1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Re-map IO memory to kernel address space so that we can access it. 4 * This is needed for high PCI addresses that aren't mapped in the 5 * 640k-1MB IO memory area on PC's 6 * 7 * (C) Copyright 1995 1996 Linus Torvalds 8 */ 9 #include <linux/vmalloc.h> 10 #include <linux/mm.h> 11 #include <linux/io.h> 12 #include <linux/export.h> 13 #include <linux/ioremap.h> 14 15 void __iomem *generic_ioremap_prot(phys_addr_t phys_addr, size_t size, 16 pgprot_t prot) 17 { 18 unsigned long offset, vaddr; 19 phys_addr_t last_addr; 20 struct vm_struct *area; 21 22 /* An early platform driver might end up here */ 23 if (WARN_ON_ONCE(!slab_is_available())) 24 return NULL; 25 26 /* Disallow wrap-around or zero size */ 27 last_addr = phys_addr + size - 1; 28 if (!size || last_addr < phys_addr) 29 return NULL; 30 31 /* Page-align mappings */ 32 offset = phys_addr & (~PAGE_MASK); 33 phys_addr -= offset; 34 size = PAGE_ALIGN(size + offset); 35 36 if (!ioremap_allowed(phys_addr, size, pgprot_val(prot))) 37 return NULL; 38 39 area = __get_vm_area_caller(size, VM_IOREMAP, IOREMAP_START, 40 IOREMAP_END, __builtin_return_address(0)); 41 if (!area) 42 return NULL; 43 vaddr = (unsigned long)area->addr; 44 area->phys_addr = phys_addr; 45 46 if (ioremap_page_range(vaddr, vaddr + size, phys_addr, prot)) { 47 free_vm_area(area); 48 return NULL; 49 } 50 51 return (void __iomem *)(vaddr + offset); 52 } 53 54 #ifndef ioremap_prot 55 void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size, 56 unsigned long prot) 57 { 58 return generic_ioremap_prot(phys_addr, size, __pgprot(prot)); 59 } 60 EXPORT_SYMBOL(ioremap_prot); 61 #endif 62 63 void generic_iounmap(volatile void __iomem *addr) 64 { 65 void *vaddr = (void *)((unsigned long)addr & PAGE_MASK); 66 67 if (!iounmap_allowed(vaddr)) 68 return; 69 70 if (is_ioremap_addr(vaddr)) 71 vunmap(vaddr); 72 } 73 74 #ifndef iounmap 75 void iounmap(volatile void __iomem *addr) 76 { 77 generic_iounmap(addr); 78 } 79 EXPORT_SYMBOL(iounmap); 80 #endif 81