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