LXR linux/include/rdma/rdmavt

   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 */
  19struct 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
  27struct rvt_segarray {
  28        struct rvt_seg segs[RVT_SEGSZ];
  29};
  30
  31struct 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
  51struct 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 */
  67struct 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
  76struct 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
  83static inline void rvt_put_mr(struct rvt_mregion *mr)
  84{
  85        percpu_ref_put(&mr->refcount);
  86}
  87
  88static inline void rvt_get_mr(struct rvt_mregion *mr)
  89{
  90        percpu_ref_get(&mr->refcount);
  91}
  92
  93static 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
 102static 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
 114static 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
 138static 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
 152bool rvt_ss_has_lkey(struct rvt_sge_state *ss, u32 lkey);
 153bool rvt_mr_has_lkey(struct rvt_mregion *mr, u32 lkey);
 154
 155#endif          /* DEF_RDMAVT_INCMRH */
 156