1 /* 2 * arch/parisc/mm/ioremap.c 3 * 4 * (C) Copyright 1995 1996 Linus Torvalds 5 * (C) Copyright 2001-2006 Helge Deller <deller@gmx.de> 6 * (C) Copyright 2005 Kyle McMartin <kyle@parisc-linux.org> 7 */ 8 9 #include <linux/vmalloc.h> 10 #include <linux/errno.h> 11 #include <linux/module.h> 12 #include <asm/io.h> 13 #include <asm/pgalloc.h> 14 #include <asm/tlbflush.h> 15 #include <asm/cacheflush.h> 16 17 static inline void 18 remap_area_pte(pte_t *pte, unsigned long address, unsigned long size, 19 unsigned long phys_addr, unsigned long flags) 20 { 21 unsigned long end, pfn; 22 pgprot_t pgprot = __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | 23 _PAGE_ACCESSED | flags); 24 25 address &= ~PMD_MASK; 26 27 end = address + size; 28 if (end > PMD_SIZE) 29 end = PMD_SIZE; 30 31 BUG_ON(address >= end); 32 33 pfn = phys_addr >> PAGE_SHIFT; 34 do { 35 BUG_ON(!pte_none(*pte)); 36 37 set_pte(pte, pfn_pte(pfn, pgprot)); 38 39 address += PAGE_SIZE; 40 pfn++; 41 pte++; 42 } while (address && (address < end)); 43 } 44 45 static inline int 46 remap_area_pmd(pmd_t *pmd, unsigned long address, unsigned long size, 47 unsigned long phys_addr, unsigned long flags) 48 { 49 unsigned long end; 50 51 address &= ~PGDIR_MASK; 52 53 end = address + size; 54 if (end > PGDIR_SIZE) 55 end = PGDIR_SIZE; 56 57 BUG_ON(address >= end); 58 59 phys_addr -= address; 60 do { 61 pte_t *pte = pte_alloc_kernel(pmd, address); 62 if (!pte) 63 return -ENOMEM; 64 65 remap_area_pte(pte, address, end - address, 66 address + phys_addr, flags); 67 68 address = (address + PMD_SIZE) & PMD_MASK; 69 pmd++; 70 } while (address && (address < end)); 71 72 return 0; 73 } 74 75 static int 76 remap_area_pages(unsigned long address, unsigned long phys_addr, 77 unsigned long size, unsigned long flags) 78 { 79 pgd_t *dir; 80 int error = 0; 81 unsigned long end = address + size; 82 83 BUG_ON(address >= end); 84 85 phys_addr -= address; 86 dir = pgd_offset_k(address); 87 88 flush_cache_all(); 89 90 do { 91 pud_t *pud; 92 pmd_t *pmd; 93 94 error = -ENOMEM; 95 pud = pud_alloc(&init_mm, dir, address); 96 if (!pud) 97 break; 98 99 pmd = pmd_alloc(&init_mm, pud, address); 100 if (!pmd) 101 break; 102 103 if (remap_area_pmd(pmd, address, end - address, 104 phys_addr + address, flags)) 105 break; 106 107 error = 0; 108 address = (address + PGDIR_SIZE) & PGDIR_MASK; 109 dir++; 110 } while (address && (address < end)); 111 112 flush_tlb_all(); 113 114 return error; 115 } 116 117 /* 118 * Generic mapping function (not visible outside): 119 */ 120 121 /* 122 * Remap an arbitrary physical address space into the kernel virtual 123 * address space. 124 * 125 * NOTE! We need to allow non-page-aligned mappings too: we will obviously 126 * have to convert them into an offset in a page-aligned mapping, but the 127 * caller shouldn't need to know that small detail. 128 */ 129 void __iomem * __ioremap(unsigned long phys_addr, unsigned long size, unsigned long flags) 130 { 131 void *addr; 132 struct vm_struct *area; 133 unsigned long offset, last_addr; 134 135 #ifdef CONFIG_EISA 136 unsigned long end = phys_addr + size - 1; 137 /* Support EISA addresses */ 138 if ((phys_addr >= 0x00080000 && end < 0x000fffff) || 139 (phys_addr >= 0x00500000 && end < 0x03bfffff)) { 140 phys_addr |= F_EXTEND(0xfc000000); 141 flags |= _PAGE_NO_CACHE; 142 } 143 #endif 144 145 /* Don't allow wraparound or zero size */ 146 last_addr = phys_addr + size - 1; 147 if (!size || last_addr < phys_addr) 148 return NULL; 149 150 /* 151 * Don't allow anybody to remap normal RAM that we're using.. 152 */ 153 if (phys_addr < virt_to_phys(high_memory)) { 154 char *t_addr, *t_end; 155 struct page *page; 156 157 t_addr = __va(phys_addr); 158 t_end = t_addr + (size - 1); 159 160 for (page = virt_to_page(t_addr); 161 page <= virt_to_page(t_end); page++) { 162 if(!PageReserved(page)) 163 return NULL; 164 } 165 } 166 167 /* 168 * Mappings have to be page-aligned 169 */ 170 offset = phys_addr & ~PAGE_MASK; 171 phys_addr &= PAGE_MASK; 172 size = PAGE_ALIGN(last_addr) - phys_addr; 173 174 /* 175 * Ok, go for it.. 176 */ 177 area = get_vm_area(size, VM_IOREMAP); 178 if (!area) 179 return NULL; 180 181 addr = area->addr; 182 if (remap_area_pages((unsigned long) addr, phys_addr, size, flags)) { 183 vfree(addr); 184 return NULL; 185 } 186 187 return (void __iomem *) (offset + (char *)addr); 188 } 189 EXPORT_SYMBOL(__ioremap); 190 191 void iounmap(void __iomem *addr) 192 { 193 if (addr > high_memory) 194 return vfree((void *) (PAGE_MASK & (unsigned long __force) addr)); 195 } 196 EXPORT_SYMBOL(iounmap); 197