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)
39 /* Free any elements in the order or isoc lists. */
40 for (i = 0; i < 2; i++) {
41 struct list_head *list;
43 list = &buf->order_list;
45 list = &buf->isoc_list;
48 struct oz_elt_info *ei =
49 container_of(e, struct oz_elt_info, link_order);
54 /* Free any elelment in the pool. */
55 while (buf->elt_pool) {
56 struct oz_elt_info *ei =
57 container_of(buf->elt_pool, struct oz_elt_info, link);
58 buf->elt_pool = buf->elt_pool->next;
63 /*------------------------------------------------------------------------------
64 * Context: softirq or process
66 struct oz_elt_info *oz_elt_info_alloc(struct oz_elt_buf *buf)
68 struct oz_elt_info *ei = NULL;
70 spin_lock_bh(&buf->lock);
71 if (buf->free_elts && buf->elt_pool) {
72 ei = container_of(buf->elt_pool, struct oz_elt_info, link);
73 buf->elt_pool = ei->link.next;
75 spin_unlock_bh(&buf->lock);
76 if (ei->magic != OZ_ELT_INFO_MAGIC_FREE) {
77 oz_dbg(ON, "%s: ei with bad magic: 0x%x\n",
81 spin_unlock_bh(&buf->lock);
82 ei = kmalloc(sizeof(struct oz_elt_info), GFP_ATOMIC);
90 ei->magic = OZ_ELT_INFO_MAGIC_USED;
91 INIT_LIST_HEAD(&ei->link);
92 INIT_LIST_HEAD(&ei->link_order);
96 /*------------------------------------------------------------------------------
97 * Precondition: oz_elt_buf.lock must be held.
98 * Context: softirq or process
100 void oz_elt_info_free(struct oz_elt_buf *buf, struct oz_elt_info *ei)
103 if (ei->magic == OZ_ELT_INFO_MAGIC_USED) {
105 ei->link.next = buf->elt_pool;
106 buf->elt_pool = &ei->link;
107 ei->magic = OZ_ELT_INFO_MAGIC_FREE;
109 oz_dbg(ON, "%s: bad magic ei: %p magic: 0x%x\n",
110 __func__, ei, ei->magic);
114 /*------------------------------------------------------------------------------
117 void oz_elt_info_free_chain(struct oz_elt_buf *buf, struct list_head *list)
122 spin_lock_bh(&buf->lock);
124 struct oz_elt_info *ei;
125 ei = container_of(e, struct oz_elt_info, link);
127 oz_elt_info_free(buf, ei);
129 spin_unlock_bh(&buf->lock);
131 /*------------------------------------------------------------------------------
133 int oz_elt_stream_create(struct oz_elt_buf *buf, u8 id, int max_buf_count)
135 struct oz_elt_stream *st;
137 oz_dbg(ON, "%s: (0x%x)\n", __func__, id);
139 st = kzalloc(sizeof(struct oz_elt_stream), GFP_ATOMIC | __GFP_ZERO);
142 atomic_set(&st->ref_count, 1);
144 st->max_buf_count = max_buf_count;
145 INIT_LIST_HEAD(&st->elt_list);
146 spin_lock_bh(&buf->lock);
147 list_add_tail(&st->link, &buf->stream_list);
148 spin_unlock_bh(&buf->lock);
151 /*------------------------------------------------------------------------------
153 int oz_elt_stream_delete(struct oz_elt_buf *buf, u8 id)
156 struct oz_elt_stream *st = NULL;
158 oz_dbg(ON, "%s: (0x%x)\n", __func__, id);
159 spin_lock_bh(&buf->lock);
160 e = buf->stream_list.next;
161 while (e != &buf->stream_list) {
162 st = container_of(e, struct oz_elt_stream, link);
170 spin_unlock_bh(&buf->lock);
173 e = st->elt_list.next;
174 while (e != &st->elt_list) {
175 struct oz_elt_info *ei =
176 container_of(e, struct oz_elt_info, link);
178 list_del_init(&ei->link);
179 list_del_init(&ei->link_order);
180 st->buf_count -= ei->length;
181 oz_dbg(STREAM, "Stream down: %d %d %d\n",
182 st->buf_count, ei->length, atomic_read(&st->ref_count));
183 oz_elt_stream_put(st);
184 oz_elt_info_free(buf, ei);
186 spin_unlock_bh(&buf->lock);
187 oz_elt_stream_put(st);
190 /*------------------------------------------------------------------------------
192 void oz_elt_stream_get(struct oz_elt_stream *st)
194 atomic_inc(&st->ref_count);
196 /*------------------------------------------------------------------------------
198 void oz_elt_stream_put(struct oz_elt_stream *st)
200 if (atomic_dec_and_test(&st->ref_count)) {
201 oz_dbg(ON, "Stream destroyed\n");
205 /*------------------------------------------------------------------------------
206 * Precondition: Element buffer lock must be held.
207 * If this function fails the caller is responsible for deallocating the elt
210 int oz_queue_elt_info(struct oz_elt_buf *buf, u8 isoc, u8 id,
211 struct oz_elt_info *ei)
213 struct oz_elt_stream *st = NULL;
217 list_for_each(e, &buf->stream_list) {
218 st = container_of(e, struct oz_elt_stream, link);
222 if (e == &buf->stream_list) {
223 /* Stream specified but stream not known so fail.
224 * Caller deallocates element info. */
229 /* If this is an ISOC fixed element that needs a frame number
230 * then insert that now. Earlier we stored the unit count in
233 struct oz_isoc_fixed *body = (struct oz_isoc_fixed *)
234 &ei->data[sizeof(struct oz_elt)];
235 if ((body->app_id == OZ_APPID_USB) && (body->type
236 == OZ_USB_ENDPOINT_DATA) &&
237 (body->format == OZ_DATA_F_ISOC_FIXED)) {
238 u8 unit_count = body->frame_number;
239 body->frame_number = st->frame_number;
240 st->frame_number += unit_count;
242 /* Claim stream and update accounts */
243 oz_elt_stream_get(st);
245 st->buf_count += ei->length;
246 /* Add to list in stream. */
247 list_add_tail(&ei->link, &st->elt_list);
248 oz_dbg(STREAM, "Stream up: %d %d\n", st->buf_count, ei->length);
249 /* Check if we have too much buffered for this stream. If so
250 * start dropping elements until we are back in bounds.
252 while ((st->buf_count > st->max_buf_count) &&
253 !list_empty(&st->elt_list)) {
254 struct oz_elt_info *ei2 =
255 list_first_entry(&st->elt_list,
256 struct oz_elt_info, link);
257 list_del_init(&ei2->link);
258 list_del_init(&ei2->link_order);
259 st->buf_count -= ei2->length;
260 oz_elt_info_free(buf, ei2);
261 oz_elt_stream_put(st);
264 list_add_tail(&ei->link_order, isoc ?
265 &buf->isoc_list : &buf->order_list);
268 /*------------------------------------------------------------------------------
270 int oz_select_elts_for_tx(struct oz_elt_buf *buf, u8 isoc, unsigned *len,
271 unsigned max_len, struct list_head *list)
275 struct list_head *el;
276 struct oz_elt_info *ei;
278 spin_lock_bh(&buf->lock);
280 el = &buf->isoc_list;
282 el = &buf->order_list;
285 struct oz_app_hdr *app_hdr;
286 ei = container_of(e, struct oz_elt_info, link_order);
288 if ((*len + ei->length) <= max_len) {
289 app_hdr = (struct oz_app_hdr *)
290 &ei->data[sizeof(struct oz_elt)];
291 app_hdr->elt_seq_num = buf->tx_seq_num[ei->app_id]++;
292 if (buf->tx_seq_num[ei->app_id] == 0)
293 buf->tx_seq_num[ei->app_id] = 1;
296 list_del(&ei->link_order);
298 ei->stream->buf_count -= ei->length;
299 oz_dbg(STREAM, "Stream down: %d %d\n",
300 ei->stream->buf_count, ei->length);
301 oz_elt_stream_put(ei->stream);
304 INIT_LIST_HEAD(&ei->link_order);
305 list_add_tail(&ei->link, list);
311 spin_unlock_bh(&buf->lock);
314 /*------------------------------------------------------------------------------
316 int oz_are_elts_available(struct oz_elt_buf *buf)
318 return buf->order_list.next != &buf->order_list;
320 /*------------------------------------------------------------------------------
322 void oz_trim_elt_pool(struct oz_elt_buf *buf)
324 struct list_head *free = NULL;
327 spin_lock_bh(&buf->lock);
328 while (buf->free_elts > buf->max_free_elts) {
330 buf->elt_pool = e->next;
335 spin_unlock_bh(&buf->lock);
337 struct oz_elt_info *ei =
338 container_of(free, struct oz_elt_info, link);