1/* 2 * Copyright (C) 2004-2006 Atmel Corporation 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 version 2 as 6 * published by the Free Software Foundation. 7 */ 8#include <linux/vmalloc.h> 9#include <linux/mm.h> 10#include <linux/module.h> 11#include <linux/io.h> 12#include <linux/slab.h> 13 14#include <asm/pgtable.h> 15#include <asm/addrspace.h> 16 17/* 18 * Re-map an arbitrary physical address space into the kernel virtual 19 * address space. Needed when the kernel wants to access physical 20 * memory directly. 21 */ 22void __iomem *__ioremap(unsigned long phys_addr, size_t size, 23 unsigned long flags) 24{ 25 unsigned long addr; 26 struct vm_struct *area; 27 unsigned long offset, last_addr; 28 pgprot_t prot; 29 30 /* 31 * Check if we can simply use the P4 segment. This area is 32 * uncacheable, so if caching/buffering is requested, we can't 33 * use it. 34 */ 35 if ((phys_addr >= P4SEG) && (flags == 0)) 36 return (void __iomem *)phys_addr; 37 38 /* Don't allow wraparound or zero size */ 39 last_addr = phys_addr + size - 1; 40 if (!size || last_addr < phys_addr) 41 return NULL; 42 43 if (PHYSADDR(P2SEGADDR(phys_addr)) == phys_addr) 44 return (void __iomem *)P2SEGADDR(phys_addr); 45 46 /* Mappings have to be page-aligned */ 47 offset = phys_addr & ~PAGE_MASK; 48 phys_addr &= PAGE_MASK; 49 size = PAGE_ALIGN(last_addr + 1) - phys_addr; 50 51 prot = __pgprot(_PAGE_PRESENT | _PAGE_GLOBAL | _PAGE_RW | _PAGE_DIRTY 52 | _PAGE_ACCESSED | _PAGE_TYPE_SMALL | flags); 53 54 /* 55 * Ok, go for it.. 56 */ 57 area = get_vm_area(size, VM_IOREMAP); 58 if (!area) 59 return NULL; 60 area->phys_addr = phys_addr; 61 addr = (unsigned long )area->addr; 62 if (ioremap_page_range(addr, addr + size, phys_addr, prot)) { 63 vunmap((void *)addr); 64 return NULL; 65 } 66 67 return (void __iomem *)(offset + (char *)addr); 68} 69EXPORT_SYMBOL(__ioremap); 70 71void __iounmap(void __iomem *addr) 72{ 73 struct vm_struct *p; 74 75 if ((unsigned long)addr >= P4SEG) 76 return; 77 if (PXSEG(addr) == P2SEG) 78 return; 79 80 p = remove_vm_area((void *)(PAGE_MASK & (unsigned long __force)addr)); 81 if (unlikely(!p)) { 82 printk (KERN_ERR "iounmap: bad address %p\n", addr); 83 return; 84 } 85 86 kfree (p); 87} 88EXPORT_SYMBOL(__iounmap); 89