1 /* -----------------------------------------------------------------------------
2 * Copyright (c) 2011 Ozmo Inc
3 * Released under the GNU General Public License Version 2 (GPLv2).
4 * -----------------------------------------------------------------------------
6 #include <linux/init.h>
7 #include <linux/module.h>
8 #include <linux/netdevice.h>
10 #include "ozprotocol.h"
14 /*------------------------------------------------------------------------------
16 #define OZ_ELT_INFO_MAGIC_USED 0x35791057
17 #define OZ_ELT_INFO_MAGIC_FREE 0x78940102
18 /*------------------------------------------------------------------------------
19 * Context: softirq-serialized
21 int oz_elt_buf_init(struct oz_elt_buf *buf)
23 memset(buf, 0, sizeof(struct oz_elt_buf));
24 INIT_LIST_HEAD(&buf->stream_list);
25 INIT_LIST_HEAD(&buf->order_list);
26 INIT_LIST_HEAD(&buf->isoc_list);
27 buf->max_free_elts = 32;
28 spin_lock_init(&buf->lock);
31 /*------------------------------------------------------------------------------
32 * Context: softirq or process
34 void oz_elt_buf_term(struct oz_elt_buf *buf)
38 /* Free any elements in the order or isoc lists. */
39 for (i = 0; i < 2; i++) {
40 struct list_head *list;
42 list = &buf->order_list;
44 list = &buf->isoc_list;
47 struct oz_elt_info *ei =
48 container_of(e, struct oz_elt_info, link_order);
53 /* Free any elelment in the pool. */
54 while (buf->elt_pool) {
55 struct oz_elt_info *ei =
56 container_of(buf->elt_pool, struct oz_elt_info, link);
57 buf->elt_pool = buf->elt_pool->next;
62 /*------------------------------------------------------------------------------
63 * Context: softirq or process
65 struct oz_elt_info *oz_elt_info_alloc(struct oz_elt_buf *buf)
67 struct oz_elt_info *ei = NULL;
68 spin_lock_bh(&buf->lock);
69 if (buf->free_elts && buf->elt_pool) {
70 ei = container_of(buf->elt_pool, struct oz_elt_info, link);
71 buf->elt_pool = ei->link.next;
73 spin_unlock_bh(&buf->lock);
74 if (ei->magic != OZ_ELT_INFO_MAGIC_FREE) {
75 oz_trace("oz_elt_info_alloc: ei with bad magic: 0x%x\n",
79 spin_unlock_bh(&buf->lock);
80 ei = kmalloc(sizeof(struct oz_elt_info), GFP_ATOMIC);
88 ei->magic = OZ_ELT_INFO_MAGIC_USED;
89 INIT_LIST_HEAD(&ei->link);
90 INIT_LIST_HEAD(&ei->link_order);
94 /*------------------------------------------------------------------------------
95 * Precondition: oz_elt_buf.lock must be held.
96 * Context: softirq or process
98 void oz_elt_info_free(struct oz_elt_buf *buf, struct oz_elt_info *ei)
101 if (ei->magic == OZ_ELT_INFO_MAGIC_USED) {
103 ei->link.next = buf->elt_pool;
104 buf->elt_pool = &ei->link;
105 ei->magic = OZ_ELT_INFO_MAGIC_FREE;
107 oz_trace("oz_elt_info_free: bad magic ei: %p"
113 /*------------------------------------------------------------------------------
116 void oz_elt_info_free_chain(struct oz_elt_buf *buf, struct list_head *list)
120 spin_lock_bh(&buf->lock);
122 struct oz_elt_info *ei;
123 ei = container_of(e, struct oz_elt_info, link);
125 oz_elt_info_free(buf, ei);
127 spin_unlock_bh(&buf->lock);
129 /*------------------------------------------------------------------------------
131 int oz_elt_stream_create(struct oz_elt_buf *buf, u8 id, int max_buf_count)
133 struct oz_elt_stream *st;
135 oz_trace("oz_elt_stream_create(0x%x)\n", id);
137 st = kzalloc(sizeof(struct oz_elt_stream), GFP_ATOMIC | __GFP_ZERO);
140 atomic_set(&st->ref_count, 1);
142 st->max_buf_count = max_buf_count;
143 INIT_LIST_HEAD(&st->elt_list);
144 spin_lock_bh(&buf->lock);
145 list_add_tail(&st->link, &buf->stream_list);
146 spin_unlock_bh(&buf->lock);
149 /*------------------------------------------------------------------------------
151 int oz_elt_stream_delete(struct oz_elt_buf *buf, u8 id)
154 struct oz_elt_stream *st = NULL;
155 oz_trace("oz_elt_stream_delete(0x%x)\n", id);
156 spin_lock_bh(&buf->lock);
157 e = buf->stream_list.next;
158 while (e != &buf->stream_list) {
159 st = container_of(e, struct oz_elt_stream, link);
167 spin_unlock_bh(&buf->lock);
170 e = st->elt_list.next;
171 while (e != &st->elt_list) {
172 struct oz_elt_info *ei =
173 container_of(e, struct oz_elt_info, link);
175 list_del_init(&ei->link);
176 list_del_init(&ei->link_order);
177 st->buf_count -= ei->length;
178 oz_trace2(OZ_TRACE_STREAM, "Stream down: %d %d %d\n",
180 ei->length, atomic_read(&st->ref_count));
181 oz_elt_stream_put(st);
182 oz_elt_info_free(buf, ei);
184 spin_unlock_bh(&buf->lock);
185 oz_elt_stream_put(st);
188 /*------------------------------------------------------------------------------
190 void oz_elt_stream_get(struct oz_elt_stream *st)
192 atomic_inc(&st->ref_count);
194 /*------------------------------------------------------------------------------
196 void oz_elt_stream_put(struct oz_elt_stream *st)
198 if (atomic_dec_and_test(&st->ref_count)) {
199 oz_trace("Stream destroyed\n");
203 /*------------------------------------------------------------------------------
204 * Precondition: Element buffer lock must be held.
205 * If this function fails the caller is responsible for deallocating the elt
208 int oz_queue_elt_info(struct oz_elt_buf *buf, u8 isoc, u8 id,
209 struct oz_elt_info *ei)
211 struct oz_elt_stream *st = NULL;
214 list_for_each(e, &buf->stream_list) {
215 st = container_of(e, struct oz_elt_stream, link);
219 if (e == &buf->stream_list) {
220 /* Stream specified but stream not known so fail.
221 * Caller deallocates element info. */
226 /* If this is an ISOC fixed element that needs a frame number
227 * then insert that now. Earlier we stored the unit count in
230 struct oz_isoc_fixed *body = (struct oz_isoc_fixed *)
231 &ei->data[sizeof(struct oz_elt)];
232 if ((body->app_id == OZ_APPID_USB) && (body->type
233 == OZ_USB_ENDPOINT_DATA) &&
234 (body->format == OZ_DATA_F_ISOC_FIXED)) {
235 u8 unit_count = body->frame_number;
236 body->frame_number = st->frame_number;
237 st->frame_number += unit_count;
239 /* Claim stream and update accounts */
240 oz_elt_stream_get(st);
242 st->buf_count += ei->length;
243 /* Add to list in stream. */
244 list_add_tail(&ei->link, &st->elt_list);
245 oz_trace2(OZ_TRACE_STREAM, "Stream up: %d %d\n",
246 st->buf_count, ei->length);
247 /* Check if we have too much buffered for this stream. If so
248 * start dropping elements until we are back in bounds.
250 while ((st->buf_count > st->max_buf_count) &&
251 !list_empty(&st->elt_list)) {
252 struct oz_elt_info *ei2 =
253 list_first_entry(&st->elt_list,
254 struct oz_elt_info, link);
255 list_del_init(&ei2->link);
256 list_del_init(&ei2->link_order);
257 st->buf_count -= ei2->length;
258 oz_elt_info_free(buf, ei2);
259 oz_elt_stream_put(st);
262 list_add_tail(&ei->link_order, isoc ?
263 &buf->isoc_list : &buf->order_list);
266 /*------------------------------------------------------------------------------
268 int oz_select_elts_for_tx(struct oz_elt_buf *buf, u8 isoc, unsigned *len,
269 unsigned max_len, struct list_head *list)
273 struct list_head *el;
274 struct oz_elt_info *ei;
275 spin_lock_bh(&buf->lock);
277 el = &buf->isoc_list;
279 el = &buf->order_list;
282 struct oz_app_hdr *app_hdr;
283 ei = container_of(e, struct oz_elt_info, link_order);
285 if ((*len + ei->length) <= max_len) {
286 app_hdr = (struct oz_app_hdr *)
287 &ei->data[sizeof(struct oz_elt)];
288 app_hdr->elt_seq_num = buf->tx_seq_num[ei->app_id]++;
289 if (buf->tx_seq_num[ei->app_id] == 0)
290 buf->tx_seq_num[ei->app_id] = 1;
293 list_del(&ei->link_order);
295 ei->stream->buf_count -= ei->length;
296 oz_trace2(OZ_TRACE_STREAM,
297 "Stream down: %d %d\n",
298 ei->stream->buf_count, ei->length);
299 oz_elt_stream_put(ei->stream);
302 INIT_LIST_HEAD(&ei->link_order);
303 list_add_tail(&ei->link, list);
309 spin_unlock_bh(&buf->lock);
312 /*------------------------------------------------------------------------------
314 int oz_are_elts_available(struct oz_elt_buf *buf)
316 return buf->order_list.next != &buf->order_list;
318 /*------------------------------------------------------------------------------
320 void oz_trim_elt_pool(struct oz_elt_buf *buf)
322 struct list_head *free = NULL;
324 spin_lock_bh(&buf->lock);
325 while (buf->free_elts > buf->max_free_elts) {
327 buf->elt_pool = e->next;
332 spin_unlock_bh(&buf->lock);
334 struct oz_elt_info *ei =
335 container_of(free, struct oz_elt_info, link);