Branch data     Line data    Source code

       1                 :            : /* SPDX-License-Identifier: GPL-2.0+ */
       2                 :            : /*
       3                 :            :  * RCU segmented callback lists, internal-to-rcu header file
       4                 :            :  *
       5                 :            :  * Copyright IBM Corporation, 2017
       6                 :            :  *
       7                 :            :  * Authors: Paul E. McKenney <paulmck@linux.ibm.com>
       8                 :            :  */
       9                 :            : 
      10                 :            : #include <linux/rcu_segcblist.h>
      11                 :            : 
      12                 :            : /* Return number of callbacks in the specified callback list. */
      13                 :            : static inline long rcu_cblist_n_cbs(struct rcu_cblist *rclp)
      14                 :            : {
      15                 :            :         return READ_ONCE(rclp->len);
      16                 :            : }
      17                 :            : 
      18                 :            : void rcu_cblist_init(struct rcu_cblist *rclp);
      19                 :            : void rcu_cblist_enqueue(struct rcu_cblist *rclp, struct rcu_head *rhp);
      20                 :            : void rcu_cblist_flush_enqueue(struct rcu_cblist *drclp,
      21                 :            :                               struct rcu_cblist *srclp,
      22                 :            :                               struct rcu_head *rhp);
      23                 :            : struct rcu_head *rcu_cblist_dequeue(struct rcu_cblist *rclp);
      24                 :            : 
      25                 :            : /*
      26                 :            :  * Is the specified rcu_segcblist structure empty?
      27                 :            :  *
      28                 :            :  * But careful!  The fact that the ->head field is NULL does not
      29                 :            :  * necessarily imply that there are no callbacks associated with
      30                 :            :  * this structure.  When callbacks are being invoked, they are
      31                 :            :  * removed as a group.  If callback invocation must be preempted,
      32                 :            :  * the remaining callbacks will be added back to the list.  Either
      33                 :            :  * way, the counts are updated later.
      34                 :            :  *
      35                 :            :  * So it is often the case that rcu_segcblist_n_cbs() should be used
      36                 :            :  * instead.
      37                 :            :  */
      38                 :     107639 : static inline bool rcu_segcblist_empty(struct rcu_segcblist *rsclp)
      39                 :            : {
      40   [ +  +  -  -  :     107639 :         return !READ_ONCE(rsclp->head);
          -  -  -  -  +  
          -  -  -  +  -  
                   +  - ]
      41                 :            : }
      42                 :            : 
      43                 :            : /* Return number of callbacks in segmented callback list. */
      44                 :    2113208 : static inline long rcu_segcblist_n_cbs(struct rcu_segcblist *rsclp)
      45                 :            : {
      46                 :            : #ifdef CONFIG_RCU_NOCB_CPU
      47                 :            :         return atomic_long_read(&rsclp->len);
      48                 :            : #else
      49   [ +  -  -  -  :    2010316 :         return READ_ONCE(rsclp->len);
          +  +  -  +  -  
                +  -  + ]
      50                 :            : #endif
      51                 :            : }
      52                 :            : 
      53                 :            : /*
      54                 :            :  * Is the specified rcu_segcblist enabled, for example, not corresponding
      55                 :            :  * to an offline CPU?
      56                 :            :  */
      57                 :    1666761 : static inline bool rcu_segcblist_is_enabled(struct rcu_segcblist *rsclp)
      58                 :            : {
      59   [ -  +  -  +  :    1666761 :         return rsclp->enabled;
          -  -  +  -  -  
          +  +  -  -  -  
             +  +  +  - ]
      60                 :            : }
      61                 :            : 
      62                 :            : /* Is the specified rcu_segcblist offloaded?  */
      63                 :       4507 : static inline bool rcu_segcblist_is_offloaded(struct rcu_segcblist *rsclp)
      64                 :            : {
      65   [ -  +  -  -  :       4507 :         return rsclp->offloaded;
          -  -  +  -  -  
                      - ]
      66                 :            : }
      67                 :            : 
      68                 :            : /*
      69                 :            :  * Are all segments following the specified segment of the specified
      70                 :            :  * rcu_segcblist structure empty of callbacks?  (The specified
      71                 :            :  * segment might well contain callbacks.)
      72                 :            :  */
      73                 :     364023 : static inline bool rcu_segcblist_restempty(struct rcu_segcblist *rsclp, int seg)
      74                 :            : {
      75   [ +  +  +  +  :     364023 :         return !READ_ONCE(*READ_ONCE(rsclp->tails[seg]));
          +  +  -  -  +  
                      + ]
      76                 :            : }
      77                 :            : 
      78                 :            : void rcu_segcblist_inc_len(struct rcu_segcblist *rsclp);
      79                 :            : void rcu_segcblist_init(struct rcu_segcblist *rsclp);
      80                 :            : void rcu_segcblist_disable(struct rcu_segcblist *rsclp);
      81                 :            : void rcu_segcblist_offload(struct rcu_segcblist *rsclp);
      82                 :            : bool rcu_segcblist_ready_cbs(struct rcu_segcblist *rsclp);
      83                 :            : bool rcu_segcblist_pend_cbs(struct rcu_segcblist *rsclp);
      84                 :            : struct rcu_head *rcu_segcblist_first_cb(struct rcu_segcblist *rsclp);
      85                 :            : struct rcu_head *rcu_segcblist_first_pend_cb(struct rcu_segcblist *rsclp);
      86                 :            : bool rcu_segcblist_nextgp(struct rcu_segcblist *rsclp, unsigned long *lp);
      87                 :            : void rcu_segcblist_enqueue(struct rcu_segcblist *rsclp,
      88                 :            :                            struct rcu_head *rhp);
      89                 :            : bool rcu_segcblist_entrain(struct rcu_segcblist *rsclp,
      90                 :            :                            struct rcu_head *rhp);
      91                 :            : void rcu_segcblist_extract_count(struct rcu_segcblist *rsclp,
      92                 :            :                                  struct rcu_cblist *rclp);
      93                 :            : void rcu_segcblist_extract_done_cbs(struct rcu_segcblist *rsclp,
      94                 :            :                                     struct rcu_cblist *rclp);
      95                 :            : void rcu_segcblist_extract_pend_cbs(struct rcu_segcblist *rsclp,
      96                 :            :                                     struct rcu_cblist *rclp);
      97                 :            : void rcu_segcblist_insert_count(struct rcu_segcblist *rsclp,
      98                 :            :                                 struct rcu_cblist *rclp);
      99                 :            : void rcu_segcblist_insert_done_cbs(struct rcu_segcblist *rsclp,
     100                 :            :                                    struct rcu_cblist *rclp);
     101                 :            : void rcu_segcblist_insert_pend_cbs(struct rcu_segcblist *rsclp,
     102                 :            :                                    struct rcu_cblist *rclp);
     103                 :            : void rcu_segcblist_advance(struct rcu_segcblist *rsclp, unsigned long seq);
     104                 :            : bool rcu_segcblist_accelerate(struct rcu_segcblist *rsclp, unsigned long seq);
     105                 :            : void rcu_segcblist_merge(struct rcu_segcblist *dst_rsclp,
     106                 :            :                          struct rcu_segcblist *src_rsclp);