6 files changed, 102 insertions, 54 deletions

diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index a1e31f274fcd..c13a0c09faea 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -140,6 +140,7 @@ enum {
 };
 
 struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *);
+void blk_mq_finish_init(struct request_queue *q);
 int blk_mq_register_disk(struct gendisk *);
 void blk_mq_unregister_disk(struct gendisk *);
 
diff --git a/include/linux/flex_proportions.h b/include/linux/flex_proportions.h
index 4ebc49fae391..0d348e011a6e 100644
--- a/include/linux/flex_proportions.h
+++ b/include/linux/flex_proportions.h
@@ -10,6 +10,7 @@
 #include <linux/percpu_counter.h>
 #include <linux/spinlock.h>
 #include <linux/seqlock.h>
+#include <linux/gfp.h>
 
 /*
  * When maximum proportion of some event type is specified, this is the
@@ -32,7 +33,7 @@ struct fprop_global {
         seqcount_t sequence;
 };
 
-int fprop_global_init(struct fprop_global *p);
+int fprop_global_init(struct fprop_global *p, gfp_t gfp);
 void fprop_global_destroy(struct fprop_global *p);
 bool fprop_new_period(struct fprop_global *p, int periods);
 
@@ -79,7 +80,7 @@ struct fprop_local_percpu {
         raw_spinlock_t lock;    /* Protect period and numerator */
 };
 
-int fprop_local_init_percpu(struct fprop_local_percpu *pl);
+int fprop_local_init_percpu(struct fprop_local_percpu *pl, gfp_t gfp);
 void fprop_local_destroy_percpu(struct fprop_local_percpu *pl);
 void __fprop_inc_percpu(struct fprop_global *p, struct fprop_local_percpu *pl);
 void __fprop_inc_percpu_max(struct fprop_global *p, struct fprop_local_percpu *pl,
diff --git a/include/linux/percpu-refcount.h b/include/linux/percpu-refcount.h
index 68a64f11ce02..d5c89e0dd0e6 100644
--- a/include/linux/percpu-refcount.h
+++ b/include/linux/percpu-refcount.h
@@ -13,7 +13,7 @@
  *
  * The refcount will have a range of 0 to ((1U << 31) - 1), i.e. one bit less
  * than an atomic_t - this is because of the way shutdown works, see
- * percpu_ref_kill()/PCPU_COUNT_BIAS.
+ * percpu_ref_kill()/PERCPU_COUNT_BIAS.
  *
  * Before you call percpu_ref_kill(), percpu_ref_put() does not check for the
  * refcount hitting 0 - it can't, if it was in percpu mode. percpu_ref_kill()
@@ -49,29 +49,60 @@
 #include <linux/kernel.h>
 #include <linux/percpu.h>
 #include <linux/rcupdate.h>
+#include <linux/gfp.h>
 
 struct percpu_ref;
 typedef void (percpu_ref_func_t)(struct percpu_ref *);
 
+/* flags set in the lower bits of percpu_ref->percpu_count_ptr */
+enum {
+        __PERCPU_REF_ATOMIC     = 1LU << 0,     /* operating in atomic mode */
+        __PERCPU_REF_DEAD       = 1LU << 1,     /* (being) killed */
+        __PERCPU_REF_ATOMIC_DEAD = __PERCPU_REF_ATOMIC | __PERCPU_REF_DEAD,
+
+        __PERCPU_REF_FLAG_BITS  = 2,
+};
+
+/* @flags for percpu_ref_init() */
+enum {
+        /*
+         * Start w/ ref == 1 in atomic mode.  Can be switched to percpu
+         * operation using percpu_ref_switch_to_percpu().  If initialized
+         * with this flag, the ref will stay in atomic mode until
+         * percpu_ref_switch_to_percpu() is invoked on it.
+         */
+        PERCPU_REF_INIT_ATOMIC  = 1 << 0,
+
+        /*
+         * Start dead w/ ref == 0 in atomic mode.  Must be revived with
+         * percpu_ref_reinit() before used.  Implies INIT_ATOMIC.
+         */
+        PERCPU_REF_INIT_DEAD    = 1 << 1,
+};
+
 struct percpu_ref {
-        atomic_t                count;
+        atomic_long_t           count;
         /*
          * The low bit of the pointer indicates whether the ref is in percpu
          * mode; if set, then get/put will manipulate the atomic_t.
          */
-        unsigned long           pcpu_count_ptr;
+        unsigned long           percpu_count_ptr;
         percpu_ref_func_t       *release;
-        percpu_ref_func_t       *confirm_kill;
+        percpu_ref_func_t       *confirm_switch;
+        bool                    force_atomic:1;
         struct rcu_head         rcu;
 };
 
 int __must_check percpu_ref_init(struct percpu_ref *ref,
-                                 percpu_ref_func_t *release);
-void percpu_ref_reinit(struct percpu_ref *ref);
+                                 percpu_ref_func_t *release, unsigned int flags,
+                                 gfp_t gfp);
 void percpu_ref_exit(struct percpu_ref *ref);
+void percpu_ref_switch_to_atomic(struct percpu_ref *ref,
+                                 percpu_ref_func_t *confirm_switch);
+void percpu_ref_switch_to_percpu(struct percpu_ref *ref);
 void percpu_ref_kill_and_confirm(struct percpu_ref *ref,
                                  percpu_ref_func_t *confirm_kill);
-void __percpu_ref_kill_expedited(struct percpu_ref *ref);
+void percpu_ref_reinit(struct percpu_ref *ref);
 
 /**
  * percpu_ref_kill - drop the initial ref
@@ -88,26 +119,24 @@ static inline void percpu_ref_kill(struct percpu_ref *ref)
         return percpu_ref_kill_and_confirm(ref, NULL);
 }
 
-#define PCPU_REF_DEAD           1
-
 /*
  * Internal helper.  Don't use outside percpu-refcount proper.  The
  * function doesn't return the pointer and let the caller test it for NULL
  * because doing so forces the compiler to generate two conditional
- * branches as it can't assume that @ref->pcpu_count is not NULL.
+ * branches as it can't assume that @ref->percpu_count is not NULL.
  */
-static inline bool __pcpu_ref_alive(struct percpu_ref *ref,
-                                    unsigned __percpu **pcpu_countp)
+static inline bool __ref_is_percpu(struct percpu_ref *ref,
+                                          unsigned long __percpu **percpu_countp)
 {
-        unsigned long pcpu_ptr = ACCESS_ONCE(ref->pcpu_count_ptr);
+        unsigned long percpu_ptr = ACCESS_ONCE(ref->percpu_count_ptr);
 
         /* paired with smp_store_release() in percpu_ref_reinit() */
         smp_read_barrier_depends();
 
-        if (unlikely(pcpu_ptr & PCPU_REF_DEAD))
+        if (unlikely(percpu_ptr & __PERCPU_REF_ATOMIC))
                 return false;
 
-        *pcpu_countp = (unsigned __percpu *)pcpu_ptr;
+        *percpu_countp = (unsigned long __percpu *)percpu_ptr;
         return true;
 }
 
@@ -115,18 +144,20 @@ static inline bool __pcpu_ref_alive(struct percpu_ref *ref,
  * percpu_ref_get - increment a percpu refcount
  * @ref: percpu_ref to get
  *
- * Analagous to atomic_inc().
-  */
+ * Analagous to atomic_long_inc().
+ *
+ * This function is safe to call as long as @ref is between init and exit.
+ */
 static inline void percpu_ref_get(struct percpu_ref *ref)
 {
-        unsigned __percpu *pcpu_count;
+        unsigned long __percpu *percpu_count;
 
         rcu_read_lock_sched();
 
-        if (__pcpu_ref_alive(ref, &pcpu_count))
-                this_cpu_inc(*pcpu_count);
+        if (__ref_is_percpu(ref, &percpu_count))
+                this_cpu_inc(*percpu_count);
         else
-                atomic_inc(&ref->count);
+                atomic_long_inc(&ref->count);
 
         rcu_read_unlock_sched();
 }
@@ -138,20 +169,20 @@ static inline void percpu_ref_get(struct percpu_ref *ref)
  * Increment a percpu refcount unless its count already reached zero.
  * Returns %true on success; %false on failure.
  *
- * The caller is responsible for ensuring that @ref stays accessible.
+ * This function is safe to call as long as @ref is between init and exit.
  */
 static inline bool percpu_ref_tryget(struct percpu_ref *ref)
 {
-        unsigned __percpu *pcpu_count;
-        int ret = false;
+        unsigned long __percpu *percpu_count;
+        int ret;
 
         rcu_read_lock_sched();
 
-        if (__pcpu_ref_alive(ref, &pcpu_count)) {
-                this_cpu_inc(*pcpu_count);
+        if (__ref_is_percpu(ref, &percpu_count)) {
+                this_cpu_inc(*percpu_count);
                 ret = true;
         } else {
-                ret = atomic_inc_not_zero(&ref->count);
+                ret = atomic_long_inc_not_zero(&ref->count);
         }
 
         rcu_read_unlock_sched();
@@ -166,23 +197,26 @@ static inline bool percpu_ref_tryget(struct percpu_ref *ref)
  * Increment a percpu refcount unless it has already been killed.  Returns
  * %true on success; %false on failure.
  *
- * Completion of percpu_ref_kill() in itself doesn't guarantee that tryget
- * will fail.  For such guarantee, percpu_ref_kill_and_confirm() should be
- * used.  After the confirm_kill callback is invoked, it's guaranteed that
- * no new reference will be given out by percpu_ref_tryget().
+ * Completion of percpu_ref_kill() in itself doesn't guarantee that this
+ * function will fail.  For such guarantee, percpu_ref_kill_and_confirm()
+ * should be used.  After the confirm_kill callback is invoked, it's
+ * guaranteed that no new reference will be given out by
+ * percpu_ref_tryget_live().
  *
- * The caller is responsible for ensuring that @ref stays accessible.
+ * This function is safe to call as long as @ref is between init and exit.
  */
 static inline bool percpu_ref_tryget_live(struct percpu_ref *ref)
 {
-        unsigned __percpu *pcpu_count;
+        unsigned long __percpu *percpu_count;
         int ret = false;
 
         rcu_read_lock_sched();
 
-        if (__pcpu_ref_alive(ref, &pcpu_count)) {
-                this_cpu_inc(*pcpu_count);
+        if (__ref_is_percpu(ref, &percpu_count)) {
+                this_cpu_inc(*percpu_count);
                 ret = true;
+        } else if (!(ACCESS_ONCE(ref->percpu_count_ptr) & __PERCPU_REF_DEAD)) {
+                ret = atomic_long_inc_not_zero(&ref->count);
         }
 
         rcu_read_unlock_sched();
@@ -196,16 +230,18 @@ static inline bool percpu_ref_tryget_live(struct percpu_ref *ref)
  *
  * Decrement the refcount, and if 0, call the release function (which was passed
  * to percpu_ref_init())
+ *
+ * This function is safe to call as long as @ref is between init and exit.
  */
 static inline void percpu_ref_put(struct percpu_ref *ref)
 {
-        unsigned __percpu *pcpu_count;
+        unsigned long __percpu *percpu_count;
 
         rcu_read_lock_sched();
 
-        if (__pcpu_ref_alive(ref, &pcpu_count))
-                this_cpu_dec(*pcpu_count);
-        else if (unlikely(atomic_dec_and_test(&ref->count)))
+        if (__ref_is_percpu(ref, &percpu_count))
+                this_cpu_dec(*percpu_count);
+        else if (unlikely(atomic_long_dec_and_test(&ref->count)))
                 ref->release(ref);
 
         rcu_read_unlock_sched();
@@ -216,14 +252,16 @@ static inline void percpu_ref_put(struct percpu_ref *ref)
  * @ref: percpu_ref to test
  *
  * Returns %true if @ref reached zero.
+ *
+ * This function is safe to call as long as @ref is between init and exit.
  */
 static inline bool percpu_ref_is_zero(struct percpu_ref *ref)
 {
-        unsigned __percpu *pcpu_count;
+        unsigned long __percpu *percpu_count;
 
-        if (__pcpu_ref_alive(ref, &pcpu_count))
+        if (__ref_is_percpu(ref, &percpu_count))
                 return false;
-        return !atomic_read(&ref->count);
+        return !atomic_long_read(&ref->count);
 }
 
 #endif
diff --git a/include/linux/percpu.h b/include/linux/percpu.h
index 6f61b61b7996..a3aa63e47637 100644
--- a/include/linux/percpu.h
+++ b/include/linux/percpu.h
@@ -48,9 +48,9 @@
  * intelligent way to determine this would be nice.
  */
 #if BITS_PER_LONG > 32
-#define PERCPU_DYNAMIC_RESERVE          (20 << 10)
+#define PERCPU_DYNAMIC_RESERVE          (28 << 10)
 #else
-#define PERCPU_DYNAMIC_RESERVE          (12 << 10)
+#define PERCPU_DYNAMIC_RESERVE          (20 << 10)
 #endif
 
 extern void *pcpu_base_addr;
@@ -122,11 +122,16 @@ extern void __init setup_per_cpu_areas(void);
 #endif
 extern void __init percpu_init_late(void);
 
+extern void __percpu *__alloc_percpu_gfp(size_t size, size_t align, gfp_t gfp);
 extern void __percpu *__alloc_percpu(size_t size, size_t align);
 extern void free_percpu(void __percpu *__pdata);
 extern phys_addr_t per_cpu_ptr_to_phys(void *addr);
 
-#define alloc_percpu(type)      \
-        (typeof(type) __percpu *)__alloc_percpu(sizeof(type), __alignof__(type))
+#define alloc_percpu_gfp(type, gfp)                                     \
+        (typeof(type) __percpu *)__alloc_percpu_gfp(sizeof(type),       \
+                                                __alignof__(type), gfp)
+#define alloc_percpu(type)                                              \
+        (typeof(type) __percpu *)__alloc_percpu(sizeof(type),           \
+                                                __alignof__(type))
 
 #endif /* __LINUX_PERCPU_H */
diff --git a/include/linux/percpu_counter.h b/include/linux/percpu_counter.h
index d5dd4657c8d6..50e50095c8d1 100644
--- a/include/linux/percpu_counter.h
+++ b/include/linux/percpu_counter.h
@@ -12,6 +12,7 @@
 #include <linux/threads.h>
 #include <linux/percpu.h>
 #include <linux/types.h>
+#include <linux/gfp.h>
 
 #ifdef CONFIG_SMP
 
@@ -26,14 +27,14 @@ struct percpu_counter {
 
 extern int percpu_counter_batch;
 
-int __percpu_counter_init(struct percpu_counter *fbc, s64 amount,
+int __percpu_counter_init(struct percpu_counter *fbc, s64 amount, gfp_t gfp,
                           struct lock_class_key *key);
 
-#define percpu_counter_init(fbc, value)                                 \
+#define percpu_counter_init(fbc, value, gfp)                            \
         ({                                                              \
                 static struct lock_class_key __key;                     \
                                                                         \
-                __percpu_counter_init(fbc, value, &__key);              \
+                __percpu_counter_init(fbc, value, gfp, &__key);         \
         })
 
 void percpu_counter_destroy(struct percpu_counter *fbc);
@@ -89,7 +90,8 @@ struct percpu_counter {
         s64 count;
 };
 
-static inline int percpu_counter_init(struct percpu_counter *fbc, s64 amount)
+static inline int percpu_counter_init(struct percpu_counter *fbc, s64 amount,
+                                      gfp_t gfp)
 {
         fbc->count = amount;
         return 0;
diff --git a/include/linux/proportions.h b/include/linux/proportions.h
index 26a8a4ed9b07..00e8e8fa7358 100644
--- a/include/linux/proportions.h
+++ b/include/linux/proportions.h
@@ -12,6 +12,7 @@
 #include <linux/percpu_counter.h>
 #include <linux/spinlock.h>
 #include <linux/mutex.h>
+#include <linux/gfp.h>
 
 struct prop_global {
         /*
@@ -40,7 +41,7 @@ struct prop_descriptor {
         struct mutex mutex;             /* serialize the prop_global switch */
 };
 
-int prop_descriptor_init(struct prop_descriptor *pd, int shift);
+int prop_descriptor_init(struct prop_descriptor *pd, int shift, gfp_t gfp);
 void prop_change_shift(struct prop_descriptor *pd, int new_shift);
 
 /*
@@ -61,7 +62,7 @@ struct prop_local_percpu {
         raw_spinlock_t lock;            /* protect the snapshot state */
 };
 
-int prop_local_init_percpu(struct prop_local_percpu *pl);
+int prop_local_init_percpu(struct prop_local_percpu *pl, gfp_t gfp);
 void prop_local_destroy_percpu(struct prop_local_percpu *pl);
 void __prop_inc_percpu(struct prop_descriptor *pd, struct prop_local_percpu *pl);
 void prop_fraction_percpu(struct prop_descriptor *pd, struct prop_local_percpu *pl,