Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Re-map IO memory to kernel address space so that we can access it.
4 * This is needed for high PCI addresses that aren't mapped in the
5 * 640k-1MB IO memory area on PC's
6 *
7 * (C) Copyright 1995 1996 Linus Torvalds
8 */
9#include <linux/vmalloc.h>
10#include <linux/mm.h>
11#include <linux/sched.h>
12#include <linux/io.h>
13#include <linux/export.h>
14#include <asm/cacheflush.h>
15
16#include "pgalloc-track.h"
17
18#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
19static int __read_mostly ioremap_p4d_capable;
20static int __read_mostly ioremap_pud_capable;
21static int __read_mostly ioremap_pmd_capable;
22static int __read_mostly ioremap_huge_disabled;
23
24static int __init set_nohugeiomap(char *str)
25{
26 ioremap_huge_disabled = 1;
27 return 0;
28}
29early_param("nohugeiomap", set_nohugeiomap);
30
31void __init ioremap_huge_init(void)
32{
33 if (!ioremap_huge_disabled) {
34 if (arch_ioremap_p4d_supported())
35 ioremap_p4d_capable = 1;
36 if (arch_ioremap_pud_supported())
37 ioremap_pud_capable = 1;
38 if (arch_ioremap_pmd_supported())
39 ioremap_pmd_capable = 1;
40 }
41}
42
43static inline int ioremap_p4d_enabled(void)
44{
45 return ioremap_p4d_capable;
46}
47
48static inline int ioremap_pud_enabled(void)
49{
50 return ioremap_pud_capable;
51}
52
53static inline int ioremap_pmd_enabled(void)
54{
55 return ioremap_pmd_capable;
56}
57
58#else /* !CONFIG_HAVE_ARCH_HUGE_VMAP */
59static inline int ioremap_p4d_enabled(void) { return 0; }
60static inline int ioremap_pud_enabled(void) { return 0; }
61static inline int ioremap_pmd_enabled(void) { return 0; }
62#endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */
63
64static int ioremap_pte_range(pmd_t *pmd, unsigned long addr,
65 unsigned long end, phys_addr_t phys_addr, pgprot_t prot,
66 pgtbl_mod_mask *mask)
67{
68 pte_t *pte;
69 u64 pfn;
70
71 pfn = phys_addr >> PAGE_SHIFT;
72 pte = pte_alloc_kernel_track(pmd, addr, mask);
73 if (!pte)
74 return -ENOMEM;
75 do {
76 BUG_ON(!pte_none(*pte));
77 set_pte_at(&init_mm, addr, pte, pfn_pte(pfn, prot));
78 pfn++;
79 } while (pte++, addr += PAGE_SIZE, addr != end);
80 *mask |= PGTBL_PTE_MODIFIED;
81 return 0;
82}
83
84static int ioremap_try_huge_pmd(pmd_t *pmd, unsigned long addr,
85 unsigned long end, phys_addr_t phys_addr,
86 pgprot_t prot)
87{
88 if (!ioremap_pmd_enabled())
89 return 0;
90
91 if ((end - addr) != PMD_SIZE)
92 return 0;
93
94 if (!IS_ALIGNED(addr, PMD_SIZE))
95 return 0;
96
97 if (!IS_ALIGNED(phys_addr, PMD_SIZE))
98 return 0;
99
100 if (pmd_present(*pmd) && !pmd_free_pte_page(pmd, addr))
101 return 0;
102
103 return pmd_set_huge(pmd, phys_addr, prot);
104}
105
106static inline int ioremap_pmd_range(pud_t *pud, unsigned long addr,
107 unsigned long end, phys_addr_t phys_addr, pgprot_t prot,
108 pgtbl_mod_mask *mask)
109{
110 pmd_t *pmd;
111 unsigned long next;
112
113 pmd = pmd_alloc_track(&init_mm, pud, addr, mask);
114 if (!pmd)
115 return -ENOMEM;
116 do {
117 next = pmd_addr_end(addr, end);
118
119 if (ioremap_try_huge_pmd(pmd, addr, next, phys_addr, prot)) {
120 *mask |= PGTBL_PMD_MODIFIED;
121 continue;
122 }
123
124 if (ioremap_pte_range(pmd, addr, next, phys_addr, prot, mask))
125 return -ENOMEM;
126 } while (pmd++, phys_addr += (next - addr), addr = next, addr != end);
127 return 0;
128}
129
130static int ioremap_try_huge_pud(pud_t *pud, unsigned long addr,
131 unsigned long end, phys_addr_t phys_addr,
132 pgprot_t prot)
133{
134 if (!ioremap_pud_enabled())
135 return 0;
136
137 if ((end - addr) != PUD_SIZE)
138 return 0;
139
140 if (!IS_ALIGNED(addr, PUD_SIZE))
141 return 0;
142
143 if (!IS_ALIGNED(phys_addr, PUD_SIZE))
144 return 0;
145
146 if (pud_present(*pud) && !pud_free_pmd_page(pud, addr))
147 return 0;
148
149 return pud_set_huge(pud, phys_addr, prot);
150}
151
152static inline int ioremap_pud_range(p4d_t *p4d, unsigned long addr,
153 unsigned long end, phys_addr_t phys_addr, pgprot_t prot,
154 pgtbl_mod_mask *mask)
155{
156 pud_t *pud;
157 unsigned long next;
158
159 pud = pud_alloc_track(&init_mm, p4d, addr, mask);
160 if (!pud)
161 return -ENOMEM;
162 do {
163 next = pud_addr_end(addr, end);
164
165 if (ioremap_try_huge_pud(pud, addr, next, phys_addr, prot)) {
166 *mask |= PGTBL_PUD_MODIFIED;
167 continue;
168 }
169
170 if (ioremap_pmd_range(pud, addr, next, phys_addr, prot, mask))
171 return -ENOMEM;
172 } while (pud++, phys_addr += (next - addr), addr = next, addr != end);
173 return 0;
174}
175
176static int ioremap_try_huge_p4d(p4d_t *p4d, unsigned long addr,
177 unsigned long end, phys_addr_t phys_addr,
178 pgprot_t prot)
179{
180 if (!ioremap_p4d_enabled())
181 return 0;
182
183 if ((end - addr) != P4D_SIZE)
184 return 0;
185
186 if (!IS_ALIGNED(addr, P4D_SIZE))
187 return 0;
188
189 if (!IS_ALIGNED(phys_addr, P4D_SIZE))
190 return 0;
191
192 if (p4d_present(*p4d) && !p4d_free_pud_page(p4d, addr))
193 return 0;
194
195 return p4d_set_huge(p4d, phys_addr, prot);
196}
197
198static inline int ioremap_p4d_range(pgd_t *pgd, unsigned long addr,
199 unsigned long end, phys_addr_t phys_addr, pgprot_t prot,
200 pgtbl_mod_mask *mask)
201{
202 p4d_t *p4d;
203 unsigned long next;
204
205 p4d = p4d_alloc_track(&init_mm, pgd, addr, mask);
206 if (!p4d)
207 return -ENOMEM;
208 do {
209 next = p4d_addr_end(addr, end);
210
211 if (ioremap_try_huge_p4d(p4d, addr, next, phys_addr, prot)) {
212 *mask |= PGTBL_P4D_MODIFIED;
213 continue;
214 }
215
216 if (ioremap_pud_range(p4d, addr, next, phys_addr, prot, mask))
217 return -ENOMEM;
218 } while (p4d++, phys_addr += (next - addr), addr = next, addr != end);
219 return 0;
220}
221
222int ioremap_page_range(unsigned long addr,
223 unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
224{
225 pgd_t *pgd;
226 unsigned long start;
227 unsigned long next;
228 int err;
229 pgtbl_mod_mask mask = 0;
230
231 might_sleep();
232 BUG_ON(addr >= end);
233
234 start = addr;
235 pgd = pgd_offset_k(addr);
236 do {
237 next = pgd_addr_end(addr, end);
238 err = ioremap_p4d_range(pgd, addr, next, phys_addr, prot,
239 &mask);
240 if (err)
241 break;
242 } while (pgd++, phys_addr += (next - addr), addr = next, addr != end);
243
244 flush_cache_vmap(start, end);
245
246 if (mask & ARCH_PAGE_TABLE_SYNC_MASK)
247 arch_sync_kernel_mappings(start, end);
248
249 return err;
250}
251
252#ifdef CONFIG_GENERIC_IOREMAP
253void __iomem *ioremap_prot(phys_addr_t addr, size_t size, unsigned long prot)
254{
255 unsigned long offset, vaddr;
256 phys_addr_t last_addr;
257 struct vm_struct *area;
258
259 /* Disallow wrap-around or zero size */
260 last_addr = addr + size - 1;
261 if (!size || last_addr < addr)
262 return NULL;
263
264 /* Page-align mappings */
265 offset = addr & (~PAGE_MASK);
266 addr -= offset;
267 size = PAGE_ALIGN(size + offset);
268
269 area = get_vm_area_caller(size, VM_IOREMAP,
270 __builtin_return_address(0));
271 if (!area)
272 return NULL;
273 vaddr = (unsigned long)area->addr;
274
275 if (ioremap_page_range(vaddr, vaddr + size, addr, __pgprot(prot))) {
276 free_vm_area(area);
277 return NULL;
278 }
279
280 return (void __iomem *)(vaddr + offset);
281}
282EXPORT_SYMBOL(ioremap_prot);
283
284void iounmap(volatile void __iomem *addr)
285{
286 vunmap((void *)((unsigned long)addr & PAGE_MASK));
287}
288EXPORT_SYMBOL(iounmap);
289#endif /* CONFIG_GENERIC_IOREMAP */