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/io_trapped.h>
22 #include <asm/page.h>
23 #include <asm/pgalloc.h>
24 #include <asm/addrspace.h>
25 #include <asm/cacheflush.h>
26 #include <asm/tlbflush.h>
27 #include <asm/mmu.h>
28 #include "ioremap.h"
29
30 /*
31 * On 32-bit SH, we traditionally have the whole physical address space mapped
32 * at all times (as MIPS does), so "ioremap()" and "iounmap()" do not need to do
33 * anything but place the address in the proper segment. This is true for P1
34 * and P2 addresses, as well as some P3 ones. However, most of the P3 addresses
35 * and newer cores using extended addressing need to map through page tables, so
36 * the ioremap() implementation becomes a bit more complicated.
37 */
38 #ifdef CONFIG_29BIT
39 static void __iomem *
__ioremap_29bit(phys_addr_t offset,unsigned long size,pgprot_t prot)40 __ioremap_29bit(phys_addr_t offset, unsigned long size, pgprot_t prot)
41 {
42 phys_addr_t last_addr = offset + size - 1;
43
44 /*
45 * For P1 and P2 space this is trivial, as everything is already
46 * mapped. Uncached access for P1 addresses are done through P2.
47 * In the P3 case or for addresses outside of the 29-bit space,
48 * mapping must be done by the PMB or by using page tables.
49 */
50 if (likely(PXSEG(offset) < P3SEG && PXSEG(last_addr) < P3SEG)) {
51 u64 flags = pgprot_val(prot);
52
53 /*
54 * Anything using the legacy PTEA space attributes needs
55 * to be kicked down to page table mappings.
56 */
57 if (unlikely(flags & _PAGE_PCC_MASK))
58 return NULL;
59 if (unlikely(flags & _PAGE_CACHABLE))
60 return (void __iomem *)P1SEGADDR(offset);
61
62 return (void __iomem *)P2SEGADDR(offset);
63 }
64
65 /* P4 above the store queues are always mapped. */
66 if (unlikely(offset >= P3_ADDR_MAX))
67 return (void __iomem *)P4SEGADDR(offset);
68
69 return NULL;
70 }
71 #else
72 #define __ioremap_29bit(offset, size, prot) NULL
73 #endif /* CONFIG_29BIT */
74
75 /*
76 * Remap an arbitrary physical address space into the kernel virtual
77 * address space. Needed when the kernel wants to access high addresses
78 * directly.
79 *
80 * NOTE! We need to allow non-page-aligned mappings too: we will obviously
81 * have to convert them into an offset in a page-aligned mapping, but the
82 * caller shouldn't need to know that small detail.
83 */
84 void __iomem * __ref
__ioremap_caller(phys_addr_t phys_addr,unsigned long size,pgprot_t pgprot,void * caller)85 __ioremap_caller(phys_addr_t phys_addr, unsigned long size,
86 pgprot_t pgprot, void *caller)
87 {
88 struct vm_struct *area;
89 unsigned long offset, last_addr, addr, orig_addr;
90 void __iomem *mapped;
91
92 mapped = __ioremap_trapped(phys_addr, size);
93 if (mapped)
94 return mapped;
95
96 mapped = __ioremap_29bit(phys_addr, size, pgprot);
97 if (mapped)
98 return mapped;
99
100 /* Don't allow wraparound or zero size */
101 last_addr = phys_addr + size - 1;
102 if (!size || last_addr < phys_addr)
103 return NULL;
104
105 /*
106 * If we can't yet use the regular approach, go the fixmap route.
107 */
108 if (!mem_init_done)
109 return ioremap_fixed(phys_addr, size, pgprot);
110
111 /*
112 * First try to remap through the PMB.
113 * PMB entries are all pre-faulted.
114 */
115 mapped = pmb_remap_caller(phys_addr, size, pgprot, caller);
116 if (mapped && !IS_ERR(mapped))
117 return mapped;
118
119 /*
120 * Mappings have to be page-aligned
121 */
122 offset = phys_addr & ~PAGE_MASK;
123 phys_addr &= PAGE_MASK;
124 size = PAGE_ALIGN(last_addr+1) - phys_addr;
125
126 /*
127 * Ok, go for it..
128 */
129 area = get_vm_area_caller(size, VM_IOREMAP, caller);
130 if (!area)
131 return NULL;
132 area->phys_addr = phys_addr;
133 orig_addr = addr = (unsigned long)area->addr;
134
135 if (ioremap_page_range(addr, addr + size, phys_addr, pgprot)) {
136 vunmap((void *)orig_addr);
137 return NULL;
138 }
139
140 return (void __iomem *)(offset + (char *)orig_addr);
141 }
142 EXPORT_SYMBOL(__ioremap_caller);
143
144 /*
145 * Simple checks for non-translatable mappings.
146 */
iomapping_nontranslatable(unsigned long offset)147 static inline int iomapping_nontranslatable(unsigned long offset)
148 {
149 #ifdef CONFIG_29BIT
150 /*
151 * In 29-bit mode this includes the fixed P1/P2 areas, as well as
152 * parts of P3.
153 */
154 if (PXSEG(offset) < P3SEG || offset >= P3_ADDR_MAX)
155 return 1;
156 #endif
157
158 return 0;
159 }
160
iounmap(void __iomem * addr)161 void iounmap(void __iomem *addr)
162 {
163 unsigned long vaddr = (unsigned long __force)addr;
164 struct vm_struct *p;
165
166 /*
167 * Nothing to do if there is no translatable mapping.
168 */
169 if (iomapping_nontranslatable(vaddr))
170 return;
171
172 /*
173 * There's no VMA if it's from an early fixed mapping.
174 */
175 if (iounmap_fixed(addr) == 0)
176 return;
177
178 /*
179 * If the PMB handled it, there's nothing else to do.
180 */
181 if (pmb_unmap(addr) == 0)
182 return;
183
184 p = remove_vm_area((void *)(vaddr & PAGE_MASK));
185 if (!p) {
186 printk(KERN_ERR "%s: bad address %p\n", __func__, addr);
187 return;
188 }
189
190 kfree(p);
191 }
192 EXPORT_SYMBOL(iounmap);
193