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