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authorIngo Molnar <mingo@elte.hu>2009-03-06 10:44:14 -0500
committerIngo Molnar <mingo@elte.hu>2009-03-06 10:45:01 -0500
commitf0ef03985130287c6c84ebe69416cf790e6cc00e (patch)
tree3ecb04cc4d82e5fc3ae5f1747e6da172ae8cbcb7 /arch/x86/mm/init.c
parent16097439703bcd38e9fe5608c12add6dacb825ea (diff)
parent31bbed527e7039203920c51c9fb48c27aed0820c (diff)
Merge branch 'x86/core' into tracing/textedit
Conflicts: arch/x86/Kconfig block/blktrace.c kernel/irq/handle.c Semantic conflict: kernel/trace/blktrace.c Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/mm/init.c')
-rw-r--r--arch/x86/mm/init.c393
1 files changed, 393 insertions, 0 deletions
diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
new file mode 100644
index 000000000000..6d63e3d1253d
--- /dev/null
+++ b/arch/x86/mm/init.c
@@ -0,0 +1,393 @@
1#include <linux/ioport.h>
2#include <linux/swap.h>
3
4#include <asm/cacheflush.h>
5#include <asm/e820.h>
6#include <asm/init.h>
7#include <asm/page.h>
8#include <asm/page_types.h>
9#include <asm/sections.h>
10#include <asm/system.h>
11#include <asm/tlbflush.h>
12
13unsigned long __initdata e820_table_start;
14unsigned long __meminitdata e820_table_end;
15unsigned long __meminitdata e820_table_top;
16
17int after_bootmem;
18
19int direct_gbpages
20#ifdef CONFIG_DIRECT_GBPAGES
21 = 1
22#endif
23;
24
25static void __init find_early_table_space(unsigned long end, int use_pse,
26 int use_gbpages)
27{
28 unsigned long puds, pmds, ptes, tables, start;
29
30 puds = (end + PUD_SIZE - 1) >> PUD_SHIFT;
31 tables = roundup(puds * sizeof(pud_t), PAGE_SIZE);
32
33 if (use_gbpages) {
34 unsigned long extra;
35
36 extra = end - ((end>>PUD_SHIFT) << PUD_SHIFT);
37 pmds = (extra + PMD_SIZE - 1) >> PMD_SHIFT;
38 } else
39 pmds = (end + PMD_SIZE - 1) >> PMD_SHIFT;
40
41 tables += roundup(pmds * sizeof(pmd_t), PAGE_SIZE);
42
43 if (use_pse) {
44 unsigned long extra;
45
46 extra = end - ((end>>PMD_SHIFT) << PMD_SHIFT);
47#ifdef CONFIG_X86_32
48 extra += PMD_SIZE;
49#endif
50 ptes = (extra + PAGE_SIZE - 1) >> PAGE_SHIFT;
51 } else
52 ptes = (end + PAGE_SIZE - 1) >> PAGE_SHIFT;
53
54 tables += roundup(ptes * sizeof(pte_t), PAGE_SIZE);
55
56#ifdef CONFIG_X86_32
57 /* for fixmap */
58 tables += roundup(__end_of_fixed_addresses * sizeof(pte_t), PAGE_SIZE);
59#endif
60
61 /*
62 * RED-PEN putting page tables only on node 0 could
63 * cause a hotspot and fill up ZONE_DMA. The page tables
64 * need roughly 0.5KB per GB.
65 */
66#ifdef CONFIG_X86_32
67 start = 0x7000;
68 e820_table_start = find_e820_area(start, max_pfn_mapped<<PAGE_SHIFT,
69 tables, PAGE_SIZE);
70#else /* CONFIG_X86_64 */
71 start = 0x8000;
72 e820_table_start = find_e820_area(start, end, tables, PAGE_SIZE);
73#endif
74 if (e820_table_start == -1UL)
75 panic("Cannot find space for the kernel page tables");
76
77 e820_table_start >>= PAGE_SHIFT;
78 e820_table_end = e820_table_start;
79 e820_table_top = e820_table_start + (tables >> PAGE_SHIFT);
80
81 printk(KERN_DEBUG "kernel direct mapping tables up to %lx @ %lx-%lx\n",
82 end, e820_table_start << PAGE_SHIFT, e820_table_top << PAGE_SHIFT);
83}
84
85struct map_range {
86 unsigned long start;
87 unsigned long end;
88 unsigned page_size_mask;
89};
90
91#ifdef CONFIG_X86_32
92#define NR_RANGE_MR 3
93#else /* CONFIG_X86_64 */
94#define NR_RANGE_MR 5
95#endif
96
97static int save_mr(struct map_range *mr, int nr_range,
98 unsigned long start_pfn, unsigned long end_pfn,
99 unsigned long page_size_mask)
100{
101 if (start_pfn < end_pfn) {
102 if (nr_range >= NR_RANGE_MR)
103 panic("run out of range for init_memory_mapping\n");
104 mr[nr_range].start = start_pfn<<PAGE_SHIFT;
105 mr[nr_range].end = end_pfn<<PAGE_SHIFT;
106 mr[nr_range].page_size_mask = page_size_mask;
107 nr_range++;
108 }
109
110 return nr_range;
111}
112
113#ifdef CONFIG_X86_64
114static void __init init_gbpages(void)
115{
116 if (direct_gbpages && cpu_has_gbpages)
117 printk(KERN_INFO "Using GB pages for direct mapping\n");
118 else
119 direct_gbpages = 0;
120}
121#else
122static inline void init_gbpages(void)
123{
124}
125#endif
126
127/*
128 * Setup the direct mapping of the physical memory at PAGE_OFFSET.
129 * This runs before bootmem is initialized and gets pages directly from
130 * the physical memory. To access them they are temporarily mapped.
131 */
132unsigned long __init_refok init_memory_mapping(unsigned long start,
133 unsigned long end)
134{
135 unsigned long page_size_mask = 0;
136 unsigned long start_pfn, end_pfn;
137 unsigned long pos;
138 unsigned long ret;
139
140 struct map_range mr[NR_RANGE_MR];
141 int nr_range, i;
142 int use_pse, use_gbpages;
143
144 printk(KERN_INFO "init_memory_mapping: %016lx-%016lx\n", start, end);
145
146 if (!after_bootmem)
147 init_gbpages();
148
149#ifdef CONFIG_DEBUG_PAGEALLOC
150 /*
151 * For CONFIG_DEBUG_PAGEALLOC, identity mapping will use small pages.
152 * This will simplify cpa(), which otherwise needs to support splitting
153 * large pages into small in interrupt context, etc.
154 */
155 use_pse = use_gbpages = 0;
156#else
157 use_pse = cpu_has_pse;
158 use_gbpages = direct_gbpages;
159#endif
160
161#ifdef CONFIG_X86_32
162#ifdef CONFIG_X86_PAE
163 set_nx();
164 if (nx_enabled)
165 printk(KERN_INFO "NX (Execute Disable) protection: active\n");
166#endif
167
168 /* Enable PSE if available */
169 if (cpu_has_pse)
170 set_in_cr4(X86_CR4_PSE);
171
172 /* Enable PGE if available */
173 if (cpu_has_pge) {
174 set_in_cr4(X86_CR4_PGE);
175 __supported_pte_mask |= _PAGE_GLOBAL;
176 }
177#endif
178
179 if (use_gbpages)
180 page_size_mask |= 1 << PG_LEVEL_1G;
181 if (use_pse)
182 page_size_mask |= 1 << PG_LEVEL_2M;
183
184 memset(mr, 0, sizeof(mr));
185 nr_range = 0;
186
187 /* head if not big page alignment ? */
188 start_pfn = start >> PAGE_SHIFT;
189 pos = start_pfn << PAGE_SHIFT;
190#ifdef CONFIG_X86_32
191 /*
192 * Don't use a large page for the first 2/4MB of memory
193 * because there are often fixed size MTRRs in there
194 * and overlapping MTRRs into large pages can cause
195 * slowdowns.
196 */
197 if (pos == 0)
198 end_pfn = 1<<(PMD_SHIFT - PAGE_SHIFT);
199 else
200 end_pfn = ((pos + (PMD_SIZE - 1))>>PMD_SHIFT)
201 << (PMD_SHIFT - PAGE_SHIFT);
202#else /* CONFIG_X86_64 */
203 end_pfn = ((pos + (PMD_SIZE - 1)) >> PMD_SHIFT)
204 << (PMD_SHIFT - PAGE_SHIFT);
205#endif
206 if (end_pfn > (end >> PAGE_SHIFT))
207 end_pfn = end >> PAGE_SHIFT;
208 if (start_pfn < end_pfn) {
209 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0);
210 pos = end_pfn << PAGE_SHIFT;
211 }
212
213 /* big page (2M) range */
214 start_pfn = ((pos + (PMD_SIZE - 1))>>PMD_SHIFT)
215 << (PMD_SHIFT - PAGE_SHIFT);
216#ifdef CONFIG_X86_32
217 end_pfn = (end>>PMD_SHIFT) << (PMD_SHIFT - PAGE_SHIFT);
218#else /* CONFIG_X86_64 */
219 end_pfn = ((pos + (PUD_SIZE - 1))>>PUD_SHIFT)
220 << (PUD_SHIFT - PAGE_SHIFT);
221 if (end_pfn > ((end>>PMD_SHIFT)<<(PMD_SHIFT - PAGE_SHIFT)))
222 end_pfn = ((end>>PMD_SHIFT)<<(PMD_SHIFT - PAGE_SHIFT));
223#endif
224
225 if (start_pfn < end_pfn) {
226 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
227 page_size_mask & (1<<PG_LEVEL_2M));
228 pos = end_pfn << PAGE_SHIFT;
229 }
230
231#ifdef CONFIG_X86_64
232 /* big page (1G) range */
233 start_pfn = ((pos + (PUD_SIZE - 1))>>PUD_SHIFT)
234 << (PUD_SHIFT - PAGE_SHIFT);
235 end_pfn = (end >> PUD_SHIFT) << (PUD_SHIFT - PAGE_SHIFT);
236 if (start_pfn < end_pfn) {
237 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
238 page_size_mask &
239 ((1<<PG_LEVEL_2M)|(1<<PG_LEVEL_1G)));
240 pos = end_pfn << PAGE_SHIFT;
241 }
242
243 /* tail is not big page (1G) alignment */
244 start_pfn = ((pos + (PMD_SIZE - 1))>>PMD_SHIFT)
245 << (PMD_SHIFT - PAGE_SHIFT);
246 end_pfn = (end >> PMD_SHIFT) << (PMD_SHIFT - PAGE_SHIFT);
247 if (start_pfn < end_pfn) {
248 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
249 page_size_mask & (1<<PG_LEVEL_2M));
250 pos = end_pfn << PAGE_SHIFT;
251 }
252#endif
253
254 /* tail is not big page (2M) alignment */
255 start_pfn = pos>>PAGE_SHIFT;
256 end_pfn = end>>PAGE_SHIFT;
257 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0);
258
259 /* try to merge same page size and continuous */
260 for (i = 0; nr_range > 1 && i < nr_range - 1; i++) {
261 unsigned long old_start;
262 if (mr[i].end != mr[i+1].start ||
263 mr[i].page_size_mask != mr[i+1].page_size_mask)
264 continue;
265 /* move it */
266 old_start = mr[i].start;
267 memmove(&mr[i], &mr[i+1],
268 (nr_range - 1 - i) * sizeof(struct map_range));
269 mr[i--].start = old_start;
270 nr_range--;
271 }
272
273 for (i = 0; i < nr_range; i++)
274 printk(KERN_DEBUG " %010lx - %010lx page %s\n",
275 mr[i].start, mr[i].end,
276 (mr[i].page_size_mask & (1<<PG_LEVEL_1G))?"1G":(
277 (mr[i].page_size_mask & (1<<PG_LEVEL_2M))?"2M":"4k"));
278
279 /*
280 * Find space for the kernel direct mapping tables.
281 *
282 * Later we should allocate these tables in the local node of the
283 * memory mapped. Unfortunately this is done currently before the
284 * nodes are discovered.
285 */
286 if (!after_bootmem)
287 find_early_table_space(end, use_pse, use_gbpages);
288
289#ifdef CONFIG_X86_32
290 for (i = 0; i < nr_range; i++)
291 kernel_physical_mapping_init(mr[i].start, mr[i].end,
292 mr[i].page_size_mask);
293 ret = end;
294#else /* CONFIG_X86_64 */
295 for (i = 0; i < nr_range; i++)
296 ret = kernel_physical_mapping_init(mr[i].start, mr[i].end,
297 mr[i].page_size_mask);
298#endif
299
300#ifdef CONFIG_X86_32
301 early_ioremap_page_table_range_init();
302
303 load_cr3(swapper_pg_dir);
304#endif
305
306#ifdef CONFIG_X86_64
307 if (!after_bootmem)
308 mmu_cr4_features = read_cr4();
309#endif
310 __flush_tlb_all();
311
312 if (!after_bootmem && e820_table_end > e820_table_start)
313 reserve_early(e820_table_start << PAGE_SHIFT,
314 e820_table_end << PAGE_SHIFT, "PGTABLE");
315
316 if (!after_bootmem)
317 early_memtest(start, end);
318
319 return ret >> PAGE_SHIFT;
320}
321
322
323/*
324 * devmem_is_allowed() checks to see if /dev/mem access to a certain address
325 * is valid. The argument is a physical page number.
326 *
327 *
328 * On x86, access has to be given to the first megabyte of ram because that area
329 * contains bios code and data regions used by X and dosemu and similar apps.
330 * Access has to be given to non-kernel-ram areas as well, these contain the PCI
331 * mmio resources as well as potential bios/acpi data regions.
332 */
333int devmem_is_allowed(unsigned long pagenr)
334{
335 if (pagenr <= 256)
336 return 1;
337 if (iomem_is_exclusive(pagenr << PAGE_SHIFT))
338 return 0;
339 if (!page_is_ram(pagenr))
340 return 1;
341 return 0;
342}
343
344void free_init_pages(char *what, unsigned long begin, unsigned long end)
345{
346 unsigned long addr = begin;
347
348 if (addr >= end)
349 return;
350
351 /*
352 * If debugging page accesses then do not free this memory but
353 * mark them not present - any buggy init-section access will
354 * create a kernel page fault:
355 */
356#ifdef CONFIG_DEBUG_PAGEALLOC
357 printk(KERN_INFO "debug: unmapping init memory %08lx..%08lx\n",
358 begin, PAGE_ALIGN(end));
359 set_memory_np(begin, (end - begin) >> PAGE_SHIFT);
360#else
361 /*
362 * We just marked the kernel text read only above, now that
363 * we are going to free part of that, we need to make that
364 * writeable first.
365 */
366 set_memory_rw(begin, (end - begin) >> PAGE_SHIFT);
367
368 printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10);
369
370 for (; addr < end; addr += PAGE_SIZE) {
371 ClearPageReserved(virt_to_page(addr));
372 init_page_count(virt_to_page(addr));
373 memset((void *)(addr & ~(PAGE_SIZE-1)),
374 POISON_FREE_INITMEM, PAGE_SIZE);
375 free_page(addr);
376 totalram_pages++;
377 }
378#endif
379}
380
381void free_initmem(void)
382{
383 free_init_pages("unused kernel memory",
384 (unsigned long)(&__init_begin),
385 (unsigned long)(&__init_end));
386}
387
388#ifdef CONFIG_BLK_DEV_INITRD
389void free_initrd_mem(unsigned long start, unsigned long end)
390{
391 free_init_pages("initrd memory", start, end);
392}
393#endif