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>
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;
34 printk("Mem-info:\n");
36 printk("Free swap: %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
37 for_each_pgdat(pgdat) {
38 for (i = 0; i < pgdat->node_spanned_pages; ++i) {
39 page = pgdat_page_nr(pgdat, i);
41 if (PageHighMem(page))
43 if (PageReserved(page))
45 else if (PageSwapCache(page))
47 else if (page_count(page))
48 shared += page_count(page) - 1;
51 printk("%d pages of RAM\n", total);
52 printk("%d pages of HIGHMEM\n",highmem);
53 printk("%d reserved pages\n",reserved);
54 printk("%d pages shared\n",shared);
55 printk("%d pages swap cached\n",cached);
59 * Associate a virtual page frame with a given physical page frame
60 * and protection flags for that frame.
62 static void set_pte_pfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags)
69 pgd = swapper_pg_dir + pgd_index(vaddr);
74 pud = pud_offset(pgd, vaddr);
79 pmd = pmd_offset(pud, vaddr);
84 pte = pte_offset_kernel(pmd, vaddr);
85 /* <pfn,flags> stored as-is, to permit clearing entries */
86 set_pte(pte, pfn_pte(pfn, flags));
89 * It's enough to flush this one mapping.
90 * (PGE mappings get flushed as well)
92 __flush_tlb_one(vaddr);
96 * Associate a large virtual page frame with a given physical page frame
97 * and protection flags for that frame. pfn is for the base of the page,
98 * vaddr is what the page gets mapped to - both must be properly aligned.
99 * The pmd must already be instantiated. Assumes PAE mode.
101 void set_pmd_pfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags)
107 if (vaddr & (PMD_SIZE-1)) { /* vaddr is misaligned */
108 printk ("set_pmd_pfn: vaddr misaligned\n");
111 if (pfn & (PTRS_PER_PTE-1)) { /* pfn is misaligned */
112 printk ("set_pmd_pfn: pfn misaligned\n");
115 pgd = swapper_pg_dir + pgd_index(vaddr);
116 if (pgd_none(*pgd)) {
117 printk ("set_pmd_pfn: pgd_none\n");
120 pud = pud_offset(pgd, vaddr);
121 pmd = pmd_offset(pud, vaddr);
122 set_pmd(pmd, pfn_pmd(pfn, flags));
124 * It's enough to flush this one mapping.
125 * (PGE mappings get flushed as well)
127 __flush_tlb_one(vaddr);
130 void __set_fixmap (enum fixed_addresses idx, unsigned long phys, pgprot_t flags)
132 unsigned long address = __fix_to_virt(idx);
134 if (idx >= __end_of_fixed_addresses) {
138 set_pte_pfn(address, phys >> PAGE_SHIFT, flags);
141 pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
143 return (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
146 struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address)
150 #ifdef CONFIG_HIGHPTE
151 pte = alloc_pages(GFP_KERNEL|__GFP_HIGHMEM|__GFP_REPEAT|__GFP_ZERO, 0);
153 pte = alloc_pages(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO, 0);
158 void pmd_ctor(void *pmd, kmem_cache_t *cache, unsigned long flags)
160 memset(pmd, 0, PTRS_PER_PMD*sizeof(pmd_t));
164 * List of all pgd's needed for non-PAE so it can invalidate entries
165 * in both cached and uncached pgd's; not needed for PAE since the
166 * kernel pmd is shared. If PAE were not to share the pmd a similar
167 * tactic would be needed. This is essentially codepath-based locking
168 * against pageattr.c; it is the unique case in which a valid change
169 * of kernel pagetables can't be lazily synchronized by vmalloc faults.
170 * vmalloc faults work because attached pagetables are never freed.
171 * The locking scheme was chosen on the basis of manfred's
172 * recommendations and having no core impact whatsoever.
175 DEFINE_SPINLOCK(pgd_lock);
176 struct page *pgd_list;
178 static inline void pgd_list_add(pgd_t *pgd)
180 struct page *page = virt_to_page(pgd);
181 page->index = (unsigned long)pgd_list;
183 pgd_list->private = (unsigned long)&page->index;
185 page->private = (unsigned long)&pgd_list;
188 static inline void pgd_list_del(pgd_t *pgd)
190 struct page *next, **pprev, *page = virt_to_page(pgd);
191 next = (struct page *)page->index;
192 pprev = (struct page **)page->private;
195 next->private = (unsigned long)pprev;
198 void pgd_ctor(void *pgd, kmem_cache_t *cache, unsigned long unused)
202 if (PTRS_PER_PMD == 1)
203 spin_lock_irqsave(&pgd_lock, flags);
205 memcpy((pgd_t *)pgd + USER_PTRS_PER_PGD,
206 swapper_pg_dir + USER_PTRS_PER_PGD,
207 (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
209 if (PTRS_PER_PMD > 1)
213 spin_unlock_irqrestore(&pgd_lock, flags);
214 memset(pgd, 0, USER_PTRS_PER_PGD*sizeof(pgd_t));
217 /* never called when PTRS_PER_PMD > 1 */
218 void pgd_dtor(void *pgd, kmem_cache_t *cache, unsigned long unused)
220 unsigned long flags; /* can be called from interrupt context */
222 spin_lock_irqsave(&pgd_lock, flags);
224 spin_unlock_irqrestore(&pgd_lock, flags);
227 pgd_t *pgd_alloc(struct mm_struct *mm)
230 pgd_t *pgd = kmem_cache_alloc(pgd_cache, GFP_KERNEL);
232 if (PTRS_PER_PMD == 1 || !pgd)
235 for (i = 0; i < USER_PTRS_PER_PGD; ++i) {
236 pmd_t *pmd = kmem_cache_alloc(pmd_cache, GFP_KERNEL);
239 set_pgd(&pgd[i], __pgd(1 + __pa(pmd)));
244 for (i--; i >= 0; i--)
245 kmem_cache_free(pmd_cache, (void *)__va(pgd_val(pgd[i])-1));
246 kmem_cache_free(pgd_cache, pgd);
250 void pgd_free(pgd_t *pgd)
254 /* in the PAE case user pgd entries are overwritten before usage */
255 if (PTRS_PER_PMD > 1)
256 for (i = 0; i < USER_PTRS_PER_PGD; ++i)
257 kmem_cache_free(pmd_cache, (void *)__va(pgd_val(pgd[i])-1));
258 /* in the non-PAE case, free_pgtables() clears user pgd entries */
259 kmem_cache_free(pgd_cache, pgd);