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 @ [mem %#010lx-%#010lx]\n",
88 end
- 1, pgt_buf_start
<< PAGE_SHIFT
,
89 (pgt_buf_top
<< PAGE_SHIFT
) - 1);
92 void __init
native_pagetable_reserve(u64 start
, u64 end
)
94 memblock_reserve(start
, end
- start
);
99 #else /* CONFIG_X86_64 */
100 #define NR_RANGE_MR 5
103 static int __meminit
save_mr(struct map_range
*mr
, int nr_range
,
104 unsigned long start_pfn
, unsigned long end_pfn
,
105 unsigned long page_size_mask
)
107 if (start_pfn
< end_pfn
) {
108 if (nr_range
>= NR_RANGE_MR
)
109 panic("run out of range for init_memory_mapping\n");
110 mr
[nr_range
].start
= start_pfn
<<PAGE_SHIFT
;
111 mr
[nr_range
].end
= end_pfn
<<PAGE_SHIFT
;
112 mr
[nr_range
].page_size_mask
= page_size_mask
;
120 * Setup the direct mapping of the physical memory at PAGE_OFFSET.
121 * This runs before bootmem is initialized and gets pages directly from
122 * the physical memory. To access them they are temporarily mapped.
124 unsigned long __init_refok
init_memory_mapping(unsigned long start
,
127 unsigned long page_size_mask
= 0;
128 unsigned long start_pfn
, end_pfn
;
129 unsigned long ret
= 0;
132 struct map_range mr
[NR_RANGE_MR
];
134 int use_pse
, use_gbpages
;
136 printk(KERN_INFO
"init_memory_mapping: [mem %#010lx-%#010lx]\n",
139 #if defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_KMEMCHECK)
141 * For CONFIG_DEBUG_PAGEALLOC, identity mapping will use small pages.
142 * This will simplify cpa(), which otherwise needs to support splitting
143 * large pages into small in interrupt context, etc.
145 use_pse
= use_gbpages
= 0;
147 use_pse
= cpu_has_pse
;
148 use_gbpages
= direct_gbpages
;
151 /* Enable PSE if available */
153 set_in_cr4(X86_CR4_PSE
);
155 /* Enable PGE if available */
157 set_in_cr4(X86_CR4_PGE
);
158 __supported_pte_mask
|= _PAGE_GLOBAL
;
162 page_size_mask
|= 1 << PG_LEVEL_1G
;
164 page_size_mask
|= 1 << PG_LEVEL_2M
;
166 memset(mr
, 0, sizeof(mr
));
169 /* head if not big page alignment ? */
170 start_pfn
= start
>> PAGE_SHIFT
;
171 pos
= start_pfn
<< PAGE_SHIFT
;
174 * Don't use a large page for the first 2/4MB of memory
175 * because there are often fixed size MTRRs in there
176 * and overlapping MTRRs into large pages can cause
180 end_pfn
= 1<<(PMD_SHIFT
- PAGE_SHIFT
);
182 end_pfn
= ((pos
+ (PMD_SIZE
- 1))>>PMD_SHIFT
)
183 << (PMD_SHIFT
- PAGE_SHIFT
);
184 #else /* CONFIG_X86_64 */
185 end_pfn
= ((pos
+ (PMD_SIZE
- 1)) >> PMD_SHIFT
)
186 << (PMD_SHIFT
- PAGE_SHIFT
);
188 if (end_pfn
> (end
>> PAGE_SHIFT
))
189 end_pfn
= end
>> PAGE_SHIFT
;
190 if (start_pfn
< end_pfn
) {
191 nr_range
= save_mr(mr
, nr_range
, start_pfn
, end_pfn
, 0);
192 pos
= end_pfn
<< PAGE_SHIFT
;
195 /* big page (2M) range */
196 start_pfn
= ((pos
+ (PMD_SIZE
- 1))>>PMD_SHIFT
)
197 << (PMD_SHIFT
- PAGE_SHIFT
);
199 end_pfn
= (end
>>PMD_SHIFT
) << (PMD_SHIFT
- PAGE_SHIFT
);
200 #else /* CONFIG_X86_64 */
201 end_pfn
= ((pos
+ (PUD_SIZE
- 1))>>PUD_SHIFT
)
202 << (PUD_SHIFT
- PAGE_SHIFT
);
203 if (end_pfn
> ((end
>>PMD_SHIFT
)<<(PMD_SHIFT
- PAGE_SHIFT
)))
204 end_pfn
= ((end
>>PMD_SHIFT
)<<(PMD_SHIFT
- PAGE_SHIFT
));
207 if (start_pfn
< end_pfn
) {
208 nr_range
= save_mr(mr
, nr_range
, start_pfn
, end_pfn
,
209 page_size_mask
& (1<<PG_LEVEL_2M
));
210 pos
= end_pfn
<< PAGE_SHIFT
;
214 /* big page (1G) range */
215 start_pfn
= ((pos
+ (PUD_SIZE
- 1))>>PUD_SHIFT
)
216 << (PUD_SHIFT
- PAGE_SHIFT
);
217 end_pfn
= (end
>> PUD_SHIFT
) << (PUD_SHIFT
- PAGE_SHIFT
);
218 if (start_pfn
< end_pfn
) {
219 nr_range
= save_mr(mr
, nr_range
, start_pfn
, end_pfn
,
221 ((1<<PG_LEVEL_2M
)|(1<<PG_LEVEL_1G
)));
222 pos
= end_pfn
<< PAGE_SHIFT
;
225 /* tail is not big page (1G) alignment */
226 start_pfn
= ((pos
+ (PMD_SIZE
- 1))>>PMD_SHIFT
)
227 << (PMD_SHIFT
- PAGE_SHIFT
);
228 end_pfn
= (end
>> PMD_SHIFT
) << (PMD_SHIFT
- PAGE_SHIFT
);
229 if (start_pfn
< end_pfn
) {
230 nr_range
= save_mr(mr
, nr_range
, start_pfn
, end_pfn
,
231 page_size_mask
& (1<<PG_LEVEL_2M
));
232 pos
= end_pfn
<< PAGE_SHIFT
;
236 /* tail is not big page (2M) alignment */
237 start_pfn
= pos
>>PAGE_SHIFT
;
238 end_pfn
= end
>>PAGE_SHIFT
;
239 nr_range
= save_mr(mr
, nr_range
, start_pfn
, end_pfn
, 0);
241 /* try to merge same page size and continuous */
242 for (i
= 0; nr_range
> 1 && i
< nr_range
- 1; i
++) {
243 unsigned long old_start
;
244 if (mr
[i
].end
!= mr
[i
+1].start
||
245 mr
[i
].page_size_mask
!= mr
[i
+1].page_size_mask
)
248 old_start
= mr
[i
].start
;
249 memmove(&mr
[i
], &mr
[i
+1],
250 (nr_range
- 1 - i
) * sizeof(struct map_range
));
251 mr
[i
--].start
= old_start
;
255 for (i
= 0; i
< nr_range
; i
++)
256 printk(KERN_DEBUG
" [mem %#010lx-%#010lx] page %s\n",
257 mr
[i
].start
, mr
[i
].end
- 1,
258 (mr
[i
].page_size_mask
& (1<<PG_LEVEL_1G
))?"1G":(
259 (mr
[i
].page_size_mask
& (1<<PG_LEVEL_2M
))?"2M":"4k"));
262 * Find space for the kernel direct mapping tables.
264 * Later we should allocate these tables in the local node of the
265 * memory mapped. Unfortunately this is done currently before the
266 * nodes are discovered.
269 find_early_table_space(&mr
[0], end
, use_pse
, use_gbpages
);
271 for (i
= 0; i
< nr_range
; i
++)
272 ret
= kernel_physical_mapping_init(mr
[i
].start
, mr
[i
].end
,
273 mr
[i
].page_size_mask
);
276 early_ioremap_page_table_range_init();
278 load_cr3(swapper_pg_dir
);
284 * Reserve the kernel pagetable pages we used (pgt_buf_start -
285 * pgt_buf_end) and free the other ones (pgt_buf_end - pgt_buf_top)
286 * so that they can be reused for other purposes.
288 * On native it just means calling memblock_reserve, on Xen it also
289 * means marking RW the pagetable pages that we allocated before
290 * but that haven't been used.
292 * In fact on xen we mark RO the whole range pgt_buf_start -
293 * pgt_buf_top, because we have to make sure that when
294 * init_memory_mapping reaches the pagetable pages area, it maps
295 * RO all the pagetable pages, including the ones that are beyond
296 * pgt_buf_end at that time.
298 if (!after_bootmem
&& pgt_buf_end
> pgt_buf_start
)
299 x86_init
.mapping
.pagetable_reserve(PFN_PHYS(pgt_buf_start
),
300 PFN_PHYS(pgt_buf_end
));
303 early_memtest(start
, end
);
305 return ret
>> PAGE_SHIFT
;
310 * devmem_is_allowed() checks to see if /dev/mem access to a certain address
311 * is valid. The argument is a physical page number.
314 * On x86, access has to be given to the first megabyte of ram because that area
315 * contains bios code and data regions used by X and dosemu and similar apps.
316 * Access has to be given to non-kernel-ram areas as well, these contain the PCI
317 * mmio resources as well as potential bios/acpi data regions.
319 int devmem_is_allowed(unsigned long pagenr
)
323 if (iomem_is_exclusive(pagenr
<< PAGE_SHIFT
))
325 if (!page_is_ram(pagenr
))
330 void free_init_pages(char *what
, unsigned long begin
, unsigned long end
)
333 unsigned long begin_aligned
, end_aligned
;
335 /* Make sure boundaries are page aligned */
336 begin_aligned
= PAGE_ALIGN(begin
);
337 end_aligned
= end
& PAGE_MASK
;
339 if (WARN_ON(begin_aligned
!= begin
|| end_aligned
!= end
)) {
340 begin
= begin_aligned
;
350 * If debugging page accesses then do not free this memory but
351 * mark them not present - any buggy init-section access will
352 * create a kernel page fault:
354 #ifdef CONFIG_DEBUG_PAGEALLOC
355 printk(KERN_INFO
"debug: unmapping init [mem %#010lx-%#010lx]\n",
357 set_memory_np(begin
, (end
- begin
) >> PAGE_SHIFT
);
360 * We just marked the kernel text read only above, now that
361 * we are going to free part of that, we need to make that
362 * writeable and non-executable first.
364 set_memory_nx(begin
, (end
- begin
) >> PAGE_SHIFT
);
365 set_memory_rw(begin
, (end
- begin
) >> PAGE_SHIFT
);
367 printk(KERN_INFO
"Freeing %s: %luk freed\n", what
, (end
- begin
) >> 10);
369 for (; addr
< end
; addr
+= PAGE_SIZE
) {
370 ClearPageReserved(virt_to_page(addr
));
371 init_page_count(virt_to_page(addr
));
372 memset((void *)addr
, POISON_FREE_INITMEM
, PAGE_SIZE
);
379 void free_initmem(void)
381 free_init_pages("unused kernel memory",
382 (unsigned long)(&__init_begin
),
383 (unsigned long)(&__init_end
));
386 #ifdef CONFIG_BLK_DEV_INITRD
387 void free_initrd_mem(unsigned long start
, unsigned long end
)
390 * end could be not aligned, and We can not align that,
391 * decompresser could be confused by aligned initrd_end
392 * We already reserve the end partial page before in
393 * - i386_start_kernel()
394 * - x86_64_start_kernel()
395 * - relocate_initrd()
396 * So here We can do PAGE_ALIGN() safely to get partial page to be freed
398 free_init_pages("initrd memory", start
, PAGE_ALIGN(end
));
402 void __init
zone_sizes_init(void)
404 unsigned long max_zone_pfns
[MAX_NR_ZONES
];
406 memset(max_zone_pfns
, 0, sizeof(max_zone_pfns
));
408 #ifdef CONFIG_ZONE_DMA
409 max_zone_pfns
[ZONE_DMA
] = MAX_DMA_PFN
;
411 #ifdef CONFIG_ZONE_DMA32
412 max_zone_pfns
[ZONE_DMA32
] = MAX_DMA32_PFN
;
414 max_zone_pfns
[ZONE_NORMAL
] = max_low_pfn
;
415 #ifdef CONFIG_HIGHMEM
416 max_zone_pfns
[ZONE_HIGHMEM
] = max_pfn
;
419 free_area_init_nodes(max_zone_pfns
);