lib/mpi: mpi_read_raw_data(): purge redundant clearing of nbits
[linux-2.6/btrfs-unstable.git] / mm / early_ioremap.c
blob6d5717bd7197ba0428c32941df27d90da04264b5
1 /*
2 * Provide common bits of early_ioremap() support for architectures needing
3 * temporary mappings during boot before ioremap() is available.
5 * This is mostly a direct copy of the x86 early_ioremap implementation.
7 * (C) Copyright 1995 1996, 2014 Linus Torvalds
9 */
10 #include <linux/kernel.h>
11 #include <linux/init.h>
12 #include <linux/io.h>
13 #include <linux/module.h>
14 #include <linux/slab.h>
15 #include <linux/mm.h>
16 #include <linux/vmalloc.h>
17 #include <asm/fixmap.h>
18 #include <asm/early_ioremap.h>
20 #ifdef CONFIG_MMU
21 static int early_ioremap_debug __initdata;
23 static int __init early_ioremap_debug_setup(char *str)
25 early_ioremap_debug = 1;
27 return 0;
29 early_param("early_ioremap_debug", early_ioremap_debug_setup);
31 static int after_paging_init __initdata;
33 void __init __weak early_ioremap_shutdown(void)
37 void __init early_ioremap_reset(void)
39 early_ioremap_shutdown();
40 after_paging_init = 1;
44 * Generally, ioremap() is available after paging_init() has been called.
45 * Architectures wanting to allow early_ioremap after paging_init() can
46 * define __late_set_fixmap and __late_clear_fixmap to do the right thing.
48 #ifndef __late_set_fixmap
49 static inline void __init __late_set_fixmap(enum fixed_addresses idx,
50 phys_addr_t phys, pgprot_t prot)
52 BUG();
54 #endif
56 #ifndef __late_clear_fixmap
57 static inline void __init __late_clear_fixmap(enum fixed_addresses idx)
59 BUG();
61 #endif
63 static void __iomem *prev_map[FIX_BTMAPS_SLOTS] __initdata;
64 static unsigned long prev_size[FIX_BTMAPS_SLOTS] __initdata;
65 static unsigned long slot_virt[FIX_BTMAPS_SLOTS] __initdata;
67 void __init early_ioremap_setup(void)
69 int i;
71 for (i = 0; i < FIX_BTMAPS_SLOTS; i++)
72 if (WARN_ON(prev_map[i]))
73 break;
75 for (i = 0; i < FIX_BTMAPS_SLOTS; i++)
76 slot_virt[i] = __fix_to_virt(FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*i);
79 static int __init check_early_ioremap_leak(void)
81 int count = 0;
82 int i;
84 for (i = 0; i < FIX_BTMAPS_SLOTS; i++)
85 if (prev_map[i])
86 count++;
88 if (WARN(count, KERN_WARNING
89 "Debug warning: early ioremap leak of %d areas detected.\n"
90 "please boot with early_ioremap_debug and report the dmesg.\n",
91 count))
92 return 1;
93 return 0;
95 late_initcall(check_early_ioremap_leak);
97 static void __init __iomem *
98 __early_ioremap(resource_size_t phys_addr, unsigned long size, pgprot_t prot)
100 unsigned long offset;
101 resource_size_t last_addr;
102 unsigned int nrpages;
103 enum fixed_addresses idx;
104 int i, slot;
106 WARN_ON(system_state != SYSTEM_BOOTING);
108 slot = -1;
109 for (i = 0; i < FIX_BTMAPS_SLOTS; i++) {
110 if (!prev_map[i]) {
111 slot = i;
112 break;
116 if (WARN(slot < 0, "%s(%08llx, %08lx) not found slot\n",
117 __func__, (u64)phys_addr, size))
118 return NULL;
120 /* Don't allow wraparound or zero size */
121 last_addr = phys_addr + size - 1;
122 if (WARN_ON(!size || last_addr < phys_addr))
123 return NULL;
125 prev_size[slot] = size;
127 * Mappings have to be page-aligned
129 offset = offset_in_page(phys_addr);
130 phys_addr &= PAGE_MASK;
131 size = PAGE_ALIGN(last_addr + 1) - phys_addr;
134 * Mappings have to fit in the FIX_BTMAP area.
136 nrpages = size >> PAGE_SHIFT;
137 if (WARN_ON(nrpages > NR_FIX_BTMAPS))
138 return NULL;
141 * Ok, go for it..
143 idx = FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*slot;
144 while (nrpages > 0) {
145 if (after_paging_init)
146 __late_set_fixmap(idx, phys_addr, prot);
147 else
148 __early_set_fixmap(idx, phys_addr, prot);
149 phys_addr += PAGE_SIZE;
150 --idx;
151 --nrpages;
153 WARN(early_ioremap_debug, "%s(%08llx, %08lx) [%d] => %08lx + %08lx\n",
154 __func__, (u64)phys_addr, size, slot, offset, slot_virt[slot]);
156 prev_map[slot] = (void __iomem *)(offset + slot_virt[slot]);
157 return prev_map[slot];
160 void __init early_iounmap(void __iomem *addr, unsigned long size)
162 unsigned long virt_addr;
163 unsigned long offset;
164 unsigned int nrpages;
165 enum fixed_addresses idx;
166 int i, slot;
168 slot = -1;
169 for (i = 0; i < FIX_BTMAPS_SLOTS; i++) {
170 if (prev_map[i] == addr) {
171 slot = i;
172 break;
176 if (WARN(slot < 0, "early_iounmap(%p, %08lx) not found slot\n",
177 addr, size))
178 return;
180 if (WARN(prev_size[slot] != size,
181 "early_iounmap(%p, %08lx) [%d] size not consistent %08lx\n",
182 addr, size, slot, prev_size[slot]))
183 return;
185 WARN(early_ioremap_debug, "early_iounmap(%p, %08lx) [%d]\n",
186 addr, size, slot);
188 virt_addr = (unsigned long)addr;
189 if (WARN_ON(virt_addr < fix_to_virt(FIX_BTMAP_BEGIN)))
190 return;
192 offset = offset_in_page(virt_addr);
193 nrpages = PAGE_ALIGN(offset + size) >> PAGE_SHIFT;
195 idx = FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*slot;
196 while (nrpages > 0) {
197 if (after_paging_init)
198 __late_clear_fixmap(idx);
199 else
200 __early_set_fixmap(idx, 0, FIXMAP_PAGE_CLEAR);
201 --idx;
202 --nrpages;
204 prev_map[slot] = NULL;
207 /* Remap an IO device */
208 void __init __iomem *
209 early_ioremap(resource_size_t phys_addr, unsigned long size)
211 return __early_ioremap(phys_addr, size, FIXMAP_PAGE_IO);
214 /* Remap memory */
215 void __init *
216 early_memremap(resource_size_t phys_addr, unsigned long size)
218 return (__force void *)__early_ioremap(phys_addr, size,
219 FIXMAP_PAGE_NORMAL);
221 #ifdef FIXMAP_PAGE_RO
222 void __init *
223 early_memremap_ro(resource_size_t phys_addr, unsigned long size)
225 return (__force void *)__early_ioremap(phys_addr, size, FIXMAP_PAGE_RO);
227 #endif
229 #define MAX_MAP_CHUNK (NR_FIX_BTMAPS << PAGE_SHIFT)
231 void __init copy_from_early_mem(void *dest, phys_addr_t src, unsigned long size)
233 unsigned long slop, clen;
234 char *p;
236 while (size) {
237 slop = offset_in_page(src);
238 clen = size;
239 if (clen > MAX_MAP_CHUNK - slop)
240 clen = MAX_MAP_CHUNK - slop;
241 p = early_memremap(src & PAGE_MASK, clen + slop);
242 memcpy(dest, p + slop, clen);
243 early_memunmap(p, clen + slop);
244 dest += clen;
245 src += clen;
246 size -= clen;
250 #else /* CONFIG_MMU */
252 void __init __iomem *
253 early_ioremap(resource_size_t phys_addr, unsigned long size)
255 return (__force void __iomem *)phys_addr;
258 /* Remap memory */
259 void __init *
260 early_memremap(resource_size_t phys_addr, unsigned long size)
262 return (void *)phys_addr;
264 void __init *
265 early_memremap_ro(resource_size_t phys_addr, unsigned long size)
267 return (void *)phys_addr;
270 void __init early_iounmap(void __iomem *addr, unsigned long size)
274 #endif /* CONFIG_MMU */
277 void __init early_memunmap(void *addr, unsigned long size)
279 early_iounmap((__force void __iomem *)addr, size);