2 * linux/arch/i386/mm/pgtable.c
5 #include <linux/config.h>
6 #include <linux/sched.h>
7 #include <linux/kernel.h>
8 #include <linux/errno.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>
18 #include <asm/system.h>
19 #include <asm/pgtable.h>
20 #include <asm/pgalloc.h>
21 #include <asm/fixmap.h>
24 #include <asm/tlbflush.h>
28 int total = 0, reserved = 0;
29 int shared = 0, cached = 0;
37 printk(KERN_INFO "Mem-info:\n");
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 page = pgdat_page_nr(pgdat, i);
45 if (PageHighMem(page))
47 if (PageReserved(page))
49 else if (PageSwapCache(page))
51 else if (page_count(page))
52 shared += page_count(page) - 1;
54 pgdat_resize_unlock(pgdat, &flags);
56 printk(KERN_INFO "%d pages of RAM\n", total);
57 printk(KERN_INFO "%d pages of HIGHMEM\n", highmem);
58 printk(KERN_INFO "%d reserved pages\n", reserved);
59 printk(KERN_INFO "%d pages shared\n", shared);
60 printk(KERN_INFO "%d pages swap cached\n", cached);
63 printk(KERN_INFO "%lu pages dirty\n", ps.nr_dirty);
64 printk(KERN_INFO "%lu pages writeback\n", ps.nr_writeback);
65 printk(KERN_INFO "%lu pages mapped\n", ps.nr_mapped);
66 printk(KERN_INFO "%lu pages slab\n", ps.nr_slab);
67 printk(KERN_INFO "%lu pages pagetables\n", ps.nr_page_table_pages);
71 * Associate a virtual page frame with a given physical page frame
72 * and protection flags for that frame.
74 static void set_pte_pfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags)
81 pgd = swapper_pg_dir + pgd_index(vaddr);
86 pud = pud_offset(pgd, vaddr);
91 pmd = pmd_offset(pud, vaddr);
96 pte = pte_offset_kernel(pmd, vaddr);
97 /* <pfn,flags> stored as-is, to permit clearing entries */
98 set_pte(pte, pfn_pte(pfn, flags));
101 * It's enough to flush this one mapping.
102 * (PGE mappings get flushed as well)
104 __flush_tlb_one(vaddr);
108 * Associate a large virtual page frame with a given physical page frame
109 * and protection flags for that frame. pfn is for the base of the page,
110 * vaddr is what the page gets mapped to - both must be properly aligned.
111 * The pmd must already be instantiated. Assumes PAE mode.
113 void set_pmd_pfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags)
119 if (vaddr & (PMD_SIZE-1)) { /* vaddr is misaligned */
120 printk(KERN_WARNING "set_pmd_pfn: vaddr misaligned\n");
123 if (pfn & (PTRS_PER_PTE-1)) { /* pfn is misaligned */
124 printk(KERN_WARNING "set_pmd_pfn: pfn misaligned\n");
127 pgd = swapper_pg_dir + pgd_index(vaddr);
128 if (pgd_none(*pgd)) {
129 printk(KERN_WARNING "set_pmd_pfn: pgd_none\n");
132 pud = pud_offset(pgd, vaddr);
133 pmd = pmd_offset(pud, vaddr);
134 set_pmd(pmd, pfn_pmd(pfn, flags));
136 * It's enough to flush this one mapping.
137 * (PGE mappings get flushed as well)
139 __flush_tlb_one(vaddr);
142 static int nr_fixmaps = 0;
143 unsigned long __FIXADDR_TOP = 0xfffff000;
144 EXPORT_SYMBOL(__FIXADDR_TOP);
146 void __set_fixmap (enum fixed_addresses idx, unsigned long phys, pgprot_t flags)
148 unsigned long address = __fix_to_virt(idx);
150 if (idx >= __end_of_fixed_addresses) {
154 set_pte_pfn(address, phys >> PAGE_SHIFT, flags);
158 void set_fixaddr_top(unsigned long top)
160 BUG_ON(nr_fixmaps > 0);
161 __FIXADDR_TOP = top - PAGE_SIZE;
164 pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
166 return (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
169 struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address)
173 #ifdef CONFIG_HIGHPTE
174 pte = alloc_pages(GFP_KERNEL|__GFP_HIGHMEM|__GFP_REPEAT|__GFP_ZERO, 0);
176 pte = alloc_pages(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO, 0);
181 void pmd_ctor(void *pmd, kmem_cache_t *cache, unsigned long flags)
183 memset(pmd, 0, PTRS_PER_PMD*sizeof(pmd_t));
187 * List of all pgd's needed for non-PAE so it can invalidate entries
188 * in both cached and uncached pgd's; not needed for PAE since the
189 * kernel pmd is shared. If PAE were not to share the pmd a similar
190 * tactic would be needed. This is essentially codepath-based locking
191 * against pageattr.c; it is the unique case in which a valid change
192 * of kernel pagetables can't be lazily synchronized by vmalloc faults.
193 * vmalloc faults work because attached pagetables are never freed.
194 * The locking scheme was chosen on the basis of manfred's
195 * recommendations and having no core impact whatsoever.
198 DEFINE_SPINLOCK(pgd_lock);
199 struct page *pgd_list;
201 static inline void pgd_list_add(pgd_t *pgd)
203 struct page *page = virt_to_page(pgd);
204 page->index = (unsigned long)pgd_list;
206 set_page_private(pgd_list, (unsigned long)&page->index);
208 set_page_private(page, (unsigned long)&pgd_list);
211 static inline void pgd_list_del(pgd_t *pgd)
213 struct page *next, **pprev, *page = virt_to_page(pgd);
214 next = (struct page *)page->index;
215 pprev = (struct page **)page_private(page);
218 set_page_private(next, (unsigned long)pprev);
221 void pgd_ctor(void *pgd, kmem_cache_t *cache, unsigned long unused)
225 if (PTRS_PER_PMD == 1) {
226 memset(pgd, 0, USER_PTRS_PER_PGD*sizeof(pgd_t));
227 spin_lock_irqsave(&pgd_lock, flags);
230 clone_pgd_range((pgd_t *)pgd + USER_PTRS_PER_PGD,
231 swapper_pg_dir + USER_PTRS_PER_PGD,
233 if (PTRS_PER_PMD > 1)
237 spin_unlock_irqrestore(&pgd_lock, flags);
240 /* never called when PTRS_PER_PMD > 1 */
241 void pgd_dtor(void *pgd, kmem_cache_t *cache, unsigned long unused)
243 unsigned long flags; /* can be called from interrupt context */
245 spin_lock_irqsave(&pgd_lock, flags);
247 spin_unlock_irqrestore(&pgd_lock, flags);
250 pgd_t *pgd_alloc(struct mm_struct *mm)
253 pgd_t *pgd = kmem_cache_alloc(pgd_cache, GFP_KERNEL);
255 if (PTRS_PER_PMD == 1 || !pgd)
258 for (i = 0; i < USER_PTRS_PER_PGD; ++i) {
259 pmd_t *pmd = kmem_cache_alloc(pmd_cache, GFP_KERNEL);
262 set_pgd(&pgd[i], __pgd(1 + __pa(pmd)));
267 for (i--; i >= 0; i--)
268 kmem_cache_free(pmd_cache, (void *)__va(pgd_val(pgd[i])-1));
269 kmem_cache_free(pgd_cache, pgd);
273 void pgd_free(pgd_t *pgd)
277 /* in the PAE case user pgd entries are overwritten before usage */
278 if (PTRS_PER_PMD > 1)
279 for (i = 0; i < USER_PTRS_PER_PGD; ++i)
280 kmem_cache_free(pmd_cache, (void *)__va(pgd_val(pgd[i])-1));
281 /* in the non-PAE case, free_pgtables() clears user pgd entries */
282 kmem_cache_free(pgd_cache, pgd);