rcu: simplify the usage of percpu data

[GitHub/mt8127/android_kernel_alcatel_ttab.git] / kernel / rcutree.c

diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index d5bc43976c5ad202fa41be0456797d40bdde0c0d..5b1c3c231bae46db5ddb9340a385c82d8b91acb7 100644 (file)
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -712,7 +712,7 @@ static void
 rcu_start_gp(struct rcu_state *rsp, unsigned long flags)
        __releases(rcu_get_root(rsp)->lock)
 {
-       struct rcu_data *rdp = rsp->rda[smp_processor_id()];
+       struct rcu_data *rdp = this_cpu_ptr(rsp->rda);
        struct rcu_node *rnp = rcu_get_root(rsp);
 
        if (!cpu_needs_another_gp(rsp, rdp) || rsp->fqs_active) {
@@ -960,7 +960,7 @@ rcu_check_quiescent_state(struct rcu_state *rsp, struct rcu_data *rdp)
 static void rcu_send_cbs_to_orphanage(struct rcu_state *rsp)
 {
        int i;
-       struct rcu_data *rdp = rsp->rda[smp_processor_id()];
+       struct rcu_data *rdp = this_cpu_ptr(rsp->rda);
 
        if (rdp->nxtlist == NULL)
                return;  /* irqs disabled, so comparison is stable. */
@@ -984,7 +984,7 @@ static void rcu_adopt_orphan_cbs(struct rcu_state *rsp)
        struct rcu_data *rdp;
 
        raw_spin_lock_irqsave(&rsp->onofflock, flags);
-       rdp = rsp->rda[smp_processor_id()];
+       rdp = this_cpu_ptr(rsp->rda);
        if (rsp->orphan_cbs_list == NULL) {
                raw_spin_unlock_irqrestore(&rsp->onofflock, flags);
                return;
@@ -1007,7 +1007,7 @@ static void __rcu_offline_cpu(int cpu, struct rcu_state *rsp)
        unsigned long flags;
        unsigned long mask;
        int need_report = 0;
-       struct rcu_data *rdp = rsp->rda[cpu];
+       struct rcu_data *rdp = per_cpu_ptr(rsp->rda, cpu);
        struct rcu_node *rnp;
 
        /* Exclude any attempts to start a new grace period. */
@@ -1226,7 +1226,8 @@ static void force_qs_rnp(struct rcu_state *rsp, int (*f)(struct rcu_data *))
                cpu = rnp->grplo;
                bit = 1;
                for (; cpu <= rnp->grphi; cpu++, bit <<= 1) {
-                       if ((rnp->qsmask & bit) != 0 && f(rsp->rda[cpu]))
+                       if ((rnp->qsmask & bit) != 0 &&
+                           f(per_cpu_ptr(rsp->rda, cpu)))
                                mask |= bit;
                }
                if (mask != 0) {
@@ -1402,7 +1403,7 @@ __call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu),
         * a quiescent state betweentimes.
         */
        local_irq_save(flags);
-       rdp = rsp->rda[smp_processor_id()];
+       rdp = this_cpu_ptr(rsp->rda);
        rcu_process_gp_end(rsp, rdp);
        check_for_new_grace_period(rsp, rdp);
 
@@ -1701,7 +1702,7 @@ rcu_boot_init_percpu_data(int cpu, struct rcu_state *rsp)
 {
        unsigned long flags;
        int i;
-       struct rcu_data *rdp = rsp->rda[cpu];
+       struct rcu_data *rdp = per_cpu_ptr(rsp->rda, cpu);
        struct rcu_node *rnp = rcu_get_root(rsp);
 
        /* Set up local state, ensuring consistent view of global state. */
@@ -1729,7 +1730,7 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp, int preemptable)
 {
        unsigned long flags;
        unsigned long mask;
-       struct rcu_data *rdp = rsp->rda[cpu];
+       struct rcu_data *rdp = per_cpu_ptr(rsp->rda, cpu);
        struct rcu_node *rnp = rcu_get_root(rsp);
 
        /* Set up local state, ensuring consistent view of global state. */
@@ -1865,7 +1866,8 @@ static void __init rcu_init_levelspread(struct rcu_state *rsp)
 /*
  * Helper function for rcu_init() that initializes one rcu_state structure.
  */
-static void __init rcu_init_one(struct rcu_state *rsp)
+static void __init rcu_init_one(struct rcu_state *rsp,
+               struct rcu_data __percpu *rda)
 {
        static char *buf[] = { "rcu_node_level_0",
                               "rcu_node_level_1",
@@ -1918,37 +1920,23 @@ static void __init rcu_init_one(struct rcu_state *rsp)
                }
        }
 
+       rsp->rda = rda;
        rnp = rsp->level[NUM_RCU_LVLS - 1];
        for_each_possible_cpu(i) {
                while (i > rnp->grphi)
                        rnp++;
-               rsp->rda[i]->mynode = rnp;
+               per_cpu_ptr(rsp->rda, i)->mynode = rnp;
                rcu_boot_init_percpu_data(i, rsp);
        }
 }
 
-/*
- * Helper macro for __rcu_init() and __rcu_init_preempt().  To be used
- * nowhere else!  Assigns leaf node pointers into each CPU's rcu_data
- * structure.
- */
-#define RCU_INIT_FLAVOR(rsp, rcu_data) \
-do { \
-       int i; \
-       \
-       for_each_possible_cpu(i) { \
-               (rsp)->rda[i] = &per_cpu(rcu_data, i); \
-       } \
-       rcu_init_one(rsp); \
-} while (0)
-
 void __init rcu_init(void)
 {
        int cpu;
 
        rcu_bootup_announce();
-       RCU_INIT_FLAVOR(&rcu_sched_state, rcu_sched_data);
-       RCU_INIT_FLAVOR(&rcu_bh_state, rcu_bh_data);
+       rcu_init_one(&rcu_sched_state, &rcu_sched_data);
+       rcu_init_one(&rcu_bh_state, &rcu_bh_data);
        __rcu_init_preempt();
        open_softirq(RCU_SOFTIRQ, rcu_process_callbacks);