4 * (C) Copyright 1995 1996 Linus Torvalds
5 * (C) Copyright 2005 - 2010 Paul Mundt
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
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.
15 #include <linux/vmalloc.h>
16 #include <linux/module.h>
18 #include <linux/pci.h>
21 #include <asm/pgalloc.h>
22 #include <asm/addrspace.h>
23 #include <asm/cacheflush.h>
24 #include <asm/tlbflush.h>
28 * Remap an arbitrary physical address space into the kernel virtual
29 * address space. Needed when the kernel wants to access high addresses
32 * NOTE! We need to allow non-page-aligned mappings too: we will obviously
33 * have to convert them into an offset in a page-aligned mapping, but the
34 * caller shouldn't need to know that small detail.
36 void __iomem * __init_refok
37 __ioremap_caller(unsigned long phys_addr, unsigned long size,
38 pgprot_t pgprot, void *caller)
40 struct vm_struct *area;
41 unsigned long offset, last_addr, addr, orig_addr;
43 /* Don't allow wraparound or zero size */
44 last_addr = phys_addr + size - 1;
45 if (!size || last_addr < phys_addr)
49 * Mappings have to be page-aligned
51 offset = phys_addr & ~PAGE_MASK;
52 phys_addr &= PAGE_MASK;
53 size = PAGE_ALIGN(last_addr+1) - phys_addr;
56 * If we can't yet use the regular approach, go the fixmap route.
59 return ioremap_fixed(phys_addr, offset, size, pgprot);
64 area = get_vm_area_caller(size, VM_IOREMAP, caller);
67 area->phys_addr = phys_addr;
68 orig_addr = addr = (unsigned long)area->addr;
72 * First try to remap through the PMB once a valid VMA has been
73 * established. Smaller allocations (or the rest of the size
74 * remaining after a PMB mapping due to the size not being
75 * perfectly aligned on a PMB size boundary) are then mapped
76 * through the UTLB using conventional page tables.
78 * PMB entries are all pre-faulted.
80 if (unlikely(phys_addr >= P1SEG)) {
83 mapped = pmb_remap(addr, phys_addr, size, pgprot);
93 if (ioremap_page_range(addr, addr + size, phys_addr, pgprot)) {
94 vunmap((void *)orig_addr);
98 return (void __iomem *)(offset + (char *)orig_addr);
100 EXPORT_SYMBOL(__ioremap_caller);
103 * Simple checks for non-translatable mappings.
105 static inline int iomapping_nontranslatable(unsigned long offset)
109 * In 29-bit mode this includes the fixed P1/P2 areas, as well as
112 if (PXSEG(offset) < P3SEG || offset >= P3_ADDR_MAX)
119 void __iounmap(void __iomem *addr)
121 unsigned long vaddr = (unsigned long __force)addr;
125 * Nothing to do if there is no translatable mapping.
127 if (iomapping_nontranslatable(vaddr))
131 * There's no VMA if it's from an early fixed mapping.
133 if (iounmap_fixed(addr) == 0)
138 * Purge any PMB entries that may have been established for this
139 * mapping, then proceed with conventional VMA teardown.
141 * XXX: Note that due to the way that remove_vm_area() does
142 * matching of the resultant VMA, we aren't able to fast-forward
143 * the address past the PMB space until the end of the VMA where
144 * the page tables reside. As such, unmap_vm_area() will be
145 * forced to linearly scan over the area until it finds the page
146 * tables where PTEs that need to be unmapped actually reside,
147 * which is far from optimal. Perhaps we need to use a separate
148 * VMA for the PMB mappings?
154 p = remove_vm_area((void *)(vaddr & PAGE_MASK));
156 printk(KERN_ERR "%s: bad address %p\n", __func__, addr);
162 EXPORT_SYMBOL(__iounmap);