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
25void brcmf_commonring_register_cb(struct brcmf_commonring *commonring,
26				  int (*cr_ring_bell)(void *ctx),
27				  int (*cr_update_rptr)(void *ctx),
28				  int (*cr_update_wptr)(void *ctx),
29				  int (*cr_write_rptr)(void *ctx),
30				  int (*cr_write_wptr)(void *ctx), void *ctx)
31{
32	commonring->cr_ring_bell = cr_ring_bell;
33	commonring->cr_update_rptr = cr_update_rptr;
34	commonring->cr_update_wptr = cr_update_wptr;
35	commonring->cr_write_rptr = cr_write_rptr;
36	commonring->cr_write_wptr = cr_write_wptr;
37	commonring->cr_ctx = ctx;
38}
39
40
41void brcmf_commonring_config(struct brcmf_commonring *commonring, u16 depth,
42			     u16 item_len, void *buf_addr)
43{
44	commonring->depth = depth;
45	commonring->item_len = item_len;
46	commonring->buf_addr = buf_addr;
47	if (!commonring->inited) {
48		spin_lock_init(&commonring->lock);
49		commonring->inited = true;
50	}
51	commonring->r_ptr = 0;
52	if (commonring->cr_write_rptr)
53		commonring->cr_write_rptr(commonring->cr_ctx);
54	commonring->w_ptr = 0;
55	if (commonring->cr_write_wptr)
56		commonring->cr_write_wptr(commonring->cr_ctx);
57	commonring->f_ptr = 0;
58}
59
60
61void brcmf_commonring_lock(struct brcmf_commonring *commonring)
62		__acquires(&commonring->lock)
63{
64	unsigned long flags;
65
66	spin_lock_irqsave(&commonring->lock, flags);
67	commonring->flags = flags;
68}
69
70
71void brcmf_commonring_unlock(struct brcmf_commonring *commonring)
72		__releases(&commonring->lock)
73{
74	spin_unlock_irqrestore(&commonring->lock, commonring->flags);
75}
76
77
78bool brcmf_commonring_write_available(struct brcmf_commonring *commonring)
79{
80	u16 available;
81	bool retry = true;
82
83again:
84	if (commonring->r_ptr <= commonring->w_ptr)
85		available = commonring->depth - commonring->w_ptr +
86			    commonring->r_ptr;
87	else
88		available = commonring->r_ptr - commonring->w_ptr;
89
90	if (available > 1) {
91		if (!commonring->was_full)
92			return true;
93		if (available > commonring->depth / 8) {
94			commonring->was_full = false;
95			return true;
96		}
97		if (retry) {
98			if (commonring->cr_update_rptr)
99				commonring->cr_update_rptr(commonring->cr_ctx);
100			retry = false;
101			goto again;
102		}
103		return false;
104	}
105
106	if (retry) {
107		if (commonring->cr_update_rptr)
108			commonring->cr_update_rptr(commonring->cr_ctx);
109		retry = false;
110		goto again;
111	}
112
113	commonring->was_full = true;
114	return false;
115}
116
117
118void *brcmf_commonring_reserve_for_write(struct brcmf_commonring *commonring)
119{
120	void *ret_ptr;
121	u16 available;
122	bool retry = true;
123
124again:
125	if (commonring->r_ptr <= commonring->w_ptr)
126		available = commonring->depth - commonring->w_ptr +
127			    commonring->r_ptr;
128	else
129		available = commonring->r_ptr - commonring->w_ptr;
130
131	if (available > 1) {
132		ret_ptr = commonring->buf_addr +
133			  (commonring->w_ptr * commonring->item_len);
134		commonring->w_ptr++;
135		if (commonring->w_ptr == commonring->depth)
136			commonring->w_ptr = 0;
137		return ret_ptr;
138	}
139
140	if (retry) {
141		if (commonring->cr_update_rptr)
142			commonring->cr_update_rptr(commonring->cr_ctx);
143		retry = false;
144		goto again;
145	}
146
147	commonring->was_full = true;
148	return NULL;
149}
150
151
152void *
153brcmf_commonring_reserve_for_write_multiple(struct brcmf_commonring *commonring,
154					    u16 n_items, u16 *alloced)
155{
156	void *ret_ptr;
157	u16 available;
158	bool retry = true;
159
160again:
161	if (commonring->r_ptr <= commonring->w_ptr)
162		available = commonring->depth - commonring->w_ptr +
163			    commonring->r_ptr;
164	else
165		available = commonring->r_ptr - commonring->w_ptr;
166
167	if (available > 1) {
168		ret_ptr = commonring->buf_addr +
169			  (commonring->w_ptr * commonring->item_len);
170		*alloced = min_t(u16, n_items, available - 1);
171		if (*alloced + commonring->w_ptr > commonring->depth)
172			*alloced = commonring->depth - commonring->w_ptr;
173		commonring->w_ptr += *alloced;
174		if (commonring->w_ptr == commonring->depth)
175			commonring->w_ptr = 0;
176		return ret_ptr;
177	}
178
179	if (retry) {
180		if (commonring->cr_update_rptr)
181			commonring->cr_update_rptr(commonring->cr_ctx);
182		retry = false;
183		goto again;
184	}
185
186	commonring->was_full = true;
187	return NULL;
188}
189
190
191int brcmf_commonring_write_complete(struct brcmf_commonring *commonring)
192{
193	void *address;
194
195	address = commonring->buf_addr;
196	address += (commonring->f_ptr * commonring->item_len);
197	if (commonring->f_ptr > commonring->w_ptr) {
198		address = commonring->buf_addr;
199		commonring->f_ptr = 0;
200	}
201
202	commonring->f_ptr = commonring->w_ptr;
203
204	if (commonring->cr_write_wptr)
205		commonring->cr_write_wptr(commonring->cr_ctx);
206	if (commonring->cr_ring_bell)
207		return commonring->cr_ring_bell(commonring->cr_ctx);
208
209	return -EIO;
210}
211
212
213void brcmf_commonring_write_cancel(struct brcmf_commonring *commonring,
214				   u16 n_items)
215{
216	if (commonring->w_ptr == 0)
217		commonring->w_ptr = commonring->depth - n_items;
218	else
219		commonring->w_ptr -= n_items;
220}
221
222
223void *brcmf_commonring_get_read_ptr(struct brcmf_commonring *commonring,
224				    u16 *n_items)
225{
226	if (commonring->cr_update_wptr)
227		commonring->cr_update_wptr(commonring->cr_ctx);
228
229	*n_items = (commonring->w_ptr >= commonring->r_ptr) ?
230				(commonring->w_ptr - commonring->r_ptr) :
231				(commonring->depth - commonring->r_ptr);
232
233	if (*n_items == 0)
234		return NULL;
235
236	return commonring->buf_addr +
237	       (commonring->r_ptr * commonring->item_len);
238}
239
240
241int brcmf_commonring_read_complete(struct brcmf_commonring *commonring,
242				   u16 n_items)
243{
244	commonring->r_ptr += n_items;
245	if (commonring->r_ptr == commonring->depth)
246		commonring->r_ptr = 0;
247
248	if (commonring->cr_write_rptr)
249		return commonring->cr_write_rptr(commonring->cr_ctx);
250
251	return -EIO;
252}
253