include/sys/abd_impl.h

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or https://opensource.org/licenses/CDDL-1.0.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright (c) 2014 by Chunwei Chen. All rights reserved.
  23  * Copyright (c) 2016, 2019 by Delphix. All rights reserved.
  24  */
  25
  26 #ifndef _ABD_IMPL_H
  27 #define _ABD_IMPL_H
  28
  29 #include <sys/abd.h>
  30 #include <sys/wmsum.h>
  31
  32 #ifdef __cplusplus
  33 extern "C" {
  34 #endif
  35
  36 typedef enum abd_stats_op {
  37         ABDSTAT_INCR, /* Increase abdstat values */
  38         ABDSTAT_DECR  /* Decrease abdstat values */
  39 } abd_stats_op_t;
  40
  41 struct scatterlist; /* forward declaration */
  42
  43 struct abd_iter {
  44         /* public interface */
  45         void            *iter_mapaddr;  /* addr corresponding to iter_pos */
  46         size_t          iter_mapsize;   /* length of data valid at mapaddr */
  47
  48         /* private */
  49         abd_t           *iter_abd;      /* ABD being iterated through */
  50         size_t          iter_pos;
  51         size_t          iter_offset;    /* offset in current sg/abd_buf, */
  52                                         /* abd_offset included */
  53         struct scatterlist *iter_sg;    /* current sg */
  54 };
  55
  56 extern abd_t *abd_zero_scatter;
  57
  58 abd_t *abd_gang_get_offset(abd_t *, size_t *);
  59 abd_t *abd_alloc_struct(size_t);
  60 void abd_free_struct(abd_t *);
  61
  62 /*
  63  * OS specific functions
  64  */
  65
  66 abd_t *abd_alloc_struct_impl(size_t);
  67 abd_t *abd_get_offset_scatter(abd_t *, abd_t *, size_t, size_t);
  68 void abd_free_struct_impl(abd_t *);
  69 void abd_alloc_chunks(abd_t *, size_t);
  70 void abd_free_chunks(abd_t *);
  71 void abd_update_scatter_stats(abd_t *, abd_stats_op_t);
  72 void abd_update_linear_stats(abd_t *, abd_stats_op_t);
  73 void abd_verify_scatter(abd_t *);
  74 void abd_free_linear_page(abd_t *);
  75 /* OS specific abd_iter functions */
  76 void abd_iter_init(struct abd_iter  *, abd_t *);
  77 boolean_t abd_iter_at_end(struct abd_iter *);
  78 void abd_iter_advance(struct abd_iter *, size_t);
  79 void abd_iter_map(struct abd_iter *);
  80 void abd_iter_unmap(struct abd_iter *);
  81
  82 /*
  83  * Helper macros
  84  */
  85 #define ABDSTAT_INCR(stat, val) \
  86         wmsum_add(&abd_sums.stat, (val))
  87 #define ABDSTAT_BUMP(stat)      ABDSTAT_INCR(stat, 1)
  88 #define ABDSTAT_BUMPDOWN(stat)  ABDSTAT_INCR(stat, -1)
  89
  90 #define ABD_SCATTER(abd)        (abd->abd_u.abd_scatter)
  91 #define ABD_LINEAR_BUF(abd)     (abd->abd_u.abd_linear.abd_buf)
  92 #define ABD_GANG(abd)           (abd->abd_u.abd_gang)
  93
  94 #if defined(_KERNEL)
  95 #if defined(__FreeBSD__)
  96 #define abd_enter_critical(flags)       critical_enter()
  97 #define abd_exit_critical(flags)        critical_exit()
  98 #else
  99 #define abd_enter_critical(flags)       local_irq_save(flags)
 100 #define abd_exit_critical(flags)        local_irq_restore(flags)
 101 #endif
 102 #else /* !_KERNEL */
 103 #define abd_enter_critical(flags)       ((void)0)
 104 #define abd_exit_critical(flags)        ((void)0)
 105 #endif
 106
 107 #ifdef __cplusplus
 108 }
 109 #endif
 110
 111 #endif  /* _ABD_IMPL_H */