1 /*
2 * The contents of this file are private to DMA engine drivers, and is not
3 * part of the API to be used by DMA engine users.
4 */
5 #ifndef DMAENGINE_H
6 #define DMAENGINE_H
7
8 #include <linux/bug.h>
9 #include <linux/dmaengine.h>
10
11 /**
12 * dma_cookie_init - initialize the cookies for a DMA channel
13 * @chan: dma channel to initialize
14 */
dma_cookie_init(struct dma_chan * chan)15 static inline void dma_cookie_init(struct dma_chan *chan)
16 {
17 chan->cookie = DMA_MIN_COOKIE;
18 chan->completed_cookie = DMA_MIN_COOKIE;
19 }
20
21 /**
22 * dma_cookie_assign - assign a DMA engine cookie to the descriptor
23 * @tx: descriptor needing cookie
24 *
25 * Assign a unique non-zero per-channel cookie to the descriptor.
26 * Note: caller is expected to hold a lock to prevent concurrency.
27 */
dma_cookie_assign(struct dma_async_tx_descriptor * tx)28 static inline dma_cookie_t dma_cookie_assign(struct dma_async_tx_descriptor *tx)
29 {
30 struct dma_chan *chan = tx->chan;
31 dma_cookie_t cookie;
32
33 cookie = chan->cookie + 1;
34 if (cookie < DMA_MIN_COOKIE)
35 cookie = DMA_MIN_COOKIE;
36 tx->cookie = chan->cookie = cookie;
37
38 return cookie;
39 }
40
41 /**
42 * dma_cookie_complete - complete a descriptor
43 * @tx: descriptor to complete
44 *
45 * Mark this descriptor complete by updating the channels completed
46 * cookie marker. Zero the descriptors cookie to prevent accidental
47 * repeated completions.
48 *
49 * Note: caller is expected to hold a lock to prevent concurrency.
50 */
dma_cookie_complete(struct dma_async_tx_descriptor * tx)51 static inline void dma_cookie_complete(struct dma_async_tx_descriptor *tx)
52 {
53 BUG_ON(tx->cookie < DMA_MIN_COOKIE);
54 tx->chan->completed_cookie = tx->cookie;
55 tx->cookie = 0;
56 }
57
58 /**
59 * dma_cookie_status - report cookie status
60 * @chan: dma channel
61 * @cookie: cookie we are interested in
62 * @state: dma_tx_state structure to return last/used cookies
63 *
64 * Report the status of the cookie, filling in the state structure if
65 * non-NULL. No locking is required.
66 */
dma_cookie_status(struct dma_chan * chan,dma_cookie_t cookie,struct dma_tx_state * state)67 static inline enum dma_status dma_cookie_status(struct dma_chan *chan,
68 dma_cookie_t cookie, struct dma_tx_state *state)
69 {
70 dma_cookie_t used, complete;
71
72 used = chan->cookie;
73 complete = chan->completed_cookie;
74 barrier();
75 if (state) {
76 state->last = complete;
77 state->used = used;
78 state->residue = 0;
79 }
80 return dma_async_is_complete(cookie, complete, used);
81 }
82
dma_set_residue(struct dma_tx_state * state,u32 residue)83 static inline void dma_set_residue(struct dma_tx_state *state, u32 residue)
84 {
85 if (state)
86 state->residue = residue;
87 }
88
89 struct dmaengine_desc_callback {
90 dma_async_tx_callback callback;
91 dma_async_tx_callback_result callback_result;
92 void *callback_param;
93 };
94
95 /**
96 * dmaengine_desc_get_callback - get the passed in callback function
97 * @tx: tx descriptor
98 * @cb: temp struct to hold the callback info
99 *
100 * Fill the passed in cb struct with what's available in the passed in
101 * tx descriptor struct
102 * No locking is required.
103 */
104 static inline void
dmaengine_desc_get_callback(struct dma_async_tx_descriptor * tx,struct dmaengine_desc_callback * cb)105 dmaengine_desc_get_callback(struct dma_async_tx_descriptor *tx,
106 struct dmaengine_desc_callback *cb)
107 {
108 cb->callback = tx->callback;
109 cb->callback_result = tx->callback_result;
110 cb->callback_param = tx->callback_param;
111 }
112
113 /**
114 * dmaengine_desc_callback_invoke - call the callback function in cb struct
115 * @cb: temp struct that is holding the callback info
116 * @result: transaction result
117 *
118 * Call the callback function provided in the cb struct with the parameter
119 * in the cb struct.
120 * Locking is dependent on the driver.
121 */
122 static inline void
dmaengine_desc_callback_invoke(struct dmaengine_desc_callback * cb,const struct dmaengine_result * result)123 dmaengine_desc_callback_invoke(struct dmaengine_desc_callback *cb,
124 const struct dmaengine_result *result)
125 {
126 struct dmaengine_result dummy_result = {
127 .result = DMA_TRANS_NOERROR,
128 .residue = 0
129 };
130
131 if (cb->callback_result) {
132 if (!result)
133 result = &dummy_result;
134 cb->callback_result(cb->callback_param, result);
135 } else if (cb->callback) {
136 cb->callback(cb->callback_param);
137 }
138 }
139
140 /**
141 * dmaengine_desc_get_callback_invoke - get the callback in tx descriptor and
142 * then immediately call the callback.
143 * @tx: dma async tx descriptor
144 * @result: transaction result
145 *
146 * Call dmaengine_desc_get_callback() and dmaengine_desc_callback_invoke()
147 * in a single function since no work is necessary in between for the driver.
148 * Locking is dependent on the driver.
149 */
150 static inline void
dmaengine_desc_get_callback_invoke(struct dma_async_tx_descriptor * tx,const struct dmaengine_result * result)151 dmaengine_desc_get_callback_invoke(struct dma_async_tx_descriptor *tx,
152 const struct dmaengine_result *result)
153 {
154 struct dmaengine_desc_callback cb;
155
156 dmaengine_desc_get_callback(tx, &cb);
157 dmaengine_desc_callback_invoke(&cb, result);
158 }
159
160 /**
161 * dmaengine_desc_callback_valid - verify the callback is valid in cb
162 * @cb: callback info struct
163 *
164 * Return a bool that verifies whether callback in cb is valid or not.
165 * No locking is required.
166 */
167 static inline bool
dmaengine_desc_callback_valid(struct dmaengine_desc_callback * cb)168 dmaengine_desc_callback_valid(struct dmaengine_desc_callback *cb)
169 {
170 return (cb->callback) ? true : false;
171 }
172
173 #endif
174