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Diffstat (limited to 'ANDROID_3.4.5/arch/s390/mm/gup.c')
-rw-r--r--ANDROID_3.4.5/arch/s390/mm/gup.c236
1 files changed, 0 insertions, 236 deletions
diff --git a/ANDROID_3.4.5/arch/s390/mm/gup.c b/ANDROID_3.4.5/arch/s390/mm/gup.c
deleted file mode 100644
index 65cb06e2..00000000
--- a/ANDROID_3.4.5/arch/s390/mm/gup.c
+++ /dev/null
@@ -1,236 +0,0 @@
-/*
- * Lockless get_user_pages_fast for s390
- *
- * Copyright IBM Corp. 2010
- * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
- */
-#include <linux/sched.h>
-#include <linux/mm.h>
-#include <linux/hugetlb.h>
-#include <linux/vmstat.h>
-#include <linux/pagemap.h>
-#include <linux/rwsem.h>
-#include <asm/pgtable.h>
-
-/*
- * The performance critical leaf functions are made noinline otherwise gcc
- * inlines everything into a single function which results in too much
- * register pressure.
- */
-static inline int gup_pte_range(pmd_t *pmdp, pmd_t pmd, unsigned long addr,
- unsigned long end, int write, struct page **pages, int *nr)
-{
- unsigned long mask;
- pte_t *ptep, pte;
- struct page *page;
-
- mask = (write ? _PAGE_RO : 0) | _PAGE_INVALID | _PAGE_SPECIAL;
-
- ptep = ((pte_t *) pmd_deref(pmd)) + pte_index(addr);
- do {
- pte = *ptep;
- barrier();
- if ((pte_val(pte) & mask) != 0)
- return 0;
- VM_BUG_ON(!pfn_valid(pte_pfn(pte)));
- page = pte_page(pte);
- if (!page_cache_get_speculative(page))
- return 0;
- if (unlikely(pte_val(pte) != pte_val(*ptep))) {
- put_page(page);
- return 0;
- }
- pages[*nr] = page;
- (*nr)++;
-
- } while (ptep++, addr += PAGE_SIZE, addr != end);
-
- return 1;
-}
-
-static inline int gup_huge_pmd(pmd_t *pmdp, pmd_t pmd, unsigned long addr,
- unsigned long end, int write, struct page **pages, int *nr)
-{
- unsigned long mask, result;
- struct page *head, *page, *tail;
- int refs;
-
- result = write ? 0 : _SEGMENT_ENTRY_RO;
- mask = result | _SEGMENT_ENTRY_INV;
- if ((pmd_val(pmd) & mask) != result)
- return 0;
- VM_BUG_ON(!pfn_valid(pmd_val(pmd) >> PAGE_SHIFT));
-
- refs = 0;
- head = pmd_page(pmd);
- page = head + ((addr & ~PMD_MASK) >> PAGE_SHIFT);
- tail = page;
- do {
- VM_BUG_ON(compound_head(page) != head);
- pages[*nr] = page;
- (*nr)++;
- page++;
- refs++;
- } while (addr += PAGE_SIZE, addr != end);
-
- if (!page_cache_add_speculative(head, refs)) {
- *nr -= refs;
- return 0;
- }
-
- if (unlikely(pmd_val(pmd) != pmd_val(*pmdp))) {
- *nr -= refs;
- while (refs--)
- put_page(head);
- return 0;
- }
-
- /*
- * Any tail page need their mapcount reference taken before we
- * return.
- */
- while (refs--) {
- if (PageTail(tail))
- get_huge_page_tail(tail);
- tail++;
- }
-
- return 1;
-}
-
-
-static inline int gup_pmd_range(pud_t *pudp, pud_t pud, unsigned long addr,
- unsigned long end, int write, struct page **pages, int *nr)
-{
- unsigned long next;
- pmd_t *pmdp, pmd;
-
- pmdp = (pmd_t *) pudp;
-#ifdef CONFIG_64BIT
- if ((pud_val(pud) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3)
- pmdp = (pmd_t *) pud_deref(pud);
- pmdp += pmd_index(addr);
-#endif
- do {
- pmd = *pmdp;
- barrier();
- next = pmd_addr_end(addr, end);
- if (pmd_none(pmd))
- return 0;
- if (unlikely(pmd_huge(pmd))) {
- if (!gup_huge_pmd(pmdp, pmd, addr, next,
- write, pages, nr))
- return 0;
- } else if (!gup_pte_range(pmdp, pmd, addr, next,
- write, pages, nr))
- return 0;
- } while (pmdp++, addr = next, addr != end);
-
- return 1;
-}
-
-static inline int gup_pud_range(pgd_t *pgdp, pgd_t pgd, unsigned long addr,
- unsigned long end, int write, struct page **pages, int *nr)
-{
- unsigned long next;
- pud_t *pudp, pud;
-
- pudp = (pud_t *) pgdp;
-#ifdef CONFIG_64BIT
- if ((pgd_val(pgd) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R2)
- pudp = (pud_t *) pgd_deref(pgd);
- pudp += pud_index(addr);
-#endif
- do {
- pud = *pudp;
- barrier();
- next = pud_addr_end(addr, end);
- if (pud_none(pud))
- return 0;
- if (!gup_pmd_range(pudp, pud, addr, next, write, pages, nr))
- return 0;
- } while (pudp++, addr = next, addr != end);
-
- return 1;
-}
-
-/**
- * get_user_pages_fast() - pin user pages in memory
- * @start: starting user address
- * @nr_pages: number of pages from start to pin
- * @write: whether pages will be written to
- * @pages: array that receives pointers to the pages pinned.
- * Should be at least nr_pages long.
- *
- * Attempt to pin user pages in memory without taking mm->mmap_sem.
- * If not successful, it will fall back to taking the lock and
- * calling get_user_pages().
- *
- * Returns number of pages pinned. This may be fewer than the number
- * requested. If nr_pages is 0 or negative, returns 0. If no pages
- * were pinned, returns -errno.
- */
-int get_user_pages_fast(unsigned long start, int nr_pages, int write,
- struct page **pages)
-{
- struct mm_struct *mm = current->mm;
- unsigned long addr, len, end;
- unsigned long next;
- pgd_t *pgdp, pgd;
- int nr = 0;
-
- start &= PAGE_MASK;
- addr = start;
- len = (unsigned long) nr_pages << PAGE_SHIFT;
- end = start + len;
- if (end < start)
- goto slow_irqon;
-
- /*
- * local_irq_disable() doesn't prevent pagetable teardown, but does
- * prevent the pagetables from being freed on s390.
- *
- * So long as we atomically load page table pointers versus teardown,
- * we can follow the address down to the the page and take a ref on it.
- */
- local_irq_disable();
- pgdp = pgd_offset(mm, addr);
- do {
- pgd = *pgdp;
- barrier();
- next = pgd_addr_end(addr, end);
- if (pgd_none(pgd))
- goto slow;
- if (!gup_pud_range(pgdp, pgd, addr, next, write, pages, &nr))
- goto slow;
- } while (pgdp++, addr = next, addr != end);
- local_irq_enable();
-
- VM_BUG_ON(nr != (end - start) >> PAGE_SHIFT);
- return nr;
-
- {
- int ret;
-slow:
- local_irq_enable();
-slow_irqon:
- /* Try to get the remaining pages with get_user_pages */
- start += nr << PAGE_SHIFT;
- pages += nr;
-
- down_read(&mm->mmap_sem);
- ret = get_user_pages(current, mm, start,
- (end - start) >> PAGE_SHIFT, write, 0, pages, NULL);
- up_read(&mm->mmap_sem);
-
- /* Have to be a bit careful with return values */
- if (nr > 0) {
- if (ret < 0)
- ret = nr;
- else
- ret += nr;
- }
-
- return ret;
- }
-}