1 | /* |
2 | * This file is subject to the terms and conditions of the GNU General Public |
3 | * License. See the file "COPYING" in the main directory of this archive |
4 | * for more details. |
5 | * |
6 | * (C) Copyright 1995 1996 Linus Torvalds |
7 | * (C) Copyright 2001, 2002 Ralf Baechle |
8 | */ |
9 | #include <linux/export.h> |
10 | #include <asm/addrspace.h> |
11 | #include <asm/byteorder.h> |
12 | #include <linux/ioport.h> |
13 | #include <linux/sched.h> |
14 | #include <linux/slab.h> |
15 | #include <linux/vmalloc.h> |
16 | #include <linux/mm_types.h> |
17 | #include <linux/io.h> |
18 | #include <asm/cacheflush.h> |
19 | #include <asm/tlbflush.h> |
20 | #include <ioremap.h> |
21 | |
22 | #define IS_LOW512(addr) (!((phys_addr_t)(addr) & (phys_addr_t) ~0x1fffffffULL)) |
23 | #define IS_KSEG1(addr) (((unsigned long)(addr) & ~0x1fffffffUL) == CKSEG1) |
24 | |
25 | static int __ioremap_check_ram(unsigned long start_pfn, unsigned long nr_pages, |
26 | void *arg) |
27 | { |
28 | unsigned long i; |
29 | |
30 | for (i = 0; i < nr_pages; i++) { |
31 | if (pfn_valid(pfn: start_pfn + i) && |
32 | !PageReserved(pfn_to_page(start_pfn + i))) |
33 | return 1; |
34 | } |
35 | |
36 | return 0; |
37 | } |
38 | |
39 | /* |
40 | * ioremap_prot - map bus memory into CPU space |
41 | * @phys_addr: bus address of the memory |
42 | * @size: size of the resource to map |
43 | * |
44 | * ioremap_prot gives the caller control over cache coherency attributes (CCA) |
45 | */ |
46 | void __iomem *ioremap_prot(phys_addr_t phys_addr, unsigned long size, |
47 | unsigned long prot_val) |
48 | { |
49 | unsigned long flags = prot_val & _CACHE_MASK; |
50 | unsigned long offset, pfn, last_pfn; |
51 | struct vm_struct *area; |
52 | phys_addr_t last_addr; |
53 | unsigned long vaddr; |
54 | void __iomem *cpu_addr; |
55 | |
56 | cpu_addr = plat_ioremap(phys_addr, size, flags); |
57 | if (cpu_addr) |
58 | return cpu_addr; |
59 | |
60 | phys_addr = fixup_bigphys_addr(phys_addr, size); |
61 | |
62 | /* Don't allow wraparound or zero size */ |
63 | last_addr = phys_addr + size - 1; |
64 | if (!size || last_addr < phys_addr) |
65 | return NULL; |
66 | |
67 | /* |
68 | * Map uncached objects in the low 512mb of address space using KSEG1, |
69 | * otherwise map using page tables. |
70 | */ |
71 | if (IS_LOW512(phys_addr) && IS_LOW512(last_addr) && |
72 | flags == _CACHE_UNCACHED) |
73 | return (void __iomem *) CKSEG1ADDR(phys_addr); |
74 | |
75 | /* Early remaps should use the unmapped regions til' VM is available */ |
76 | if (WARN_ON_ONCE(!slab_is_available())) |
77 | return NULL; |
78 | |
79 | /* |
80 | * Don't allow anybody to remap RAM that may be allocated by the page |
81 | * allocator, since that could lead to races & data clobbering. |
82 | */ |
83 | pfn = PFN_DOWN(phys_addr); |
84 | last_pfn = PFN_DOWN(last_addr); |
85 | if (walk_system_ram_range(start_pfn: pfn, nr_pages: last_pfn - pfn + 1, NULL, |
86 | func: __ioremap_check_ram) == 1) { |
87 | WARN_ONCE(1, "ioremap on RAM at %pa - %pa\n" , |
88 | &phys_addr, &last_addr); |
89 | return NULL; |
90 | } |
91 | |
92 | /* |
93 | * Mappings have to be page-aligned |
94 | */ |
95 | offset = phys_addr & ~PAGE_MASK; |
96 | phys_addr &= PAGE_MASK; |
97 | size = PAGE_ALIGN(last_addr + 1) - phys_addr; |
98 | |
99 | /* |
100 | * Ok, go for it.. |
101 | */ |
102 | area = get_vm_area(size, VM_IOREMAP); |
103 | if (!area) |
104 | return NULL; |
105 | vaddr = (unsigned long)area->addr; |
106 | |
107 | flags |= _PAGE_GLOBAL | _PAGE_PRESENT | __READABLE | __WRITEABLE; |
108 | if (ioremap_page_range(addr: vaddr, end: vaddr + size, phys_addr, |
109 | __pgprot(flags))) { |
110 | free_vm_area(area); |
111 | return NULL; |
112 | } |
113 | |
114 | return (void __iomem *)(vaddr + offset); |
115 | } |
116 | EXPORT_SYMBOL(ioremap_prot); |
117 | |
118 | void iounmap(const volatile void __iomem *addr) |
119 | { |
120 | if (!plat_iounmap(addr) && !IS_KSEG1(addr)) |
121 | vunmap(addr: (void *)((unsigned long)addr & PAGE_MASK)); |
122 | } |
123 | EXPORT_SYMBOL(iounmap); |
124 | |