1/* 2 * linux/arch/m32r/mm/ioremap.c 3 * 4 * Copyright (c) 2001, 2002 Hiroyuki Kondo 5 * 6 * Taken from mips version. 7 * (C) Copyright 1995 1996 Linus Torvalds 8 * (C) Copyright 2001 Ralf Baechle 9 */ 10 11/* 12 * This file is subject to the terms and conditions of the GNU General Public 13 * License. See the file "COPYING" in the main directory of this archive 14 * for more details. 15 * 16 */ 17 18#include <linux/module.h> 19#include <asm/addrspace.h> 20#include <asm/byteorder.h> 21 22#include <linux/vmalloc.h> 23#include <linux/io.h> 24#include <asm/pgalloc.h> 25 26/* 27 * Generic mapping function (not visible outside): 28 */ 29 30/* 31 * Remap an arbitrary physical address space into the kernel virtual 32 * address space. Needed when the kernel wants to access high addresses 33 * directly. 34 * 35 * NOTE! We need to allow non-page-aligned mappings too: we will obviously 36 * have to convert them into an offset in a page-aligned mapping, but the 37 * caller shouldn't need to know that small detail. 38 */ 39 40#define IS_LOW512(addr) (!((unsigned long)(addr) & ~0x1fffffffUL)) 41 42void __iomem * 43__ioremap(unsigned long phys_addr, unsigned long size, unsigned long flags) 44{ 45 void __iomem * addr; 46 struct vm_struct * area; 47 unsigned long offset, last_addr; 48 pgprot_t pgprot; 49 50 /* Don't allow wraparound or zero size */ 51 last_addr = phys_addr + size - 1; 52 if (!size || last_addr < phys_addr) 53 return NULL; 54 55 /* 56 * Map objects in the low 512mb of address space using KSEG1, otherwise 57 * map using page tables. 58 */ 59 if (IS_LOW512(phys_addr) && IS_LOW512(phys_addr + size - 1)) 60 return (void *) KSEG1ADDR(phys_addr); 61 62 /* 63 * Don't allow anybody to remap normal RAM that we're using.. 64 */ 65 if (phys_addr < virt_to_phys(high_memory)) { 66 char *t_addr, *t_end; 67 struct page *page; 68 69 t_addr = __va(phys_addr); 70 t_end = t_addr + (size - 1); 71 72 for(page = virt_to_page(t_addr); page <= virt_to_page(t_end); page++) 73 if(!PageReserved(page)) 74 return NULL; 75 } 76 77 pgprot = __pgprot(_PAGE_GLOBAL | _PAGE_PRESENT | _PAGE_READ 78 | _PAGE_WRITE | flags); 79 80 /* 81 * Mappings have to be page-aligned 82 */ 83 offset = phys_addr & ~PAGE_MASK; 84 phys_addr &= PAGE_MASK; 85 size = PAGE_ALIGN(last_addr + 1) - phys_addr; 86 87 /* 88 * Ok, go for it.. 89 */ 90 area = get_vm_area(size, VM_IOREMAP); 91 if (!area) 92 return NULL; 93 area->phys_addr = phys_addr; 94 addr = (void __iomem *) area->addr; 95 if (ioremap_page_range((unsigned long)addr, (unsigned long)addr + size, 96 phys_addr, pgprot)) { 97 vunmap((void __force *) addr); 98 return NULL; 99 } 100 101 return (void __iomem *) (offset + (char __iomem *)addr); 102} 103 104#define IS_KSEG1(addr) (((unsigned long)(addr) & ~0x1fffffffUL) == KSEG1) 105 106void iounmap(volatile void __iomem *addr) 107{ 108 if (!IS_KSEG1(addr)) 109 vfree((void *) (PAGE_MASK & (unsigned long) addr)); 110} 111