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
  ...

4 files changed, 34 insertions, 1 deletions

diff --git a/include/linux/hashtable.h b/include/linux/hashtable.h
index a9df51f5d54c..519b6e2d769e 100644
--- a/include/linux/hashtable.h
+++ b/include/linux/hashtable.h
@@ -174,6 +174,21 @@ static inline void hash_del_rcu(struct hlist_node *node)
 		member)
 
 /**
+ * hash_for_each_possible_rcu_notrace - iterate over all possible objects hashing
+ * to the same bucket in an rcu enabled hashtable in a rcu enabled hashtable
+ * @name: hashtable to iterate
+ * @obj: the type * to use as a loop cursor for each entry
+ * @member: the name of the hlist_node within the struct
+ * @key: the key of the objects to iterate over
+ *
+ * This is the same as hash_for_each_possible_rcu() except that it does
+ * not do any RCU debugging or tracing.
+ */
+#define hash_for_each_possible_rcu_notrace(name, obj, member, key) \
+	hlist_for_each_entry_rcu_notrace(obj, \
+		&name[hash_min(key, HASH_BITS(name))], member)
+
+/**
  * hash_for_each_possible_safe - iterate over all possible objects hashing to the
  * same bucket safe against removals
  * @name: hashtable to iterate
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 */
diff --git a/include/linux/of.h b/include/linux/of.h
index f95aee391e30..c08c07e249b3 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -226,6 +226,8 @@ static inline int of_get_child_count(const struct device_node *np)
 	return num;
 }
 
+/* cache lookup */
+extern struct device_node *of_find_next_cache_node(const struct device_node *);
 extern struct device_node *of_find_node_with_property(
 	struct device_node *from, const char *prop_name);
 #define for_each_node_with_property(dn, prop_name) \
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index 6d53675c2b54..98ada58f9942 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -329,7 +329,9 @@ static inline void set_page_writeback(struct page *page)
  * System with lots of page flags available. This allows separate
  * flags for PageHead() and PageTail() checks of compound pages so that bit
  * tests can be used in performance sensitive paths. PageCompound is
- * generally not used in hot code paths.
+ * generally not used in hot code paths except arch/powerpc/mm/init_64.c
+ * and arch/powerpc/kvm/book3s_64_vio_hv.c which use it to detect huge pages
+ * and avoid handling those in real mode.
  */
 __PAGEFLAG(Head, head) CLEARPAGEFLAG(Head, head)
 __PAGEFLAG(Tail, tail)