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 <linux/io.h> 13 #include <asm/pgalloc.h> 14 15 /* 16 * Generic mapping function (not visible outside): 17 */ 18 19 /* 20 * Remap an arbitrary physical address space into the kernel virtual 21 * address space. 22 * 23 * NOTE! We need to allow non-page-aligned mappings too: we will obviously 24 * have to convert them into an offset in a page-aligned mapping, but the 25 * caller shouldn't need to know that small detail. 26 */ 27 void __iomem * __ioremap(unsigned long phys_addr, unsigned long size, unsigned long flags) 28 { 29 void __iomem *addr; 30 struct vm_struct *area; 31 unsigned long offset, last_addr; 32 pgprot_t pgprot; 33 34 #ifdef CONFIG_EISA 35 unsigned long end = phys_addr + size - 1; 36 /* Support EISA addresses */ 37 if ((phys_addr >= 0x00080000 && end < 0x000fffff) || 38 (phys_addr >= 0x00500000 && end < 0x03bfffff)) { 39 phys_addr |= F_EXTEND(0xfc000000); 40 flags |= _PAGE_NO_CACHE; 41 } 42 #endif 43 44 /* Don't allow wraparound or zero size */ 45 last_addr = phys_addr + size - 1; 46 if (!size || last_addr < phys_addr) 47 return NULL; 48 49 /* 50 * Don't allow anybody to remap normal RAM that we're using.. 51 */ 52 if (phys_addr < virt_to_phys(high_memory)) { 53 char *t_addr, *t_end; 54 struct page *page; 55 56 t_addr = __va(phys_addr); 57 t_end = t_addr + (size - 1); 58 59 for (page = virt_to_page(t_addr); 60 page <= virt_to_page(t_end); page++) { 61 if(!PageReserved(page)) 62 return NULL; 63 } 64 } 65 66 pgprot = __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | 67 _PAGE_ACCESSED | flags); 68 69 /* 70 * Mappings have to be page-aligned 71 */ 72 offset = phys_addr & ~PAGE_MASK; 73 phys_addr &= PAGE_MASK; 74 size = PAGE_ALIGN(last_addr) - phys_addr; 75 76 /* 77 * Ok, go for it.. 78 */ 79 area = get_vm_area(size, VM_IOREMAP); 80 if (!area) 81 return NULL; 82 83 addr = (void __iomem *) area->addr; 84 if (ioremap_page_range((unsigned long)addr, (unsigned long)addr + size, 85 phys_addr, pgprot)) { 86 vfree(addr); 87 return NULL; 88 } 89 90 return (void __iomem *) (offset + (char __iomem *)addr); 91 } 92 EXPORT_SYMBOL(__ioremap); 93 94 void iounmap(const volatile void __iomem *addr) 95 { 96 if (addr > high_memory) 97 return vfree((void *) (PAGE_MASK & (unsigned long __force) addr)); 98 } 99 EXPORT_SYMBOL(iounmap); 100