ceph/src/spdk/ocf/inc/ocf_io_class.h

   1 /*
   2  * Copyright(c) 2012-2018 Intel Corporation
   3  * SPDX-License-Identifier: BSD-3-Clause-Clear
   4  */
   5
   6 /**
   7  * @file
   8  * @brief IO class API
   9  *
  10  * File contains structures and methods for handling IO Class
  11  * differentiation features
  12  */
  13
  14 #ifndef __OCF_IO_CLASS_H__
  15 #define __OCF_IO_CLASS_H__
  16
  17 /**
  18  * @brief OCF IO class information
  19  */
  20 struct ocf_io_class_info {
  21         char name[OCF_IO_CLASS_NAME_MAX];
  22                 /*!< The name of the IO class */
  23
  24         ocf_cache_mode_t cache_mode;
  25                 /*!< Cache mode of the IO class */
  26
  27         int16_t priority;
  28                 /*!< IO class priority */
  29
  30         uint32_t curr_size;
  31                 /*!< Current size of the IO class - number of cache lines which
  32                  * were assigned into this IO class
  33                  */
  34
  35         uint32_t min_size;
  36                 /*!< Minimum number of cache lines that were guaranteed
  37                  * for specified IO class. If current size reach minimum size
  38                  * that no more eviction takes place
  39                  */
  40
  41         uint32_t max_size;
  42                 /*!< Maximum number of cache lines that might be assigned into
  43                  * this IO class. If current size reach maximum size no more
  44                  * allocation for this IO class takes place
  45                  */
  46
  47         uint8_t eviction_policy_type;
  48                 /*!< The type of eviction policy for given IO class */
  49
  50         ocf_cleaning_t cleaning_policy_type;
  51                 /*!< The type of cleaning policy for given IO class */
  52 };
  53
  54 /**
  55  * @brief retrieve io class info
  56  *
  57  * function meant to retrieve information pertaining to particular IO class,
  58  * specifically to fill ocf_io_class_info structure based on input parameters.
  59  *
  60  * @param[in] cache cache handle, to which specified request pertains.
  61  * @param[in] io_class id of an io class which shall be retreived.
  62  * @param[out] info io class info structures to be filled as a
  63  *             result of this function call.
  64  *
  65  * @return function returns 0 upon successful completion; appropriate error
  66  *         code is returned otherwise
  67  */
  68 int ocf_cache_io_class_get_info(ocf_cache_t cache, uint32_t io_class,
  69                 struct ocf_io_class_info *info);
  70
  71 /**
  72  * @brief helper function for ocf_io_class_visit
  73  *
  74  * This function is called back from ocf_io_class_visit for each valid
  75  * configured io class; henceforth all parameters are input parameters,
  76  * no exceptions. It is usable to enumerate all the io classes.
  77  *
  78  * @param[in] cache cache id of cache for which data is being retrieved
  79  * @param[in] io_class_id id of an io class for which callback herein
  80  *            is invoked.
  81  * @param[in] cntx a context pointer passed herein from within
  82  *            ocf_io_class_visit down to this callback.
  83  *
  84  * @return 0 upon success; Nonzero upon failure (when nonzero is returned,
  85  *         this callback won't be invoked for any more io classes)
  86  */
  87 typedef int (*ocf_io_class_visitor_t)(ocf_cache_t cache,
  88                 uint32_t io_class_id, void *cntx);
  89
  90 /**
  91  * @brief enumerate all of the available IO classes.
  92  *
  93  * This function allows enumeration and retrieval of all io class id's that
  94  * are valid for given cache id via visiting all those with callback function
  95  * that is supplied by caller.
  96  *
  97  * @param[in] cache cache id to which given call pertains
  98  * @param[in] visitor a callback function that will be issued for each and every
  99  *            IO class that is configured and valid within given cache instance
 100  * @param[in] cntx a context variable - structure that shall be passed to a
 101  *            callback function for every call
 102  *
 103  * @return 0 upon successful completion of the function; otherwise nonzero result
 104  *         shall be returned
 105  */
 106 int ocf_io_class_visit(ocf_cache_t cache, ocf_io_class_visitor_t visitor,
 107                 void *cntx);
 108
 109 #endif /* __OCF_IO_CLASS_H__ */