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 19 /* 20 * Fixed TLB translations in the processor. 21 */ 22 23 #define XCHAL_KSEG_CACHED_VADDR 0xd0000000 24 #define XCHAL_KSEG_BYPASS_VADDR 0xd8000000 25 #define XCHAL_KSEG_PADDR 0x00000000 26 #define XCHAL_KSEG_SIZE 0x08000000 27 28 /* 29 * PAGE_SHIFT determines the page size 30 */ 31 32 #define PAGE_SHIFT 12 33 #define PAGE_SIZE (__XTENSA_UL_CONST(1) << PAGE_SHIFT) 34 #define PAGE_MASK (~(PAGE_SIZE-1)) 35 36 #ifdef CONFIG_MMU 37 #define PAGE_OFFSET XCHAL_KSEG_CACHED_VADDR 38 #define MAX_MEM_PFN XCHAL_KSEG_SIZE 39 #else 40 #define PAGE_OFFSET 0 41 #define MAX_MEM_PFN (PLATFORM_DEFAULT_MEM_START + PLATFORM_DEFAULT_MEM_SIZE) 42 #endif 43 44 #define PGTABLE_START 0x80000000 45 46 /* 47 * Cache aliasing: 48 * 49 * If the cache size for one way is greater than the page size, we have to 50 * deal with cache aliasing. The cache index is wider than the page size: 51 * 52 * | |cache| cache index 53 * | pfn |off| virtual address 54 * |xxxx:X|zzz| 55 * | : | | 56 * | \ / | | 57 * |trans.| | 58 * | / \ | | 59 * |yyyy:Y|zzz| physical address 60 * 61 * When the page number is translated to the physical page address, the lowest 62 * bit(s) (X) that are part of the cache index are also translated (Y). 63 * If this translation changes bit(s) (X), the cache index is also afected, 64 * thus resulting in a different cache line than before. 65 * The kernel does not provide a mechanism to ensure that the page color 66 * (represented by this bit) remains the same when allocated or when pages 67 * are remapped. When user pages are mapped into kernel space, the color of 68 * the page might also change. 69 * 70 * We use the address space VMALLOC_END ... VMALLOC_END + DCACHE_WAY_SIZE * 2 71 * to temporarily map a patch so we can match the color. 72 */ 73 74 #if DCACHE_WAY_SIZE > PAGE_SIZE 75 # define DCACHE_ALIAS_ORDER (DCACHE_WAY_SHIFT - PAGE_SHIFT) 76 # define DCACHE_ALIAS_MASK (PAGE_MASK & (DCACHE_WAY_SIZE - 1)) 77 # define DCACHE_ALIAS(a) (((a) & DCACHE_ALIAS_MASK) >> PAGE_SHIFT) 78 # define DCACHE_ALIAS_EQ(a,b) ((((a) ^ (b)) & DCACHE_ALIAS_MASK) == 0) 79 #else 80 # define DCACHE_ALIAS_ORDER 0 81 #endif 82 83 #if ICACHE_WAY_SIZE > PAGE_SIZE 84 # define ICACHE_ALIAS_ORDER (ICACHE_WAY_SHIFT - PAGE_SHIFT) 85 # define ICACHE_ALIAS_MASK (PAGE_MASK & (ICACHE_WAY_SIZE - 1)) 86 # define ICACHE_ALIAS(a) (((a) & ICACHE_ALIAS_MASK) >> PAGE_SHIFT) 87 # define ICACHE_ALIAS_EQ(a,b) ((((a) ^ (b)) & ICACHE_ALIAS_MASK) == 0) 88 #else 89 # define ICACHE_ALIAS_ORDER 0 90 #endif 91 92 93 #ifdef __ASSEMBLY__ 94 95 #define __pgprot(x) (x) 96 97 #else 98 99 /* 100 * These are used to make use of C type-checking.. 101 */ 102 103 typedef struct { unsigned long pte; } pte_t; /* page table entry */ 104 typedef struct { unsigned long pgd; } pgd_t; /* PGD table entry */ 105 typedef struct { unsigned long pgprot; } pgprot_t; 106 typedef struct page *pgtable_t; 107 108 #define pte_val(x) ((x).pte) 109 #define pgd_val(x) ((x).pgd) 110 #define pgprot_val(x) ((x).pgprot) 111 112 #define __pte(x) ((pte_t) { (x) } ) 113 #define __pgd(x) ((pgd_t) { (x) } ) 114 #define __pgprot(x) ((pgprot_t) { (x) } ) 115 116 /* 117 * Pure 2^n version of get_order 118 * Use 'nsau' instructions if supported by the processor or the generic version. 119 */ 120 121 #if XCHAL_HAVE_NSA 122 123 static inline __attribute_const__ int get_order(unsigned long size) 124 { 125 int lz; 126 asm ("nsau %0, %1" : "=r" (lz) : "r" ((size - 1) >> PAGE_SHIFT)); 127 return 32 - lz; 128 } 129 130 #else 131 132 # include <asm-generic/page.h> 133 134 #endif 135 136 struct page; 137 extern void clear_page(void *page); 138 extern void copy_page(void *to, void *from); 139 140 /* 141 * If we have cache aliasing and writeback caches, we might have to do 142 * some extra work 143 */ 144 145 #if DCACHE_WAY_SIZE > PAGE_SIZE 146 extern void clear_user_page(void*, unsigned long, struct page*); 147 extern void copy_user_page(void*, void*, unsigned long, struct page*); 148 #else 149 # define clear_user_page(page, vaddr, pg) clear_page(page) 150 # define copy_user_page(to, from, vaddr, pg) copy_page(to, from) 151 #endif 152 153 /* 154 * This handles the memory map. We handle pages at 155 * XCHAL_KSEG_CACHED_VADDR for kernels with 32 bit address space. 156 * These macros are for conversion of kernel address, not user 157 * addresses. 158 */ 159 160 #define ARCH_PFN_OFFSET (PLATFORM_DEFAULT_MEM_START >> PAGE_SHIFT) 161 162 #define __pa(x) ((unsigned long) (x) - PAGE_OFFSET) 163 #define __va(x) ((void *)((unsigned long) (x) + PAGE_OFFSET)) 164 #define pfn_valid(pfn) ((pfn) >= ARCH_PFN_OFFSET && ((pfn) - ARCH_PFN_OFFSET) < max_mapnr) 165 #ifdef CONFIG_DISCONTIGMEM 166 # error CONFIG_DISCONTIGMEM not supported 167 #endif 168 169 #define virt_to_page(kaddr) pfn_to_page(__pa(kaddr) >> PAGE_SHIFT) 170 #define page_to_virt(page) __va(page_to_pfn(page) << PAGE_SHIFT) 171 #define virt_addr_valid(kaddr) pfn_valid(__pa(kaddr) >> PAGE_SHIFT) 172 #define page_to_phys(page) (page_to_pfn(page) << PAGE_SHIFT) 173 174 #ifdef CONFIG_MMU 175 #define WANT_PAGE_VIRTUAL 176 #endif 177 178 #endif /* __ASSEMBLY__ */ 179 180 #define VM_DATA_DEFAULT_FLAGS (VM_READ | VM_WRITE | VM_EXEC | \ 181 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC) 182 183 #include <asm-generic/memory_model.h> 184 #endif /* _XTENSA_PAGE_H */ 185