linux-imx

/* SPDX-License-Identifier: GPL-2.0+ */

/*

 * Read-Copy Update mechanism for mutual exclusion (tree-based version)

 * Internal non-public definitions.

 *

 * Copyright IBM Corporation, 2008

 *

 * Author: Ingo Molnar <mingo@elte.hu>

 *     Paul E. McKenney <paulmck@linux.ibm.com>

 */

​

#include <linux/cache.h>

#include <linux/spinlock.h>

#include <linux/rtmutex.h>

#include <linux/threads.h>

#include <linux/cpumask.h>

#include <linux/seqlock.h>

#include <linux/swait.h>

#include <linux/stop_machine.h>

#include <linux/rcu_node_tree.h>

​

#include "rcu_segcblist.h"

​

/* Communicate arguments to a workqueue handler. */

struct rcu_exp_work {

    unsigned long rew_s;

    struct work_struct rew_work;

};

​

/* RCU's kthread states for tracing. */

#define RCU_KTHREAD_STOPPED  0

#define RCU_KTHREAD_RUNNING  1

#define RCU_KTHREAD_WAITING  2

#define RCU_KTHREAD_OFFCPU   3

#define RCU_KTHREAD_YIELDING 4

#define RCU_KTHREAD_MAX      4

​

/*

 * Definition for node within the RCU grace-period-detection hierarchy.

 */

struct rcu_node {

    raw_spinlock_t __private lock;  /* Root rcu_node's lock protects */

                    /*  some rcu_state fields as well as */

                    /*  following. */

    unsigned long gp_seq;   /* Track rsp->rcu_gp_seq. */

    unsigned long gp_seq_needed; /* Track furthest future GP request. */

    unsigned long completedqs; /* All QSes done for this node. */

    unsigned long qsmask;   /* CPUs or groups that need to switch in */

                /*  order for current grace period to proceed.*/

                /*  In leaf rcu_node, each bit corresponds to */

                /*  an rcu_data structure, otherwise, each */

                /*  bit corresponds to a child rcu_node */

                /*  structure. */

    unsigned long rcu_gp_init_mask; /* Mask of offline CPUs at GP init. */

    unsigned long qsmaskinit;

                /* Per-GP initial value for qsmask. */

                /*  Initialized from ->qsmaskinitnext at the */

                /*  beginning of each grace period. */

    unsigned long qsmaskinitnext;

                /* Online CPUs for next grace period. */

    unsigned long expmask;  /* CPUs or groups that need to check in */

                /*  to allow the current expedited GP */

                /*  to complete. */