aboutsummaryrefslogtreecommitdiffstats
path: root/mm
diff options
context:
space:
mode:
authorNick Piggin <npiggin@suse.de>2007-02-12 03:51:36 -0500
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-02-12 12:48:27 -0500
commite0dc0d8f4a327d033bfb63d43f113d5f31d11b3c (patch)
tree7af435f3caacd18eef6e30577e61d62e0afbe4d2 /mm
parent2ca48ed5cc5935cbd2a6f5d14fecd4ddbbdb4315 (diff)
[PATCH] add vm_insert_pfn()
Add a vm_insert_pfn helper, so that ->fault handlers can have nopfn functionality by installing their own pte and returning NULL. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Arnd Bergmann <arnd.bergmann@de.ibm.com> Cc: Hugh Dickins <hugh@veritas.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/memory.c45
1 files changed, 45 insertions, 0 deletions
diff --git a/mm/memory.c b/mm/memory.c
index 072c1135ad37..8b8f0d2b453d 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1277,6 +1277,51 @@ int vm_insert_page(struct vm_area_struct *vma, unsigned long addr, struct page *
1277} 1277}
1278EXPORT_SYMBOL(vm_insert_page); 1278EXPORT_SYMBOL(vm_insert_page);
1279 1279
1280/**
1281 * vm_insert_pfn - insert single pfn into user vma
1282 * @vma: user vma to map to
1283 * @addr: target user address of this page
1284 * @pfn: source kernel pfn
1285 *
1286 * Similar to vm_inert_page, this allows drivers to insert individual pages
1287 * they've allocated into a user vma. Same comments apply.
1288 *
1289 * This function should only be called from a vm_ops->fault handler, and
1290 * in that case the handler should return NULL.
1291 */
1292int vm_insert_pfn(struct vm_area_struct *vma, unsigned long addr,
1293 unsigned long pfn)
1294{
1295 struct mm_struct *mm = vma->vm_mm;
1296 int retval;
1297 pte_t *pte, entry;
1298 spinlock_t *ptl;
1299
1300 BUG_ON(!(vma->vm_flags & VM_PFNMAP));
1301 BUG_ON(is_cow_mapping(vma->vm_flags));
1302
1303 retval = -ENOMEM;
1304 pte = get_locked_pte(mm, addr, &ptl);
1305 if (!pte)
1306 goto out;
1307 retval = -EBUSY;
1308 if (!pte_none(*pte))
1309 goto out_unlock;
1310
1311 /* Ok, finally just insert the thing.. */
1312 entry = pfn_pte(pfn, vma->vm_page_prot);
1313 set_pte_at(mm, addr, pte, entry);
1314 update_mmu_cache(vma, addr, entry);
1315
1316 retval = 0;
1317out_unlock:
1318 pte_unmap_unlock(pte, ptl);
1319
1320out:
1321 return retval;
1322}
1323EXPORT_SYMBOL(vm_insert_pfn);
1324
1280/* 1325/*
1281 * maps a range of physical memory into the requested pages. the old 1326 * maps a range of physical memory into the requested pages. the old
1282 * mappings are removed. any references to nonexistent pages results 1327 * mappings are removed. any references to nonexistent pages results