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 
do_mmap_info(struct rxe_dev * rxe,struct mminfo __user * outbuf,struct ib_udata * udata,struct rxe_queue_buf * buf,size_t buf_size,struct rxe_mmap_info ** ip_p)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)
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 
40 err2:
41 	kfree(ip);
42 err1:
43 	return err;
44 }
45 
rxe_queue_reset(struct rxe_queue * q)46 inline 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 
rxe_queue_init(struct rxe_dev * rxe,int * num_elem,unsigned int elem_size,enum queue_type type)55 struct 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 		goto err1;
65 
66 	q = kzalloc(sizeof(*q), GFP_KERNEL);
67 	if (!q)
68 		goto err1;
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 
101 err2:
102 	kfree(q);
103 err1:
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  */
resize_finish(struct rxe_queue * q,struct rxe_queue * new_q,unsigned int num_elem)111 static int resize_finish(struct rxe_queue *q, struct rxe_queue *new_q,
112 			 unsigned int num_elem)
113 {
114 	enum queue_type type = q->type;
115 	u32 new_prod;
116 	u32 prod;
117 	u32 cons;
118 
119 	if (!queue_empty(q, q->type) && (num_elem < queue_count(q, type)))
120 		return -EINVAL;
121 
122 	new_prod = queue_get_producer(new_q, type);
123 	prod = queue_get_producer(q, type);
124 	cons = queue_get_consumer(q, type);
125 
126 	while ((prod - cons) & q->index_mask) {
127 		memcpy(queue_addr_from_index(new_q, new_prod),
128 		       queue_addr_from_index(q, cons), new_q->elem_size);
129 		new_prod = queue_next_index(new_q, new_prod);
130 		cons = queue_next_index(q, cons);
131 	}
132 
133 	new_q->buf->producer_index = new_prod;
134 	q->buf->consumer_index = cons;
135 
136 	/* update private index copies */
137 	if (type == QUEUE_TYPE_TO_CLIENT)
138 		new_q->index = new_q->buf->producer_index;
139 	else
140 		q->index = q->buf->consumer_index;
141 
142 	/* exchange rxe_queue headers */
143 	swap(*q, *new_q);
144 
145 	return 0;
146 }
147 
rxe_queue_resize(struct rxe_queue * q,unsigned int * num_elem_p,unsigned int elem_size,struct ib_udata * udata,struct mminfo __user * outbuf,spinlock_t * producer_lock,spinlock_t * consumer_lock)148 int rxe_queue_resize(struct rxe_queue *q, unsigned int *num_elem_p,
149 		     unsigned int elem_size, struct ib_udata *udata,
150 		     struct mminfo __user *outbuf, spinlock_t *producer_lock,
151 		     spinlock_t *consumer_lock)
152 {
153 	struct rxe_queue *new_q;
154 	unsigned int num_elem = *num_elem_p;
155 	int err;
156 	unsigned long producer_flags;
157 	unsigned long consumer_flags;
158 
159 	new_q = rxe_queue_init(q->rxe, &num_elem, elem_size, q->type);
160 	if (!new_q)
161 		return -ENOMEM;
162 
163 	err = do_mmap_info(new_q->rxe, outbuf, udata, new_q->buf,
164 			   new_q->buf_size, &new_q->ip);
165 	if (err) {
166 		vfree(new_q->buf);
167 		kfree(new_q);
168 		goto err1;
169 	}
170 
171 	spin_lock_irqsave(consumer_lock, consumer_flags);
172 
173 	if (producer_lock) {
174 		spin_lock_irqsave(producer_lock, producer_flags);
175 		err = resize_finish(q, new_q, num_elem);
176 		spin_unlock_irqrestore(producer_lock, producer_flags);
177 	} else {
178 		err = resize_finish(q, new_q, num_elem);
179 	}
180 
181 	spin_unlock_irqrestore(consumer_lock, consumer_flags);
182 
183 	rxe_queue_cleanup(new_q);	/* new/old dep on err */
184 	if (err)
185 		goto err1;
186 
187 	*num_elem_p = num_elem;
188 	return 0;
189 
190 err1:
191 	return err;
192 }
193 
rxe_queue_cleanup(struct rxe_queue * q)194 void rxe_queue_cleanup(struct rxe_queue *q)
195 {
196 	if (q->ip)
197 		kref_put(&q->ip->ref, rxe_mmap_release);
198 	else
199 		vfree(q->buf);
200 
201 	kfree(q);
202 }
203