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2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
61e85e36 JB |
2 | /* |
3 | * OpenRISC ioremap.c | |
4 | * | |
5 | * Linux architectural port borrowing liberally from similar works of | |
6 | * others. All original copyrights apply as per the original source | |
7 | * declaration. | |
8 | * | |
9 | * Modifications for the OpenRISC architecture: | |
10 | * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com> | |
11 | * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se> | |
61e85e36 JB |
12 | */ |
13 | ||
14 | #include <linux/vmalloc.h> | |
15 | #include <linux/io.h> | |
65fddcfc | 16 | #include <linux/pgtable.h> |
61e85e36 JB |
17 | #include <asm/pgalloc.h> |
18 | #include <asm/kmap_types.h> | |
19 | #include <asm/fixmap.h> | |
20 | #include <asm/bug.h> | |
61e85e36 JB |
21 | #include <linux/sched.h> |
22 | #include <asm/tlbflush.h> | |
23 | ||
24 | extern int mem_init_done; | |
25 | ||
26 | static unsigned int fixmaps_used __initdata; | |
27 | ||
28 | /* | |
29 | * Remap an arbitrary physical address space into the kernel virtual | |
30 | * address space. Needed when the kernel wants to access high addresses | |
31 | * directly. | |
32 | * | |
33 | * NOTE! We need to allow non-page-aligned mappings too: we will obviously | |
34 | * have to convert them into an offset in a page-aligned mapping, but the | |
35 | * caller shouldn't need to know that small detail. | |
36 | */ | |
f3b17320 | 37 | void __iomem *__ref ioremap(phys_addr_t addr, unsigned long size) |
61e85e36 JB |
38 | { |
39 | phys_addr_t p; | |
40 | unsigned long v; | |
41 | unsigned long offset, last_addr; | |
42 | struct vm_struct *area = NULL; | |
43 | ||
44 | /* Don't allow wraparound or zero size */ | |
45 | last_addr = addr + size - 1; | |
46 | if (!size || last_addr < addr) | |
47 | return NULL; | |
48 | ||
49 | /* | |
50 | * Mappings have to be page-aligned | |
51 | */ | |
52 | offset = addr & ~PAGE_MASK; | |
53 | p = addr & PAGE_MASK; | |
54 | size = PAGE_ALIGN(last_addr + 1) - p; | |
55 | ||
56 | if (likely(mem_init_done)) { | |
57 | area = get_vm_area(size, VM_IOREMAP); | |
58 | if (!area) | |
59 | return NULL; | |
60 | v = (unsigned long)area->addr; | |
61 | } else { | |
62 | if ((fixmaps_used + (size >> PAGE_SHIFT)) > FIX_N_IOREMAPS) | |
63 | return NULL; | |
64 | v = fix_to_virt(FIX_IOREMAP_BEGIN + fixmaps_used); | |
65 | fixmaps_used += (size >> PAGE_SHIFT); | |
66 | } | |
67 | ||
f3b17320 CH |
68 | if (ioremap_page_range(v, v + size, p, |
69 | __pgprot(pgprot_val(PAGE_KERNEL) | _PAGE_CI))) { | |
61e85e36 JB |
70 | if (likely(mem_init_done)) |
71 | vfree(area->addr); | |
72 | else | |
73 | fixmaps_used -= (size >> PAGE_SHIFT); | |
74 | return NULL; | |
75 | } | |
76 | ||
77 | return (void __iomem *)(offset + (char *)v); | |
78 | } | |
f3b17320 | 79 | EXPORT_SYMBOL(ioremap); |
61e85e36 JB |
80 | |
81 | void iounmap(void *addr) | |
82 | { | |
83 | /* If the page is from the fixmap pool then we just clear out | |
84 | * the fixmap mapping. | |
85 | */ | |
86 | if (unlikely((unsigned long)addr > FIXADDR_START)) { | |
87 | /* This is a bit broken... we don't really know | |
88 | * how big the area is so it's difficult to know | |
89 | * how many fixed pages to invalidate... | |
90 | * just flush tlb and hope for the best... | |
91 | * consider this a FIXME | |
92 | * | |
93 | * Really we should be clearing out one or more page | |
94 | * table entries for these virtual addresses so that | |
95 | * future references cause a page fault... for now, we | |
96 | * rely on two things: | |
97 | * i) this code never gets called on known boards | |
98 | * ii) invalid accesses to the freed areas aren't made | |
99 | */ | |
100 | flush_tlb_all(); | |
101 | return; | |
102 | } | |
103 | ||
104 | return vfree((void *)(PAGE_MASK & (unsigned long)addr)); | |
105 | } | |
a0eba4f7 | 106 | EXPORT_SYMBOL(iounmap); |
61e85e36 JB |
107 | |
108 | /** | |
109 | * OK, this one's a bit tricky... ioremap can get called before memory is | |
110 | * initialized (early serial console does this) and will want to alloc a page | |
111 | * for its mapping. No userspace pages will ever get allocated before memory | |
112 | * is initialized so this applies only to kernel pages. In the event that | |
113 | * this is called before memory is initialized we allocate the page using | |
114 | * the memblock infrastructure. | |
115 | */ | |
116 | ||
4cf58924 | 117 | pte_t __ref *pte_alloc_one_kernel(struct mm_struct *mm) |
61e85e36 JB |
118 | { |
119 | pte_t *pte; | |
120 | ||
8a7f97b9 | 121 | if (likely(mem_init_done)) { |
1e8ffd50 | 122 | pte = (pte_t *)get_zeroed_page(GFP_KERNEL); |
8a7f97b9 | 123 | } else { |
1e8ffd50 | 124 | pte = memblock_alloc(PAGE_SIZE, PAGE_SIZE); |
8a7f97b9 MR |
125 | if (!pte) |
126 | panic("%s: Failed to allocate %lu bytes align=0x%lx\n", | |
127 | __func__, PAGE_SIZE, PAGE_SIZE); | |
128 | } | |
61e85e36 | 129 | |
61e85e36 JB |
130 | return pte; |
131 | } |