1 #include <linux/ioport.h>
2 #include <linux/swap.h>
4 #include <asm/cacheflush.h>
8 #include <asm/page_types.h>
9 #include <asm/sections.h>
10 #include <asm/system.h>
11 #include <asm/tlbflush.h>
14 DEFINE_PER_CPU(struct mmu_gather
, mmu_gathers
);
16 unsigned long __initdata e820_table_start
;
17 unsigned long __meminitdata e820_table_end
;
18 unsigned long __meminitdata e820_table_top
;
23 #ifdef CONFIG_DIRECT_GBPAGES
30 #if defined(CONFIG_X86_64) || defined(CONFIG_X86_PAE)
31 static int disable_nx __cpuinitdata
;
36 * Control non-executable mappings for processes.
41 static int __init
noexec_setup(char *str
)
45 if (!strncmp(str
, "on", 2)) {
46 __supported_pte_mask
|= _PAGE_NX
;
48 } else if (!strncmp(str
, "off", 3)) {
50 __supported_pte_mask
&= ~_PAGE_NX
;
54 early_param("noexec", noexec_setup
);
58 static void __init
set_nx(void)
60 unsigned int v
[4], l
, h
;
62 if (cpu_has_pae
&& (cpuid_eax(0x80000000) > 0x80000001)) {
63 cpuid(0x80000001, &v
[0], &v
[1], &v
[2], &v
[3]);
65 if ((v
[3] & (1 << 20)) && !disable_nx
) {
66 rdmsr(MSR_EFER
, l
, h
);
68 wrmsr(MSR_EFER
, l
, h
);
70 __supported_pte_mask
|= _PAGE_NX
;
75 static inline void set_nx(void)
81 void __cpuinit
check_efer(void)
85 rdmsrl(MSR_EFER
, efer
);
86 if (!(efer
& EFER_NX
) || disable_nx
)
87 __supported_pte_mask
&= ~_PAGE_NX
;
91 static void __init
find_early_table_space(unsigned long end
, int use_pse
,
94 unsigned long puds
, pmds
, ptes
, tables
, start
;
96 puds
= (end
+ PUD_SIZE
- 1) >> PUD_SHIFT
;
97 tables
= roundup(puds
* sizeof(pud_t
), PAGE_SIZE
);
102 extra
= end
- ((end
>>PUD_SHIFT
) << PUD_SHIFT
);
103 pmds
= (extra
+ PMD_SIZE
- 1) >> PMD_SHIFT
;
105 pmds
= (end
+ PMD_SIZE
- 1) >> PMD_SHIFT
;
107 tables
+= roundup(pmds
* sizeof(pmd_t
), PAGE_SIZE
);
112 extra
= end
- ((end
>>PMD_SHIFT
) << PMD_SHIFT
);
116 ptes
= (extra
+ PAGE_SIZE
- 1) >> PAGE_SHIFT
;
118 ptes
= (end
+ PAGE_SIZE
- 1) >> PAGE_SHIFT
;
120 tables
+= roundup(ptes
* sizeof(pte_t
), PAGE_SIZE
);
124 tables
+= roundup(__end_of_fixed_addresses
* sizeof(pte_t
), PAGE_SIZE
);
128 * RED-PEN putting page tables only on node 0 could
129 * cause a hotspot and fill up ZONE_DMA. The page tables
130 * need roughly 0.5KB per GB.
134 e820_table_start
= find_e820_area(start
, max_pfn_mapped
<<PAGE_SHIFT
,
136 #else /* CONFIG_X86_64 */
138 e820_table_start
= find_e820_area(start
, end
, tables
, PAGE_SIZE
);
140 if (e820_table_start
== -1UL)
141 panic("Cannot find space for the kernel page tables");
143 e820_table_start
>>= PAGE_SHIFT
;
144 e820_table_end
= e820_table_start
;
145 e820_table_top
= e820_table_start
+ (tables
>> PAGE_SHIFT
);
147 printk(KERN_DEBUG
"kernel direct mapping tables up to %lx @ %lx-%lx\n",
148 end
, e820_table_start
<< PAGE_SHIFT
, e820_table_top
<< PAGE_SHIFT
);
154 unsigned page_size_mask
;
158 #define NR_RANGE_MR 3
159 #else /* CONFIG_X86_64 */
160 #define NR_RANGE_MR 5
163 static int __meminit
save_mr(struct map_range
*mr
, int nr_range
,
164 unsigned long start_pfn
, unsigned long end_pfn
,
165 unsigned long page_size_mask
)
167 if (start_pfn
< end_pfn
) {
168 if (nr_range
>= NR_RANGE_MR
)
169 panic("run out of range for init_memory_mapping\n");
170 mr
[nr_range
].start
= start_pfn
<<PAGE_SHIFT
;
171 mr
[nr_range
].end
= end_pfn
<<PAGE_SHIFT
;
172 mr
[nr_range
].page_size_mask
= page_size_mask
;
180 static void __init
init_gbpages(void)
182 if (direct_gbpages
&& cpu_has_gbpages
)
183 printk(KERN_INFO
"Using GB pages for direct mapping\n");
188 static inline void init_gbpages(void)
194 * Setup the direct mapping of the physical memory at PAGE_OFFSET.
195 * This runs before bootmem is initialized and gets pages directly from
196 * the physical memory. To access them they are temporarily mapped.
198 unsigned long __init_refok
init_memory_mapping(unsigned long start
,
201 unsigned long page_size_mask
= 0;
202 unsigned long start_pfn
, end_pfn
;
203 unsigned long ret
= 0;
206 struct map_range mr
[NR_RANGE_MR
];
208 int use_pse
, use_gbpages
;
210 printk(KERN_INFO
"init_memory_mapping: %016lx-%016lx\n", start
, end
);
215 #ifdef CONFIG_DEBUG_PAGEALLOC
217 * For CONFIG_DEBUG_PAGEALLOC, identity mapping will use small pages.
218 * This will simplify cpa(), which otherwise needs to support splitting
219 * large pages into small in interrupt context, etc.
221 use_pse
= use_gbpages
= 0;
223 use_pse
= cpu_has_pse
;
224 use_gbpages
= direct_gbpages
;
229 printk(KERN_INFO
"NX (Execute Disable) protection: active\n");
231 /* Enable PSE if available */
233 set_in_cr4(X86_CR4_PSE
);
235 /* Enable PGE if available */
237 set_in_cr4(X86_CR4_PGE
);
238 __supported_pte_mask
|= _PAGE_GLOBAL
;
242 page_size_mask
|= 1 << PG_LEVEL_1G
;
244 page_size_mask
|= 1 << PG_LEVEL_2M
;
246 memset(mr
, 0, sizeof(mr
));
249 /* head if not big page alignment ? */
250 start_pfn
= start
>> PAGE_SHIFT
;
251 pos
= start_pfn
<< PAGE_SHIFT
;
254 * Don't use a large page for the first 2/4MB of memory
255 * because there are often fixed size MTRRs in there
256 * and overlapping MTRRs into large pages can cause
260 end_pfn
= 1<<(PMD_SHIFT
- PAGE_SHIFT
);
262 end_pfn
= ((pos
+ (PMD_SIZE
- 1))>>PMD_SHIFT
)
263 << (PMD_SHIFT
- PAGE_SHIFT
);
264 #else /* CONFIG_X86_64 */
265 end_pfn
= ((pos
+ (PMD_SIZE
- 1)) >> PMD_SHIFT
)
266 << (PMD_SHIFT
- PAGE_SHIFT
);
268 if (end_pfn
> (end
>> PAGE_SHIFT
))
269 end_pfn
= end
>> PAGE_SHIFT
;
270 if (start_pfn
< end_pfn
) {
271 nr_range
= save_mr(mr
, nr_range
, start_pfn
, end_pfn
, 0);
272 pos
= end_pfn
<< PAGE_SHIFT
;
275 /* big page (2M) range */
276 start_pfn
= ((pos
+ (PMD_SIZE
- 1))>>PMD_SHIFT
)
277 << (PMD_SHIFT
- PAGE_SHIFT
);
279 end_pfn
= (end
>>PMD_SHIFT
) << (PMD_SHIFT
- PAGE_SHIFT
);
280 #else /* CONFIG_X86_64 */
281 end_pfn
= ((pos
+ (PUD_SIZE
- 1))>>PUD_SHIFT
)
282 << (PUD_SHIFT
- PAGE_SHIFT
);
283 if (end_pfn
> ((end
>>PMD_SHIFT
)<<(PMD_SHIFT
- PAGE_SHIFT
)))
284 end_pfn
= ((end
>>PMD_SHIFT
)<<(PMD_SHIFT
- PAGE_SHIFT
));
287 if (start_pfn
< end_pfn
) {
288 nr_range
= save_mr(mr
, nr_range
, start_pfn
, end_pfn
,
289 page_size_mask
& (1<<PG_LEVEL_2M
));
290 pos
= end_pfn
<< PAGE_SHIFT
;
294 /* big page (1G) range */
295 start_pfn
= ((pos
+ (PUD_SIZE
- 1))>>PUD_SHIFT
)
296 << (PUD_SHIFT
- PAGE_SHIFT
);
297 end_pfn
= (end
>> PUD_SHIFT
) << (PUD_SHIFT
- PAGE_SHIFT
);
298 if (start_pfn
< end_pfn
) {
299 nr_range
= save_mr(mr
, nr_range
, start_pfn
, end_pfn
,
301 ((1<<PG_LEVEL_2M
)|(1<<PG_LEVEL_1G
)));
302 pos
= end_pfn
<< PAGE_SHIFT
;
305 /* tail is not big page (1G) alignment */
306 start_pfn
= ((pos
+ (PMD_SIZE
- 1))>>PMD_SHIFT
)
307 << (PMD_SHIFT
- PAGE_SHIFT
);
308 end_pfn
= (end
>> PMD_SHIFT
) << (PMD_SHIFT
- PAGE_SHIFT
);
309 if (start_pfn
< end_pfn
) {
310 nr_range
= save_mr(mr
, nr_range
, start_pfn
, end_pfn
,
311 page_size_mask
& (1<<PG_LEVEL_2M
));
312 pos
= end_pfn
<< PAGE_SHIFT
;
316 /* tail is not big page (2M) alignment */
317 start_pfn
= pos
>>PAGE_SHIFT
;
318 end_pfn
= end
>>PAGE_SHIFT
;
319 nr_range
= save_mr(mr
, nr_range
, start_pfn
, end_pfn
, 0);
321 /* try to merge same page size and continuous */
322 for (i
= 0; nr_range
> 1 && i
< nr_range
- 1; i
++) {
323 unsigned long old_start
;
324 if (mr
[i
].end
!= mr
[i
+1].start
||
325 mr
[i
].page_size_mask
!= mr
[i
+1].page_size_mask
)
328 old_start
= mr
[i
].start
;
329 memmove(&mr
[i
], &mr
[i
+1],
330 (nr_range
- 1 - i
) * sizeof(struct map_range
));
331 mr
[i
--].start
= old_start
;
335 for (i
= 0; i
< nr_range
; i
++)
336 printk(KERN_DEBUG
" %010lx - %010lx page %s\n",
337 mr
[i
].start
, mr
[i
].end
,
338 (mr
[i
].page_size_mask
& (1<<PG_LEVEL_1G
))?"1G":(
339 (mr
[i
].page_size_mask
& (1<<PG_LEVEL_2M
))?"2M":"4k"));
342 * Find space for the kernel direct mapping tables.
344 * Later we should allocate these tables in the local node of the
345 * memory mapped. Unfortunately this is done currently before the
346 * nodes are discovered.
349 find_early_table_space(end
, use_pse
, use_gbpages
);
352 for (i
= 0; i
< nr_range
; i
++)
353 kernel_physical_mapping_init(mr
[i
].start
, mr
[i
].end
,
354 mr
[i
].page_size_mask
);
356 #else /* CONFIG_X86_64 */
357 for (i
= 0; i
< nr_range
; i
++)
358 ret
= kernel_physical_mapping_init(mr
[i
].start
, mr
[i
].end
,
359 mr
[i
].page_size_mask
);
363 early_ioremap_page_table_range_init();
365 load_cr3(swapper_pg_dir
);
370 mmu_cr4_features
= read_cr4();
374 if (!after_bootmem
&& e820_table_end
> e820_table_start
)
375 reserve_early(e820_table_start
<< PAGE_SHIFT
,
376 e820_table_end
<< PAGE_SHIFT
, "PGTABLE");
379 early_memtest(start
, end
);
381 return ret
>> PAGE_SHIFT
;
386 * devmem_is_allowed() checks to see if /dev/mem access to a certain address
387 * is valid. The argument is a physical page number.
390 * On x86, access has to be given to the first megabyte of ram because that area
391 * contains bios code and data regions used by X and dosemu and similar apps.
392 * Access has to be given to non-kernel-ram areas as well, these contain the PCI
393 * mmio resources as well as potential bios/acpi data regions.
395 int devmem_is_allowed(unsigned long pagenr
)
399 if (iomem_is_exclusive(pagenr
<< PAGE_SHIFT
))
401 if (!page_is_ram(pagenr
))
406 void free_init_pages(char *what
, unsigned long begin
, unsigned long end
)
408 unsigned long addr
= begin
;
414 * If debugging page accesses then do not free this memory but
415 * mark them not present - any buggy init-section access will
416 * create a kernel page fault:
418 #ifdef CONFIG_DEBUG_PAGEALLOC
419 printk(KERN_INFO
"debug: unmapping init memory %08lx..%08lx\n",
420 begin
, PAGE_ALIGN(end
));
421 set_memory_np(begin
, (end
- begin
) >> PAGE_SHIFT
);
424 * We just marked the kernel text read only above, now that
425 * we are going to free part of that, we need to make that
428 set_memory_rw(begin
, (end
- begin
) >> PAGE_SHIFT
);
430 printk(KERN_INFO
"Freeing %s: %luk freed\n", what
, (end
- begin
) >> 10);
432 for (; addr
< end
; addr
+= PAGE_SIZE
) {
433 ClearPageReserved(virt_to_page(addr
));
434 init_page_count(virt_to_page(addr
));
435 memset((void *)(addr
& ~(PAGE_SIZE
-1)),
436 POISON_FREE_INITMEM
, PAGE_SIZE
);
443 void free_initmem(void)
445 free_init_pages("unused kernel memory",
446 (unsigned long)(&__init_begin
),
447 (unsigned long)(&__init_end
));
450 #ifdef CONFIG_BLK_DEV_INITRD
451 void free_initrd_mem(unsigned long start
, unsigned long end
)
453 free_init_pages("initrd memory", start
, end
);