blob: 882a32ebc6b7c593c303a4d711cce5ae03001222 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * arch/sh/mm/ioremap.c
3 *
4 * Re-map IO memory to kernel address space so that we can access it.
5 * This is needed for high PCI addresses that aren't mapped in the
6 * 640k-1MB IO memory area on PC's
7 *
8 * (C) Copyright 1995 1996 Linus Torvalds
Paul Mundtb66c1a32006-01-16 22:14:15 -08009 * (C) Copyright 2005, 2006 Paul Mundt
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.
Linus Torvalds1da177e2005-04-16 15:20:36 -070014 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070015#include <linux/vmalloc.h>
Paul Mundtb66c1a32006-01-16 22:14:15 -080016#include <linux/module.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070017#include <linux/mm.h>
Paul Mundta3e61d52006-09-27 16:45:22 +090018#include <linux/pci.h>
Haavard Skinnemoen5b3e1a82006-12-08 02:38:07 -080019#include <linux/io.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070020#include <asm/page.h>
21#include <asm/pgalloc.h>
Paul Mundtb66c1a32006-01-16 22:14:15 -080022#include <asm/addrspace.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070023#include <asm/cacheflush.h>
24#include <asm/tlbflush.h>
Paul Mundt0fd14752007-06-04 10:58:23 +090025#include <asm/mmu.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070026
Linus Torvalds1da177e2005-04-16 15:20:36 -070027/*
Linus Torvalds1da177e2005-04-16 15:20:36 -070028 * Remap an arbitrary physical address space into the kernel virtual
29 * address space. Needed when the kernel wants to access high addresses
30 * directly.
31 *
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.
35 */
Paul Mundtb66c1a32006-01-16 22:14:15 -080036void __iomem *__ioremap(unsigned long phys_addr, unsigned long size,
37 unsigned long flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -070038{
Linus Torvalds1da177e2005-04-16 15:20:36 -070039 struct vm_struct * area;
Paul Mundtb66c1a32006-01-16 22:14:15 -080040 unsigned long offset, last_addr, addr, orig_addr;
Haavard Skinnemoen5b3e1a82006-12-08 02:38:07 -080041 pgprot_t pgprot;
Linus Torvalds1da177e2005-04-16 15:20:36 -070042
43 /* Don't allow wraparound or zero size */
44 last_addr = phys_addr + size - 1;
45 if (!size || last_addr < phys_addr)
46 return NULL;
47
48 /*
Paul Mundta3e61d52006-09-27 16:45:22 +090049 * If we're on an SH7751 or SH7780 PCI controller, PCI memory is
50 * mapped at the end of the address space (typically 0xfd000000)
51 * in a non-translatable area, so mapping through page tables for
52 * this area is not only pointless, but also fundamentally
53 * broken. Just return the physical address instead.
54 *
55 * For boards that map a small PCI memory aperture somewhere in
56 * P1/P2 space, ioremap() will already do the right thing,
57 * and we'll never get this far.
58 */
59 if (is_pci_memaddr(phys_addr) && is_pci_memaddr(last_addr))
60 return (void __iomem *)phys_addr;
61
62 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -070063 * Don't allow anybody to remap normal RAM that we're using..
64 */
65 if (phys_addr < virt_to_phys(high_memory))
66 return NULL;
67
68 /*
69 * Mappings have to be page-aligned
70 */
71 offset = phys_addr & ~PAGE_MASK;
72 phys_addr &= PAGE_MASK;
73 size = PAGE_ALIGN(last_addr+1) - phys_addr;
74
75 /*
76 * Ok, go for it..
77 */
78 area = get_vm_area(size, VM_IOREMAP);
79 if (!area)
80 return NULL;
81 area->phys_addr = phys_addr;
Paul Mundtb66c1a32006-01-16 22:14:15 -080082 orig_addr = addr = (unsigned long)area->addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -070083
Paul Mundtb66c1a32006-01-16 22:14:15 -080084#ifdef CONFIG_32BIT
85 /*
86 * First try to remap through the PMB once a valid VMA has been
87 * established. Smaller allocations (or the rest of the size
88 * remaining after a PMB mapping due to the size not being
89 * perfectly aligned on a PMB size boundary) are then mapped
90 * through the UTLB using conventional page tables.
91 *
92 * PMB entries are all pre-faulted.
93 */
94 if (unlikely(size >= 0x1000000)) {
95 unsigned long mapped = pmb_remap(addr, phys_addr, size, flags);
96
97 if (likely(mapped)) {
98 addr += mapped;
99 phys_addr += mapped;
100 size -= mapped;
101 }
102 }
103#endif
104
Haavard Skinnemoen5b3e1a82006-12-08 02:38:07 -0800105 pgprot = __pgprot(pgprot_val(PAGE_KERNEL_NOCACHE) | flags);
Paul Mundtb66c1a32006-01-16 22:14:15 -0800106 if (likely(size))
Haavard Skinnemoen5b3e1a82006-12-08 02:38:07 -0800107 if (ioremap_page_range(addr, addr + size, phys_addr, pgprot)) {
Paul Mundtb66c1a32006-01-16 22:14:15 -0800108 vunmap((void *)orig_addr);
109 return NULL;
110 }
111
112 return (void __iomem *)(offset + (char *)orig_addr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700113}
Paul Mundtb66c1a32006-01-16 22:14:15 -0800114EXPORT_SYMBOL(__ioremap);
115
116void __iounmap(void __iomem *addr)
117{
118 unsigned long vaddr = (unsigned long __force)addr;
119 struct vm_struct *p;
120
Paul Mundta3e61d52006-09-27 16:45:22 +0900121 if (PXSEG(vaddr) < P3SEG || is_pci_memaddr(vaddr))
Paul Mundtb66c1a32006-01-16 22:14:15 -0800122 return;
123
124#ifdef CONFIG_32BIT
125 /*
126 * Purge any PMB entries that may have been established for this
127 * mapping, then proceed with conventional VMA teardown.
128 *
129 * XXX: Note that due to the way that remove_vm_area() does
130 * matching of the resultant VMA, we aren't able to fast-forward
131 * the address past the PMB space until the end of the VMA where
132 * the page tables reside. As such, unmap_vm_area() will be
133 * forced to linearly scan over the area until it finds the page
134 * tables where PTEs that need to be unmapped actually reside,
135 * which is far from optimal. Perhaps we need to use a separate
136 * VMA for the PMB mappings?
137 * -- PFM.
138 */
139 pmb_unmap(vaddr);
140#endif
141
142 p = remove_vm_area((void *)(vaddr & PAGE_MASK));
143 if (!p) {
Harvey Harrison866e6b92008-03-04 15:23:47 -0800144 printk(KERN_ERR "%s: bad address %p\n", __func__, addr);
Paul Mundtb66c1a32006-01-16 22:14:15 -0800145 return;
146 }
147
148 kfree(p);
149}
150EXPORT_SYMBOL(__iounmap);