arch/parisc/mm/ioremap.c

   1 /*
   2  * arch/parisc/mm/ioremap.c
   3  *
   4  * (C) Copyright 1995 1996 Linus Torvalds
   5  * (C) Copyright 2001 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 #ifdef CONFIG_HPPA_IOREMAP
  76 static int
  77 remap_area_pages(unsigned long address, unsigned long phys_addr,
  78                  unsigned long size, unsigned long flags)
  79 {
  80         pgd_t *dir;
  81         int error = 0;
  82         unsigned long end = address + size;
  83
  84         BUG_ON(address >= end);
  85
  86         phys_addr -= address;
  87         dir = pgd_offset_k(address);
  88
  89         flush_cache_all();
  90
  91         do {
  92                 pud_t *pud;
  93                 pmd_t *pmd;
  94
  95                 error = -ENOMEM;
  96                 pud = pud_alloc(&init_mm, dir, address);
  97                 if (!pud)
  98                         break;
  99
 100                 pmd = pmd_alloc(&init_mm, pud, address);
 101                 if (!pmd)
 102                         break;
 103
 104                 if (remap_area_pmd(pmd, address, end - address,
 105                                    phys_addr + address, flags))
 106                         break;
 107
 108                 error = 0;
 109                 address = (address + PGDIR_SIZE) & PGDIR_MASK;
 110                 dir++;
 111         } while (address && (address < end));
 112
 113         flush_tlb_all();
 114
 115         return error;
 116 }
 117 #endif /* CONFIG_HPPA_IOREMAP */
 118
 119 #ifdef CONFIG_DEBUG_IOREMAP
 120 static unsigned long last = 0;
 121
 122 void gsc_bad_addr(unsigned long addr)
 123 {
 124         if (time_after(jiffies, last + HZ*10)) {
 125                 printk("gsc_foo() called with bad address 0x%lx\n", addr);
 126                 dump_stack();
 127                 last = jiffies;
 128         }
 129 }
 130 EXPORT_SYMBOL(gsc_bad_addr);
 131
 132 void __raw_bad_addr(const volatile void __iomem *addr)
 133 {
 134         if (time_after(jiffies, last + HZ*10)) {
 135                 printk("__raw_foo() called with bad address 0x%p\n", addr);
 136                 dump_stack();
 137                 last = jiffies;
 138         }
 139 }
 140 EXPORT_SYMBOL(__raw_bad_addr);
 141 #endif
 142
 143 /*
 144  * Generic mapping function (not visible outside):
 145  */
 146
 147 /*
 148  * Remap an arbitrary physical address space into the kernel virtual
 149  * address space.
 150  *
 151  * NOTE! We need to allow non-page-aligned mappings too: we will obviously
 152  * have to convert them into an offset in a page-aligned mapping, but the
 153  * caller shouldn't need to know that small detail.
 154  */
 155 void __iomem * __ioremap(unsigned long phys_addr, unsigned long size, unsigned long flags)
 156 {
 157 #if !defined(CONFIG_HPPA_IOREMAP)
 158         unsigned long end = phys_addr + size - 1;
 159         /* Support EISA addresses */
 160         if ((phys_addr >= 0x00080000 && end < 0x000fffff)
 161                         || (phys_addr >= 0x00500000 && end < 0x03bfffff)) {
 162                 phys_addr |= 0xfc000000;
 163         }
 164
 165 #ifdef CONFIG_DEBUG_IOREMAP
 166         return (void __iomem *)(phys_addr - (0x1UL << NYBBLE_SHIFT));
 167 #else
 168         return (void __iomem *)phys_addr;
 169 #endif
 170
 171 #else
 172         void *addr;
 173         struct vm_struct *area;
 174         unsigned long offset, last_addr;
 175
 176         /* Don't allow wraparound or zero size */
 177         last_addr = phys_addr + size - 1;
 178         if (!size || last_addr < phys_addr)
 179                 return NULL;
 180
 181         /*
 182          * Don't allow anybody to remap normal RAM that we're using..
 183          */
 184         if (phys_addr < virt_to_phys(high_memory)) {
 185                 char *t_addr, *t_end;
 186                 struct page *page;
 187
 188                 t_addr = __va(phys_addr);
 189                 t_end = t_addr + (size - 1);
 190
 191                 for (page = virt_to_page(t_addr);
 192                      page <= virt_to_page(t_end); page++) {
 193                         if(!PageReserved(page))
 194                                 return NULL;
 195                 }
 196         }
 197
 198         /*
 199          * Mappings have to be page-aligned
 200          */
 201         offset = phys_addr & ~PAGE_MASK;
 202         phys_addr &= PAGE_MASK;
 203         size = PAGE_ALIGN(last_addr) - phys_addr;
 204
 205         /*
 206          * Ok, go for it..
 207          */
 208         area = get_vm_area(size, VM_IOREMAP);
 209         if (!area)
 210                 return NULL;
 211
 212         addr = area->addr;
 213         if (remap_area_pages((unsigned long) addr, phys_addr, size, flags)) {
 214                 vfree(addr);
 215                 return NULL;
 216         }
 217
 218         return (void __iomem *) (offset + (char *)addr);
 219 #endif
 220 }
 221
 222 void iounmap(void __iomem *addr)
 223 {
 224 #ifdef CONFIG_HPPA_IOREMAP
 225         if (addr > high_memory)
 226                 return vfree((void *) (PAGE_MASK & (unsigned long __force) addr));
 227 #else
 228         return;
 229 #endif
 230 }