pgtable_32.c (36d99df2fb474222ab47fbe8ae7385661033223b) pgtable_32.c (4f76cd382213b29dd3658e3e1ea47c0c2be06f3c)
1#include <linux/sched.h>
2#include <linux/kernel.h>
3#include <linux/errno.h>
4#include <linux/mm.h>
5#include <linux/nmi.h>
6#include <linux/swap.h>
7#include <linux/smp.h>
8#include <linux/highmem.h>

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168{
169 BUG_ON(fixmaps > 0);
170 printk(KERN_INFO "Reserving virtual address space above 0x%08x\n",
171 (int)-reserve);
172 __FIXADDR_TOP = -reserve - PAGE_SIZE;
173 __VMALLOC_RESERVE += reserve;
174}
175
1#include <linux/sched.h>
2#include <linux/kernel.h>
3#include <linux/errno.h>
4#include <linux/mm.h>
5#include <linux/nmi.h>
6#include <linux/swap.h>
7#include <linux/smp.h>
8#include <linux/highmem.h>

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168{
169 BUG_ON(fixmaps > 0);
170 printk(KERN_INFO "Reserving virtual address space above 0x%08x\n",
171 (int)-reserve);
172 __FIXADDR_TOP = -reserve - PAGE_SIZE;
173 __VMALLOC_RESERVE += reserve;
174}
175
176pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
177{
178 return (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
179}
180
181pgtable_t pte_alloc_one(struct mm_struct *mm, unsigned long address)
182{
183 struct page *pte;
184
185#ifdef CONFIG_HIGHPTE
186 pte = alloc_pages(GFP_KERNEL|__GFP_HIGHMEM|__GFP_REPEAT|__GFP_ZERO, 0);
187#else
188 pte = alloc_pages(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO, 0);
189#endif
190 if (pte)
191 pgtable_page_ctor(pte);
192 return pte;
193}
194
195/*
196 * List of all pgd's needed for non-PAE so it can invalidate entries
197 * in both cached and uncached pgd's; not needed for PAE since the
198 * kernel pmd is shared. If PAE were not to share the pmd a similar
199 * tactic would be needed. This is essentially codepath-based locking
200 * against pageattr.c; it is the unique case in which a valid change
201 * of kernel pagetables can't be lazily synchronized by vmalloc faults.
202 * vmalloc faults work because attached pagetables are never freed.
203 * -- wli
204 */
205static inline void pgd_list_add(pgd_t *pgd)
206{
207 struct page *page = virt_to_page(pgd);
208
209 list_add(&page->lru, &pgd_list);
210}
211
212static inline void pgd_list_del(pgd_t *pgd)
213{
214 struct page *page = virt_to_page(pgd);
215
216 list_del(&page->lru);
217}
218
219#define UNSHARED_PTRS_PER_PGD \
220 (SHARED_KERNEL_PMD ? USER_PTRS_PER_PGD : PTRS_PER_PGD)
221
222static void pgd_ctor(void *p)
223{
224 pgd_t *pgd = p;
225 unsigned long flags;
226
227 /* Clear usermode parts of PGD */
228 memset(pgd, 0, USER_PTRS_PER_PGD*sizeof(pgd_t));
229
230 spin_lock_irqsave(&pgd_lock, flags);
231
232 /* If the pgd points to a shared pagetable level (either the
233 ptes in non-PAE, or shared PMD in PAE), then just copy the
234 references from swapper_pg_dir. */
235 if (PAGETABLE_LEVELS == 2 ||
236 (PAGETABLE_LEVELS == 3 && SHARED_KERNEL_PMD)) {
237 clone_pgd_range(pgd + USER_PTRS_PER_PGD,
238 swapper_pg_dir + USER_PTRS_PER_PGD,
239 KERNEL_PGD_PTRS);
240 paravirt_alloc_pd_clone(__pa(pgd) >> PAGE_SHIFT,
241 __pa(swapper_pg_dir) >> PAGE_SHIFT,
242 USER_PTRS_PER_PGD,
243 KERNEL_PGD_PTRS);
244 }
245
246 /* list required to sync kernel mapping updates */
247 if (!SHARED_KERNEL_PMD)
248 pgd_list_add(pgd);
249
250 spin_unlock_irqrestore(&pgd_lock, flags);
251}
252
253static void pgd_dtor(void *pgd)
254{
255 unsigned long flags; /* can be called from interrupt context */
256
257 if (SHARED_KERNEL_PMD)
258 return;
259
260 spin_lock_irqsave(&pgd_lock, flags);
261 pgd_list_del(pgd);
262 spin_unlock_irqrestore(&pgd_lock, flags);
263}
264
265#ifdef CONFIG_X86_PAE
266/*
267 * Mop up any pmd pages which may still be attached to the pgd.
268 * Normally they will be freed by munmap/exit_mmap, but any pmd we
269 * preallocate which never got a corresponding vma will need to be
270 * freed manually.
271 */
272static void pgd_mop_up_pmds(struct mm_struct *mm, pgd_t *pgdp)
273{
274 int i;
275
276 for(i = 0; i < UNSHARED_PTRS_PER_PGD; i++) {
277 pgd_t pgd = pgdp[i];
278
279 if (pgd_val(pgd) != 0) {
280 pmd_t *pmd = (pmd_t *)pgd_page_vaddr(pgd);
281
282 pgdp[i] = native_make_pgd(0);
283
284 paravirt_release_pd(pgd_val(pgd) >> PAGE_SHIFT);
285 pmd_free(mm, pmd);
286 }
287 }
288}
289
290/*
291 * In PAE mode, we need to do a cr3 reload (=tlb flush) when
292 * updating the top-level pagetable entries to guarantee the
293 * processor notices the update. Since this is expensive, and
294 * all 4 top-level entries are used almost immediately in a
295 * new process's life, we just pre-populate them here.
296 *
297 * Also, if we're in a paravirt environment where the kernel pmd is
298 * not shared between pagetables (!SHARED_KERNEL_PMDS), we allocate
299 * and initialize the kernel pmds here.
300 */
301static int pgd_prepopulate_pmd(struct mm_struct *mm, pgd_t *pgd)
302{
303 pud_t *pud;
304 unsigned long addr;
305 int i;
306
307 pud = pud_offset(pgd, 0);
308 for (addr = i = 0; i < UNSHARED_PTRS_PER_PGD;
309 i++, pud++, addr += PUD_SIZE) {
310 pmd_t *pmd = pmd_alloc_one(mm, addr);
311
312 if (!pmd) {
313 pgd_mop_up_pmds(mm, pgd);
314 return 0;
315 }
316
317 if (i >= USER_PTRS_PER_PGD)
318 memcpy(pmd, (pmd_t *)pgd_page_vaddr(swapper_pg_dir[i]),
319 sizeof(pmd_t) * PTRS_PER_PMD);
320
321 pud_populate(mm, pud, pmd);
322 }
323
324 return 1;
325}
326#else /* !CONFIG_X86_PAE */
327/* No need to prepopulate any pagetable entries in non-PAE modes. */
328static int pgd_prepopulate_pmd(struct mm_struct *mm, pgd_t *pgd)
329{
330 return 1;
331}
332
333static void pgd_mop_up_pmds(struct mm_struct *mm, pgd_t *pgdp)
334{
335}
336#endif /* CONFIG_X86_PAE */
337
338pgd_t *pgd_alloc(struct mm_struct *mm)
339{
340 pgd_t *pgd = (pgd_t *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
341
342 /* so that alloc_pd can use it */
343 mm->pgd = pgd;
344 if (pgd)
345 pgd_ctor(pgd);
346
347 if (pgd && !pgd_prepopulate_pmd(mm, pgd)) {
348 pgd_dtor(pgd);
349 free_page((unsigned long)pgd);
350 pgd = NULL;
351 }
352
353 return pgd;
354}
355
356void pgd_free(struct mm_struct *mm, pgd_t *pgd)
357{
358 pgd_mop_up_pmds(mm, pgd);
359 pgd_dtor(pgd);
360 free_page((unsigned long)pgd);
361}
362
363void __pte_free_tlb(struct mmu_gather *tlb, struct page *pte)
364{
365 pgtable_page_dtor(pte);
366 paravirt_release_pt(page_to_pfn(pte));
367 tlb_remove_page(tlb, pte);
368}
369
370#ifdef CONFIG_X86_PAE

--- 15 unchanged lines hidden --- 		176void __pte_free_tlb(struct mmu_gather *tlb, struct page *pte)
177{
178 pgtable_page_dtor(pte);
179 paravirt_release_pt(page_to_pfn(pte));
180 tlb_remove_page(tlb, pte);
181}
182
183#ifdef CONFIG_X86_PAE

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