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(rxe, buf_size, udata, buf);
21		if (IS_ERR(ip)) {
22			err = PTR_ERR(ip);
23			goto err1;
24		}
25
26		if (copy_to_user(outbuf, &ip->info, sizeof(ip->info))) {
27			err = -EFAULT;
28			goto err2;
29		}
30
31		spin_lock_bh(&rxe->pending_lock);
32		list_add(&ip->pending_mmaps, &rxe->pending_mmaps);
33		spin_unlock_bh(&rxe->pending_lock);
34	}
35
36	*ip_p = ip;
37
38	return 0;
39
40err2:
41	kfree(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,
56				 int *num_elem,
57				 unsigned int elem_size)
58{
59	struct rxe_queue *q;
60	size_t buf_size;
61	unsigned int num_slots;
62
63	/* num_elem == 0 is allowed, but uninteresting */
64	if (*num_elem < 0)
65		goto err1;
66
67	q = kmalloc(sizeof(*q), GFP_KERNEL);
68	if (!q)
69		goto err1;
70
71	q->rxe = rxe;
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(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(q);
103err1:
104	return NULL;
105}
106
107/* copies elements from original q to new q and then swaps the contents of the
108 * two q headers. This is so that if anyone is holding a pointer to q it will
109 * still work
110 */
111static int resize_finish(struct rxe_queue *q, struct rxe_queue *new_q,
112			 unsigned int num_elem)
113{
114	if (!queue_empty(q) && (num_elem < queue_count(q)))
115		return -EINVAL;
116
117	while (!queue_empty(q)) {
118		memcpy(producer_addr(new_q), consumer_addr(q),
119		       new_q->elem_size);
120		advance_producer(new_q);
121		advance_consumer(q);
122	}
123
124	swap(*q, *new_q);
125
126	return 0;
127}
128
129int rxe_queue_resize(struct rxe_queue *q, unsigned int *num_elem_p,
130		     unsigned int elem_size, struct ib_udata *udata,
131		     struct mminfo __user *outbuf, spinlock_t *producer_lock,
132		     spinlock_t *consumer_lock)
133{
134	struct rxe_queue *new_q;
135	unsigned int num_elem = *num_elem_p;
136	int err;
137	unsigned long flags = 0, flags1;
138
139	new_q = rxe_queue_init(q->rxe, &num_elem, elem_size);
140	if (!new_q)
141		return -ENOMEM;
142
143	err = do_mmap_info(new_q->rxe, outbuf, udata, new_q->buf,
144			   new_q->buf_size, &new_q->ip);
145	if (err) {
146		vfree(new_q->buf);
147		kfree(new_q);
148		goto err1;
149	}
150
151	spin_lock_irqsave(consumer_lock, flags1);
152
153	if (producer_lock) {
154		spin_lock_irqsave(producer_lock, flags);
155		err = resize_finish(q, new_q, num_elem);
156		spin_unlock_irqrestore(producer_lock, flags);
157	} else {
158		err = resize_finish(q, new_q, num_elem);
159	}
160
161	spin_unlock_irqrestore(consumer_lock, flags1);
162
163	rxe_queue_cleanup(new_q);	/* new/old dep on err */
164	if (err)
165		goto err1;
166
167	*num_elem_p = num_elem;
168	return 0;
169
170err1:
171	return err;
172}
173
174void rxe_queue_cleanup(struct rxe_queue *q)
175{
176	if (q->ip)
177		kref_put(&q->ip->ref, rxe_mmap_release);
178	else
179		vfree(q->buf);
180
181	kfree(q);
182}
183