return (get_vma_private_data(vma) & flag) != 0;
}
-/* Decrement the reserved pages in the hugepage pool by one */
-static void decrement_hugepage_resv_vma(struct hstate *h,
- struct vm_area_struct *vma)
-{
- if (vma->vm_flags & VM_NORESERVE)
- return;
-
- if (vma->vm_flags & VM_MAYSHARE) {
- /* Shared mappings always use reserves */
- h->resv_huge_pages--;
- } else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) {
- /*
- * Only the process that called mmap() has reserves for
- * private mappings.
- */
- h->resv_huge_pages--;
- }
-}
-
/* Reset counters to 0 and clear all HPAGE_RESV_* flags */
void reset_vma_resv_huge_pages(struct vm_area_struct *vma)
{
}
/* Returns true if the VMA has associated reserve pages */
-static int vma_has_reserves(struct vm_area_struct *vma)
+static int vma_has_reserves(struct vm_area_struct *vma, long chg)
{
+ if (vma->vm_flags & VM_NORESERVE) {
+ /*
+ * This address is already reserved by other process(chg == 0),
+ * so, we should decrement reserved count. Without decrementing,
+ * reserve count remains after releasing inode, because this
+ * allocated page will go into page cache and is regarded as
+ * coming from reserved pool in releasing step. Currently, we
+ * don't have any other solution to deal with this situation
+ * properly, so add work-around here.
+ */
+ if (vma->vm_flags & VM_MAYSHARE && chg == 0)
+ return 1;
+ else
+ return 0;
+ }
+
+ /* Shared mappings always use reserves */
if (vma->vm_flags & VM_MAYSHARE)
return 1;
+
+ /*
+ * Only the process that called mmap() has reserves for
+ * private mappings.
+ */
if (is_vma_resv_set(vma, HPAGE_RESV_OWNER))
return 1;
+
return 0;
}
static struct page *dequeue_huge_page_vma(struct hstate *h,
struct vm_area_struct *vma,
- unsigned long address, int avoid_reserve)
+ unsigned long address, int avoid_reserve,
+ long chg)
{
struct page *page = NULL;
struct mempolicy *mpol;
* have no page reserves. This check ensures that reservations are
* not "stolen". The child may still get SIGKILLed
*/
- if (!vma_has_reserves(vma) &&
+ if (!vma_has_reserves(vma, chg) &&
h->free_huge_pages - h->resv_huge_pages == 0)
goto err;
if (cpuset_zone_allowed_softwall(zone, htlb_alloc_mask)) {
page = dequeue_huge_page_node(h, zone_to_nid(zone));
if (page) {
- if (!avoid_reserve)
- decrement_hugepage_resv_vma(h, vma);
+ if (avoid_reserve)
+ break;
+ if (!vma_has_reserves(vma, chg))
+ break;
+
+ SetPagePrivate(page);
+ h->resv_huge_pages--;
break;
}
}
int nid = page_to_nid(page);
struct hugepage_subpool *spool =
(struct hugepage_subpool *)page_private(page);
+ bool restore_reserve;
set_page_private(page, 0);
page->mapping = NULL;
BUG_ON(page_count(page));
BUG_ON(page_mapcount(page));
+ restore_reserve = PagePrivate(page);
spin_lock(&hugetlb_lock);
hugetlb_cgroup_uncharge_page(hstate_index(h),
pages_per_huge_page(h), page);
+ if (restore_reserve)
+ h->resv_huge_pages++;
+
if (h->surplus_huge_pages_node[nid] && huge_page_order(h) < MAX_ORDER) {
/* remove the page from active list */
list_del(&page->lru);
return nid;
}
-static int alloc_fresh_huge_page(struct hstate *h, nodemask_t *nodes_allowed)
-{
- struct page *page;
- int start_nid;
- int next_nid;
- int ret = 0;
-
- start_nid = hstate_next_node_to_alloc(h, nodes_allowed);
- next_nid = start_nid;
-
- do {
- page = alloc_fresh_huge_page_node(h, next_nid);
- if (page) {
- ret = 1;
- break;
- }
- next_nid = hstate_next_node_to_alloc(h, nodes_allowed);
- } while (next_nid != start_nid);
-
- if (ret)
- count_vm_event(HTLB_BUDDY_PGALLOC);
- else
- count_vm_event(HTLB_BUDDY_PGALLOC_FAIL);
-
- return ret;
-}
-
/*
* helper for free_pool_huge_page() - return the previously saved
* node ["this node"] from which to free a huge page. Advance the
return nid;
}
+#define for_each_node_mask_to_alloc(hs, nr_nodes, node, mask) \
+ for (nr_nodes = nodes_weight(*mask); \
+ nr_nodes > 0 && \
+ ((node = hstate_next_node_to_alloc(hs, mask)) || 1); \
+ nr_nodes--)
+
+#define for_each_node_mask_to_free(hs, nr_nodes, node, mask) \
+ for (nr_nodes = nodes_weight(*mask); \
+ nr_nodes > 0 && \
+ ((node = hstate_next_node_to_free(hs, mask)) || 1); \
+ nr_nodes--)
+
+static int alloc_fresh_huge_page(struct hstate *h, nodemask_t *nodes_allowed)
+{
+ struct page *page;
+ int nr_nodes, node;
+ int ret = 0;
+
+ for_each_node_mask_to_alloc(h, nr_nodes, node, nodes_allowed) {
+ page = alloc_fresh_huge_page_node(h, node);
+ if (page) {
+ ret = 1;
+ break;
+ }
+ }
+
+ if (ret)
+ count_vm_event(HTLB_BUDDY_PGALLOC);
+ else
+ count_vm_event(HTLB_BUDDY_PGALLOC_FAIL);
+
+ return ret;
+}
+
/*
* Free huge page from pool from next node to free.
* Attempt to keep persistent huge pages more or less
static int free_pool_huge_page(struct hstate *h, nodemask_t *nodes_allowed,
bool acct_surplus)
{
- int start_nid;
- int next_nid;
+ int nr_nodes, node;
int ret = 0;
- start_nid = hstate_next_node_to_free(h, nodes_allowed);
- next_nid = start_nid;
-
- do {
+ for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) {
/*
* If we're returning unused surplus pages, only examine
* nodes with surplus pages.
*/
- if ((!acct_surplus || h->surplus_huge_pages_node[next_nid]) &&
- !list_empty(&h->hugepage_freelists[next_nid])) {
+ if ((!acct_surplus || h->surplus_huge_pages_node[node]) &&
+ !list_empty(&h->hugepage_freelists[node])) {
struct page *page =
- list_entry(h->hugepage_freelists[next_nid].next,
+ list_entry(h->hugepage_freelists[node].next,
struct page, lru);
list_del(&page->lru);
h->free_huge_pages--;
- h->free_huge_pages_node[next_nid]--;
+ h->free_huge_pages_node[node]--;
if (acct_surplus) {
h->surplus_huge_pages--;
- h->surplus_huge_pages_node[next_nid]--;
+ h->surplus_huge_pages_node[node]--;
}
update_and_free_page(h, page);
ret = 1;
break;
}
- next_nid = hstate_next_node_to_free(h, nodes_allowed);
- } while (next_nid != start_nid);
+ }
return ret;
}
*/
struct page *alloc_huge_page_node(struct hstate *h, int nid)
{
- struct page *page;
+ struct page *page = NULL;
spin_lock(&hugetlb_lock);
- page = dequeue_huge_page_node(h, nid);
+ if (h->free_huge_pages - h->resv_huge_pages > 0)
+ page = dequeue_huge_page_node(h, nid);
spin_unlock(&hugetlb_lock);
if (!page)
spin_unlock(&hugetlb_lock);
/* Free unnecessary surplus pages to the buddy allocator */
- if (!list_empty(&surplus_list)) {
- list_for_each_entry_safe(page, tmp, &surplus_list, lru) {
- put_page(page);
- }
- }
+ list_for_each_entry_safe(page, tmp, &surplus_list, lru)
+ put_page(page);
spin_lock(&hugetlb_lock);
return ret;
} else {
long err;
pgoff_t idx = vma_hugecache_offset(h, vma, addr);
- struct resv_map *reservations = vma_resv_map(vma);
+ struct resv_map *resv = vma_resv_map(vma);
- err = region_chg(&reservations->regions, idx, idx + 1);
+ err = region_chg(&resv->regions, idx, idx + 1);
if (err < 0)
return err;
return 0;
} else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) {
pgoff_t idx = vma_hugecache_offset(h, vma, addr);
- struct resv_map *reservations = vma_resv_map(vma);
+ struct resv_map *resv = vma_resv_map(vma);
/* Mark this page used in the map. */
- region_add(&reservations->regions, idx, idx + 1);
+ region_add(&resv->regions, idx, idx + 1);
}
}
chg = vma_needs_reservation(h, vma, addr);
if (chg < 0)
return ERR_PTR(-ENOMEM);
- if (chg)
- if (hugepage_subpool_get_pages(spool, chg))
+ if (chg || avoid_reserve)
+ if (hugepage_subpool_get_pages(spool, 1))
return ERR_PTR(-ENOSPC);
ret = hugetlb_cgroup_charge_cgroup(idx, pages_per_huge_page(h), &h_cg);
if (ret) {
- hugepage_subpool_put_pages(spool, chg);
+ if (chg || avoid_reserve)
+ hugepage_subpool_put_pages(spool, 1);
return ERR_PTR(-ENOSPC);
}
spin_lock(&hugetlb_lock);
- page = dequeue_huge_page_vma(h, vma, addr, avoid_reserve);
- if (page) {
- /* update page cgroup details */
- hugetlb_cgroup_commit_charge(idx, pages_per_huge_page(h),
- h_cg, page);
- spin_unlock(&hugetlb_lock);
- } else {
+ page = dequeue_huge_page_vma(h, vma, addr, avoid_reserve, chg);
+ if (!page) {
spin_unlock(&hugetlb_lock);
page = alloc_buddy_huge_page(h, NUMA_NO_NODE);
if (!page) {
hugetlb_cgroup_uncharge_cgroup(idx,
pages_per_huge_page(h),
h_cg);
- hugepage_subpool_put_pages(spool, chg);
+ if (chg || avoid_reserve)
+ hugepage_subpool_put_pages(spool, 1);
return ERR_PTR(-ENOSPC);
}
spin_lock(&hugetlb_lock);
- hugetlb_cgroup_commit_charge(idx, pages_per_huge_page(h),
- h_cg, page);
list_move(&page->lru, &h->hugepage_activelist);
- spin_unlock(&hugetlb_lock);
+ /* Fall through */
}
+ hugetlb_cgroup_commit_charge(idx, pages_per_huge_page(h), h_cg, page);
+ spin_unlock(&hugetlb_lock);
set_page_private(page, (unsigned long)spool);
int __weak alloc_bootmem_huge_page(struct hstate *h)
{
struct huge_bootmem_page *m;
- int nr_nodes = nodes_weight(node_states[N_MEMORY]);
+ int nr_nodes, node;
- while (nr_nodes) {
+ for_each_node_mask_to_alloc(h, nr_nodes, node, &node_states[N_MEMORY]) {
void *addr;
- addr = __alloc_bootmem_node_nopanic(
- NODE_DATA(hstate_next_node_to_alloc(h,
- &node_states[N_MEMORY])),
+ addr = __alloc_bootmem_node_nopanic(NODE_DATA(node),
huge_page_size(h), huge_page_size(h), 0);
if (addr) {
m = addr;
goto found;
}
- nr_nodes--;
}
return 0;
static int adjust_pool_surplus(struct hstate *h, nodemask_t *nodes_allowed,
int delta)
{
- int start_nid, next_nid;
- int ret = 0;
+ int nr_nodes, node;
VM_BUG_ON(delta != -1 && delta != 1);
- if (delta < 0)
- start_nid = hstate_next_node_to_alloc(h, nodes_allowed);
- else
- start_nid = hstate_next_node_to_free(h, nodes_allowed);
- next_nid = start_nid;
-
- do {
- int nid = next_nid;
- if (delta < 0) {
- /*
- * To shrink on this node, there must be a surplus page
- */
- if (!h->surplus_huge_pages_node[nid]) {
- next_nid = hstate_next_node_to_alloc(h,
- nodes_allowed);
- continue;
- }
+ if (delta < 0) {
+ for_each_node_mask_to_alloc(h, nr_nodes, node, nodes_allowed) {
+ if (h->surplus_huge_pages_node[node])
+ goto found;
}
- if (delta > 0) {
- /*
- * Surplus cannot exceed the total number of pages
- */
- if (h->surplus_huge_pages_node[nid] >=
- h->nr_huge_pages_node[nid]) {
- next_nid = hstate_next_node_to_free(h,
- nodes_allowed);
- continue;
- }
+ } else {
+ for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) {
+ if (h->surplus_huge_pages_node[node] <
+ h->nr_huge_pages_node[node])
+ goto found;
}
+ }
+ return 0;
- h->surplus_huge_pages += delta;
- h->surplus_huge_pages_node[nid] += delta;
- ret = 1;
- break;
- } while (next_nid != start_nid);
-
- return ret;
+found:
+ h->surplus_huge_pages += delta;
+ h->surplus_huge_pages_node[node] += delta;
+ return 1;
}
#define persistent_huge_pages(h) (h->nr_huge_pages - h->surplus_huge_pages)
static void hugetlb_vm_op_open(struct vm_area_struct *vma)
{
- struct resv_map *reservations = vma_resv_map(vma);
+ struct resv_map *resv = vma_resv_map(vma);
/*
* This new VMA should share its siblings reservation map if present.
* after this open call completes. It is therefore safe to take a
* new reference here without additional locking.
*/
- if (reservations)
- kref_get(&reservations->refs);
+ if (resv)
+ kref_get(&resv->refs);
}
static void resv_map_put(struct vm_area_struct *vma)
{
- struct resv_map *reservations = vma_resv_map(vma);
+ struct resv_map *resv = vma_resv_map(vma);
- if (!reservations)
+ if (!resv)
return;
- kref_put(&reservations->refs, resv_map_release);
+ kref_put(&resv->refs, resv_map_release);
}
static void hugetlb_vm_op_close(struct vm_area_struct *vma)
{
struct hstate *h = hstate_vma(vma);
- struct resv_map *reservations = vma_resv_map(vma);
+ struct resv_map *resv = vma_resv_map(vma);
struct hugepage_subpool *spool = subpool_vma(vma);
unsigned long reserve;
unsigned long start;
unsigned long end;
- if (reservations) {
+ if (resv) {
start = vma_hugecache_offset(h, vma, vma->vm_start);
end = vma_hugecache_offset(h, vma, vma->vm_end);
reserve = (end - start) -
- region_count(&reservations->regions, start, end);
+ region_count(&resv->regions, start, end);
resv_map_put(vma);
int cow;
struct hstate *h = hstate_vma(vma);
unsigned long sz = huge_page_size(h);
+ unsigned long mmun_start; /* For mmu_notifiers */
+ unsigned long mmun_end; /* For mmu_notifiers */
+ int ret = 0;
cow = (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE;
+ mmun_start = vma->vm_start;
+ mmun_end = vma->vm_end;
+ if (cow)
+ mmu_notifier_invalidate_range_start(src, mmun_start, mmun_end);
+
for (addr = vma->vm_start; addr < vma->vm_end; addr += sz) {
src_pte = huge_pte_offset(src, addr);
if (!src_pte)
continue;
dst_pte = huge_pte_alloc(dst, addr, sz);
- if (!dst_pte)
- goto nomem;
+ if (!dst_pte) {
+ ret = -ENOMEM;
+ break;
+ }
/* If the pagetables are shared don't copy or take references */
if (dst_pte == src_pte)
} else {
if (cow)
huge_ptep_set_wrprotect(src, addr, src_pte);
+ entry = huge_ptep_get(src_pte);
ptepage = pte_page(entry);
get_page(ptepage);
page_dup_rmap(ptepage);
spin_unlock(&src->page_table_lock);
spin_unlock(&dst->page_table_lock);
}
- return 0;
-nomem:
- return -ENOMEM;
+ if (cow)
+ mmu_notifier_invalidate_range_end(src, mmun_start, mmun_end);
+
+ return ret;
}
void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma,
{
struct hstate *h = hstate_vma(vma);
struct page *old_page, *new_page;
- int avoidcopy;
int outside_reserve = 0;
unsigned long mmun_start; /* For mmu_notifiers */
unsigned long mmun_end; /* For mmu_notifiers */
retry_avoidcopy:
/* If no-one else is actually using this page, avoid the copy
* and just make the page writable */
- avoidcopy = (page_mapcount(old_page) == 1);
- if (avoidcopy) {
- if (PageAnon(old_page))
- page_move_anon_rmap(old_page, vma, address);
+ if (page_mapcount(old_page) == 1 && PageAnon(old_page)) {
+ page_move_anon_rmap(old_page, vma, address);
set_huge_ptep_writable(vma, address, ptep);
return 0;
}
* at the time of fork() could consume its reserves on COW instead
* of the full address range.
*/
- if (!(vma->vm_flags & VM_MAYSHARE) &&
- is_vma_resv_set(vma, HPAGE_RESV_OWNER) &&
+ if (is_vma_resv_set(vma, HPAGE_RESV_OWNER) &&
old_page != pagecache_page)
outside_reserve = 1;
spin_lock(&mm->page_table_lock);
ptep = huge_pte_offset(mm, address & huge_page_mask(h));
if (likely(pte_same(huge_ptep_get(ptep), pte))) {
+ ClearPagePrivate(new_page);
+
/* Break COW */
huge_ptep_clear_flush(vma, address, ptep);
set_huge_pte_at(mm, address, ptep,
}
spin_unlock(&mm->page_table_lock);
mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
- /* Caller expects lock to be held */
- spin_lock(&mm->page_table_lock);
page_cache_release(new_page);
page_cache_release(old_page);
+
+ /* Caller expects lock to be held */
+ spin_lock(&mm->page_table_lock);
return 0;
}
goto retry;
goto out;
}
+ ClearPagePrivate(page);
spin_lock(&inode->i_lock);
inode->i_blocks += blocks_per_huge_page(h);
if (!huge_pte_none(huge_ptep_get(ptep)))
goto backout;
- if (anon_rmap)
+ if (anon_rmap) {
+ ClearPagePrivate(page);
hugepage_add_new_anon_rmap(page, vma, address);
+ }
else
page_dup_rmap(page);
new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE)
return ret;
}
-/* Can be overriden by architectures */
-__attribute__((weak)) struct page *
-follow_huge_pud(struct mm_struct *mm, unsigned long address,
- pud_t *pud, int write)
-{
- BUG();
- return NULL;
-}
-
long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma,
struct page **pages, struct vm_area_struct **vmas,
unsigned long *position, unsigned long *nr_pages,
hugetlb_acct_memory(h, -(chg - freed));
}
+#ifdef CONFIG_ARCH_WANT_HUGE_PMD_SHARE
+static unsigned long page_table_shareable(struct vm_area_struct *svma,
+ struct vm_area_struct *vma,
+ unsigned long addr, pgoff_t idx)
+{
+ unsigned long saddr = ((idx - svma->vm_pgoff) << PAGE_SHIFT) +
+ svma->vm_start;
+ unsigned long sbase = saddr & PUD_MASK;
+ unsigned long s_end = sbase + PUD_SIZE;
+
+ /* Allow segments to share if only one is marked locked */
+ unsigned long vm_flags = vma->vm_flags & ~VM_LOCKED;
+ unsigned long svm_flags = svma->vm_flags & ~VM_LOCKED;
+
+ /*
+ * match the virtual addresses, permission and the alignment of the
+ * page table page.
+ */
+ if (pmd_index(addr) != pmd_index(saddr) ||
+ vm_flags != svm_flags ||
+ sbase < svma->vm_start || svma->vm_end < s_end)
+ return 0;
+
+ return saddr;
+}
+
+static int vma_shareable(struct vm_area_struct *vma, unsigned long addr)
+{
+ unsigned long base = addr & PUD_MASK;
+ unsigned long end = base + PUD_SIZE;
+
+ /*
+ * check on proper vm_flags and page table alignment
+ */
+ if (vma->vm_flags & VM_MAYSHARE &&
+ vma->vm_start <= base && end <= vma->vm_end)
+ return 1;
+ return 0;
+}
+
+/*
+ * Search for a shareable pmd page for hugetlb. In any case calls pmd_alloc()
+ * and returns the corresponding pte. While this is not necessary for the
+ * !shared pmd case because we can allocate the pmd later as well, it makes the
+ * code much cleaner. pmd allocation is essential for the shared case because
+ * pud has to be populated inside the same i_mmap_mutex section - otherwise
+ * racing tasks could either miss the sharing (see huge_pte_offset) or select a
+ * bad pmd for sharing.
+ */
+pte_t *huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud)
+{
+ struct vm_area_struct *vma = find_vma(mm, addr);
+ struct address_space *mapping = vma->vm_file->f_mapping;
+ pgoff_t idx = ((addr - vma->vm_start) >> PAGE_SHIFT) +
+ vma->vm_pgoff;
+ struct vm_area_struct *svma;
+ unsigned long saddr;
+ pte_t *spte = NULL;
+ pte_t *pte;
+
+ if (!vma_shareable(vma, addr))
+ return (pte_t *)pmd_alloc(mm, pud, addr);
+
+ mutex_lock(&mapping->i_mmap_mutex);
+ vma_interval_tree_foreach(svma, &mapping->i_mmap, idx, idx) {
+ if (svma == vma)
+ continue;
+
+ saddr = page_table_shareable(svma, vma, addr, idx);
+ if (saddr) {
+ spte = huge_pte_offset(svma->vm_mm, saddr);
+ if (spte) {
+ get_page(virt_to_page(spte));
+ break;
+ }
+ }
+ }
+
+ if (!spte)
+ goto out;
+
+ spin_lock(&mm->page_table_lock);
+ if (pud_none(*pud))
+ pud_populate(mm, pud,
+ (pmd_t *)((unsigned long)spte & PAGE_MASK));
+ else
+ put_page(virt_to_page(spte));
+ spin_unlock(&mm->page_table_lock);
+out:
+ pte = (pte_t *)pmd_alloc(mm, pud, addr);
+ mutex_unlock(&mapping->i_mmap_mutex);
+ return pte;
+}
+
+/*
+ * unmap huge page backed by shared pte.
+ *
+ * Hugetlb pte page is ref counted at the time of mapping. If pte is shared
+ * indicated by page_count > 1, unmap is achieved by clearing pud and
+ * decrementing the ref count. If count == 1, the pte page is not shared.
+ *
+ * called with vma->vm_mm->page_table_lock held.
+ *
+ * returns: 1 successfully unmapped a shared pte page
+ * 0 the underlying pte page is not shared, or it is the last user
+ */
+int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep)
+{
+ pgd_t *pgd = pgd_offset(mm, *addr);
+ pud_t *pud = pud_offset(pgd, *addr);
+
+ BUG_ON(page_count(virt_to_page(ptep)) == 0);
+ if (page_count(virt_to_page(ptep)) == 1)
+ return 0;
+
+ pud_clear(pud);
+ put_page(virt_to_page(ptep));
+ *addr = ALIGN(*addr, HPAGE_SIZE * PTRS_PER_PTE) - HPAGE_SIZE;
+ return 1;
+}
+#define want_pmd_share() (1)
+#else /* !CONFIG_ARCH_WANT_HUGE_PMD_SHARE */
+pte_t *huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud)
+{
+ return NULL;
+}
+#define want_pmd_share() (0)
+#endif /* CONFIG_ARCH_WANT_HUGE_PMD_SHARE */
+
+#ifdef CONFIG_ARCH_WANT_GENERAL_HUGETLB
+pte_t *huge_pte_alloc(struct mm_struct *mm,
+ unsigned long addr, unsigned long sz)
+{
+ pgd_t *pgd;
+ pud_t *pud;
+ pte_t *pte = NULL;
+
+ pgd = pgd_offset(mm, addr);
+ pud = pud_alloc(mm, pgd, addr);
+ if (pud) {
+ if (sz == PUD_SIZE) {
+ pte = (pte_t *)pud;
+ } else {
+ BUG_ON(sz != PMD_SIZE);
+ if (want_pmd_share() && pud_none(*pud))
+ pte = huge_pmd_share(mm, addr, pud);
+ else
+ pte = (pte_t *)pmd_alloc(mm, pud, addr);
+ }
+ }
+ BUG_ON(pte && !pte_none(*pte) && !pte_huge(*pte));
+
+ return pte;
+}
+
+pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
+{
+ pgd_t *pgd;
+ pud_t *pud;
+ pmd_t *pmd = NULL;
+
+ pgd = pgd_offset(mm, addr);
+ if (pgd_present(*pgd)) {
+ pud = pud_offset(pgd, addr);
+ if (pud_present(*pud)) {
+ if (pud_huge(*pud))
+ return (pte_t *)pud;
+ pmd = pmd_offset(pud, addr);
+ }
+ }
+ return (pte_t *) pmd;
+}
+
+struct page *
+follow_huge_pmd(struct mm_struct *mm, unsigned long address,
+ pmd_t *pmd, int write)
+{
+ struct page *page;
+
+ page = pte_page(*(pte_t *)pmd);
+ if (page)
+ page += ((address & ~PMD_MASK) >> PAGE_SHIFT);
+ return page;
+}
+
+struct page *
+follow_huge_pud(struct mm_struct *mm, unsigned long address,
+ pud_t *pud, int write)
+{
+ struct page *page;
+
+ page = pte_page(*(pte_t *)pud);
+ if (page)
+ page += ((address & ~PUD_MASK) >> PAGE_SHIFT);
+ return page;
+}
+
+#else /* !CONFIG_ARCH_WANT_GENERAL_HUGETLB */
+
+/* Can be overriden by architectures */
+__attribute__((weak)) struct page *
+follow_huge_pud(struct mm_struct *mm, unsigned long address,
+ pud_t *pud, int write)
+{
+ BUG();
+ return NULL;
+}
+
+#endif /* CONFIG_ARCH_WANT_GENERAL_HUGETLB */
+
#ifdef CONFIG_MEMORY_FAILURE
/* Should be called in hugetlb_lock */
projects / firefly-linux-kernel-4.4.55.git / commitdiff