1// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
2/*
3 * Copyright (c) 2016 Mellanox Technologies Ltd. All rights reserved.
4 * Copyright (c) 2015 System Fabric Works, Inc. All rights reserved.
5 */
6
7#include <linux/vmalloc.h>
8#include "rxe.h"
9#include "rxe_loc.h"
10#include "rxe_queue.h"
11
12int do_mmap_info(struct rxe_dev *rxe, struct mminfo __user *outbuf,
13 struct ib_udata *udata, struct rxe_queue_buf *buf,
14 size_t buf_size, struct rxe_mmap_info **ip_p)
15{
16 int err;
17 struct rxe_mmap_info *ip = NULL;
18
19 if (outbuf) {
20 ip = rxe_create_mmap_info(dev: rxe, size: buf_size, udata, obj: buf);
21 if (IS_ERR(ptr: ip)) {
22 err = PTR_ERR(ptr: ip);
23 goto err1;
24 }
25
26 if (copy_to_user(to: outbuf, from: &ip->info, n: sizeof(ip->info))) {
27 err = -EFAULT;
28 goto err2;
29 }
30
31 spin_lock_bh(lock: &rxe->pending_lock);
32 list_add(new: &ip->pending_mmaps, head: &rxe->pending_mmaps);
33 spin_unlock_bh(lock: &rxe->pending_lock);
34 }
35
36 *ip_p = ip;
37
38 return 0;
39
40err2:
41 kfree(objp: ip);
42err1:
43 return err;
44}
45
46inline void rxe_queue_reset(struct rxe_queue *q)
47{
48 /* queue is comprised from header and the memory
49 * of the actual queue. See "struct rxe_queue_buf" in rxe_queue.h
50 * reset only the queue itself and not the management header
51 */
52 memset(q->buf->data, 0, q->buf_size - sizeof(struct rxe_queue_buf));
53}
54
55struct rxe_queue *rxe_queue_init(struct rxe_dev *rxe, int *num_elem,
56 unsigned int elem_size, enum queue_type type)
57{
58 struct rxe_queue *q;
59 size_t buf_size;
60 unsigned int num_slots;
61
62 /* num_elem == 0 is allowed, but uninteresting */
63 if (*num_elem < 0)
64 return NULL;
65
66 q = kzalloc(size: sizeof(*q), GFP_KERNEL);
67 if (!q)
68 return NULL;
69
70 q->rxe = rxe;
71 q->type = type;
72
73 /* used in resize, only need to copy used part of queue */
74 q->elem_size = elem_size;
75
76 /* pad element up to at least a cacheline and always a power of 2 */
77 if (elem_size < cache_line_size())
78 elem_size = cache_line_size();
79 elem_size = roundup_pow_of_two(elem_size);
80
81 q->log2_elem_size = order_base_2(elem_size);
82
83 num_slots = *num_elem + 1;
84 num_slots = roundup_pow_of_two(num_slots);
85 q->index_mask = num_slots - 1;
86
87 buf_size = sizeof(struct rxe_queue_buf) + num_slots * elem_size;
88
89 q->buf = vmalloc_user(size: buf_size);
90 if (!q->buf)
91 goto err2;
92
93 q->buf->log2_elem_size = q->log2_elem_size;
94 q->buf->index_mask = q->index_mask;
95
96 q->buf_size = buf_size;
97
98 *num_elem = num_slots - 1;
99 return q;
100
101err2:
102 kfree(objp: q);
103 return NULL;
104}
105
106/* copies elements from original q to new q and then swaps the contents of the
107 * two q headers. This is so that if anyone is holding a pointer to q it will
108 * still work
109 */
110static int resize_finish(struct rxe_queue *q, struct rxe_queue *new_q,
111 unsigned int num_elem)
112{
113 enum queue_type type = q->type;
114 u32 new_prod;
115 u32 prod;
116 u32 cons;
117
118 if (!queue_empty(q, type: q->type) && (num_elem < queue_count(q, type)))
119 return -EINVAL;
120
121 new_prod = queue_get_producer(q: new_q, type);
122 prod = queue_get_producer(q, type);
123 cons = queue_get_consumer(q, type);
124
125 while ((prod - cons) & q->index_mask) {
126 memcpy(queue_addr_from_index(new_q, new_prod),
127 queue_addr_from_index(q, cons), new_q->elem_size);
128 new_prod = queue_next_index(q: new_q, index: new_prod);
129 cons = queue_next_index(q, index: cons);
130 }
131
132 new_q->buf->producer_index = new_prod;
133 q->buf->consumer_index = cons;
134
135 /* update private index copies */
136 if (type == QUEUE_TYPE_TO_CLIENT)
137 new_q->index = new_q->buf->producer_index;
138 else
139 q->index = q->buf->consumer_index;
140
141 /* exchange rxe_queue headers */
142 swap(*q, *new_q);
143
144 return 0;
145}
146
147int rxe_queue_resize(struct rxe_queue *q, unsigned int *num_elem_p,
148 unsigned int elem_size, struct ib_udata *udata,
149 struct mminfo __user *outbuf, spinlock_t *producer_lock,
150 spinlock_t *consumer_lock)
151{
152 struct rxe_queue *new_q;
153 unsigned int num_elem = *num_elem_p;
154 int err;
155 unsigned long producer_flags;
156 unsigned long consumer_flags;
157
158 new_q = rxe_queue_init(rxe: q->rxe, num_elem: &num_elem, elem_size, type: q->type);
159 if (!new_q)
160 return -ENOMEM;
161
162 err = do_mmap_info(rxe: new_q->rxe, outbuf, udata, buf: new_q->buf,
163 buf_size: new_q->buf_size, ip_p: &new_q->ip);
164 if (err) {
165 vfree(addr: new_q->buf);
166 kfree(objp: new_q);
167 goto err1;
168 }
169
170 spin_lock_irqsave(consumer_lock, consumer_flags);
171
172 if (producer_lock) {
173 spin_lock_irqsave(producer_lock, producer_flags);
174 err = resize_finish(q, new_q, num_elem);
175 spin_unlock_irqrestore(lock: producer_lock, flags: producer_flags);
176 } else {
177 err = resize_finish(q, new_q, num_elem);
178 }
179
180 spin_unlock_irqrestore(lock: consumer_lock, flags: consumer_flags);
181
182 rxe_queue_cleanup(queue: new_q); /* new/old dep on err */
183 if (err)
184 goto err1;
185
186 *num_elem_p = num_elem;
187 return 0;
188
189err1:
190 return err;
191}
192
193void rxe_queue_cleanup(struct rxe_queue *q)
194{
195 if (q->ip)
196 kref_put(kref: &q->ip->ref, release: rxe_mmap_release);
197 else
198 vfree(addr: q->buf);
199
200 kfree(objp: q);
201}
202

source code of linux/drivers/infiniband/sw/rxe/rxe_queue.c