE_MASK & (ICACHE_WAY_SIZE - 1))
  81 # define ICACHE_ALIAS(a)        (((a) & ICACHE_ALIAS_MASK) >> PAGE_SHIFT)
  82 # define ICACHE_ALIAS_EQ(a,b)   ((((a) ^ (b)) & ICACHE_ALIAS_MASK) == 0)
  83 #else
  84 # define ICACHE_ALIAS_ORDER     0
  85 #endif
  86
  87
  88 #ifdef __ASSEMBLY__
  89
  90 #define __pgprot(x)     (x)
  91
  92 #else
  93
  94 /*
  95  * These are used to make use of C type-checking..
  96  */
  97
  98 typedef struct { unsigned long pte; } pte_t;            /* page table entry */
  99 typedef struct { unsigned long pgd; } pgd_t;            /* PGD table entry */
 100 typedef struct { unsigned long pgprot; } pgprot_t;
 101 typedef struct page *pgtable_t;
 102
 103 #define pte_val(x)      ((x).pte)
 104 #define pgd_val(x)      ((x).pgd)
 105 #define pgprot_val(x)   ((x).pgprot)
 106
 107 #define __pte(x)        ((pte_t) { (x) } )
 108 #define __pgd(x)        ((pgd_t) { (x) } )
 109 #define __pgprot(x)     ((pgprot_t) { (x) } )
 110
 111 /*
 112  * Pure 2^n version of get_order
 113  * Use 'nsau' instructions if supported by the processor or the generic version.
 114  */
 115
 116 #if XCHAL_HAVE_NSA
 117
 118 static inline __attribute_const__ int get_order(unsigned long size)
 119 {
 120         int lz;
 121         asm ("nsau %0, %1" : "=r" (lz) : "r" ((size - 1) >> PAGE_SHIFT));
 122         return 32 - lz;
 123 }
 124
 125 #else
 126
 127 # include <asm-generic/getorder.h>
 128
 129 #endif
 130
 131 struct page;
 132 struct vm_area_struct;
 133 extern void clear_page(void *page);
 134 extern void copy_page(void *to, void *from);
 135
 136 /*
 137  * If we have cache aliasing and writeback caches, we might have to do
 138  * some extra work
 139  */
 140
 141 #if defined(CONFIG_MMU) && DCACHE_WAY_SIZE > PAGE_SIZE
 142 extern void clear_page_alias(void *vaddr, unsigned long paddr);
 143 extern void copy_page_alias(void *to, void *from,
 144                             unsigned long to_paddr, unsigned long from_paddr);
 145
 146 #define clear_user_highpage clear_user_highpage
 147 void clear_user_highpage(struct page *page, unsigned long vaddr);
 148 #define __HAVE_ARCH_COPY_USER_HIGHPAGE
 149 void copy_user_highpage(struct page *to, struct page *from,
 150                         unsigned long vaddr, struct vm_area_struct *vma);
 151 #else
 152 # define clear_user_page(page, vaddr, pg)       clear_page(page)
 153 # define copy_user_page(to, from, vaddr, pg)    copy_page(to, from)
 154 #endif
 155
 156 /*
 157  * This handles the memory map.  We handle pages at
 158  * XCHAL_KSEG_CACHED_VADDR for kernels with 32 bit address space.
 159  * These macros are for conversion of kernel address, not user
 160  * addresses.
 161  */
 162
 163 #define ARCH_PFN_OFFSET         (PHYS_OFFSET >> PAGE_SHIFT)
 164
 165 #ifdef CONFIG_MMU
 166 static inline unsigned long ___pa(unsigned long va)
 167 {
 168         unsigned long off = va - PAGE_OFFSET;
 169
 170         if (off >= XCHAL_KSEG_SIZE)
 171                 off -= XCHAL_KSEG_SIZE;
 172
 173         return off + PHYS_OFFSET;
 174 }
 175 #define __pa(x) ___pa((unsigned long)(x))
 176 #else
 177 #define __pa(x) \
 178         ((unsigned long) (x) - PAGE_OFFSET + PHYS_OFFSET)
 179 #endif
 180 #define __va(x) \
 181         ((void *)((unsigned long) (x) - PHYS_OFFSET + PAGE_OFFSET))
 182 #define pfn_valid(pfn) \
 183         ((pfn) >= ARCH_PFN_OFFSET && ((pfn) - ARCH_PFN_OFFSET) < max_mapnr)
 184
 185 #ifdef CONFIG_DISCONTIGMEM
 186 # error CONFIG_DISCONTIGMEM not supported
 187 #endif
 188
 189 #define virt_to_page(kaddr)     pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
 190 #define page_to_virt(page)      __va(page_to_pfn(page) << PAGE_SHIFT)
 191 #define virt_addr_valid(kaddr)  pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
 192 #define page_to_phys(page)      (page_to_pfn(page) << PAGE_SHIFT)
 193
 194 #endif /* __ASSEMBLY__ */
 195
 196 #define VM_DATA_DEFAULT_FLAGS   (VM_READ | VM_WRITE | VM_EXEC | \
 197                                  VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
 198
 199 #include <asm-generic/memory_model.h>
 200 #endif /* _XTENSA_PAGE_H */