1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Based on arch/arm/mm/ioremap.c 4 * 5 * (C) Copyright 1995 1996 Linus Torvalds 6 * Hacked for ARM by Phil Blundell <philb@gnu.org> 7 * Hacked to allow all architectures to build, and various cleanups 8 * by Russell King 9 * Copyright (C) 2012 ARM Ltd. 10 */ 11 12 #include <linux/export.h> 13 #include <linux/mm.h> 14 #include <linux/vmalloc.h> 15 #include <linux/io.h> 16 17 #include <asm/fixmap.h> 18 #include <asm/tlbflush.h> 19 #include <asm/pgalloc.h> 20 21 static void __iomem *__ioremap_caller(phys_addr_t phys_addr, size_t size, 22 pgprot_t prot, void *caller) 23 { 24 unsigned long last_addr; 25 unsigned long offset = phys_addr & ~PAGE_MASK; 26 int err; 27 unsigned long addr; 28 struct vm_struct *area; 29 30 /* 31 * Page align the mapping address and size, taking account of any 32 * offset. 33 */ 34 phys_addr &= PAGE_MASK; 35 size = PAGE_ALIGN(size + offset); 36 37 /* 38 * Don't allow wraparound, zero size or outside PHYS_MASK. 39 */ 40 last_addr = phys_addr + size - 1; 41 if (!size || last_addr < phys_addr || (last_addr & ~PHYS_MASK)) 42 return NULL; 43 44 /* 45 * Don't allow RAM to be mapped. 46 */ 47 if (WARN_ON(pfn_valid(__phys_to_pfn(phys_addr)))) 48 return NULL; 49 50 area = get_vm_area_caller(size, VM_IOREMAP, caller); 51 if (!area) 52 return NULL; 53 addr = (unsigned long)area->addr; 54 area->phys_addr = phys_addr; 55 56 err = ioremap_page_range(addr, addr + size, phys_addr, prot); 57 if (err) { 58 vunmap((void *)addr); 59 return NULL; 60 } 61 62 return (void __iomem *)(offset + addr); 63 } 64 65 void __iomem *__ioremap(phys_addr_t phys_addr, size_t size, pgprot_t prot) 66 { 67 return __ioremap_caller(phys_addr, size, prot, 68 __builtin_return_address(0)); 69 } 70 EXPORT_SYMBOL(__ioremap); 71 72 void iounmap(volatile void __iomem *io_addr) 73 { 74 unsigned long addr = (unsigned long)io_addr & PAGE_MASK; 75 76 /* 77 * We could get an address outside vmalloc range in case 78 * of ioremap_cache() reusing a RAM mapping. 79 */ 80 if (is_vmalloc_addr((void *)addr)) 81 vunmap((void *)addr); 82 } 83 EXPORT_SYMBOL(iounmap); 84 85 void __iomem *ioremap_cache(phys_addr_t phys_addr, size_t size) 86 { 87 /* For normal memory we already have a cacheable mapping. */ 88 if (pfn_valid(__phys_to_pfn(phys_addr))) 89 return (void __iomem *)__phys_to_virt(phys_addr); 90 91 return __ioremap_caller(phys_addr, size, __pgprot(PROT_NORMAL), 92 __builtin_return_address(0)); 93 } 94 EXPORT_SYMBOL(ioremap_cache); 95 96 /* 97 * Must be called after early_fixmap_init 98 */ 99 void __init early_ioremap_init(void) 100 { 101 early_ioremap_setup(); 102 } 103