include/rdma/rdmavt_mr.h

0001 /* SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause */
0002 /*
0003  * Copyright(c) 2016 Intel Corporation.
0004  */
0005
0006 #ifndef DEF_RDMAVT_INCMR_H
0007 #define DEF_RDMAVT_INCMR_H
0008
0009 /*
0010  * For Memory Regions. This stuff should probably be moved into rdmavt/mr.h once
0011  * drivers no longer need access to the MR directly.
0012  */
0013 #include <linux/percpu-refcount.h>
0014
0015 /*
0016  * A segment is a linear region of low physical memory.
0017  * Used by the verbs layer.
0018  */
0019 struct rvt_seg {
0020     void *vaddr;
0021     size_t length;
0022 };
0023
0024 /* The number of rvt_segs that fit in a page. */
0025 #define RVT_SEGSZ     (PAGE_SIZE / sizeof(struct rvt_seg))
0026
0027 struct rvt_segarray {
0028     struct rvt_seg segs[RVT_SEGSZ];
0029 };
0030
0031 struct rvt_mregion {
0032     struct ib_pd *pd;       /* shares refcnt of ibmr.pd */
0033     u64 user_base;          /* User's address for this region */
0034     u64 iova;               /* IB start address of this region */
0035     size_t length;
0036     u32 lkey;
0037     u32 offset;             /* offset (bytes) to start of region */
0038     int access_flags;
0039     u32 max_segs;           /* number of rvt_segs in all the arrays */
0040     u32 mapsz;              /* size of the map array */
0041     atomic_t lkey_invalid;  /* true if current lkey is invalid */
0042     u8  page_shift;         /* 0 - non unform/non powerof2 sizes */
0043     u8  lkey_published;     /* in global table */
0044     struct percpu_ref refcount;
0045     struct completion comp; /* complete when refcount goes to zero */
0046     struct rvt_segarray *map[];    /* the segments */
0047 };
0048
0049 #define RVT_MAX_LKEY_TABLE_BITS 23
0050
0051 struct rvt_lkey_table {
0052     /* read mostly fields */
0053     u32 max;                /* size of the table */
0054     u32 shift;              /* lkey/rkey shift */
0055     struct rvt_mregion __rcu **table;
0056     /* writeable fields */
0057     /* protect changes in this struct */
0058     spinlock_t lock ____cacheline_aligned_in_smp;
0059     u32 next;               /* next unused index (speeds search) */
0060     u32 gen;                /* generation count */
0061 };
0062
0063 /*
0064  * These keep track of the copy progress within a memory region.
0065  * Used by the verbs layer.
0066  */
0067 struct rvt_sge {
0068     struct rvt_mregion *mr;
0069     void *vaddr;            /* kernel virtual address of segment */
0070     u32 sge_length;         /* length of the SGE */
0071     u32 length;             /* remaining length of the segment */
0072     u16 m;                  /* current index: mr->map[m] */
0073     u16 n;                  /* current index: mr->map[m]->segs[n] */
0074 };
0075
0076 struct rvt_sge_state {
0077     struct rvt_sge *sg_list;      /* next SGE to be used if any */
0078     struct rvt_sge sge;   /* progress state for the current SGE */
0079     u32 total_len;
0080     u8 num_sge;
0081 };
0082
0083 static inline void rvt_put_mr(struct rvt_mregion *mr)
0084 {
0085     percpu_ref_put(&mr->refcount);
0086 }
0087
0088 static inline void rvt_get_mr(struct rvt_mregion *mr)
0089 {
0090     percpu_ref_get(&mr->refcount);
0091 }
0092
0093 static inline void rvt_put_ss(struct rvt_sge_state *ss)
0094 {
0095     while (ss->num_sge) {
0096         rvt_put_mr(ss->sge.mr);
0097         if (--ss->num_sge)
0098             ss->sge = *ss->sg_list++;
0099     }
0100 }
0101
0102 static inline u32 rvt_get_sge_length(struct rvt_sge *sge, u32 length)
0103 {
0104     u32 len = sge->length;
0105
0106     if (len > length)
0107         len = length;
0108     if (len > sge->sge_length)
0109         len = sge->sge_length;
0110
0111     return len;
0112 }
0113
0114 static inline void rvt_update_sge(struct rvt_sge_state *ss, u32 length,
0115                   bool release)
0116 {
0117     struct rvt_sge *sge = &ss->sge;
0118
0119     sge->vaddr += length;
0120     sge->length -= length;
0121     sge->sge_length -= length;
0122     if (sge->sge_length == 0) {
0123         if (release)
0124             rvt_put_mr(sge->mr);
0125         if (--ss->num_sge)
0126             *sge = *ss->sg_list++;
0127     } else if (sge->length == 0 && sge->mr->lkey) {
0128         if (++sge->n >= RVT_SEGSZ) {
0129             if (++sge->m >= sge->mr->mapsz)
0130                 return;
0131             sge->n = 0;
0132         }
0133         sge->vaddr = sge->mr->map[sge->m]->segs[sge->n].vaddr;
0134         sge->length = sge->mr->map[sge->m]->segs[sge->n].length;
0135     }
0136 }
0137
0138 static inline void rvt_skip_sge(struct rvt_sge_state *ss, u32 length,
0139                 bool release)
0140 {
0141     struct rvt_sge *sge = &ss->sge;
0142
0143     while (length) {
0144         u32 len = rvt_get_sge_length(sge, length);
0145
0146         WARN_ON_ONCE(len == 0);
0147         rvt_update_sge(ss, len, release);
0148         length -= len;
0149     }
0150 }
0151
0152 bool rvt_ss_has_lkey(struct rvt_sge_state *ss, u32 lkey);
0153 bool rvt_mr_has_lkey(struct rvt_mregion *mr, u32 lkey);
0154
0155 #endif          /* DEF_RDMAVT_INCMRH */