2 * linux/arch/i386/mm/pgtable.c
5 #include <linux/sched.h>
6 #include <linux/kernel.h>
7 #include <linux/errno.h>
9 #include <linux/swap.h>
10 #include <linux/smp.h>
11 #include <linux/highmem.h>
12 #include <linux/slab.h>
13 #include <linux/pagemap.h>
14 #include <linux/spinlock.h>
15 #include <linux/module.h>
17 #include <asm/system.h>
18 #include <asm/pgtable.h>
19 #include <asm/pgalloc.h>
20 #include <asm/fixmap.h>
23 #include <asm/tlbflush.h>
27 int total = 0, reserved = 0;
28 int shared = 0, cached = 0;
35 printk(KERN_INFO "Mem-info:\n");
37 printk(KERN_INFO "Free swap: %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
38 for_each_online_pgdat(pgdat) {
39 pgdat_resize_lock(pgdat, &flags);
40 for (i = 0; i < pgdat->node_spanned_pages; ++i) {
41 page = pgdat_page_nr(pgdat, i);
43 if (PageHighMem(page))
45 if (PageReserved(page))
47 else if (PageSwapCache(page))
49 else if (page_count(page))
50 shared += page_count(page) - 1;
52 pgdat_resize_unlock(pgdat, &flags);
54 printk(KERN_INFO "%d pages of RAM\n", total);
55 printk(KERN_INFO "%d pages of HIGHMEM\n", highmem);
56 printk(KERN_INFO "%d reserved pages\n", reserved);
57 printk(KERN_INFO "%d pages shared\n", shared);
58 printk(KERN_INFO "%d pages swap cached\n", cached);
60 printk(KERN_INFO "%lu pages dirty\n", global_page_state(NR_FILE_DIRTY));
61 printk(KERN_INFO "%lu pages writeback\n",
62 global_page_state(NR_WRITEBACK));
63 printk(KERN_INFO "%lu pages mapped\n", global_page_state(NR_FILE_MAPPED));
64 printk(KERN_INFO "%lu pages slab\n",
65 global_page_state(NR_SLAB_RECLAIMABLE) +
66 global_page_state(NR_SLAB_UNRECLAIMABLE));
67 printk(KERN_INFO "%lu pages pagetables\n",
68 global_page_state(NR_PAGETABLE));
72 * Associate a virtual page frame with a given physical page frame
73 * and protection flags for that frame.
75 static void set_pte_pfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags)
82 pgd = swapper_pg_dir + pgd_index(vaddr);
87 pud = pud_offset(pgd, vaddr);
92 pmd = pmd_offset(pud, vaddr);
97 pte = pte_offset_kernel(pmd, vaddr);
98 /* <pfn,flags> stored as-is, to permit clearing entries */
99 set_pte(pte, pfn_pte(pfn, flags));
102 * It's enough to flush this one mapping.
103 * (PGE mappings get flushed as well)
105 __flush_tlb_one(vaddr);
109 * Associate a large virtual page frame with a given physical page frame
110 * and protection flags for that frame. pfn is for the base of the page,
111 * vaddr is what the page gets mapped to - both must be properly aligned.
112 * The pmd must already be instantiated. Assumes PAE mode.
114 void set_pmd_pfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags)
120 if (vaddr & (PMD_SIZE-1)) { /* vaddr is misaligned */
121 printk(KERN_WARNING "set_pmd_pfn: vaddr misaligned\n");
124 if (pfn & (PTRS_PER_PTE-1)) { /* pfn is misaligned */
125 printk(KERN_WARNING "set_pmd_pfn: pfn misaligned\n");
128 pgd = swapper_pg_dir + pgd_index(vaddr);
129 if (pgd_none(*pgd)) {
130 printk(KERN_WARNING "set_pmd_pfn: pgd_none\n");
133 pud = pud_offset(pgd, vaddr);
134 pmd = pmd_offset(pud, vaddr);
135 set_pmd(pmd, pfn_pmd(pfn, flags));
137 * It's enough to flush this one mapping.
138 * (PGE mappings get flushed as well)
140 __flush_tlb_one(vaddr);
144 #ifndef CONFIG_COMPAT_VDSO
145 unsigned long __FIXADDR_TOP = 0xfffff000;
146 EXPORT_SYMBOL(__FIXADDR_TOP);
149 void __set_fixmap (enum fixed_addresses idx, unsigned long phys, pgprot_t flags)
151 unsigned long address = __fix_to_virt(idx);
153 if (idx >= __end_of_fixed_addresses) {
157 set_pte_pfn(address, phys >> PAGE_SHIFT, flags);
162 * reserve_top_address - reserves a hole in the top of kernel address space
163 * @reserve - size of hole to reserve
165 * Can be used to relocate the fixmap area and poke a hole in the top
166 * of kernel address space to make room for a hypervisor.
168 void reserve_top_address(unsigned long reserve)
171 #ifdef CONFIG_COMPAT_VDSO
172 BUG_ON(reserve != 0);
174 __FIXADDR_TOP = -reserve - PAGE_SIZE;
175 __VMALLOC_RESERVE += reserve;
179 pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
181 return (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
184 struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address)
188 #ifdef CONFIG_HIGHPTE
189 pte = alloc_pages(GFP_KERNEL|__GFP_HIGHMEM|__GFP_REPEAT|__GFP_ZERO, 0);
191 pte = alloc_pages(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO, 0);
196 void pmd_ctor(void *pmd, kmem_cache_t *cache, unsigned long flags)
198 memset(pmd, 0, PTRS_PER_PMD*sizeof(pmd_t));
202 * List of all pgd's needed for non-PAE so it can invalidate entries
203 * in both cached and uncached pgd's; not needed for PAE since the
204 * kernel pmd is shared. If PAE were not to share the pmd a similar
205 * tactic would be needed. This is essentially codepath-based locking
206 * against pageattr.c; it is the unique case in which a valid change
207 * of kernel pagetables can't be lazily synchronized by vmalloc faults.
208 * vmalloc faults work because attached pagetables are never freed.
209 * The locking scheme was chosen on the basis of manfred's
210 * recommendations and having no core impact whatsoever.
213 DEFINE_SPINLOCK(pgd_lock);
214 struct page *pgd_list;
216 static inline void pgd_list_add(pgd_t *pgd)
218 struct page *page = virt_to_page(pgd);
219 page->index = (unsigned long)pgd_list;
221 set_page_private(pgd_list, (unsigned long)&page->index);
223 set_page_private(page, (unsigned long)&pgd_list);
226 static inline void pgd_list_del(pgd_t *pgd)
228 struct page *next, **pprev, *page = virt_to_page(pgd);
229 next = (struct page *)page->index;
230 pprev = (struct page **)page_private(page);
233 set_page_private(next, (unsigned long)pprev);
236 void pgd_ctor(void *pgd, kmem_cache_t *cache, unsigned long unused)
240 if (PTRS_PER_PMD == 1) {
241 memset(pgd, 0, USER_PTRS_PER_PGD*sizeof(pgd_t));
242 spin_lock_irqsave(&pgd_lock, flags);
245 clone_pgd_range((pgd_t *)pgd + USER_PTRS_PER_PGD,
246 swapper_pg_dir + USER_PTRS_PER_PGD,
248 if (PTRS_PER_PMD > 1)
252 spin_unlock_irqrestore(&pgd_lock, flags);
255 /* never called when PTRS_PER_PMD > 1 */
256 void pgd_dtor(void *pgd, kmem_cache_t *cache, unsigned long unused)
258 unsigned long flags; /* can be called from interrupt context */
260 spin_lock_irqsave(&pgd_lock, flags);
262 spin_unlock_irqrestore(&pgd_lock, flags);
265 pgd_t *pgd_alloc(struct mm_struct *mm)
268 pgd_t *pgd = kmem_cache_alloc(pgd_cache, GFP_KERNEL);
270 if (PTRS_PER_PMD == 1 || !pgd)
273 for (i = 0; i < USER_PTRS_PER_PGD; ++i) {
274 pmd_t *pmd = kmem_cache_alloc(pmd_cache, GFP_KERNEL);
277 set_pgd(&pgd[i], __pgd(1 + __pa(pmd)));
282 for (i--; i >= 0; i--)
283 kmem_cache_free(pmd_cache, (void *)__va(pgd_val(pgd[i])-1));
284 kmem_cache_free(pgd_cache, pgd);
288 void pgd_free(pgd_t *pgd)
292 /* in the PAE case user pgd entries are overwritten before usage */
293 if (PTRS_PER_PMD > 1)
294 for (i = 0; i < USER_PTRS_PER_PGD; ++i)
295 kmem_cache_free(pmd_cache, (void *)__va(pgd_val(pgd[i])-1));
296 /* in the non-PAE case, free_pgtables() clears user pgd entries */
297 kmem_cache_free(pgd_cache, pgd);