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 static void __iomem *__ioremap_caller(phys_addr_t phys_addr, size_t size, 29 pgprot_t prot, void *caller) 30 { 31 unsigned long last_addr; 32 unsigned long offset = phys_addr & ~PAGE_MASK; 33 int err; 34 unsigned long addr; 35 struct vm_struct *area; 36 37 /* 38 * Page align the mapping address and size, taking account of any 39 * offset. 40 */ 41 phys_addr &= PAGE_MASK; 42 size = PAGE_ALIGN(size + offset); 43 44 /* 45 * Don't allow wraparound, zero size or outside PHYS_MASK. 46 */ 47 last_addr = phys_addr + size - 1; 48 if (!size || last_addr < phys_addr || (last_addr & ~PHYS_MASK)) 49 return NULL; 50 51 /* 52 * Don't allow RAM to be mapped. 53 */ 54 if (WARN_ON(pfn_valid(__phys_to_pfn(phys_addr)))) 55 return NULL; 56 57 area = get_vm_area_caller(size, VM_IOREMAP, caller); 58 if (!area) 59 return NULL; 60 addr = (unsigned long)area->addr; 61 62 err = ioremap_page_range(addr, addr + size, phys_addr, prot); 63 if (err) { 64 vunmap((void *)addr); 65 return NULL; 66 } 67 68 return (void __iomem *)(offset + addr); 69 } 70 71 void __iomem *__ioremap(phys_addr_t phys_addr, size_t size, pgprot_t prot) 72 { 73 return __ioremap_caller(phys_addr, size, prot, 74 __builtin_return_address(0)); 75 } 76 EXPORT_SYMBOL(__ioremap); 77 78 void __iounmap(volatile void __iomem *io_addr) 79 { 80 unsigned long addr = (unsigned long)io_addr & PAGE_MASK; 81 82 /* 83 * We could get an address outside vmalloc range in case 84 * of ioremap_cache() reusing a RAM mapping. 85 */ 86 if (VMALLOC_START <= addr && addr < VMALLOC_END) 87 vunmap((void *)addr); 88 } 89 EXPORT_SYMBOL(__iounmap); 90 91 void __iomem *ioremap_cache(phys_addr_t phys_addr, size_t size) 92 { 93 /* For normal memory we already have a cacheable mapping. */ 94 if (pfn_valid(__phys_to_pfn(phys_addr))) 95 return (void __iomem *)__phys_to_virt(phys_addr); 96 97 return __ioremap_caller(phys_addr, size, __pgprot(PROT_NORMAL), 98 __builtin_return_address(0)); 99 } 100 EXPORT_SYMBOL(ioremap_cache); 101