2 #include <linux/initrd.h>
3 #include <linux/ioport.h>
4 #include <linux/swap.h>
5 #include <linux/memblock.h>
6 #include <linux/bootmem.h> /* for max_low_pfn */
8 #include <asm/cacheflush.h>
12 #include <asm/page_types.h>
13 #include <asm/sections.h>
14 #include <asm/setup.h>
15 #include <asm/tlbflush.h>
17 #include <asm/proto.h>
18 #include <asm/dma.h> /* for MAX_DMA_PFN */
20 #include "mm_internal.h"
22 static unsigned long __initdata pgt_buf_start;
23 static unsigned long __initdata pgt_buf_end;
24 static unsigned long __initdata pgt_buf_top;
26 static unsigned long min_pfn_mapped;
28 static bool __initdata can_use_brk_pgt = true;
31 * Pages returned are already directly mapped.
33 * Changing that is likely to break Xen, see commit:
35 * 279b706 x86,xen: introduce x86_init.mapping.pagetable_reserve
37 * for detailed information.
39 __ref void *alloc_low_pages(unsigned int num)
47 order = get_order((unsigned long)num << PAGE_SHIFT);
48 return (void *)__get_free_pages(GFP_ATOMIC | __GFP_NOTRACK |
52 if ((pgt_buf_end + num) > pgt_buf_top || !can_use_brk_pgt) {
54 if (min_pfn_mapped >= max_pfn_mapped)
55 panic("alloc_low_page: ran out of memory");
56 ret = memblock_find_in_range(min_pfn_mapped << PAGE_SHIFT,
57 max_pfn_mapped << PAGE_SHIFT,
58 PAGE_SIZE * num , PAGE_SIZE);
60 panic("alloc_low_page: can not alloc memory");
61 memblock_reserve(ret, PAGE_SIZE * num);
62 pfn = ret >> PAGE_SHIFT;
66 printk(KERN_DEBUG "BRK [%#010lx, %#010lx] PGTABLE\n",
67 pfn << PAGE_SHIFT, (pgt_buf_end << PAGE_SHIFT) - 1);
70 for (i = 0; i < num; i++) {
73 adr = __va((pfn + i) << PAGE_SHIFT);
77 return __va(pfn << PAGE_SHIFT);
80 /* need 4 4k for initial PMD_SIZE, 4k for 0-ISA_END_ADDRESS */
81 #define INIT_PGT_BUF_SIZE (5 * PAGE_SIZE)
82 RESERVE_BRK(early_pgt_alloc, INIT_PGT_BUF_SIZE);
83 void __init early_alloc_pgt_buf(void)
85 unsigned long tables = INIT_PGT_BUF_SIZE;
88 base = __pa(extend_brk(tables, PAGE_SIZE));
90 pgt_buf_start = base >> PAGE_SHIFT;
91 pgt_buf_end = pgt_buf_start;
92 pgt_buf_top = pgt_buf_start + (tables >> PAGE_SHIFT);
98 #ifdef CONFIG_DIRECT_GBPAGES
103 static void __init init_gbpages(void)
106 if (direct_gbpages && cpu_has_gbpages)
107 printk(KERN_INFO "Using GB pages for direct mapping\n");
116 unsigned page_size_mask;
119 static int page_size_mask;
121 static void __init probe_page_size_mask(void)
125 #if !defined(CONFIG_DEBUG_PAGEALLOC) && !defined(CONFIG_KMEMCHECK)
127 * For CONFIG_DEBUG_PAGEALLOC, identity mapping will use small pages.
128 * This will simplify cpa(), which otherwise needs to support splitting
129 * large pages into small in interrupt context, etc.
132 page_size_mask |= 1 << PG_LEVEL_1G;
134 page_size_mask |= 1 << PG_LEVEL_2M;
137 /* Enable PSE if available */
139 set_in_cr4(X86_CR4_PSE);
141 /* Enable PGE if available */
143 set_in_cr4(X86_CR4_PGE);
144 __supported_pte_mask |= _PAGE_GLOBAL;
149 #define NR_RANGE_MR 3
150 #else /* CONFIG_X86_64 */
151 #define NR_RANGE_MR 5
154 static int __meminit save_mr(struct map_range *mr, int nr_range,
155 unsigned long start_pfn, unsigned long end_pfn,
156 unsigned long page_size_mask)
158 if (start_pfn < end_pfn) {
159 if (nr_range >= NR_RANGE_MR)
160 panic("run out of range for init_memory_mapping\n");
161 mr[nr_range].start = start_pfn<<PAGE_SHIFT;
162 mr[nr_range].end = end_pfn<<PAGE_SHIFT;
163 mr[nr_range].page_size_mask = page_size_mask;
171 * adjust the page_size_mask for small range to go with
172 * big page size instead small one if nearby are ram too.
174 static void __init_refok adjust_range_page_size_mask(struct map_range *mr,
179 for (i = 0; i < nr_range; i++) {
180 if ((page_size_mask & (1<<PG_LEVEL_2M)) &&
181 !(mr[i].page_size_mask & (1<<PG_LEVEL_2M))) {
182 unsigned long start = round_down(mr[i].start, PMD_SIZE);
183 unsigned long end = round_up(mr[i].end, PMD_SIZE);
186 if ((end >> PAGE_SHIFT) > max_low_pfn)
190 if (memblock_is_region_memory(start, end - start))
191 mr[i].page_size_mask |= 1<<PG_LEVEL_2M;
193 if ((page_size_mask & (1<<PG_LEVEL_1G)) &&
194 !(mr[i].page_size_mask & (1<<PG_LEVEL_1G))) {
195 unsigned long start = round_down(mr[i].start, PUD_SIZE);
196 unsigned long end = round_up(mr[i].end, PUD_SIZE);
198 if (memblock_is_region_memory(start, end - start))
199 mr[i].page_size_mask |= 1<<PG_LEVEL_1G;
204 static int __meminit split_mem_range(struct map_range *mr, int nr_range,
208 unsigned long start_pfn, end_pfn, limit_pfn;
212 limit_pfn = PFN_DOWN(end);
214 /* head if not big page alignment ? */
215 pfn = start_pfn = PFN_DOWN(start);
218 * Don't use a large page for the first 2/4MB of memory
219 * because there are often fixed size MTRRs in there
220 * and overlapping MTRRs into large pages can cause
224 end_pfn = PFN_DOWN(PMD_SIZE);
226 end_pfn = round_up(pfn, PFN_DOWN(PMD_SIZE));
227 #else /* CONFIG_X86_64 */
228 end_pfn = round_up(pfn, PFN_DOWN(PMD_SIZE));
230 if (end_pfn > limit_pfn)
232 if (start_pfn < end_pfn) {
233 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0);
237 /* big page (2M) range */
238 start_pfn = round_up(pfn, PFN_DOWN(PMD_SIZE));
240 end_pfn = round_down(limit_pfn, PFN_DOWN(PMD_SIZE));
241 #else /* CONFIG_X86_64 */
242 end_pfn = round_up(pfn, PFN_DOWN(PUD_SIZE));
243 if (end_pfn > round_down(limit_pfn, PFN_DOWN(PMD_SIZE)))
244 end_pfn = round_down(limit_pfn, PFN_DOWN(PMD_SIZE));
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));
254 /* big page (1G) range */
255 start_pfn = round_up(pfn, PFN_DOWN(PUD_SIZE));
256 end_pfn = round_down(limit_pfn, PFN_DOWN(PUD_SIZE));
257 if (start_pfn < end_pfn) {
258 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
260 ((1<<PG_LEVEL_2M)|(1<<PG_LEVEL_1G)));
264 /* tail is not big page (1G) alignment */
265 start_pfn = round_up(pfn, PFN_DOWN(PMD_SIZE));
266 end_pfn = round_down(limit_pfn, PFN_DOWN(PMD_SIZE));
267 if (start_pfn < end_pfn) {
268 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
269 page_size_mask & (1<<PG_LEVEL_2M));
274 /* tail is not big page (2M) alignment */
277 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0);
279 /* try to merge same page size and continuous */
280 for (i = 0; nr_range > 1 && i < nr_range - 1; i++) {
281 unsigned long old_start;
282 if (mr[i].end != mr[i+1].start ||
283 mr[i].page_size_mask != mr[i+1].page_size_mask)
286 old_start = mr[i].start;
287 memmove(&mr[i], &mr[i+1],
288 (nr_range - 1 - i) * sizeof(struct map_range));
289 mr[i--].start = old_start;
294 adjust_range_page_size_mask(mr, nr_range);
296 for (i = 0; i < nr_range; i++)
297 printk(KERN_DEBUG " [mem %#010lx-%#010lx] page %s\n",
298 mr[i].start, mr[i].end - 1,
299 (mr[i].page_size_mask & (1<<PG_LEVEL_1G))?"1G":(
300 (mr[i].page_size_mask & (1<<PG_LEVEL_2M))?"2M":"4k"));
305 static struct range pfn_mapped[E820_X_MAX];
306 static int nr_pfn_mapped;
308 static void add_pfn_range_mapped(unsigned long start_pfn, unsigned long end_pfn)
310 nr_pfn_mapped = add_range_with_merge(pfn_mapped, E820_X_MAX,
311 nr_pfn_mapped, start_pfn, end_pfn);
312 nr_pfn_mapped = clean_sort_range(pfn_mapped, E820_X_MAX);
314 max_pfn_mapped = max(max_pfn_mapped, end_pfn);
316 if (start_pfn < (1UL<<(32-PAGE_SHIFT)))
317 max_low_pfn_mapped = max(max_low_pfn_mapped,
318 min(end_pfn, 1UL<<(32-PAGE_SHIFT)));
321 bool pfn_range_is_mapped(unsigned long start_pfn, unsigned long end_pfn)
325 for (i = 0; i < nr_pfn_mapped; i++)
326 if ((start_pfn >= pfn_mapped[i].start) &&
327 (end_pfn <= pfn_mapped[i].end))
334 * Setup the direct mapping of the physical memory at PAGE_OFFSET.
335 * This runs before bootmem is initialized and gets pages directly from
336 * the physical memory. To access them they are temporarily mapped.
338 unsigned long __init_refok init_memory_mapping(unsigned long start,
341 struct map_range mr[NR_RANGE_MR];
342 unsigned long ret = 0;
345 pr_info("init_memory_mapping: [mem %#010lx-%#010lx]\n",
348 memset(mr, 0, sizeof(mr));
349 nr_range = split_mem_range(mr, 0, start, end);
351 for (i = 0; i < nr_range; i++)
352 ret = kernel_physical_mapping_init(mr[i].start, mr[i].end,
353 mr[i].page_size_mask);
355 add_pfn_range_mapped(start >> PAGE_SHIFT, ret >> PAGE_SHIFT);
357 return ret >> PAGE_SHIFT;
361 * would have hole in the middle or ends, and only ram parts will be mapped.
363 static unsigned long __init init_range_memory_mapping(
364 unsigned long r_start,
367 unsigned long start_pfn, end_pfn;
368 unsigned long mapped_ram_size = 0;
371 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, NULL) {
372 u64 start = clamp_val(PFN_PHYS(start_pfn), r_start, r_end);
373 u64 end = clamp_val(PFN_PHYS(end_pfn), r_start, r_end);
378 * if it is overlapping with brk pgt, we need to
379 * alloc pgt buf from memblock instead.
381 can_use_brk_pgt = max(start, (u64)pgt_buf_end<<PAGE_SHIFT) >=
382 min(end, (u64)pgt_buf_top<<PAGE_SHIFT);
383 init_memory_mapping(start, end);
384 mapped_ram_size += end - start;
385 can_use_brk_pgt = true;
388 return mapped_ram_size;
391 /* (PUD_SHIFT-PMD_SHIFT)/2 */
392 #define STEP_SIZE_SHIFT 5
393 void __init init_mem_mapping(void)
395 unsigned long end, real_end, start, last_start;
396 unsigned long step_size;
398 unsigned long mapped_ram_size = 0;
399 unsigned long new_mapped_ram_size;
401 probe_page_size_mask();
404 end = max_pfn << PAGE_SHIFT;
406 end = max_low_pfn << PAGE_SHIFT;
409 /* the ISA range is always mapped regardless of memory holes */
410 init_memory_mapping(0, ISA_END_ADDRESS);
412 /* xen has big range in reserved near end of ram, skip it at first */
413 addr = memblock_find_in_range(ISA_END_ADDRESS, end, PMD_SIZE,
415 real_end = addr + PMD_SIZE;
417 /* step_size need to be small so pgt_buf from BRK could cover it */
418 step_size = PMD_SIZE;
419 max_pfn_mapped = 0; /* will get exact value next */
420 min_pfn_mapped = real_end >> PAGE_SHIFT;
421 last_start = start = real_end;
422 while (last_start > ISA_END_ADDRESS) {
423 if (last_start > step_size) {
424 start = round_down(last_start - 1, step_size);
425 if (start < ISA_END_ADDRESS)
426 start = ISA_END_ADDRESS;
428 start = ISA_END_ADDRESS;
429 new_mapped_ram_size = init_range_memory_mapping(start,
432 min_pfn_mapped = last_start >> PAGE_SHIFT;
433 /* only increase step_size after big range get mapped */
434 if (new_mapped_ram_size > mapped_ram_size)
435 step_size <<= STEP_SIZE_SHIFT;
436 mapped_ram_size += new_mapped_ram_size;
440 init_range_memory_mapping(real_end, end);
443 if (max_pfn > max_low_pfn) {
444 /* can we preseve max_low_pfn ?*/
445 max_low_pfn = max_pfn;
448 early_ioremap_page_table_range_init();
449 load_cr3(swapper_pg_dir);
453 early_memtest(0, max_pfn_mapped << PAGE_SHIFT);
457 * devmem_is_allowed() checks to see if /dev/mem access to a certain address
458 * is valid. The argument is a physical page number.
461 * On x86, access has to be given to the first megabyte of ram because that area
462 * contains bios code and data regions used by X and dosemu and similar apps.
463 * Access has to be given to non-kernel-ram areas as well, these contain the PCI
464 * mmio resources as well as potential bios/acpi data regions.
466 int devmem_is_allowed(unsigned long pagenr)
470 if (iomem_is_exclusive(pagenr << PAGE_SHIFT))
472 if (!page_is_ram(pagenr))
477 void free_init_pages(char *what, unsigned long begin, unsigned long end)
480 unsigned long begin_aligned, end_aligned;
482 /* Make sure boundaries are page aligned */
483 begin_aligned = PAGE_ALIGN(begin);
484 end_aligned = end & PAGE_MASK;
486 if (WARN_ON(begin_aligned != begin || end_aligned != end)) {
487 begin = begin_aligned;
497 * If debugging page accesses then do not free this memory but
498 * mark them not present - any buggy init-section access will
499 * create a kernel page fault:
501 #ifdef CONFIG_DEBUG_PAGEALLOC
502 printk(KERN_INFO "debug: unmapping init [mem %#010lx-%#010lx]\n",
504 set_memory_np(begin, (end - begin) >> PAGE_SHIFT);
507 * We just marked the kernel text read only above, now that
508 * we are going to free part of that, we need to make that
509 * writeable and non-executable first.
511 set_memory_nx(begin, (end - begin) >> PAGE_SHIFT);
512 set_memory_rw(begin, (end - begin) >> PAGE_SHIFT);
514 printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10);
516 for (; addr < end; addr += PAGE_SIZE) {
517 ClearPageReserved(virt_to_page(addr));
518 init_page_count(virt_to_page(addr));
519 memset((void *)addr, POISON_FREE_INITMEM, PAGE_SIZE);
526 void free_initmem(void)
528 free_init_pages("unused kernel memory",
529 (unsigned long)(&__init_begin),
530 (unsigned long)(&__init_end));
533 #ifdef CONFIG_BLK_DEV_INITRD
534 void __init free_initrd_mem(unsigned long start, unsigned long end)
537 * end could be not aligned, and We can not align that,
538 * decompresser could be confused by aligned initrd_end
539 * We already reserve the end partial page before in
540 * - i386_start_kernel()
541 * - x86_64_start_kernel()
542 * - relocate_initrd()
543 * So here We can do PAGE_ALIGN() safely to get partial page to be freed
545 free_init_pages("initrd memory", start, PAGE_ALIGN(end));
549 void __init zone_sizes_init(void)
551 unsigned long max_zone_pfns[MAX_NR_ZONES];
553 memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
555 #ifdef CONFIG_ZONE_DMA
556 max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
558 #ifdef CONFIG_ZONE_DMA32
559 max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
561 max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
562 #ifdef CONFIG_HIGHMEM
563 max_zone_pfns[ZONE_HIGHMEM] = max_pfn;
566 free_area_init_nodes(max_zone_pfns);