x86: mm/discontig_32.c: make code static
[linux-2.6] / arch / x86 / mm / pgtable_32.c
1 /*
2  *  linux/arch/i386/mm/pgtable.c
3  */
4
5 #include <linux/sched.h>
6 #include <linux/kernel.h>
7 #include <linux/errno.h>
8 #include <linux/mm.h>
9 #include <linux/nmi.h>
10 #include <linux/swap.h>
11 #include <linux/smp.h>
12 #include <linux/highmem.h>
13 #include <linux/slab.h>
14 #include <linux/pagemap.h>
15 #include <linux/spinlock.h>
16 #include <linux/module.h>
17 #include <linux/quicklist.h>
18
19 #include <asm/system.h>
20 #include <asm/pgtable.h>
21 #include <asm/pgalloc.h>
22 #include <asm/fixmap.h>
23 #include <asm/e820.h>
24 #include <asm/tlb.h>
25 #include <asm/tlbflush.h>
26
27 void show_mem(void)
28 {
29         int total = 0, reserved = 0;
30         int shared = 0, cached = 0;
31         int highmem = 0;
32         struct page *page;
33         pg_data_t *pgdat;
34         unsigned long i;
35         unsigned long flags;
36
37         printk(KERN_INFO "Mem-info:\n");
38         show_free_areas();
39         printk(KERN_INFO "Free swap:       %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
40         for_each_online_pgdat(pgdat) {
41                 pgdat_resize_lock(pgdat, &flags);
42                 for (i = 0; i < pgdat->node_spanned_pages; ++i) {
43                         if (unlikely(i % MAX_ORDER_NR_PAGES == 0))
44                                 touch_nmi_watchdog();
45                         page = pgdat_page_nr(pgdat, i);
46                         total++;
47                         if (PageHighMem(page))
48                                 highmem++;
49                         if (PageReserved(page))
50                                 reserved++;
51                         else if (PageSwapCache(page))
52                                 cached++;
53                         else if (page_count(page))
54                                 shared += page_count(page) - 1;
55                 }
56                 pgdat_resize_unlock(pgdat, &flags);
57         }
58         printk(KERN_INFO "%d pages of RAM\n", total);
59         printk(KERN_INFO "%d pages of HIGHMEM\n", highmem);
60         printk(KERN_INFO "%d reserved pages\n", reserved);
61         printk(KERN_INFO "%d pages shared\n", shared);
62         printk(KERN_INFO "%d pages swap cached\n", cached);
63
64         printk(KERN_INFO "%lu pages dirty\n", global_page_state(NR_FILE_DIRTY));
65         printk(KERN_INFO "%lu pages writeback\n",
66                                         global_page_state(NR_WRITEBACK));
67         printk(KERN_INFO "%lu pages mapped\n", global_page_state(NR_FILE_MAPPED));
68         printk(KERN_INFO "%lu pages slab\n",
69                 global_page_state(NR_SLAB_RECLAIMABLE) +
70                 global_page_state(NR_SLAB_UNRECLAIMABLE));
71         printk(KERN_INFO "%lu pages pagetables\n",
72                                         global_page_state(NR_PAGETABLE));
73 }
74
75 /*
76  * Associate a virtual page frame with a given physical page frame 
77  * and protection flags for that frame.
78  */ 
79 static void set_pte_pfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags)
80 {
81         pgd_t *pgd;
82         pud_t *pud;
83         pmd_t *pmd;
84         pte_t *pte;
85
86         pgd = swapper_pg_dir + pgd_index(vaddr);
87         if (pgd_none(*pgd)) {
88                 BUG();
89                 return;
90         }
91         pud = pud_offset(pgd, vaddr);
92         if (pud_none(*pud)) {
93                 BUG();
94                 return;
95         }
96         pmd = pmd_offset(pud, vaddr);
97         if (pmd_none(*pmd)) {
98                 BUG();
99                 return;
100         }
101         pte = pte_offset_kernel(pmd, vaddr);
102         if (pgprot_val(flags))
103                 set_pte_present(&init_mm, vaddr, pte, pfn_pte(pfn, flags));
104         else
105                 pte_clear(&init_mm, vaddr, pte);
106
107         /*
108          * It's enough to flush this one mapping.
109          * (PGE mappings get flushed as well)
110          */
111         __flush_tlb_one(vaddr);
112 }
113
114 /*
115  * Associate a large virtual page frame with a given physical page frame 
116  * and protection flags for that frame. pfn is for the base of the page,
117  * vaddr is what the page gets mapped to - both must be properly aligned. 
118  * The pmd must already be instantiated. Assumes PAE mode.
119  */ 
120 void set_pmd_pfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags)
121 {
122         pgd_t *pgd;
123         pud_t *pud;
124         pmd_t *pmd;
125
126         if (vaddr & (PMD_SIZE-1)) {             /* vaddr is misaligned */
127                 printk(KERN_WARNING "set_pmd_pfn: vaddr misaligned\n");
128                 return; /* BUG(); */
129         }
130         if (pfn & (PTRS_PER_PTE-1)) {           /* pfn is misaligned */
131                 printk(KERN_WARNING "set_pmd_pfn: pfn misaligned\n");
132                 return; /* BUG(); */
133         }
134         pgd = swapper_pg_dir + pgd_index(vaddr);
135         if (pgd_none(*pgd)) {
136                 printk(KERN_WARNING "set_pmd_pfn: pgd_none\n");
137                 return; /* BUG(); */
138         }
139         pud = pud_offset(pgd, vaddr);
140         pmd = pmd_offset(pud, vaddr);
141         set_pmd(pmd, pfn_pmd(pfn, flags));
142         /*
143          * It's enough to flush this one mapping.
144          * (PGE mappings get flushed as well)
145          */
146         __flush_tlb_one(vaddr);
147 }
148
149 static int fixmaps;
150 unsigned long __FIXADDR_TOP = 0xfffff000;
151 EXPORT_SYMBOL(__FIXADDR_TOP);
152
153 void __set_fixmap (enum fixed_addresses idx, unsigned long phys, pgprot_t flags)
154 {
155         unsigned long address = __fix_to_virt(idx);
156
157         if (idx >= __end_of_fixed_addresses) {
158                 BUG();
159                 return;
160         }
161         set_pte_pfn(address, phys >> PAGE_SHIFT, flags);
162         fixmaps++;
163 }
164
165 /**
166  * reserve_top_address - reserves a hole in the top of kernel address space
167  * @reserve - size of hole to reserve
168  *
169  * Can be used to relocate the fixmap area and poke a hole in the top
170  * of kernel address space to make room for a hypervisor.
171  */
172 void reserve_top_address(unsigned long reserve)
173 {
174         BUG_ON(fixmaps > 0);
175         printk(KERN_INFO "Reserving virtual address space above 0x%08x\n",
176                (int)-reserve);
177         __FIXADDR_TOP = -reserve - PAGE_SIZE;
178         __VMALLOC_RESERVE += reserve;
179 }
180
181 pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
182 {
183         return (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
184 }
185
186 struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address)
187 {
188         struct page *pte;
189
190 #ifdef CONFIG_HIGHPTE
191         pte = alloc_pages(GFP_KERNEL|__GFP_HIGHMEM|__GFP_REPEAT|__GFP_ZERO, 0);
192 #else
193         pte = alloc_pages(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO, 0);
194 #endif
195         return pte;
196 }
197
198 void pmd_ctor(struct kmem_cache *cache, void *pmd)
199 {
200         memset(pmd, 0, PTRS_PER_PMD*sizeof(pmd_t));
201 }
202
203 /*
204  * List of all pgd's needed for non-PAE so it can invalidate entries
205  * in both cached and uncached pgd's; not needed for PAE since the
206  * kernel pmd is shared. If PAE were not to share the pmd a similar
207  * tactic would be needed. This is essentially codepath-based locking
208  * against pageattr.c; it is the unique case in which a valid change
209  * of kernel pagetables can't be lazily synchronized by vmalloc faults.
210  * vmalloc faults work because attached pagetables are never freed.
211  * -- wli
212  */
213 DEFINE_SPINLOCK(pgd_lock);
214 struct page *pgd_list;
215
216 static inline void pgd_list_add(pgd_t *pgd)
217 {
218         struct page *page = virt_to_page(pgd);
219         page->index = (unsigned long)pgd_list;
220         if (pgd_list)
221                 set_page_private(pgd_list, (unsigned long)&page->index);
222         pgd_list = page;
223         set_page_private(page, (unsigned long)&pgd_list);
224 }
225
226 static inline void pgd_list_del(pgd_t *pgd)
227 {
228         struct page *next, **pprev, *page = virt_to_page(pgd);
229         next = (struct page *)page->index;
230         pprev = (struct page **)page_private(page);
231         *pprev = next;
232         if (next)
233                 set_page_private(next, (unsigned long)pprev);
234 }
235
236
237
238 #if (PTRS_PER_PMD == 1)
239 /* Non-PAE pgd constructor */
240 static void pgd_ctor(void *pgd)
241 {
242         unsigned long flags;
243
244         /* !PAE, no pagetable sharing */
245         memset(pgd, 0, USER_PTRS_PER_PGD*sizeof(pgd_t));
246
247         spin_lock_irqsave(&pgd_lock, flags);
248
249         /* must happen under lock */
250         clone_pgd_range((pgd_t *)pgd + USER_PTRS_PER_PGD,
251                         swapper_pg_dir + USER_PTRS_PER_PGD,
252                         KERNEL_PGD_PTRS);
253         paravirt_alloc_pd_clone(__pa(pgd) >> PAGE_SHIFT,
254                                 __pa(swapper_pg_dir) >> PAGE_SHIFT,
255                                 USER_PTRS_PER_PGD,
256                                 KERNEL_PGD_PTRS);
257         pgd_list_add(pgd);
258         spin_unlock_irqrestore(&pgd_lock, flags);
259 }
260 #else  /* PTRS_PER_PMD > 1 */
261 /* PAE pgd constructor */
262 static void pgd_ctor(void *pgd)
263 {
264         /* PAE, kernel PMD may be shared */
265
266         if (SHARED_KERNEL_PMD) {
267                 clone_pgd_range((pgd_t *)pgd + USER_PTRS_PER_PGD,
268                                 swapper_pg_dir + USER_PTRS_PER_PGD,
269                                 KERNEL_PGD_PTRS);
270         } else {
271                 unsigned long flags;
272
273                 memset(pgd, 0, USER_PTRS_PER_PGD*sizeof(pgd_t));
274                 spin_lock_irqsave(&pgd_lock, flags);
275                 pgd_list_add(pgd);
276                 spin_unlock_irqrestore(&pgd_lock, flags);
277         }
278 }
279 #endif  /* PTRS_PER_PMD */
280
281 static void pgd_dtor(void *pgd)
282 {
283         unsigned long flags; /* can be called from interrupt context */
284
285         if (SHARED_KERNEL_PMD)
286                 return;
287
288         paravirt_release_pd(__pa(pgd) >> PAGE_SHIFT);
289         spin_lock_irqsave(&pgd_lock, flags);
290         pgd_list_del(pgd);
291         spin_unlock_irqrestore(&pgd_lock, flags);
292 }
293
294 #define UNSHARED_PTRS_PER_PGD                           \
295         (SHARED_KERNEL_PMD ? USER_PTRS_PER_PGD : PTRS_PER_PGD)
296
297 /* If we allocate a pmd for part of the kernel address space, then
298    make sure its initialized with the appropriate kernel mappings.
299    Otherwise use a cached zeroed pmd.  */
300 static pmd_t *pmd_cache_alloc(int idx)
301 {
302         pmd_t *pmd;
303
304         if (idx >= USER_PTRS_PER_PGD) {
305                 pmd = (pmd_t *)__get_free_page(GFP_KERNEL);
306
307                 if (pmd)
308                         memcpy(pmd,
309                                (void *)pgd_page_vaddr(swapper_pg_dir[idx]),
310                                sizeof(pmd_t) * PTRS_PER_PMD);
311         } else
312                 pmd = kmem_cache_alloc(pmd_cache, GFP_KERNEL);
313
314         return pmd;
315 }
316
317 static void pmd_cache_free(pmd_t *pmd, int idx)
318 {
319         if (idx >= USER_PTRS_PER_PGD)
320                 free_page((unsigned long)pmd);
321         else
322                 kmem_cache_free(pmd_cache, pmd);
323 }
324
325 pgd_t *pgd_alloc(struct mm_struct *mm)
326 {
327         int i;
328         pgd_t *pgd = quicklist_alloc(0, GFP_KERNEL, pgd_ctor);
329
330         if (PTRS_PER_PMD == 1 || !pgd)
331                 return pgd;
332
333         for (i = 0; i < UNSHARED_PTRS_PER_PGD; ++i) {
334                 pmd_t *pmd = pmd_cache_alloc(i);
335
336                 if (!pmd)
337                         goto out_oom;
338
339                 paravirt_alloc_pd(__pa(pmd) >> PAGE_SHIFT);
340                 set_pgd(&pgd[i], __pgd(1 + __pa(pmd)));
341         }
342         return pgd;
343
344 out_oom:
345         for (i--; i >= 0; i--) {
346                 pgd_t pgdent = pgd[i];
347                 void* pmd = (void *)__va(pgd_val(pgdent)-1);
348                 paravirt_release_pd(__pa(pmd) >> PAGE_SHIFT);
349                 pmd_cache_free(pmd, i);
350         }
351         quicklist_free(0, pgd_dtor, pgd);
352         return NULL;
353 }
354
355 void pgd_free(pgd_t *pgd)
356 {
357         int i;
358
359         /* in the PAE case user pgd entries are overwritten before usage */
360         if (PTRS_PER_PMD > 1)
361                 for (i = 0; i < UNSHARED_PTRS_PER_PGD; ++i) {
362                         pgd_t pgdent = pgd[i];
363                         void* pmd = (void *)__va(pgd_val(pgdent)-1);
364                         paravirt_release_pd(__pa(pmd) >> PAGE_SHIFT);
365                         pmd_cache_free(pmd, i);
366                 }
367         /* in the non-PAE case, free_pgtables() clears user pgd entries */
368         quicklist_free(0, pgd_dtor, pgd);
369 }
370
371 void check_pgt_cache(void)
372 {
373         quicklist_trim(0, pgd_dtor, 25, 16);
374 }
375