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 unsigned long __initdata pgt_buf_start;
21 unsigned long __meminitdata pgt_buf_end;
22 unsigned long __meminitdata pgt_buf_top;
27 #ifdef CONFIG_DIRECT_GBPAGES
35 unsigned page_size_mask;
38 static int page_size_mask;
40 void probe_page_size_mask(void)
42 #if !defined(CONFIG_DEBUG_PAGEALLOC) && !defined(CONFIG_KMEMCHECK)
44 * For CONFIG_DEBUG_PAGEALLOC, identity mapping will use small pages.
45 * This will simplify cpa(), which otherwise needs to support splitting
46 * large pages into small in interrupt context, etc.
49 page_size_mask |= 1 << PG_LEVEL_1G;
51 page_size_mask |= 1 << PG_LEVEL_2M;
54 /* Enable PSE if available */
56 set_in_cr4(X86_CR4_PSE);
58 /* Enable PGE if available */
60 set_in_cr4(X86_CR4_PGE);
61 __supported_pte_mask |= _PAGE_GLOBAL;
64 void __init native_pagetable_reserve(u64 start, u64 end)
66 memblock_reserve(start, end - start);
71 #else /* CONFIG_X86_64 */
75 static int __meminit save_mr(struct map_range *mr, int nr_range,
76 unsigned long start_pfn, unsigned long end_pfn,
77 unsigned long page_size_mask)
79 if (start_pfn < end_pfn) {
80 if (nr_range >= NR_RANGE_MR)
81 panic("run out of range for init_memory_mapping\n");
82 mr[nr_range].start = start_pfn<<PAGE_SHIFT;
83 mr[nr_range].end = end_pfn<<PAGE_SHIFT;
84 mr[nr_range].page_size_mask = page_size_mask;
91 static int __meminit split_mem_range(struct map_range *mr, int nr_range,
95 unsigned long start_pfn, end_pfn;
99 /* head if not big page alignment ? */
100 start_pfn = start >> PAGE_SHIFT;
101 pos = start_pfn << PAGE_SHIFT;
104 * Don't use a large page for the first 2/4MB of memory
105 * because there are often fixed size MTRRs in there
106 * and overlapping MTRRs into large pages can cause
110 end_pfn = 1<<(PMD_SHIFT - PAGE_SHIFT);
112 end_pfn = ((pos + (PMD_SIZE - 1))>>PMD_SHIFT)
113 << (PMD_SHIFT - PAGE_SHIFT);
114 #else /* CONFIG_X86_64 */
115 end_pfn = ((pos + (PMD_SIZE - 1)) >> PMD_SHIFT)
116 << (PMD_SHIFT - PAGE_SHIFT);
118 if (end_pfn > (end >> PAGE_SHIFT))
119 end_pfn = end >> PAGE_SHIFT;
120 if (start_pfn < end_pfn) {
121 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0);
122 pos = end_pfn << PAGE_SHIFT;
125 /* big page (2M) range */
126 start_pfn = ((pos + (PMD_SIZE - 1))>>PMD_SHIFT)
127 << (PMD_SHIFT - PAGE_SHIFT);
129 end_pfn = (end>>PMD_SHIFT) << (PMD_SHIFT - PAGE_SHIFT);
130 #else /* CONFIG_X86_64 */
131 end_pfn = ((pos + (PUD_SIZE - 1))>>PUD_SHIFT)
132 << (PUD_SHIFT - PAGE_SHIFT);
133 if (end_pfn > ((end>>PMD_SHIFT)<<(PMD_SHIFT - PAGE_SHIFT)))
134 end_pfn = ((end>>PMD_SHIFT)<<(PMD_SHIFT - PAGE_SHIFT));
137 if (start_pfn < end_pfn) {
138 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
139 page_size_mask & (1<<PG_LEVEL_2M));
140 pos = end_pfn << PAGE_SHIFT;
144 /* big page (1G) range */
145 start_pfn = ((pos + (PUD_SIZE - 1))>>PUD_SHIFT)
146 << (PUD_SHIFT - PAGE_SHIFT);
147 end_pfn = (end >> PUD_SHIFT) << (PUD_SHIFT - PAGE_SHIFT);
148 if (start_pfn < end_pfn) {
149 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
151 ((1<<PG_LEVEL_2M)|(1<<PG_LEVEL_1G)));
152 pos = end_pfn << PAGE_SHIFT;
155 /* tail is not big page (1G) alignment */
156 start_pfn = ((pos + (PMD_SIZE - 1))>>PMD_SHIFT)
157 << (PMD_SHIFT - PAGE_SHIFT);
158 end_pfn = (end >> PMD_SHIFT) << (PMD_SHIFT - PAGE_SHIFT);
159 if (start_pfn < end_pfn) {
160 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
161 page_size_mask & (1<<PG_LEVEL_2M));
162 pos = end_pfn << PAGE_SHIFT;
166 /* tail is not big page (2M) alignment */
167 start_pfn = pos>>PAGE_SHIFT;
168 end_pfn = end>>PAGE_SHIFT;
169 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0);
171 /* try to merge same page size and continuous */
172 for (i = 0; nr_range > 1 && i < nr_range - 1; i++) {
173 unsigned long old_start;
174 if (mr[i].end != mr[i+1].start ||
175 mr[i].page_size_mask != mr[i+1].page_size_mask)
178 old_start = mr[i].start;
179 memmove(&mr[i], &mr[i+1],
180 (nr_range - 1 - i) * sizeof(struct map_range));
181 mr[i--].start = old_start;
185 for (i = 0; i < nr_range; i++)
186 printk(KERN_DEBUG " [mem %#010lx-%#010lx] page %s\n",
187 mr[i].start, mr[i].end - 1,
188 (mr[i].page_size_mask & (1<<PG_LEVEL_1G))?"1G":(
189 (mr[i].page_size_mask & (1<<PG_LEVEL_2M))?"2M":"4k"));
195 * First calculate space needed for kernel direct mapping page tables to cover
196 * mr[0].start to mr[nr_range - 1].end, while accounting for possible 2M and 1GB
197 * pages. Then find enough contiguous space for those page tables.
199 static void __init find_early_table_space(struct map_range *mr, int nr_range)
202 unsigned long puds = 0, pmds = 0, ptes = 0, tables;
203 unsigned long start = 0, good_end;
206 for (i = 0; i < nr_range; i++) {
207 unsigned long range, extra;
209 range = mr[i].end - mr[i].start;
210 puds += (range + PUD_SIZE - 1) >> PUD_SHIFT;
212 if (mr[i].page_size_mask & (1 << PG_LEVEL_1G)) {
213 extra = range - ((range >> PUD_SHIFT) << PUD_SHIFT);
214 pmds += (extra + PMD_SIZE - 1) >> PMD_SHIFT;
216 pmds += (range + PMD_SIZE - 1) >> PMD_SHIFT;
219 if (mr[i].page_size_mask & (1 << PG_LEVEL_2M)) {
220 extra = range - ((range >> PMD_SHIFT) << PMD_SHIFT);
224 ptes += (extra + PAGE_SIZE - 1) >> PAGE_SHIFT;
226 ptes += (range + PAGE_SIZE - 1) >> PAGE_SHIFT;
230 tables = roundup(puds * sizeof(pud_t), PAGE_SIZE);
231 tables += roundup(pmds * sizeof(pmd_t), PAGE_SIZE);
232 tables += roundup(ptes * sizeof(pte_t), PAGE_SIZE);
236 tables += roundup(__end_of_fixed_addresses * sizeof(pte_t), PAGE_SIZE);
238 good_end = max_pfn_mapped << PAGE_SHIFT;
240 base = memblock_find_in_range(start, good_end, tables, PAGE_SIZE);
242 panic("Cannot find space for the kernel page tables");
244 pgt_buf_start = base >> PAGE_SHIFT;
245 pgt_buf_end = pgt_buf_start;
246 pgt_buf_top = pgt_buf_start + (tables >> PAGE_SHIFT);
248 printk(KERN_DEBUG "kernel direct mapping tables up to %#lx @ [mem %#010lx-%#010lx]\n",
249 mr[nr_range - 1].end - 1, pgt_buf_start << PAGE_SHIFT,
250 (pgt_buf_top << PAGE_SHIFT) - 1);
254 * Setup the direct mapping of the physical memory at PAGE_OFFSET.
255 * This runs before bootmem is initialized and gets pages directly from
256 * the physical memory. To access them they are temporarily mapped.
258 unsigned long __init_refok init_memory_mapping(unsigned long start,
261 struct map_range mr[NR_RANGE_MR];
262 unsigned long ret = 0;
265 pr_info("init_memory_mapping: [mem %#010lx-%#010lx]\n",
268 memset(mr, 0, sizeof(mr));
269 nr_range = split_mem_range(mr, 0, start, end);
272 * Find space for the kernel direct mapping tables.
274 * Later we should allocate these tables in the local node of the
275 * memory mapped. Unfortunately this is done currently before the
276 * nodes are discovered.
279 find_early_table_space(mr, nr_range);
281 for (i = 0; i < nr_range; i++)
282 ret = kernel_physical_mapping_init(mr[i].start, mr[i].end,
283 mr[i].page_size_mask);
286 early_ioremap_page_table_range_init();
288 load_cr3(swapper_pg_dir);
294 * Reserve the kernel pagetable pages we used (pgt_buf_start -
295 * pgt_buf_end) and free the other ones (pgt_buf_end - pgt_buf_top)
296 * so that they can be reused for other purposes.
298 * On native it just means calling memblock_reserve, on Xen it also
299 * means marking RW the pagetable pages that we allocated before
300 * but that haven't been used.
302 * In fact on xen we mark RO the whole range pgt_buf_start -
303 * pgt_buf_top, because we have to make sure that when
304 * init_memory_mapping reaches the pagetable pages area, it maps
305 * RO all the pagetable pages, including the ones that are beyond
306 * pgt_buf_end at that time.
308 if (!after_bootmem && pgt_buf_end > pgt_buf_start)
309 x86_init.mapping.pagetable_reserve(PFN_PHYS(pgt_buf_start),
310 PFN_PHYS(pgt_buf_end));
313 early_memtest(start, end);
315 return ret >> PAGE_SHIFT;
320 * devmem_is_allowed() checks to see if /dev/mem access to a certain address
321 * is valid. The argument is a physical page number.
324 * On x86, access has to be given to the first megabyte of ram because that area
325 * contains bios code and data regions used by X and dosemu and similar apps.
326 * Access has to be given to non-kernel-ram areas as well, these contain the PCI
327 * mmio resources as well as potential bios/acpi data regions.
329 int devmem_is_allowed(unsigned long pagenr)
333 if (iomem_is_exclusive(pagenr << PAGE_SHIFT))
335 if (!page_is_ram(pagenr))
340 void free_init_pages(char *what, unsigned long begin, unsigned long end)
343 unsigned long begin_aligned, end_aligned;
345 /* Make sure boundaries are page aligned */
346 begin_aligned = PAGE_ALIGN(begin);
347 end_aligned = end & PAGE_MASK;
349 if (WARN_ON(begin_aligned != begin || end_aligned != end)) {
350 begin = begin_aligned;
360 * If debugging page accesses then do not free this memory but
361 * mark them not present - any buggy init-section access will
362 * create a kernel page fault:
364 #ifdef CONFIG_DEBUG_PAGEALLOC
365 printk(KERN_INFO "debug: unmapping init [mem %#010lx-%#010lx]\n",
367 set_memory_np(begin, (end - begin) >> PAGE_SHIFT);
370 * We just marked the kernel text read only above, now that
371 * we are going to free part of that, we need to make that
372 * writeable and non-executable first.
374 set_memory_nx(begin, (end - begin) >> PAGE_SHIFT);
375 set_memory_rw(begin, (end - begin) >> PAGE_SHIFT);
377 printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10);
379 for (; addr < end; addr += PAGE_SIZE) {
380 ClearPageReserved(virt_to_page(addr));
381 init_page_count(virt_to_page(addr));
382 memset((void *)addr, POISON_FREE_INITMEM, PAGE_SIZE);
389 void free_initmem(void)
391 free_init_pages("unused kernel memory",
392 (unsigned long)(&__init_begin),
393 (unsigned long)(&__init_end));
396 #ifdef CONFIG_BLK_DEV_INITRD
397 void __init free_initrd_mem(unsigned long start, unsigned long end)
400 * end could be not aligned, and We can not align that,
401 * decompresser could be confused by aligned initrd_end
402 * We already reserve the end partial page before in
403 * - i386_start_kernel()
404 * - x86_64_start_kernel()
405 * - relocate_initrd()
406 * So here We can do PAGE_ALIGN() safely to get partial page to be freed
408 free_init_pages("initrd memory", start, PAGE_ALIGN(end));
412 void __init zone_sizes_init(void)
414 unsigned long max_zone_pfns[MAX_NR_ZONES];
416 memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
418 #ifdef CONFIG_ZONE_DMA
419 max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
421 #ifdef CONFIG_ZONE_DMA32
422 max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
424 max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
425 #ifdef CONFIG_HIGHMEM
426 max_zone_pfns[ZONE_HIGHMEM] = max_pfn;
429 free_area_init_nodes(max_zone_pfns);