1/* Copyright (c) 2014 Broadcom Corporation
2 *
3 * Permission to use, copy, modify, and/or distribute this software for any
4 * purpose with or without fee is hereby granted, provided that the above
5 * copyright notice and this permission notice appear in all copies.
6 *
7 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
8 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
9 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
10 * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
11 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
12 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
13 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
14 */
15
16#include <linux/types.h>
17#include <linux/netdevice.h>
18
19#include <brcmu_utils.h>
20#include <brcmu_wifi.h>
21
22#include "core.h"
23#include "commonring.h"
24
25
26/* dma flushing needs implementation for mips and arm platforms. Should
27 * be put in util. Note, this is not real flushing. It is virtual non
28 * cached memory. Only write buffers should have to be drained. Though
29 * this may be different depending on platform......
30 * SEE ALSO msgbuf.c
31 */
32#define brcmf_dma_flush(addr, len)
33#define brcmf_dma_invalidate_cache(addr, len)
34
35
36void brcmf_commonring_register_cb(struct brcmf_commonring *commonring,
37				  int (*cr_ring_bell)(void *ctx),
38				  int (*cr_update_rptr)(void *ctx),
39				  int (*cr_update_wptr)(void *ctx),
40				  int (*cr_write_rptr)(void *ctx),
41				  int (*cr_write_wptr)(void *ctx), void *ctx)
42{
43	commonring->cr_ring_bell = cr_ring_bell;
44	commonring->cr_update_rptr = cr_update_rptr;
45	commonring->cr_update_wptr = cr_update_wptr;
46	commonring->cr_write_rptr = cr_write_rptr;
47	commonring->cr_write_wptr = cr_write_wptr;
48	commonring->cr_ctx = ctx;
49}
50
51
52void brcmf_commonring_config(struct brcmf_commonring *commonring, u16 depth,
53			     u16 item_len, void *buf_addr)
54{
55	commonring->depth = depth;
56	commonring->item_len = item_len;
57	commonring->buf_addr = buf_addr;
58	if (!commonring->inited) {
59		spin_lock_init(&commonring->lock);
60		commonring->inited = true;
61	}
62	commonring->r_ptr = 0;
63	if (commonring->cr_write_rptr)
64		commonring->cr_write_rptr(commonring->cr_ctx);
65	commonring->w_ptr = 0;
66	if (commonring->cr_write_wptr)
67		commonring->cr_write_wptr(commonring->cr_ctx);
68	commonring->f_ptr = 0;
69}
70
71
72void brcmf_commonring_lock(struct brcmf_commonring *commonring)
73		__acquires(&commonring->lock)
74{
75	unsigned long flags;
76
77	spin_lock_irqsave(&commonring->lock, flags);
78	commonring->flags = flags;
79}
80
81
82void brcmf_commonring_unlock(struct brcmf_commonring *commonring)
83		__releases(&commonring->lock)
84{
85	spin_unlock_irqrestore(&commonring->lock, commonring->flags);
86}
87
88
89bool brcmf_commonring_write_available(struct brcmf_commonring *commonring)
90{
91	u16 available;
92	bool retry = true;
93
94again:
95	if (commonring->r_ptr <= commonring->w_ptr)
96		available = commonring->depth - commonring->w_ptr +
97			    commonring->r_ptr;
98	else
99		available = commonring->r_ptr - commonring->w_ptr;
100
101	if (available > 1) {
102		if (!commonring->was_full)
103			return true;
104		if (available > commonring->depth / 8) {
105			commonring->was_full = false;
106			return true;
107		}
108		if (retry) {
109			if (commonring->cr_update_rptr)
110				commonring->cr_update_rptr(commonring->cr_ctx);
111			retry = false;
112			goto again;
113		}
114		return false;
115	}
116
117	if (retry) {
118		if (commonring->cr_update_rptr)
119			commonring->cr_update_rptr(commonring->cr_ctx);
120		retry = false;
121		goto again;
122	}
123
124	commonring->was_full = true;
125	return false;
126}
127
128
129void *brcmf_commonring_reserve_for_write(struct brcmf_commonring *commonring)
130{
131	void *ret_ptr;
132	u16 available;
133	bool retry = true;
134
135again:
136	if (commonring->r_ptr <= commonring->w_ptr)
137		available = commonring->depth - commonring->w_ptr +
138			    commonring->r_ptr;
139	else
140		available = commonring->r_ptr - commonring->w_ptr;
141
142	if (available > 1) {
143		ret_ptr = commonring->buf_addr +
144			  (commonring->w_ptr * commonring->item_len);
145		commonring->w_ptr++;
146		if (commonring->w_ptr == commonring->depth)
147			commonring->w_ptr = 0;
148		return ret_ptr;
149	}
150
151	if (retry) {
152		if (commonring->cr_update_rptr)
153			commonring->cr_update_rptr(commonring->cr_ctx);
154		retry = false;
155		goto again;
156	}
157
158	commonring->was_full = true;
159	return NULL;
160}
161
162
163void *
164brcmf_commonring_reserve_for_write_multiple(struct brcmf_commonring *commonring,
165					    u16 n_items, u16 *alloced)
166{
167	void *ret_ptr;
168	u16 available;
169	bool retry = true;
170
171again:
172	if (commonring->r_ptr <= commonring->w_ptr)
173		available = commonring->depth - commonring->w_ptr +
174			    commonring->r_ptr;
175	else
176		available = commonring->r_ptr - commonring->w_ptr;
177
178	if (available > 1) {
179		ret_ptr = commonring->buf_addr +
180			  (commonring->w_ptr * commonring->item_len);
181		*alloced = min_t(u16, n_items, available - 1);
182		if (*alloced + commonring->w_ptr > commonring->depth)
183			*alloced = commonring->depth - commonring->w_ptr;
184		commonring->w_ptr += *alloced;
185		if (commonring->w_ptr == commonring->depth)
186			commonring->w_ptr = 0;
187		return ret_ptr;
188	}
189
190	if (retry) {
191		if (commonring->cr_update_rptr)
192			commonring->cr_update_rptr(commonring->cr_ctx);
193		retry = false;
194		goto again;
195	}
196
197	commonring->was_full = true;
198	return NULL;
199}
200
201
202int brcmf_commonring_write_complete(struct brcmf_commonring *commonring)
203{
204	void *address;
205
206	address = commonring->buf_addr;
207	address += (commonring->f_ptr * commonring->item_len);
208	if (commonring->f_ptr > commonring->w_ptr) {
209		brcmf_dma_flush(address,
210				(commonring->depth - commonring->f_ptr) *
211				commonring->item_len);
212		address = commonring->buf_addr;
213		commonring->f_ptr = 0;
214	}
215	brcmf_dma_flush(address, (commonring->w_ptr - commonring->f_ptr) *
216			commonring->item_len);
217
218	commonring->f_ptr = commonring->w_ptr;
219
220	if (commonring->cr_write_wptr)
221		commonring->cr_write_wptr(commonring->cr_ctx);
222	if (commonring->cr_ring_bell)
223		return commonring->cr_ring_bell(commonring->cr_ctx);
224
225	return -EIO;
226}
227
228
229void brcmf_commonring_write_cancel(struct brcmf_commonring *commonring,
230				   u16 n_items)
231{
232	if (commonring->w_ptr == 0)
233		commonring->w_ptr = commonring->depth - n_items;
234	else
235		commonring->w_ptr -= n_items;
236}
237
238
239void *brcmf_commonring_get_read_ptr(struct brcmf_commonring *commonring,
240				    u16 *n_items)
241{
242	void *ret_addr;
243
244	if (commonring->cr_update_wptr)
245		commonring->cr_update_wptr(commonring->cr_ctx);
246
247	*n_items = (commonring->w_ptr >= commonring->r_ptr) ?
248				(commonring->w_ptr - commonring->r_ptr) :
249				(commonring->depth - commonring->r_ptr);
250
251	if (*n_items == 0)
252		return NULL;
253
254	ret_addr = commonring->buf_addr +
255		   (commonring->r_ptr * commonring->item_len);
256
257	commonring->r_ptr += *n_items;
258	if (commonring->r_ptr == commonring->depth)
259		commonring->r_ptr = 0;
260
261	brcmf_dma_invalidate_cache(ret_addr, *n_ items * commonring->item_len);
262
263	return ret_addr;
264}
265
266
267int brcmf_commonring_read_complete(struct brcmf_commonring *commonring)
268{
269	if (commonring->cr_write_rptr)
270		return commonring->cr_write_rptr(commonring->cr_ctx);
271
272	return -EIO;
273}
274