xref: /openbmc/linux/include/rdma/rdmavt_mr.h (revision e2c75e76)
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 bool rvt_ss_has_lkey(struct rvt_sge_state *ss, u32 lkey);
195 bool rvt_mr_has_lkey(struct rvt_mregion *mr, u32 lkey);
196 
197 #endif          /* DEF_RDMAVT_INCMRH */
198