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 void __init find_early_table_space(struct map_range *mr, unsigned long end,
39 int use_pse, int use_gbpages)
41 unsigned long puds, pmds, ptes, tables, start = 0, good_end = end;
44 puds = (end + PUD_SIZE - 1) >> PUD_SHIFT;
45 tables = roundup(puds * sizeof(pud_t), PAGE_SIZE);
50 extra = end - ((end>>PUD_SHIFT) << PUD_SHIFT);
51 pmds = (extra + PMD_SIZE - 1) >> PMD_SHIFT;
53 pmds = (end + PMD_SIZE - 1) >> PMD_SHIFT;
55 tables += roundup(pmds * sizeof(pmd_t), PAGE_SIZE);
60 extra = end - ((end>>PMD_SHIFT) << PMD_SHIFT);
64 /* The first 2/4M doesn't use large pages. */
65 extra += mr->end - mr->start;
67 ptes = (extra + PAGE_SIZE - 1) >> PAGE_SHIFT;
69 ptes = (end + PAGE_SIZE - 1) >> PAGE_SHIFT;
71 tables += roundup(ptes * sizeof(pte_t), PAGE_SIZE);
75 tables += roundup(__end_of_fixed_addresses * sizeof(pte_t), PAGE_SIZE);
77 good_end = max_pfn_mapped << PAGE_SHIFT;
79 base = memblock_find_in_range(start, good_end, tables, PAGE_SIZE);
81 panic("Cannot find space for the kernel page tables");
83 pgt_buf_start = base >> PAGE_SHIFT;
84 pgt_buf_end = pgt_buf_start;
85 pgt_buf_top = pgt_buf_start + (tables >> PAGE_SHIFT);
87 printk(KERN_DEBUG "kernel direct mapping tables up to %lx @ %lx-%lx\n",
88 end, pgt_buf_start << PAGE_SHIFT, pgt_buf_top << PAGE_SHIFT);
91 void __init native_pagetable_reserve(u64 start, u64 end)
93 memblock_reserve(start, end - start);
98 #else /* CONFIG_X86_64 */
102 static int __meminit save_mr(struct map_range *mr, int nr_range,
103 unsigned long start_pfn, unsigned long end_pfn,
104 unsigned long page_size_mask)
106 if (start_pfn < end_pfn) {
107 if (nr_range >= NR_RANGE_MR)
108 panic("run out of range for init_memory_mapping\n");
109 mr[nr_range].start = start_pfn<<PAGE_SHIFT;
110 mr[nr_range].end = end_pfn<<PAGE_SHIFT;
111 mr[nr_range].page_size_mask = page_size_mask;
119 * Setup the direct mapping of the physical memory at PAGE_OFFSET.
120 * This runs before bootmem is initialized and gets pages directly from
121 * the physical memory. To access them they are temporarily mapped.
123 unsigned long __init_refok init_memory_mapping(unsigned long start,
126 unsigned long page_size_mask = 0;
127 unsigned long start_pfn, end_pfn;
128 unsigned long ret = 0;
131 struct map_range mr[NR_RANGE_MR];
133 int use_pse, use_gbpages;
135 printk(KERN_INFO "init_memory_mapping: %016lx-%016lx\n", start, end);
137 #if defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_KMEMCHECK)
139 * For CONFIG_DEBUG_PAGEALLOC, identity mapping will use small pages.
140 * This will simplify cpa(), which otherwise needs to support splitting
141 * large pages into small in interrupt context, etc.
143 use_pse = use_gbpages = 0;
145 use_pse = cpu_has_pse;
146 use_gbpages = direct_gbpages;
149 /* Enable PSE if available */
151 set_in_cr4(X86_CR4_PSE);
153 /* Enable PGE if available */
155 set_in_cr4(X86_CR4_PGE);
156 __supported_pte_mask |= _PAGE_GLOBAL;
160 page_size_mask |= 1 << PG_LEVEL_1G;
162 page_size_mask |= 1 << PG_LEVEL_2M;
164 memset(mr, 0, sizeof(mr));
167 /* head if not big page alignment ? */
168 start_pfn = start >> PAGE_SHIFT;
169 pos = start_pfn << PAGE_SHIFT;
172 * Don't use a large page for the first 2/4MB of memory
173 * because there are often fixed size MTRRs in there
174 * and overlapping MTRRs into large pages can cause
178 end_pfn = 1<<(PMD_SHIFT - PAGE_SHIFT);
180 end_pfn = ((pos + (PMD_SIZE - 1))>>PMD_SHIFT)
181 << (PMD_SHIFT - PAGE_SHIFT);
182 #else /* CONFIG_X86_64 */
183 end_pfn = ((pos + (PMD_SIZE - 1)) >> PMD_SHIFT)
184 << (PMD_SHIFT - PAGE_SHIFT);
186 if (end_pfn > (end >> PAGE_SHIFT))
187 end_pfn = end >> PAGE_SHIFT;
188 if (start_pfn < end_pfn) {
189 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0);
190 pos = end_pfn << PAGE_SHIFT;
193 /* big page (2M) range */
194 start_pfn = ((pos + (PMD_SIZE - 1))>>PMD_SHIFT)
195 << (PMD_SHIFT - PAGE_SHIFT);
197 end_pfn = (end>>PMD_SHIFT) << (PMD_SHIFT - PAGE_SHIFT);
198 #else /* CONFIG_X86_64 */
199 end_pfn = ((pos + (PUD_SIZE - 1))>>PUD_SHIFT)
200 << (PUD_SHIFT - PAGE_SHIFT);
201 if (end_pfn > ((end>>PMD_SHIFT)<<(PMD_SHIFT - PAGE_SHIFT)))
202 end_pfn = ((end>>PMD_SHIFT)<<(PMD_SHIFT - PAGE_SHIFT));
205 if (start_pfn < end_pfn) {
206 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
207 page_size_mask & (1<<PG_LEVEL_2M));
208 pos = end_pfn << PAGE_SHIFT;
212 /* big page (1G) range */
213 start_pfn = ((pos + (PUD_SIZE - 1))>>PUD_SHIFT)
214 << (PUD_SHIFT - PAGE_SHIFT);
215 end_pfn = (end >> PUD_SHIFT) << (PUD_SHIFT - PAGE_SHIFT);
216 if (start_pfn < end_pfn) {
217 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
219 ((1<<PG_LEVEL_2M)|(1<<PG_LEVEL_1G)));
220 pos = end_pfn << PAGE_SHIFT;
223 /* tail is not big page (1G) alignment */
224 start_pfn = ((pos + (PMD_SIZE - 1))>>PMD_SHIFT)
225 << (PMD_SHIFT - PAGE_SHIFT);
226 end_pfn = (end >> PMD_SHIFT) << (PMD_SHIFT - PAGE_SHIFT);
227 if (start_pfn < end_pfn) {
228 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
229 page_size_mask & (1<<PG_LEVEL_2M));
230 pos = end_pfn << PAGE_SHIFT;
234 /* tail is not big page (2M) alignment */
235 start_pfn = pos>>PAGE_SHIFT;
236 end_pfn = end>>PAGE_SHIFT;
237 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0);
239 /* try to merge same page size and continuous */
240 for (i = 0; nr_range > 1 && i < nr_range - 1; i++) {
241 unsigned long old_start;
242 if (mr[i].end != mr[i+1].start ||
243 mr[i].page_size_mask != mr[i+1].page_size_mask)
246 old_start = mr[i].start;
247 memmove(&mr[i], &mr[i+1],
248 (nr_range - 1 - i) * sizeof(struct map_range));
249 mr[i--].start = old_start;
253 for (i = 0; i < nr_range; i++)
254 printk(KERN_DEBUG " %010lx - %010lx page %s\n",
255 mr[i].start, mr[i].end,
256 (mr[i].page_size_mask & (1<<PG_LEVEL_1G))?"1G":(
257 (mr[i].page_size_mask & (1<<PG_LEVEL_2M))?"2M":"4k"));
260 * Find space for the kernel direct mapping tables.
262 * Later we should allocate these tables in the local node of the
263 * memory mapped. Unfortunately this is done currently before the
264 * nodes are discovered.
267 find_early_table_space(&mr[0], end, use_pse, use_gbpages);
269 for (i = 0; i < nr_range; i++)
270 ret = kernel_physical_mapping_init(mr[i].start, mr[i].end,
271 mr[i].page_size_mask);
274 early_ioremap_page_table_range_init();
276 load_cr3(swapper_pg_dir);
282 * Reserve the kernel pagetable pages we used (pgt_buf_start -
283 * pgt_buf_end) and free the other ones (pgt_buf_end - pgt_buf_top)
284 * so that they can be reused for other purposes.
286 * On native it just means calling memblock_reserve, on Xen it also
287 * means marking RW the pagetable pages that we allocated before
288 * but that haven't been used.
290 * In fact on xen we mark RO the whole range pgt_buf_start -
291 * pgt_buf_top, because we have to make sure that when
292 * init_memory_mapping reaches the pagetable pages area, it maps
293 * RO all the pagetable pages, including the ones that are beyond
294 * pgt_buf_end at that time.
296 if (!after_bootmem && pgt_buf_end > pgt_buf_start)
297 x86_init.mapping.pagetable_reserve(PFN_PHYS(pgt_buf_start),
298 PFN_PHYS(pgt_buf_end));
301 early_memtest(start, end);
303 return ret >> PAGE_SHIFT;
308 * devmem_is_allowed() checks to see if /dev/mem access to a certain address
309 * is valid. The argument is a physical page number.
312 * On x86, access has to be given to the first megabyte of ram because that area
313 * contains bios code and data regions used by X and dosemu and similar apps.
314 * Access has to be given to non-kernel-ram areas as well, these contain the PCI
315 * mmio resources as well as potential bios/acpi data regions.
317 int devmem_is_allowed(unsigned long pagenr)
321 if (iomem_is_exclusive(pagenr << PAGE_SHIFT))
323 if (!page_is_ram(pagenr))
328 void free_init_pages(char *what, unsigned long begin, unsigned long end)
331 unsigned long begin_aligned, end_aligned;
333 /* Make sure boundaries are page aligned */
334 begin_aligned = PAGE_ALIGN(begin);
335 end_aligned = end & PAGE_MASK;
337 if (WARN_ON(begin_aligned != begin || end_aligned != end)) {
338 begin = begin_aligned;
348 * If debugging page accesses then do not free this memory but
349 * mark them not present - any buggy init-section access will
350 * create a kernel page fault:
352 #ifdef CONFIG_DEBUG_PAGEALLOC
353 printk(KERN_INFO "debug: unmapping init memory %08lx..%08lx\n",
355 set_memory_np(begin, (end - begin) >> PAGE_SHIFT);
358 * We just marked the kernel text read only above, now that
359 * we are going to free part of that, we need to make that
360 * writeable and non-executable first.
362 set_memory_nx(begin, (end - begin) >> PAGE_SHIFT);
363 set_memory_rw(begin, (end - begin) >> PAGE_SHIFT);
365 printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10);
367 for (; addr < end; addr += PAGE_SIZE) {
368 ClearPageReserved(virt_to_page(addr));
369 init_page_count(virt_to_page(addr));
370 memset((void *)addr, POISON_FREE_INITMEM, PAGE_SIZE);
377 void free_initmem(void)
379 free_init_pages("unused kernel memory",
380 (unsigned long)(&__init_begin),
381 (unsigned long)(&__init_end));
384 #ifdef CONFIG_BLK_DEV_INITRD
385 void free_initrd_mem(unsigned long start, unsigned long end)
388 * end could be not aligned, and We can not align that,
389 * decompresser could be confused by aligned initrd_end
390 * We already reserve the end partial page before in
391 * - i386_start_kernel()
392 * - x86_64_start_kernel()
393 * - relocate_initrd()
394 * So here We can do PAGE_ALIGN() safely to get partial page to be freed
396 free_init_pages("initrd memory", start, PAGE_ALIGN(end));
400 void __init zone_sizes_init(void)
402 unsigned long max_zone_pfns[MAX_NR_ZONES];
404 memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
406 #ifdef CONFIG_ZONE_DMA
407 max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
409 #ifdef CONFIG_ZONE_DMA32
410 max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
412 max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
413 #ifdef CONFIG_HIGHMEM
414 max_zone_pfns[ZONE_HIGHMEM] = max_pfn;
417 free_area_init_nodes(max_zone_pfns);