6 files changed, 376 insertions, 12 deletions

diff --git a/include/linux/bottom_half.h b/include/linux/bottom_half.h
index 777dbf695d44..27b1bcffe408 100644
--- a/include/linux/bottom_half.h
+++ b/include/linux/bottom_half.h
@@ -2,7 +2,6 @@
 #define _LINUX_BH_H
 
 extern void local_bh_disable(void);
-extern void __local_bh_enable(void);
 extern void _local_bh_enable(void);
 extern void local_bh_enable(void);
 extern void local_bh_enable_ip(unsigned long ip);
diff --git a/include/linux/hardirq.h b/include/linux/hardirq.h
index 181006cc94a0..9b70b9231693 100644
--- a/include/linux/hardirq.h
+++ b/include/linux/hardirq.h
@@ -118,13 +118,17 @@ static inline void account_system_vtime(struct task_struct *tsk)
 }
 #endif
 
-#if defined(CONFIG_PREEMPT_RCU) && defined(CONFIG_NO_HZ)
+#if defined(CONFIG_NO_HZ) && !defined(CONFIG_CLASSIC_RCU)
 extern void rcu_irq_enter(void);
 extern void rcu_irq_exit(void);
+extern void rcu_nmi_enter(void);
+extern void rcu_nmi_exit(void);
 #else
 # define rcu_irq_enter() do { } while (0)
 # define rcu_irq_exit() do { } while (0)
-#endif /* CONFIG_PREEMPT_RCU */
+# define rcu_nmi_enter() do { } while (0)
+# define rcu_nmi_exit() do { } while (0)
+#endif /* #if defined(CONFIG_NO_HZ) && !defined(CONFIG_CLASSIC_RCU) */
 
 /*
  * It is safe to do non-atomic ops on ->hardirq_context,
@@ -134,7 +138,6 @@ extern void rcu_irq_exit(void);
  */
 #define __irq_enter()                                   \
         do {                                            \
-                rcu_irq_enter();                        \
                 account_system_vtime(current);          \
                 add_preempt_count(HARDIRQ_OFFSET);      \
                 trace_hardirq_enter();                  \
@@ -153,7 +156,6 @@ extern void irq_enter(void);
                 trace_hardirq_exit();                   \
                 account_system_vtime(current);          \
                 sub_preempt_count(HARDIRQ_OFFSET);      \
-                rcu_irq_exit();                         \
         } while (0)
 
 /*
@@ -161,7 +163,7 @@ extern void irq_enter(void);
  */
 extern void irq_exit(void);
 
-#define nmi_enter()             do { lockdep_off(); __irq_enter(); } while (0)
-#define nmi_exit()              do { __irq_exit(); lockdep_on(); } while (0)
+#define nmi_enter()             do { lockdep_off(); rcu_nmi_enter(); __irq_enter(); } while (0)
+#define nmi_exit()              do { __irq_exit(); rcu_nmi_exit(); lockdep_on(); } while (0)
 
 #endif /* LINUX_HARDIRQ_H */
diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
index 8956daf64abd..37a0361f4685 100644
--- a/include/linux/lockdep.h
+++ b/include/linux/lockdep.h
@@ -314,8 +314,15 @@ extern void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
 extern void lock_release(struct lockdep_map *lock, int nested,
                          unsigned long ip);
 
-extern void lock_set_subclass(struct lockdep_map *lock, unsigned int subclass,
-                              unsigned long ip);
+extern void lock_set_class(struct lockdep_map *lock, const char *name,
+                           struct lock_class_key *key, unsigned int subclass,
+                           unsigned long ip);
+
+static inline void lock_set_subclass(struct lockdep_map *lock,
+                unsigned int subclass, unsigned long ip)
+{
+        lock_set_class(lock, lock->name, lock->key, subclass, ip);
+}
 
 # define INIT_LOCKDEP                           .lockdep_recursion = 0,
 
@@ -333,6 +340,7 @@ static inline void lockdep_on(void)
 
 # define lock_acquire(l, s, t, r, c, n, i)      do { } while (0)
 # define lock_release(l, n, i)                  do { } while (0)
+# define lock_set_class(l, n, k, s, i)          do { } while (0)
 # define lock_set_subclass(l, s, i)             do { } while (0)
 # define lockdep_init()                         do { } while (0)
 # define lockdep_info()                         do { } while (0)
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index 86f1f5e43e33..bfd289aff576 100644
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -52,11 +52,15 @@ struct rcu_head {
         void (*func)(struct rcu_head *head);
 };
 
-#ifdef CONFIG_CLASSIC_RCU
+#if defined(CONFIG_CLASSIC_RCU)
 #include <linux/rcuclassic.h>
-#else /* #ifdef CONFIG_CLASSIC_RCU */
+#elif defined(CONFIG_TREE_RCU)
+#include <linux/rcutree.h>
+#elif defined(CONFIG_PREEMPT_RCU)
 #include <linux/rcupreempt.h>
-#endif /* #else #ifdef CONFIG_CLASSIC_RCU */
+#else
+#error "Unknown RCU implementation specified to kernel configuration"
+#endif /* #else #if defined(CONFIG_CLASSIC_RCU) */
 
 #define RCU_HEAD_INIT   { .next = NULL, .func = NULL }
 #define RCU_HEAD(head) struct rcu_head head = RCU_HEAD_INIT
diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h
new file mode 100644
index 000000000000..d4368b7975c3
--- /dev/null
+++ b/include/linux/rcutree.h
@@ -0,0 +1,329 @@
+/*
+ * Read-Copy Update mechanism for mutual exclusion (tree-based version)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ * Copyright IBM Corporation, 2008
+ *
+ * Author: Dipankar Sarma <dipankar@in.ibm.com>
+ *         Paul E. McKenney <paulmck@linux.vnet.ibm.com> Hierarchical algorithm
+ *
+ * Based on the original work by Paul McKenney <paulmck@us.ibm.com>
+ * and inputs from Rusty Russell, Andrea Arcangeli and Andi Kleen.
+ *
+ * For detailed explanation of Read-Copy Update mechanism see -
+ *      Documentation/RCU
+ */
+
+#ifndef __LINUX_RCUTREE_H
+#define __LINUX_RCUTREE_H
+
+#include <linux/cache.h>
+#include <linux/spinlock.h>
+#include <linux/threads.h>
+#include <linux/percpu.h>
+#include <linux/cpumask.h>
+#include <linux/seqlock.h>
+
+/*
+ * Define shape of hierarchy based on NR_CPUS and CONFIG_RCU_FANOUT.
+ * In theory, it should be possible to add more levels straightforwardly.
+ * In practice, this has not been tested, so there is probably some
+ * bug somewhere.
+ */
+#define MAX_RCU_LVLS 3
+#define RCU_FANOUT            (CONFIG_RCU_FANOUT)
+#define RCU_FANOUT_SQ         (RCU_FANOUT * RCU_FANOUT)
+#define RCU_FANOUT_CUBE       (RCU_FANOUT_SQ * RCU_FANOUT)
+
+#if NR_CPUS <= RCU_FANOUT
+#  define NUM_RCU_LVLS        1
+#  define NUM_RCU_LVL_0       1
+#  define NUM_RCU_LVL_1       (NR_CPUS)
+#  define NUM_RCU_LVL_2       0
+#  define NUM_RCU_LVL_3       0
+#elif NR_CPUS <= RCU_FANOUT_SQ
+#  define NUM_RCU_LVLS        2
+#  define NUM_RCU_LVL_0       1
+#  define NUM_RCU_LVL_1       (((NR_CPUS) + RCU_FANOUT - 1) / RCU_FANOUT)
+#  define NUM_RCU_LVL_2       (NR_CPUS)
+#  define NUM_RCU_LVL_3       0
+#elif NR_CPUS <= RCU_FANOUT_CUBE
+#  define NUM_RCU_LVLS        3
+#  define NUM_RCU_LVL_0       1
+#  define NUM_RCU_LVL_1       (((NR_CPUS) + RCU_FANOUT_SQ - 1) / RCU_FANOUT_SQ)
+#  define NUM_RCU_LVL_2       (((NR_CPUS) + (RCU_FANOUT) - 1) / (RCU_FANOUT))
+#  define NUM_RCU_LVL_3       NR_CPUS
+#else
+# error "CONFIG_RCU_FANOUT insufficient for NR_CPUS"
+#endif /* #if (NR_CPUS) <= RCU_FANOUT */
+
+#define RCU_SUM (NUM_RCU_LVL_0 + NUM_RCU_LVL_1 + NUM_RCU_LVL_2 + NUM_RCU_LVL_3)
+#define NUM_RCU_NODES (RCU_SUM - NR_CPUS)
+
+/*
+ * Dynticks per-CPU state.
+ */
+struct rcu_dynticks {
+        int dynticks_nesting;   /* Track nesting level, sort of. */
+        int dynticks;           /* Even value for dynticks-idle, else odd. */
+        int dynticks_nmi;       /* Even value for either dynticks-idle or */
+                                /*  not in nmi handler, else odd.  So this */
+                                /*  remains even for nmi from irq handler. */
+};
+
+/*
+ * Definition for node within the RCU grace-period-detection hierarchy.
+ */
+struct rcu_node {
+        spinlock_t lock;
+        unsigned long qsmask;   /* CPUs or groups that need to switch in */
+                                /*  order for current grace period to proceed.*/
+        unsigned long qsmaskinit;
+                                /* Per-GP initialization for qsmask. */
+        unsigned long grpmask;  /* Mask to apply to parent qsmask. */
+        int     grplo;          /* lowest-numbered CPU or group here. */
+        int     grphi;          /* highest-numbered CPU or group here. */
+        u8      grpnum;         /* CPU/group number for next level up. */
+        u8      level;          /* root is at level 0. */
+        struct rcu_node *parent;
+} ____cacheline_internodealigned_in_smp;
+
+/* Index values for nxttail array in struct rcu_data. */
+#define RCU_DONE_TAIL           0       /* Also RCU_WAIT head. */
+#define RCU_WAIT_TAIL           1       /* Also RCU_NEXT_READY head. */
+#define RCU_NEXT_READY_TAIL     2       /* Also RCU_NEXT head. */
+#define RCU_NEXT_TAIL           3
+#define RCU_NEXT_SIZE           4
+
+/* Per-CPU data for read-copy update. */
+struct rcu_data {
+        /* 1) quiescent-state and grace-period handling : */
+        long            completed;      /* Track rsp->completed gp number */
+                                        /*  in order to detect GP end. */
+        long            gpnum;          /* Highest gp number that this CPU */
+                                        /*  is aware of having started. */
+        long            passed_quiesc_completed;
+                                        /* Value of completed at time of qs. */
+        bool            passed_quiesc;  /* User-mode/idle loop etc. */
+        bool            qs_pending;     /* Core waits for quiesc state. */
+        bool            beenonline;     /* CPU online at least once. */
+        struct rcu_node *mynode;        /* This CPU's leaf of hierarchy */
+        unsigned long grpmask;          /* Mask to apply to leaf qsmask. */
+
+        /* 2) batch handling */
+        /*
+         * If nxtlist is not NULL, it is partitioned as follows.
+         * Any of the partitions might be empty, in which case the
+         * pointer to that partition will be equal to the pointer for
+         * the following partition.  When the list is empty, all of
+         * the nxttail elements point to nxtlist, which is NULL.
+         *
+         * [*nxttail[RCU_NEXT_READY_TAIL], NULL = *nxttail[RCU_NEXT_TAIL]):
+         *      Entries that might have arrived after current GP ended
+         * [*nxttail[RCU_WAIT_TAIL], *nxttail[RCU_NEXT_READY_TAIL]):
+         *      Entries known to have arrived before current GP ended
+         * [*nxttail[RCU_DONE_TAIL], *nxttail[RCU_WAIT_TAIL]):
+         *      Entries that batch # <= ->completed - 1: waiting for current GP
+         * [nxtlist, *nxttail[RCU_DONE_TAIL]):
+         *      Entries that batch # <= ->completed
+         *      The grace period for these entries has completed, and
+         *      the other grace-period-completed entries may be moved
+         *      here temporarily in rcu_process_callbacks().
+         */
+        struct rcu_head *nxtlist;
+        struct rcu_head **nxttail[RCU_NEXT_SIZE];
+        long            qlen;           /* # of queued callbacks */
+        long            blimit;         /* Upper limit on a processed batch */
+
+#ifdef CONFIG_NO_HZ
+        /* 3) dynticks interface. */
+        struct rcu_dynticks *dynticks;  /* Shared per-CPU dynticks state. */
+        int dynticks_snap;              /* Per-GP tracking for dynticks. */
+        int dynticks_nmi_snap;          /* Per-GP tracking for dynticks_nmi. */
+#endif /* #ifdef CONFIG_NO_HZ */
+
+        /* 4) reasons this CPU needed to be kicked by force_quiescent_state */
+#ifdef CONFIG_NO_HZ
+        unsigned long dynticks_fqs;     /* Kicked due to dynticks idle. */
+#endif /* #ifdef CONFIG_NO_HZ */
+        unsigned long offline_fqs;      /* Kicked due to being offline. */
+        unsigned long resched_ipi;      /* Sent a resched IPI. */
+
+        /* 5) state to allow this CPU to force_quiescent_state on others */
+        long n_rcu_pending;             /* rcu_pending() calls since boot. */
+        long n_rcu_pending_force_qs;    /* when to force quiescent states. */
+
+        int cpu;
+};
+
+/* Values for signaled field in struct rcu_state. */
+#define RCU_GP_INIT             0       /* Grace period being initialized. */
+#define RCU_SAVE_DYNTICK        1       /* Need to scan dyntick state. */
+#define RCU_FORCE_QS            2       /* Need to force quiescent state. */
+#ifdef CONFIG_NO_HZ
+#define RCU_SIGNAL_INIT         RCU_SAVE_DYNTICK
+#else /* #ifdef CONFIG_NO_HZ */
+#define RCU_SIGNAL_INIT         RCU_FORCE_QS
+#endif /* #else #ifdef CONFIG_NO_HZ */
+
+#define RCU_JIFFIES_TILL_FORCE_QS        3      /* for rsp->jiffies_force_qs */
+#ifdef CONFIG_RCU_CPU_STALL_DETECTOR
+#define RCU_SECONDS_TILL_STALL_CHECK   (10 * HZ)  /* for rsp->jiffies_stall */
+#define RCU_SECONDS_TILL_STALL_RECHECK (30 * HZ)  /* for rsp->jiffies_stall */
+#define RCU_STALL_RAT_DELAY             2         /* Allow other CPUs time */
+                                                  /*  to take at least one */
+                                                  /*  scheduling clock irq */
+                                                  /*  before ratting on them. */
+
+#endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */
+
+/*
+ * RCU global state, including node hierarchy.  This hierarchy is
+ * represented in "heap" form in a dense array.  The root (first level)
+ * of the hierarchy is in ->node[0] (referenced by ->level[0]), the second
+ * level in ->node[1] through ->node[m] (->node[1] referenced by ->level[1]),
+ * and the third level in ->node[m+1] and following (->node[m+1] referenced
+ * by ->level[2]).  The number of levels is determined by the number of
+ * CPUs and by CONFIG_RCU_FANOUT.  Small systems will have a "hierarchy"
+ * consisting of a single rcu_node.
+ */
+struct rcu_state {
+        struct rcu_node node[NUM_RCU_NODES];    /* Hierarchy. */
+        struct rcu_node *level[NUM_RCU_LVLS];   /* Hierarchy levels. */
+        u32 levelcnt[MAX_RCU_LVLS + 1];         /* # nodes in each level. */
+        u8 levelspread[NUM_RCU_LVLS];           /* kids/node in each level. */
+        struct rcu_data *rda[NR_CPUS];          /* array of rdp pointers. */
+
+        /* The following fields are guarded by the root rcu_node's lock. */
+
+        u8      signaled ____cacheline_internodealigned_in_smp;
+                                                /* Force QS state. */
+        long    gpnum;                          /* Current gp number. */
+        long    completed;                      /* # of last completed gp. */
+        spinlock_t onofflock;                   /* exclude on/offline and */
+                                                /*  starting new GP. */
+        spinlock_t fqslock;                     /* Only one task forcing */
+                                                /*  quiescent states. */
+        unsigned long jiffies_force_qs;         /* Time at which to invoke */
+                                                /*  force_quiescent_state(). */
+        unsigned long n_force_qs;               /* Number of calls to */
+                                                /*  force_quiescent_state(). */
+        unsigned long n_force_qs_lh;            /* ~Number of calls leaving */
+                                                /*  due to lock unavailable. */
+        unsigned long n_force_qs_ngp;           /* Number of calls leaving */
+                                                /*  due to no GP active. */
+#ifdef CONFIG_RCU_CPU_STALL_DETECTOR
+        unsigned long gp_start;                 /* Time at which GP started, */
+                                                /*  but in jiffies. */
+        unsigned long jiffies_stall;            /* Time at which to check */
+                                                /*  for CPU stalls. */
+#endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */
+#ifdef CONFIG_NO_HZ
+        long dynticks_completed;                /* Value of completed @ snap. */
+#endif /* #ifdef CONFIG_NO_HZ */
+};
+
+extern struct rcu_state rcu_state;
+DECLARE_PER_CPU(struct rcu_data, rcu_data);
+
+extern struct rcu_state rcu_bh_state;
+DECLARE_PER_CPU(struct rcu_data, rcu_bh_data);
+
+/*
+ * Increment the quiescent state counter.
+ * The counter is a bit degenerated: We do not need to know
+ * how many quiescent states passed, just if there was at least
+ * one since the start of the grace period. Thus just a flag.
+ */
+static inline void rcu_qsctr_inc(int cpu)
+{
+        struct rcu_data *rdp = &per_cpu(rcu_data, cpu);
+        rdp->passed_quiesc = 1;
+        rdp->passed_quiesc_completed = rdp->completed;
+}
+static inline void rcu_bh_qsctr_inc(int cpu)
+{
+        struct rcu_data *rdp = &per_cpu(rcu_bh_data, cpu);
+        rdp->passed_quiesc = 1;
+        rdp->passed_quiesc_completed = rdp->completed;
+}
+
+extern int rcu_pending(int cpu);
+extern int rcu_needs_cpu(int cpu);
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+extern struct lockdep_map rcu_lock_map;
+# define rcu_read_acquire()     \
+                        lock_acquire(&rcu_lock_map, 0, 0, 2, 1, NULL, _THIS_IP_)
+# define rcu_read_release()     lock_release(&rcu_lock_map, 1, _THIS_IP_)
+#else
+# define rcu_read_acquire()     do { } while (0)
+# define rcu_read_release()     do { } while (0)
+#endif
+
+static inline void __rcu_read_lock(void)
+{
+        preempt_disable();
+        __acquire(RCU);
+        rcu_read_acquire();
+}
+static inline void __rcu_read_unlock(void)
+{
+        rcu_read_release();
+        __release(RCU);
+        preempt_enable();
+}
+static inline void __rcu_read_lock_bh(void)
+{
+        local_bh_disable();
+        __acquire(RCU_BH);
+        rcu_read_acquire();
+}
+static inline void __rcu_read_unlock_bh(void)
+{
+        rcu_read_release();
+        __release(RCU_BH);
+        local_bh_enable();
+}
+
+#define __synchronize_sched() synchronize_rcu()
+
+#define call_rcu_sched(head, func) call_rcu(head, func)
+
+static inline void rcu_init_sched(void)
+{
+}
+
+extern void __rcu_init(void);
+extern void rcu_check_callbacks(int cpu, int user);
+extern void rcu_restart_cpu(int cpu);
+
+extern long rcu_batches_completed(void);
+extern long rcu_batches_completed_bh(void);
+
+#ifdef CONFIG_NO_HZ
+void rcu_enter_nohz(void);
+void rcu_exit_nohz(void);
+#else /* CONFIG_NO_HZ */
+static inline void rcu_enter_nohz(void)
+{
+}
+static inline void rcu_exit_nohz(void)
+{
+}
+#endif /* CONFIG_NO_HZ */
+
+#endif /* __LINUX_RCUTREE_H */
diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
index b18ec5533e8c..325af1de0351 100644
--- a/include/linux/swiotlb.h
+++ b/include/linux/swiotlb.h
@@ -7,9 +7,31 @@ struct device;
 struct dma_attrs;
 struct scatterlist;
 
+/*
+ * Maximum allowable number of contiguous slabs to map,
+ * must be a power of 2.  What is the appropriate value ?
+ * The complexity of {map,unmap}_single is linearly dependent on this value.
+ */
+#define IO_TLB_SEGSIZE  128
+
+
+/*
+ * log of the size of each IO TLB slab.  The number of slabs is command line
+ * controllable.
+ */
+#define IO_TLB_SHIFT 11
+
 extern void
 swiotlb_init(void);
 
+extern void *swiotlb_alloc_boot(size_t bytes, unsigned long nslabs);
+extern void *swiotlb_alloc(unsigned order, unsigned long nslabs);
+
+extern dma_addr_t swiotlb_phys_to_bus(phys_addr_t address);
+extern phys_addr_t swiotlb_bus_to_phys(dma_addr_t address);
+
+extern int swiotlb_arch_range_needs_mapping(void *ptr, size_t size);
+
 extern void
 *swiotlb_alloc_coherent(struct device *hwdev, size_t size,
                         dma_addr_t *dma_handle, gfp_t flags);