rxe_queue.c

  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, 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(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(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);
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, q->type) && (num_elem < queue_count(q, type)))
119		return -EINVAL;
120
121	new_prod = queue_get_producer(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(new_q, new_prod);
129		cons = queue_next_index(q, 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(q->rxe, &num_elem, elem_size, q->type);
159	if (!new_q)
160		return -ENOMEM;
161
162	err = do_mmap_info(new_q->rxe, outbuf, udata, new_q->buf,
163			   new_q->buf_size, &new_q->ip);
164	if (err) {
165		vfree(new_q->buf);
166		kfree(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(producer_lock, producer_flags);
176	} else {
177		err = resize_finish(q, new_q, num_elem);
178	}
179
180	spin_unlock_irqrestore(consumer_lock, consumer_flags);
181
182	rxe_queue_cleanup(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(&q->ip->ref, rxe_mmap_release);
197	else
198		vfree(q->buf);
199
200	kfree(q);
201}