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-rw-r--r--arch/powerpc/mm/gup.c235
1 files changed, 0 insertions, 235 deletions
diff --git a/arch/powerpc/mm/gup.c b/arch/powerpc/mm/gup.c
deleted file mode 100644
index d8746684f606..000000000000
--- a/arch/powerpc/mm/gup.c
+++ /dev/null
@@ -1,235 +0,0 @@
-/*
- * Lockless get_user_pages_fast for powerpc
- *
- * Copyright (C) 2008 Nick Piggin
- * Copyright (C) 2008 Novell Inc.
- */
-#undef DEBUG
-
-#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>
-
-#ifdef __HAVE_ARCH_PTE_SPECIAL
-
-/*
- * The performance critical leaf functions are made noinline otherwise gcc
- * inlines everything into a single function which results in too much
- * register pressure.
- */
-static noinline int gup_pte_range(pmd_t pmd, unsigned long addr,
- unsigned long end, int write, struct page **pages, int *nr)
-{
- unsigned long mask, result;
- pte_t *ptep;
-
- result = _PAGE_PRESENT|_PAGE_USER;
- if (write)
- result |= _PAGE_RW;
- mask = result | _PAGE_SPECIAL;
-
- ptep = pte_offset_kernel(&pmd, addr);
- do {
- pte_t pte = ACCESS_ONCE(*ptep);
- struct page *page;
- /*
- * Similar to the PMD case, NUMA hinting must take slow path
- */
- if (pte_numa(pte))
- return 0;
-
- if ((pte_val(pte) & mask) != result)
- 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 int gup_pmd_range(pud_t pud, unsigned long addr, unsigned long end,
- int write, struct page **pages, int *nr)
-{
- unsigned long next;
- pmd_t *pmdp;
-
- pmdp = pmd_offset(&pud, addr);
- do {
- pmd_t pmd = ACCESS_ONCE(*pmdp);
-
- next = pmd_addr_end(addr, end);
- /*
- * If we find a splitting transparent hugepage we
- * return zero. That will result in taking the slow
- * path which will call wait_split_huge_page()
- * if the pmd is still in splitting state
- */
- if (pmd_none(pmd) || pmd_trans_splitting(pmd))
- return 0;
- if (pmd_huge(pmd) || pmd_large(pmd)) {
- /*
- * NUMA hinting faults need to be handled in the GUP
- * slowpath for accounting purposes and so that they
- * can be serialised against THP migration.
- */
- if (pmd_numa(pmd))
- return 0;
-
- if (!gup_hugepte((pte_t *)pmdp, PMD_SIZE, addr, next,
- write, pages, nr))
- return 0;
- } else if (is_hugepd(pmdp)) {
- if (!gup_hugepd((hugepd_t *)pmdp, PMD_SHIFT,
- addr, next, write, pages, nr))
- return 0;
- } else if (!gup_pte_range(pmd, addr, next, write, pages, nr))
- return 0;
- } while (pmdp++, addr = next, addr != end);
-
- return 1;
-}
-
-static int gup_pud_range(pgd_t pgd, unsigned long addr, unsigned long end,
- int write, struct page **pages, int *nr)
-{
- unsigned long next;
- pud_t *pudp;
-
- pudp = pud_offset(&pgd, addr);
- do {
- pud_t pud = ACCESS_ONCE(*pudp);
-
- next = pud_addr_end(addr, end);
- if (pud_none(pud))
- return 0;
- if (pud_huge(pud)) {
- if (!gup_hugepte((pte_t *)pudp, PUD_SIZE, addr, next,
- write, pages, nr))
- return 0;
- } else if (is_hugepd(pudp)) {
- if (!gup_hugepd((hugepd_t *)pudp, PUD_SHIFT,
- addr, next, write, pages, nr))
- return 0;
- } else if (!gup_pmd_range(pud, addr, next, write, pages, nr))
- return 0;
- } while (pudp++, addr = next, addr != end);
-
- return 1;
-}
-
-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;
- unsigned long flags;
- pgd_t *pgdp;
- int nr = 0;
-
- pr_devel("%s(%lx,%x,%s)\n", __func__, start, nr_pages, write ? "write" : "read");
-
- start &= PAGE_MASK;
- addr = start;
- len = (unsigned long) nr_pages << PAGE_SHIFT;
- end = start + len;
-
- if (unlikely(!access_ok(write ? VERIFY_WRITE : VERIFY_READ,
- start, len)))
- return 0;
-
- pr_devel(" aligned: %lx .. %lx\n", start, end);
-
- /*
- * XXX: batch / limit 'nr', to avoid large irq off latency
- * needs some instrumenting to determine the common sizes used by
- * important workloads (eg. DB2), and whether limiting the batch size
- * will decrease performance.
- *
- * It seems like we're in the clear for the moment. Direct-IO is
- * the main guy that batches up lots of get_user_pages, and even
- * they are limited to 64-at-a-time which is not so many.
- */
- /*
- * This doesn't prevent pagetable teardown, but does prevent
- * the pagetables from being freed on powerpc.
- *
- * 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_save(flags);
-
- pgdp = pgd_offset(mm, addr);
- do {
- pgd_t pgd = ACCESS_ONCE(*pgdp);
-
- pr_devel(" %016lx: normal pgd %p\n", addr,
- (void *)pgd_val(pgd));
- next = pgd_addr_end(addr, end);
- if (pgd_none(pgd))
- break;
- if (pgd_huge(pgd)) {
- if (!gup_hugepte((pte_t *)pgdp, PGDIR_SIZE, addr, next,
- write, pages, &nr))
- break;
- } else if (is_hugepd(pgdp)) {
- if (!gup_hugepd((hugepd_t *)pgdp, PGDIR_SHIFT,
- addr, next, write, pages, &nr))
- break;
- } else if (!gup_pud_range(pgd, addr, next, write, pages, &nr))
- break;
- } while (pgdp++, addr = next, addr != end);
-
- local_irq_restore(flags);
-
- return nr;
-}
-
-int get_user_pages_fast(unsigned long start, int nr_pages, int write,
- struct page **pages)
-{
- struct mm_struct *mm = current->mm;
- int nr, ret;
-
- start &= PAGE_MASK;
- nr = __get_user_pages_fast(start, nr_pages, write, pages);
- ret = nr;
-
- if (nr < nr_pages) {
- pr_devel(" slow path ! nr = %d\n", nr);
-
- /* 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,
- nr_pages - nr, 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;
-}
-
-#endif /* __HAVE_ARCH_PTE_SPECIAL */
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