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-rw-r--r--arch/s390/mm/gup.c300
1 files changed, 0 insertions, 300 deletions
diff --git a/arch/s390/mm/gup.c b/arch/s390/mm/gup.c
deleted file mode 100644
index 2809d11c7a28..000000000000
--- a/arch/s390/mm/gup.c
+++ /dev/null
@@ -1,300 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * 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)
-{
- struct page *head, *page;
- unsigned long mask;
- pte_t *ptep, pte;
-
- mask = (write ? _PAGE_PROTECT : 0) | _PAGE_INVALID | _PAGE_SPECIAL;
-
- ptep = ((pte_t *) pmd_deref(pmd)) + pte_index(addr);
- do {
- pte = *ptep;
- barrier();
- /* Similar to the PMD case, NUMA hinting must take slow path */
- if (pte_protnone(pte))
- return 0;
- if ((pte_val(pte) & mask) != 0)
- return 0;
- VM_BUG_ON(!pfn_valid(pte_pfn(pte)));
- page = pte_page(pte);
- head = compound_head(page);
- if (!page_cache_get_speculative(head))
- return 0;
- if (unlikely(pte_val(pte) != pte_val(*ptep))) {
- put_page(head);
- return 0;
- }
- VM_BUG_ON_PAGE(compound_head(page) != head, page);
- 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)
-{
- struct page *head, *page;
- unsigned long mask;
- int refs;
-
- mask = (write ? _SEGMENT_ENTRY_PROTECT : 0) | _SEGMENT_ENTRY_INVALID;
- if ((pmd_val(pmd) & mask) != 0)
- 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);
- 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;
- }
-
- 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;
- if ((pud_val(pud) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3)
- pmdp = (pmd_t *) pud_deref(pud);
- pmdp += pmd_index(addr);
- do {
- pmd = *pmdp;
- barrier();
- next = pmd_addr_end(addr, end);
- if (pmd_none(pmd))
- return 0;
- if (unlikely(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_protnone(pmd))
- return 0;
- 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 int gup_huge_pud(pud_t *pudp, pud_t pud, unsigned long addr,
- unsigned long end, int write, struct page **pages, int *nr)
-{
- struct page *head, *page;
- unsigned long mask;
- int refs;
-
- mask = (write ? _REGION_ENTRY_PROTECT : 0) | _REGION_ENTRY_INVALID;
- if ((pud_val(pud) & mask) != 0)
- return 0;
- VM_BUG_ON(!pfn_valid(pud_pfn(pud)));
-
- refs = 0;
- head = pud_page(pud);
- page = head + ((addr & ~PUD_MASK) >> PAGE_SHIFT);
- do {
- VM_BUG_ON_PAGE(compound_head(page) != head, page);
- 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(pud_val(pud) != pud_val(*pudp))) {
- *nr -= refs;
- while (refs--)
- put_page(head);
- return 0;
- }
-
- return 1;
-}
-
-static inline int gup_pud_range(p4d_t *p4dp, p4d_t p4d, unsigned long addr,
- unsigned long end, int write, struct page **pages, int *nr)
-{
- unsigned long next;
- pud_t *pudp, pud;
-
- pudp = (pud_t *) p4dp;
- if ((p4d_val(p4d) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R2)
- pudp = (pud_t *) p4d_deref(p4d);
- pudp += pud_index(addr);
- do {
- pud = *pudp;
- barrier();
- next = pud_addr_end(addr, end);
- if (pud_none(pud))
- return 0;
- if (unlikely(pud_large(pud))) {
- if (!gup_huge_pud(pudp, pud, addr, next, write, pages,
- nr))
- return 0;
- } else if (!gup_pmd_range(pudp, pud, addr, next, write, pages,
- nr))
- return 0;
- } while (pudp++, addr = next, addr != end);
-
- return 1;
-}
-
-static inline int gup_p4d_range(pgd_t *pgdp, pgd_t pgd, unsigned long addr,
- unsigned long end, int write, struct page **pages, int *nr)
-{
- unsigned long next;
- p4d_t *p4dp, p4d;
-
- p4dp = (p4d_t *) pgdp;
- if ((pgd_val(pgd) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R1)
- p4dp = (p4d_t *) pgd_deref(pgd);
- p4dp += p4d_index(addr);
- do {
- p4d = *p4dp;
- barrier();
- next = p4d_addr_end(addr, end);
- if (p4d_none(p4d))
- return 0;
- if (!gup_pud_range(p4dp, p4d, addr, next, write, pages, nr))
- return 0;
- } while (p4dp++, addr = next, addr != end);
-
- return 1;
-}
-
-/*
- * Like get_user_pages_fast() except its IRQ-safe in that it won't fall
- * back to the regular GUP.
- * Note a difference with get_user_pages_fast: this always returns the
- * number of pages pinned, 0 if no pages were pinned.
- */
-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, flags;
- 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) || (end > mm->context.asce_limit))
- return 0;
- /*
- * local_irq_save() 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_save(flags);
- pgdp = pgd_offset(mm, addr);
- do {
- pgd = *pgdp;
- barrier();
- next = pgd_addr_end(addr, end);
- if (pgd_none(pgd))
- break;
- if (!gup_p4d_range(pgdp, pgd, addr, next, write, pages, &nr))
- break;
- } while (pgdp++, addr = next, addr != end);
- local_irq_restore(flags);
-
- return nr;
-}
-
-/**
- * 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)
-{
- int nr, ret;
-
- might_sleep();
- start &= PAGE_MASK;
- nr = __get_user_pages_fast(start, nr_pages, write, pages);
- if (nr == nr_pages)
- return nr;
-
- /* Try to get the remaining pages with get_user_pages */
- start += nr << PAGE_SHIFT;
- pages += nr;
- ret = get_user_pages_unlocked(start, nr_pages - nr, pages,
- write ? FOLL_WRITE : 0);
- /* Have to be a bit careful with return values */
- if (nr > 0)
- ret = (ret < 0) ? nr : ret + nr;
- return ret;
-}