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 */
 61struct 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
 69struct rvt_segarray {
 70	struct rvt_seg segs[RVT_SEGSZ];
 71};
 72
 73struct 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
 93struct 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 */
109struct 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
118struct 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
125static inline void rvt_put_mr(struct rvt_mregion *mr)
126{
127	percpu_ref_put(&mr->refcount);
128}
129
130static inline void rvt_get_mr(struct rvt_mregion *mr)
131{
132	percpu_ref_get(&mr->refcount);
133}
134
135static 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
144static 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
156static 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
180static 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
194bool rvt_ss_has_lkey(struct rvt_sge_state *ss, u32 lkey);
195bool rvt_mr_has_lkey(struct rvt_mregion *mr, u32 lkey);
196
197#endif          /* DEF_RDMAVT_INCMRH */