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
ioremap_prot(phys_addr_t phys_addr,size_t size,pgprot_t pgprot)75 void __iomem __ref *ioremap_prot(phys_addr_t phys_addr, size_t size,
76 pgprot_t pgprot)
77 {
78 void __iomem *mapped;
79
80 mapped = __ioremap_trapped(phys_addr, size);
81 if (mapped)
82 return mapped;
83
84 mapped = __ioremap_29bit(phys_addr, size, pgprot);
85 if (mapped)
86 return mapped;
87
88 /*
89 * If we can't yet use the regular approach, go the fixmap route.
90 */
91 if (!mem_init_done)
92 return ioremap_fixed(phys_addr, size, pgprot);
93
94 /*
95 * First try to remap through the PMB.
96 * PMB entries are all pre-faulted.
97 */
98 mapped = pmb_remap_caller(phys_addr, size, pgprot,
99 __builtin_return_address(0));
100 if (mapped && !IS_ERR(mapped))
101 return mapped;
102
103 return generic_ioremap_prot(phys_addr, size, pgprot);
104 }
105 EXPORT_SYMBOL(ioremap_prot);
106
107 /*
108 * Simple checks for non-translatable mappings.
109 */
iomapping_nontranslatable(unsigned long offset)110 static inline int iomapping_nontranslatable(unsigned long offset)
111 {
112 #ifdef CONFIG_29BIT
113 /*
114 * In 29-bit mode this includes the fixed P1/P2 areas, as well as
115 * parts of P3.
116 */
117 if (PXSEG(offset) < P3SEG || offset >= P3_ADDR_MAX)
118 return 1;
119 #endif
120
121 return 0;
122 }
123
iounmap(volatile void __iomem * addr)124 void iounmap(volatile void __iomem *addr)
125 {
126 unsigned long vaddr = (unsigned long __force)addr;
127
128 /*
129 * Nothing to do if there is no translatable mapping.
130 */
131 if (iomapping_nontranslatable(vaddr))
132 return;
133
134 /*
135 * There's no VMA if it's from an early fixed mapping.
136 */
137 if (iounmap_fixed((void __iomem *)addr) == 0)
138 return;
139
140 /*
141 * If the PMB handled it, there's nothing else to do.
142 */
143 if (pmb_unmap((void __iomem *)addr) == 0)
144 return;
145
146 generic_iounmap(addr);
147 }
148 EXPORT_SYMBOL(iounmap);
149