include/rdma/rdmavt_mr.h

   1 /* SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause */
   2 /*
   3  * Copyright(c) 2016 Intel Corporation.
   4  */
   5
   6 #ifndef DEF_RDMAVT_INCMR_H
   7 #define DEF_RDMAVT_INCMR_H
   8
   9 /*
  10  * For Memory Regions. This stuff should probably be moved into rdmavt/mr.h once
  11  * drivers no longer need access to the MR directly.
  12  */
  13 #include <linux/percpu-refcount.h>
  14
  15 /*
  16  * A segment is a linear region of low physical memory.
  17  * Used by the verbs layer.
  18  */
  19 struct rvt_seg {
  20         void *vaddr;
  21         size_t length;
  22 };
  23
  24 /* The number of rvt_segs that fit in a page. */
  25 #define RVT_SEGSZ     (PAGE_SIZE / sizeof(struct rvt_seg))
  26
  27 struct rvt_segarray {
  28         struct rvt_seg segs[RVT_SEGSZ];
  29 };
  30
  31 struct rvt_mregion {
  32         struct ib_pd *pd;       /* shares refcnt of ibmr.pd */
  33         u64 user_base;          /* User's address for this region */
  34         u64 iova;               /* IB start address of this region */
  35         size_t length;
  36         u32 lkey;
  37         u32 offset;             /* offset (bytes) to start of region */
  38         int access_flags;
  39         u32 max_segs;           /* number of rvt_segs in all the arrays */
  40         u32 mapsz;              /* size of the map array */
  41         atomic_t lkey_invalid;  /* true if current lkey is invalid */
  42         u8  page_shift;         /* 0 - non unform/non powerof2 sizes */
  43         u8  lkey_published;     /* in global table */
  44         struct percpu_ref refcount;
  45         struct completion comp; /* complete when refcount goes to zero */
  46         struct rvt_segarray *map[];    /* the segments */
  47 };
  48
  49 #define RVT_MAX_LKEY_TABLE_BITS 23
  50
  51 struct rvt_lkey_table {
  52         /* read mostly fields */
  53         u32 max;                /* size of the table */
  54         u32 shift;              /* lkey/rkey shift */
  55         struct rvt_mregion __rcu **table;
  56         /* writeable fields */
  57         /* protect changes in this struct */
  58         spinlock_t lock ____cacheline_aligned_in_smp;
  59         u32 next;               /* next unused index (speeds search) */
  60         u32 gen;                /* generation count */
  61 };
  62
  63 /*
  64  * These keep track of the copy progress within a memory region.
  65  * Used by the verbs layer.
  66  */
  67 struct rvt_sge {
  68         struct rvt_mregion *mr;
  69         void *vaddr;            /* kernel virtual address of segment */
  70         u32 sge_length;         /* length of the SGE */
  71         u32 length;             /* remaining length of the segment */
  72         u16 m;                  /* current index: mr->map[m] */
  73         u16 n;                  /* current index: mr->map[m]->segs[n] */
  74 };
  75
  76 struct rvt_sge_state {
  77         struct rvt_sge *sg_list;      /* next SGE to be used if any */
  78         struct rvt_sge sge;   /* progress state for the current SGE */
  79         u32 total_len;
  80         u8 num_sge;
  81 };
  82
  83 static inline void rvt_put_mr(struct rvt_mregion *mr)
  84 {
  85         percpu_ref_put(&mr->refcount);
  86 }
  87
  88 static inline void rvt_get_mr(struct rvt_mregion *mr)
  89 {
  90         percpu_ref_get(&mr->refcount);
  91 }
  92
  93 static inline void rvt_put_ss(struct rvt_sge_state *ss)
  94 {
  95         while (ss->num_sge) {
  96                 rvt_put_mr(ss->sge.mr);
  97                 if (--ss->num_sge)
  98                         ss->sge = *ss->sg_list++;
  99         }
 100 }
 101
 102 static inline u32 rvt_get_sge_length(struct rvt_sge *sge, u32 length)
 103 {
 104         u32 len = sge->length;
 105
 106         if (len > length)
 107                 len = length;
 108         if (len > sge->sge_length)
 109                 len = sge->sge_length;
 110
 111         return len;
 112 }
 113
 114 static inline void rvt_update_sge(struct rvt_sge_state *ss, u32 length,
 115                                   bool release)
 116 {
 117         struct rvt_sge *sge = &ss->sge;
 118
 119         sge->vaddr += length;
 120         sge->length -= length;
 121         sge->sge_length -= length;
 122         if (sge->sge_length == 0) {
 123                 if (release)
 124                         rvt_put_mr(sge->mr);
 125                 if (--ss->num_sge)
 126                         *sge = *ss->sg_list++;
 127         } else if (sge->length == 0 && sge->mr->lkey) {
 128                 if (++sge->n >= RVT_SEGSZ) {
 129                         if (++sge->m >= sge->mr->mapsz)
 130                                 return;
 131                         sge->n = 0;
 132                 }
 133                 sge->vaddr = sge->mr->map[sge->m]->segs[sge->n].vaddr;
 134                 sge->length = sge->mr->map[sge->m]->segs[sge->n].length;
 135         }
 136 }
 137
 138 static inline void rvt_skip_sge(struct rvt_sge_state *ss, u32 length,
 139                                 bool release)
 140 {
 141         struct rvt_sge *sge = &ss->sge;
 142
 143         while (length) {
 144                 u32 len = rvt_get_sge_length(sge, length);
 145
 146                 WARN_ON_ONCE(len == 0);
 147                 rvt_update_sge(ss, len, release);
 148                 length -= len;
 149         }
 150 }
 151
 152 bool rvt_ss_has_lkey(struct rvt_sge_state *ss, u32 lkey);
 153 bool rvt_mr_has_lkey(struct rvt_mregion *mr, u32 lkey);
 154
 155 #endif          /* DEF_RDMAVT_INCMRH */