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authorArnd Bergmann <arnd@arndb.de>2012-10-04 20:57:00 (GMT)
committerArnd Bergmann <arnd@arndb.de>2012-10-04 20:57:51 (GMT)
commitc37d6154c0b9163c27e53cc1d0be3867b4abd760 (patch)
tree7a24522c56d1cb284dff1d3c225bbdaba0901bb5 /arch/s390/mm/gup.c
parente7a570ff7dff9af6e54ff5e580a61ec7652137a0 (diff)
parent8a1ab3155c2ac7fbe5f2038d6e26efeb607a1498 (diff)
downloadlinux-fsl-qoriq-c37d6154c0b9163c27e53cc1d0be3867b4abd760.tar.xz
Merge branch 'disintegrate-asm-generic' of git://git.infradead.org/users/dhowells/linux-headers into asm-generic
Patches from David Howells <dhowells@redhat.com>: This is to complete part of the UAPI disintegration for which the preparatory patches were pulled recently. Note that there are some fixup patches which are at the base of the branch aimed at you, plus all arches get the asm-generic branch merged in too. * 'disintegrate-asm-generic' of git://git.infradead.org/users/dhowells/linux-headers: UAPI: (Scripted) Disintegrate include/asm-generic UAPI: Fix conditional header installation handling (notably kvm_para.h on m68k) c6x: remove c6x signal.h UAPI: Split compound conditionals containing __KERNEL__ in Arm64 UAPI: Fix the guards on various asm/unistd.h files Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'arch/s390/mm/gup.c')
-rw-r--r--arch/s390/mm/gup.c37
1 files changed, 37 insertions, 0 deletions
diff --git a/arch/s390/mm/gup.c b/arch/s390/mm/gup.c
index 65cb06e..eeaf802 100644
--- a/arch/s390/mm/gup.c
+++ b/arch/s390/mm/gup.c
@@ -154,6 +154,43 @@ static inline int gup_pud_range(pgd_t *pgdp, pgd_t pgd, unsigned long addr,
return 1;
}
+/*
+ * Like get_user_pages_fast() except its IRQ-safe in that it won't fall
+ * back to the regular GUP.
+ */
+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 (unlikely(!access_ok(write ? VERIFY_WRITE : VERIFY_READ,
+ (void __user *)start, len)))
+ return 0;
+
+ 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_pud_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