1 // SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
3 * Copyright (c) 2016 Mellanox Technologies Ltd. All rights reserved.
4 * Copyright (c) 2015 System Fabric Works, Inc. All rights reserved.
7 #include <linux/vmalloc.h>
10 #include "rxe_queue.h"
12 int 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)
17 struct rxe_mmap_info *ip = NULL;
20 ip = rxe_create_mmap_info(rxe, buf_size, udata, buf);
26 if (copy_to_user(outbuf, &ip->info, sizeof(ip->info))) {
31 spin_lock_bh(&rxe->pending_lock);
32 list_add(&ip->pending_mmaps, &rxe->pending_mmaps);
33 spin_unlock_bh(&rxe->pending_lock);
46 inline void rxe_queue_reset(struct rxe_queue *q)
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
52 memset(q->buf->data, 0, q->buf_size - sizeof(struct rxe_queue_buf));
55 struct rxe_queue *rxe_queue_init(struct rxe_dev *rxe, int *num_elem,
56 unsigned int elem_size, enum queue_type type)
60 unsigned int num_slots;
62 /* num_elem == 0 is allowed, but uninteresting */
66 q = kzalloc(sizeof(*q), GFP_KERNEL);
73 /* used in resize, only need to copy used part of queue */
74 q->elem_size = elem_size;
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);
81 q->log2_elem_size = order_base_2(elem_size);
83 num_slots = *num_elem + 1;
84 num_slots = roundup_pow_of_two(num_slots);
85 q->index_mask = num_slots - 1;
87 buf_size = sizeof(struct rxe_queue_buf) + num_slots * elem_size;
89 q->buf = vmalloc_user(buf_size);
93 q->buf->log2_elem_size = q->log2_elem_size;
94 q->buf->index_mask = q->index_mask;
96 q->buf_size = buf_size;
98 *num_elem = num_slots - 1;
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
110 static int resize_finish(struct rxe_queue *q, struct rxe_queue *new_q,
111 unsigned int num_elem)
113 enum queue_type type = q->type;
118 if (!queue_empty(q, q->type) && (num_elem < queue_count(q, type)))
121 new_prod = queue_get_producer(new_q, type);
122 prod = queue_get_producer(q, type);
123 cons = queue_get_consumer(q, type);
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);
132 new_q->buf->producer_index = new_prod;
133 q->buf->consumer_index = cons;
135 /* update private index copies */
136 if (type == QUEUE_TYPE_TO_CLIENT)
137 new_q->index = new_q->buf->producer_index;
139 q->index = q->buf->consumer_index;
141 /* exchange rxe_queue headers */
147 int 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)
152 struct rxe_queue *new_q;
153 unsigned int num_elem = *num_elem_p;
155 unsigned long producer_flags;
156 unsigned long consumer_flags;
158 new_q = rxe_queue_init(q->rxe, &num_elem, elem_size, q->type);
162 err = do_mmap_info(new_q->rxe, outbuf, udata, new_q->buf,
163 new_q->buf_size, &new_q->ip);
170 spin_lock_irqsave(consumer_lock, consumer_flags);
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);
177 err = resize_finish(q, new_q, num_elem);
180 spin_unlock_irqrestore(consumer_lock, consumer_flags);
182 rxe_queue_cleanup(new_q); /* new/old dep on err */
186 *num_elem_p = num_elem;
193 void rxe_queue_cleanup(struct rxe_queue *q)
196 kref_put(&q->ip->ref, rxe_mmap_release);