1 /* 2 * arch/sh/mm/ioremap.c 3 * 4 * (C) Copyright 1995 1996 Linus Torvalds 5 * (C) Copyright 2005 - 2010 Paul Mundt 6 * 7 * Re-map IO memory to kernel address space so that we can access it. 8 * This is needed for high PCI addresses that aren't mapped in the 9 * 640k-1MB IO memory area on PC's 10 * 11 * This file is subject to the terms and conditions of the GNU General 12 * Public License. See the file "COPYING" in the main directory of this 13 * archive for more details. 14 */ 15 #include <linux/vmalloc.h> 16 #include <linux/module.h> 17 #include <linux/slab.h> 18 #include <linux/mm.h> 19 #include <linux/pci.h> 20 #include <linux/io.h> 21 #include <asm/page.h> 22 #include <asm/pgalloc.h> 23 #include <asm/addrspace.h> 24 #include <asm/cacheflush.h> 25 #include <asm/tlbflush.h> 26 #include <asm/mmu.h> 27 28 /* 29 * Remap an arbitrary physical address space into the kernel virtual 30 * address space. Needed when the kernel wants to access high addresses 31 * directly. 32 * 33 * NOTE! We need to allow non-page-aligned mappings too: we will obviously 34 * have to convert them into an offset in a page-aligned mapping, but the 35 * caller shouldn't need to know that small detail. 36 */ 37 void __iomem * __ref 38 __ioremap_caller(phys_addr_t phys_addr, unsigned long size, 39 pgprot_t pgprot, void *caller) 40 { 41 struct vm_struct *area; 42 unsigned long offset, last_addr, addr, orig_addr; 43 void __iomem *mapped; 44 45 /* Don't allow wraparound or zero size */ 46 last_addr = phys_addr + size - 1; 47 if (!size || last_addr < phys_addr) 48 return NULL; 49 50 /* 51 * If we can't yet use the regular approach, go the fixmap route. 52 */ 53 if (!mem_init_done) 54 return ioremap_fixed(phys_addr, size, pgprot); 55 56 /* 57 * First try to remap through the PMB. 58 * PMB entries are all pre-faulted. 59 */ 60 mapped = pmb_remap_caller(phys_addr, size, pgprot, caller); 61 if (mapped && !IS_ERR(mapped)) 62 return mapped; 63 64 /* 65 * Mappings have to be page-aligned 66 */ 67 offset = phys_addr & ~PAGE_MASK; 68 phys_addr &= PAGE_MASK; 69 size = PAGE_ALIGN(last_addr+1) - phys_addr; 70 71 /* 72 * Ok, go for it.. 73 */ 74 area = get_vm_area_caller(size, VM_IOREMAP, caller); 75 if (!area) 76 return NULL; 77 area->phys_addr = phys_addr; 78 orig_addr = addr = (unsigned long)area->addr; 79 80 if (ioremap_page_range(addr, addr + size, phys_addr, pgprot)) { 81 vunmap((void *)orig_addr); 82 return NULL; 83 } 84 85 return (void __iomem *)(offset + (char *)orig_addr); 86 } 87 EXPORT_SYMBOL(__ioremap_caller); 88 89 /* 90 * Simple checks for non-translatable mappings. 91 */ 92 static inline int iomapping_nontranslatable(unsigned long offset) 93 { 94 #ifdef CONFIG_29BIT 95 /* 96 * In 29-bit mode this includes the fixed P1/P2 areas, as well as 97 * parts of P3. 98 */ 99 if (PXSEG(offset) < P3SEG || offset >= P3_ADDR_MAX) 100 return 1; 101 #endif 102 103 return 0; 104 } 105 106 void iounmap(void __iomem *addr) 107 { 108 unsigned long vaddr = (unsigned long __force)addr; 109 struct vm_struct *p; 110 111 /* 112 * Nothing to do if there is no translatable mapping. 113 */ 114 if (iomapping_nontranslatable(vaddr)) 115 return; 116 117 /* 118 * There's no VMA if it's from an early fixed mapping. 119 */ 120 if (iounmap_fixed(addr) == 0) 121 return; 122 123 /* 124 * If the PMB handled it, there's nothing else to do. 125 */ 126 if (pmb_unmap(addr) == 0) 127 return; 128 129 p = remove_vm_area((void *)(vaddr & PAGE_MASK)); 130 if (!p) { 131 printk(KERN_ERR "%s: bad address %p\n", __func__, addr); 132 return; 133 } 134 135 kfree(p); 136 } 137 EXPORT_SYMBOL(iounmap); 138