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authorLinus Torvalds <torvalds@linux-foundation.org>2013-11-12 14:34:19 +0900
committerLinus Torvalds <torvalds@linux-foundation.org>2013-11-12 14:34:19 +0900
commit66a173b926891023e34e78cb32f4681d19777e01 (patch)
treee6018f50fbceea7c07e6e27368ee817f9adb34f2 /include/linux/mm.h
parent11db81a59d0b2e563e30512cd76f23d0db384780 (diff)
parent0c4888ef1d8a8b82c29075ce7e257ff795af15c7 (diff)
Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc
Pull powerpc updates from Benjamin Herrenschmidt: "The bulk of this is LE updates. One should now be able to build an LE kernel and even run some things in it. I'm still sitting on a handful of patches to enable the new ABI that I *might* still send this merge window around, but due to the incertainty (they are pretty fresh) I want to keep them separate. Other notable changes are some infrastructure bits to better handle PCI pass-through under KVM, some bits and pieces added to the new PowerNV platform support such as access to the CPU SCOM bus via sysfs, and support for EEH error handling on PHB3 (Power8 PCIe). We also grew arch_get_random_long() for both pseries and powernv when running on P7+ and P8, exploiting the HW rng. And finally various embedded updates from freescale" * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (154 commits) powerpc: Fix fatal SLB miss when restoring PPR powerpc/powernv: Reserve the correct PE number powerpc/powernv: Add PE to its own PELTV powerpc/powernv: Add support for indirect XSCOM via debugfs powerpc/scom: Improve debugfs interface powerpc/scom: Enable 64-bit addresses powerpc/boot: Properly handle the base "of" boot wrapper powerpc/bpf: Support MOD operation powerpc/bpf: Fix DIVWU instruction opcode of: Move definition of of_find_next_cache_node into common code. powerpc: Remove big endianness assumption in of_find_next_cache_node powerpc/tm: Remove interrupt disable in __switch_to() powerpc: word-at-a-time optimization for 64-bit Little Endian powerpc/bpf: BPF JIT compiler for 64-bit Little Endian powerpc: Only save/restore SDR1 if in hypervisor mode powerpc/pmu: Fix ADB_PMU_LED_IDE dependencies powerpc/nvram: Fix endian issue when using the partition length powerpc/nvram: Fix endian issue when reading the NVRAM size powerpc/nvram: Scan partitions only once powerpc/mpc512x: remove unnecessary #if ...
Diffstat (limited to 'include/linux/mm.h')
-rw-r--r--include/linux/mm.h14
1 files changed, 14 insertions, 0 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 81443d557a2e..8aa4006b9636 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -297,12 +297,26 @@ static inline int put_page_testzero(struct page *page)
/*
* Try to grab a ref unless the page has a refcount of zero, return false if
* that is the case.
+ * This can be called when MMU is off so it must not access
+ * any of the virtual mappings.
*/
static inline int get_page_unless_zero(struct page *page)
{
return atomic_inc_not_zero(&page->_count);
}
+/*
+ * Try to drop a ref unless the page has a refcount of one, return false if
+ * that is the case.
+ * This is to make sure that the refcount won't become zero after this drop.
+ * This can be called when MMU is off so it must not access
+ * any of the virtual mappings.
+ */
+static inline int put_page_unless_one(struct page *page)
+{
+ return atomic_add_unless(&page->_count, -1, 1);
+}
+
extern int page_is_ram(unsigned long pfn);
/* Support for virtually mapped pages */