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 *
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 void __iomem __ref *ioremap_prot(phys_addr_t phys_addr, size_t size,
76 unsigned long prot)
77 {
78 void __iomem *mapped;
79 pgprot_t pgprot = __pgprot(prot);
80
81 mapped = __ioremap_trapped(phys_addr, size);
82 if (mapped)
83 return mapped;
84
85 mapped = __ioremap_29bit(phys_addr, size, pgprot);
86 if (mapped)
87 return mapped;
88
89 /*
90 * If we can't yet use the regular approach, go the fixmap route.
91 */
92 if (!mem_init_done)
93 return ioremap_fixed(phys_addr, size, pgprot);
94
95 /*
96 * First try to remap through the PMB.
97 * PMB entries are all pre-faulted.
98 */
99 mapped = pmb_remap_caller(phys_addr, size, pgprot,
100 __builtin_return_address(0));
101 if (mapped && !IS_ERR(mapped))
102 return mapped;
103
104 return generic_ioremap_prot(phys_addr, size, pgprot);
105 }
106 EXPORT_SYMBOL(ioremap_prot);
107
108 /*
109 * Simple checks for non-translatable mappings.
110 */
111 static inline int iomapping_nontranslatable(unsigned long offset)
112 {
113 #ifdef CONFIG_29BIT
114 /*
115 * In 29-bit mode this includes the fixed P1/P2 areas, as well as
116 * parts of P3.
117 */
118 if (PXSEG(offset) < P3SEG || offset >= P3_ADDR_MAX)
119 return 1;
120 #endif
121
122 return 0;
123 }
124
125 void iounmap(volatile void __iomem *addr)
126 {
127 unsigned long vaddr = (unsigned long __force)addr;
128
129 /*
130 * Nothing to do if there is no translatable mapping.
131 */
132 if (iomapping_nontranslatable(vaddr))
133 return;
134
135 /*
136 * There's no VMA if it's from an early fixed mapping.
137 */
138 if (iounmap_fixed((void __iomem *)addr) == 0)
139 return;
140
141 /*
142 * If the PMB handled it, there's nothing else to do.
143 */
144 if (pmb_unmap((void __iomem *)addr) == 0)
145 return;
146
147 generic_iounmap(addr);
148 }
149 EXPORT_SYMBOL(iounmap);
150
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