include/rdma/rdmavt_mr.h

   1 #ifndef DEF_RDMAVT_INCMR_H
   2 #define DEF_RDMAVT_INCMR_H
   3
   4 /*
   5  * Copyright(c) 2016 Intel Corporation.
   6  *
   7  * This file is provided under a dual BSD/GPLv2 license.  When using or
   8  * redistributing this file, you may do so under either license.
   9  *
  10  * GPL LICENSE SUMMARY
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of version 2 of the GNU General Public License as
  14  * published by the Free Software Foundation.
  15  *
  16  * This program is distributed in the hope that it will be useful, but
  17  * WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  19  * General Public License for more details.
  20  *
  21  * BSD LICENSE
  22  *
  23  * Redistribution and use in source and binary forms, with or without
  24  * modification, are permitted provided that the following conditions
  25  * are met:
  26  *
  27  *  - Redistributions of source code must retain the above copyright
  28  *    notice, this list of conditions and the following disclaimer.
  29  *  - Redistributions in binary form must reproduce the above copyright
  30  *    notice, this list of conditions and the following disclaimer in
  31  *    the documentation and/or other materials provided with the
  32  *    distribution.
  33  *  - Neither the name of Intel Corporation nor the names of its
  34  *    contributors may be used to endorse or promote products derived
  35  *    from this software without specific prior written permission.
  36  *
  37  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  38  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  39  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  40  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  41  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  42  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  43  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  44  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  45  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  46  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  47  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  48  *
  49  */
  50
  51 /*
  52  * For Memory Regions. This stuff should probably be moved into rdmavt/mr.h once
  53  * drivers no longer need access to the MR directly.
  54  */
  55 #include <linux/percpu-refcount.h>
  56
  57 /*
  58  * A segment is a linear region of low physical memory.
  59  * Used by the verbs layer.
  60  */
  61 struct rvt_seg {
  62         void *vaddr;
  63         size_t length;
  64 };
  65
  66 /* The number of rvt_segs that fit in a page. */
  67 #define RVT_SEGSZ     (PAGE_SIZE / sizeof(struct rvt_seg))
  68
  69 struct rvt_segarray {
  70         struct rvt_seg segs[RVT_SEGSZ];
  71 };
  72
  73 struct rvt_mregion {
  74         struct ib_pd *pd;       /* shares refcnt of ibmr.pd */
  75         u64 user_base;          /* User's address for this region */
  76         u64 iova;               /* IB start address of this region */
  77         size_t length;
  78         u32 lkey;
  79         u32 offset;             /* offset (bytes) to start of region */
  80         int access_flags;
  81         u32 max_segs;           /* number of rvt_segs in all the arrays */
  82         u32 mapsz;              /* size of the map array */
  83         atomic_t lkey_invalid;  /* true if current lkey is invalid */
  84         u8  page_shift;         /* 0 - non unform/non powerof2 sizes */
  85         u8  lkey_published;     /* in global table */
  86         struct percpu_ref refcount;
  87         struct completion comp; /* complete when refcount goes to zero */
  88         struct rvt_segarray *map[0];    /* the segments */
  89 };
  90
  91 #define RVT_MAX_LKEY_TABLE_BITS 23
  92
  93 struct rvt_lkey_table {
  94         /* read mostly fields */
  95         u32 max;                /* size of the table */
  96         u32 shift;              /* lkey/rkey shift */
  97         struct rvt_mregion __rcu **table;
  98         /* writeable fields */
  99         /* protect changes in this struct */
 100         spinlock_t lock ____cacheline_aligned_in_smp;
 101         u32 next;               /* next unused index (speeds search) */
 102         u32 gen;                /* generation count */
 103 };
 104
 105 /*
 106  * These keep track of the copy progress within a memory region.
 107  * Used by the verbs layer.
 108  */
 109 struct rvt_sge {
 110         struct rvt_mregion *mr;
 111         void *vaddr;            /* kernel virtual address of segment */
 112         u32 sge_length;         /* length of the SGE */
 113         u32 length;             /* remaining length of the segment */
 114         u16 m;                  /* current index: mr->map[m] */
 115         u16 n;                  /* current index: mr->map[m]->segs[n] */
 116 };
 117
 118 struct rvt_sge_state {
 119         struct rvt_sge *sg_list;      /* next SGE to be used if any */
 120         struct rvt_sge sge;   /* progress state for the current SGE */
 121         u32 total_len;
 122         u8 num_sge;
 123 };
 124
 125 static inline void rvt_put_mr(struct rvt_mregion *mr)
 126 {
 127         percpu_ref_put(&mr->refcount);
 128 }
 129
 130 static inline void rvt_get_mr(struct rvt_mregion *mr)
 131 {
 132         percpu_ref_get(&mr->refcount);
 133 }
 134
 135 static inline void rvt_put_ss(struct rvt_sge_state *ss)
 136 {
 137         while (ss->num_sge) {
 138                 rvt_put_mr(ss->sge.mr);
 139                 if (--ss->num_sge)
 140                         ss->sge = *ss->sg_list++;
 141         }
 142 }
 143
 144 static inline u32 rvt_get_sge_length(struct rvt_sge *sge, u32 length)
 145 {
 146         u32 len = sge->length;
 147
 148         if (len > length)
 149                 len = length;
 150         if (len > sge->sge_length)
 151                 len = sge->sge_length;
 152
 153         return len;
 154 }
 155
 156 static inline void rvt_update_sge(struct rvt_sge_state *ss, u32 length,
 157                                   bool release)
 158 {
 159         struct rvt_sge *sge = &ss->sge;
 160
 161         sge->vaddr += length;
 162         sge->length -= length;
 163         sge->sge_length -= length;
 164         if (sge->sge_length == 0) {
 165                 if (release)
 166                         rvt_put_mr(sge->mr);
 167                 if (--ss->num_sge)
 168                         *sge = *ss->sg_list++;
 169         } else if (sge->length == 0 && sge->mr->lkey) {
 170                 if (++sge->n >= RVT_SEGSZ) {
 171                         if (++sge->m >= sge->mr->mapsz)
 172                                 return;
 173                         sge->n = 0;
 174                 }
 175                 sge->vaddr = sge->mr->map[sge->m]->segs[sge->n].vaddr;
 176                 sge->length = sge->mr->map[sge->m]->segs[sge->n].length;
 177         }
 178 }
 179
 180 static inline void rvt_skip_sge(struct rvt_sge_state *ss, u32 length,
 181                                 bool release)
 182 {
 183         struct rvt_sge *sge = &ss->sge;
 184
 185         while (length) {
 186                 u32 len = rvt_get_sge_length(sge, length);
 187
 188                 WARN_ON_ONCE(len == 0);
 189                 rvt_update_sge(ss, len, release);
 190                 length -= len;
 191         }
 192 }
 193
 194 #endif          /* DEF_RDMAVT_INCMRH */