1 /* 2 * arch/parisc/mm/ioremap.c 3 * 4 * Re-map IO memory to kernel address space so that we can access it. 5 * This is needed for high PCI addresses that aren't mapped in the 6 * 640k-1MB IO memory area on PC's 7 * 8 * (C) Copyright 1995 1996 Linus Torvalds 9 * (C) Copyright 2001 Helge Deller <deller@gmx.de> 10 */ 11 12 #include <linux/vmalloc.h> 13 #include <linux/errno.h> 14 #include <linux/module.h> 15 #include <asm/io.h> 16 #include <asm/pgalloc.h> 17 18 static inline void 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; 22 23 address &= ~PMD_MASK; 24 end = address + size; 25 if (end > PMD_SIZE) 26 end = PMD_SIZE; 27 if (address >= end) 28 BUG(); 29 do { 30 if (!pte_none(*pte)) { 31 printk(KERN_ERR "remap_area_pte: page already exists\n"); 32 BUG(); 33 } 34 set_pte(pte, mk_pte_phys(phys_addr, __pgprot(_PAGE_PRESENT | _PAGE_RW | 35 _PAGE_DIRTY | _PAGE_ACCESSED | flags))); 36 address += PAGE_SIZE; 37 phys_addr += PAGE_SIZE; 38 pte++; 39 } while (address && (address < end)); 40 } 41 42 static inline int remap_area_pmd(pmd_t * pmd, unsigned long address, unsigned long size, 43 unsigned long phys_addr, unsigned long flags) 44 { 45 unsigned long end; 46 47 address &= ~PGDIR_MASK; 48 end = address + size; 49 if (end > PGDIR_SIZE) 50 end = PGDIR_SIZE; 51 phys_addr -= address; 52 if (address >= end) 53 BUG(); 54 do { 55 pte_t * pte = pte_alloc_kernel(NULL, pmd, address); 56 if (!pte) 57 return -ENOMEM; 58 remap_area_pte(pte, address, end - address, address + phys_addr, flags); 59 address = (address + PMD_SIZE) & PMD_MASK; 60 pmd++; 61 } while (address && (address < end)); 62 return 0; 63 } 64 65 #if (USE_HPPA_IOREMAP) 66 static int remap_area_pages(unsigned long address, unsigned long phys_addr, 67 unsigned long size, unsigned long flags) 68 { 69 int error; 70 pgd_t * dir; 71 unsigned long end = address + size; 72 73 phys_addr -= address; 74 dir = pgd_offset(&init_mm, address); 75 flush_cache_all(); 76 if (address >= end) 77 BUG(); 78 spin_lock(&init_mm.page_table_lock); 79 do { 80 pmd_t *pmd; 81 pmd = pmd_alloc(dir, address); 82 error = -ENOMEM; 83 if (!pmd) 84 break; 85 if (remap_area_pmd(pmd, address, end - address, 86 phys_addr + address, flags)) 87 break; 88 error = 0; 89 address = (address + PGDIR_SIZE) & PGDIR_MASK; 90 dir++; 91 } while (address && (address < end)); 92 spin_unlock(&init_mm.page_table_lock); 93 flush_tlb_all(); 94 return error; 95 } 96 #endif /* USE_HPPA_IOREMAP */ 97 98 #ifdef CONFIG_DEBUG_IOREMAP 99 static unsigned long last = 0; 100 101 void gsc_bad_addr(unsigned long addr) 102 { 103 if (time_after(jiffies, last + HZ*10)) { 104 printk("gsc_foo() called with bad address 0x%lx\n", addr); 105 dump_stack(); 106 last = jiffies; 107 } 108 } 109 EXPORT_SYMBOL(gsc_bad_addr); 110 111 void __raw_bad_addr(const volatile void __iomem *addr) 112 { 113 if (time_after(jiffies, last + HZ*10)) { 114 printk("__raw_foo() called with bad address 0x%p\n", addr); 115 dump_stack(); 116 last = jiffies; 117 } 118 } 119 EXPORT_SYMBOL(__raw_bad_addr); 120 #endif 121 122 /* 123 * Generic mapping function (not visible outside): 124 */ 125 126 /* 127 * Remap an arbitrary physical address space into the kernel virtual 128 * address space. Needed when the kernel wants to access high addresses 129 * directly. 130 * 131 * NOTE! We need to allow non-page-aligned mappings too: we will obviously 132 * have to convert them into an offset in a page-aligned mapping, but the 133 * caller shouldn't need to know that small detail. 134 */ 135 void __iomem * __ioremap(unsigned long phys_addr, unsigned long size, unsigned long flags) 136 { 137 #if !(USE_HPPA_IOREMAP) 138 139 unsigned long end = phys_addr + size - 1; 140 /* Support EISA addresses */ 141 if ((phys_addr >= 0x00080000 && end < 0x000fffff) 142 || (phys_addr >= 0x00500000 && end < 0x03bfffff)) { 143 phys_addr |= 0xfc000000; 144 } 145 146 #ifdef CONFIG_DEBUG_IOREMAP 147 return (void __iomem *)(phys_addr - (0x1UL << NYBBLE_SHIFT)); 148 #else 149 return (void __iomem *)phys_addr; 150 #endif 151 152 #else 153 void * addr; 154 struct vm_struct * area; 155 unsigned long offset, last_addr; 156 157 /* Don't allow wraparound or zero size */ 158 last_addr = phys_addr + size - 1; 159 if (!size || last_addr < phys_addr) 160 return NULL; 161 162 /* 163 * Don't allow anybody to remap normal RAM that we're using.. 164 */ 165 if (phys_addr < virt_to_phys(high_memory)) { 166 char *t_addr, *t_end; 167 struct page *page; 168 169 t_addr = __va(phys_addr); 170 t_end = t_addr + (size - 1); 171 172 for(page = virt_to_page(t_addr); page <= virt_to_page(t_end); page++) 173 if(!PageReserved(page)) 174 return NULL; 175 } 176 177 /* 178 * Mappings have to be page-aligned 179 */ 180 offset = phys_addr & ~PAGE_MASK; 181 phys_addr &= PAGE_MASK; 182 size = PAGE_ALIGN(last_addr) - phys_addr; 183 184 /* 185 * Ok, go for it.. 186 */ 187 area = get_vm_area(size, VM_IOREMAP); 188 if (!area) 189 return NULL; 190 addr = area->addr; 191 if (remap_area_pages((unsigned long) addr, phys_addr, size, flags)) { 192 vfree(addr); 193 return NULL; 194 } 195 return (void __iomem *) (offset + (char *)addr); 196 #endif 197 } 198 199 void iounmap(void __iomem *addr) 200 { 201 #if !(USE_HPPA_IOREMAP) 202 return; 203 #else 204 if (addr > high_memory) 205 return vfree((void *) (PAGE_MASK & (unsigned long __force) addr)); 206 #endif 207 } 208