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 void 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 
41 void 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 
61 void 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 
71 void brcmf_commonring_unlock(struct brcmf_commonring *commonring)
72 		__releases(&commonring->lock)
73 {
74 	spin_unlock_irqrestore(&commonring->lock, commonring->flags);
75 }
76 
77 
78 bool brcmf_commonring_write_available(struct brcmf_commonring *commonring)
79 {
80 	u16 available;
81 	bool retry = true;
82 
83 again:
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 
118 void *brcmf_commonring_reserve_for_write(struct brcmf_commonring *commonring)
119 {
120 	void *ret_ptr;
121 	u16 available;
122 	bool retry = true;
123 
124 again:
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 
152 void *
153 brcmf_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 
160 again:
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 
191 int 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 
213 void 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 
223 void *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 
241 int 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