1 /* 2 * Based on arch/arm/mm/ioremap.c 3 * 4 * (C) Copyright 1995 1996 Linus Torvalds 5 * Hacked for ARM by Phil Blundell <philb@gnu.org> 6 * Hacked to allow all architectures to build, and various cleanups 7 * by Russell King 8 * Copyright (C) 2012 ARM Ltd. 9 * 10 * This program is free software; you can redistribute it and/or modify 11 * it under the terms of the GNU General Public License version 2 as 12 * published by the Free Software Foundation. 13 * 14 * This program is distributed in the hope that it will be useful, 15 * but WITHOUT ANY WARRANTY; without even the implied warranty of 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17 * GNU General Public License for more details. 18 * 19 * You should have received a copy of the GNU General Public License 20 * along with this program. If not, see <http://www.gnu.org/licenses/>. 21 */ 22 23 #include <linux/export.h> 24 #include <linux/mm.h> 25 #include <linux/vmalloc.h> 26 #include <linux/io.h> 27 28 #include <asm/fixmap.h> 29 #include <asm/tlbflush.h> 30 #include <asm/pgalloc.h> 31 32 static void __iomem *__ioremap_caller(phys_addr_t phys_addr, size_t size, 33 pgprot_t prot, void *caller) 34 { 35 unsigned long last_addr; 36 unsigned long offset = phys_addr & ~PAGE_MASK; 37 int err; 38 unsigned long addr; 39 struct vm_struct *area; 40 41 /* 42 * Page align the mapping address and size, taking account of any 43 * offset. 44 */ 45 phys_addr &= PAGE_MASK; 46 size = PAGE_ALIGN(size + offset); 47 48 /* 49 * Don't allow wraparound, zero size or outside PHYS_MASK. 50 */ 51 last_addr = phys_addr + size - 1; 52 if (!size || last_addr < phys_addr || (last_addr & ~PHYS_MASK)) 53 return NULL; 54 55 /* 56 * Don't allow RAM to be mapped. 57 */ 58 if (WARN_ON(pfn_valid(__phys_to_pfn(phys_addr)))) 59 return NULL; 60 61 area = get_vm_area_caller(size, VM_IOREMAP, caller); 62 if (!area) 63 return NULL; 64 addr = (unsigned long)area->addr; 65 66 err = ioremap_page_range(addr, addr + size, phys_addr, prot); 67 if (err) { 68 vunmap((void *)addr); 69 return NULL; 70 } 71 72 return (void __iomem *)(offset + addr); 73 } 74 75 void __iomem *__ioremap(phys_addr_t phys_addr, size_t size, pgprot_t prot) 76 { 77 return __ioremap_caller(phys_addr, size, prot, 78 __builtin_return_address(0)); 79 } 80 EXPORT_SYMBOL(__ioremap); 81 82 void __iounmap(volatile void __iomem *io_addr) 83 { 84 unsigned long addr = (unsigned long)io_addr & PAGE_MASK; 85 86 /* 87 * We could get an address outside vmalloc range in case 88 * of ioremap_cache() reusing a RAM mapping. 89 */ 90 if (VMALLOC_START <= addr && addr < VMALLOC_END) 91 vunmap((void *)addr); 92 } 93 EXPORT_SYMBOL(__iounmap); 94 95 void __iomem *ioremap_cache(phys_addr_t phys_addr, size_t size) 96 { 97 /* For normal memory we already have a cacheable mapping. */ 98 if (pfn_valid(__phys_to_pfn(phys_addr))) 99 return (void __iomem *)__phys_to_virt(phys_addr); 100 101 return __ioremap_caller(phys_addr, size, __pgprot(PROT_NORMAL), 102 __builtin_return_address(0)); 103 } 104 EXPORT_SYMBOL(ioremap_cache); 105 106 /* 107 * Must be called after early_fixmap_init 108 */ 109 void __init early_ioremap_init(void) 110 { 111 early_ioremap_setup(); 112 } 113