aboutsummaryrefslogtreecommitdiff
path: root/drivers/dma/dmaengine.h
blob: 53f16d3f002943c609ffe7027213e8dae23a25ab (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
/* SPDX-License-Identifier: GPL-2.0 */
/*
 * The contents of this file are private to DMA engine drivers, and is not
 * part of the API to be used by DMA engine users.
 */
#ifndef DMAENGINE_H
#define DMAENGINE_H

#include <linux/bug.h>
#include <linux/dmaengine.h>

/**
 * dma_cookie_init - initialize the cookies for a DMA channel
 * @chan: dma channel to initialize
 */
static inline void dma_cookie_init(struct dma_chan *chan)
{
	chan->cookie = DMA_MIN_COOKIE;
	chan->completed_cookie = DMA_MIN_COOKIE;
}

/**
 * dma_cookie_assign - assign a DMA engine cookie to the descriptor
 * @tx: descriptor needing cookie
 *
 * Assign a unique non-zero per-channel cookie to the descriptor.
 * Note: caller is expected to hold a lock to prevent concurrency.
 */
static inline dma_cookie_t dma_cookie_assign(struct dma_async_tx_descriptor *tx)
{
	struct dma_chan *chan = tx->chan;
	dma_cookie_t cookie;

	cookie = chan->cookie + 1;
	if (cookie < DMA_MIN_COOKIE)
		cookie = DMA_MIN_COOKIE;
	tx->cookie = chan->cookie = cookie;

	return cookie;
}

/**
 * dma_cookie_complete - complete a descriptor
 * @tx: descriptor to complete
 *
 * Mark this descriptor complete by updating the channels completed
 * cookie marker.  Zero the descriptors cookie to prevent accidental
 * repeated completions.
 *
 * Note: caller is expected to hold a lock to prevent concurrency.
 */
static inline void dma_cookie_complete(struct dma_async_tx_descriptor *tx)
{
	BUG_ON(tx->cookie < DMA_MIN_COOKIE);
	tx->chan->completed_cookie = tx->cookie;
	tx->cookie = 0;
}

/**
 * dma_cookie_status - report cookie status
 * @chan: dma channel
 * @cookie: cookie we are interested in
 * @state: dma_tx_state structure to return last/used cookies
 *
 * Report the status of the cookie, filling in the state structure if
 * non-NULL.  No locking is required.
 */
static inline enum dma_status dma_cookie_status(struct dma_chan *chan,
	dma_cookie_t cookie, struct dma_tx_state *state)
{
	dma_cookie_t used, complete;

	used = chan->cookie;
	complete = chan->completed_cookie;
	barrier();
	if (state) {
		state->last = complete;
		state->used = used;
		state->residue = 0;
		state->in_flight_bytes = 0;
	}
	return dma_async_is_complete(cookie, complete, used);
}

static inline void dma_set_residue(struct dma_tx_state *state, u32 residue)
{
	if (state)
		state->residue = residue;
}

static inline void dma_set_in_flight_bytes(struct dma_tx_state *state,
					   u32 in_flight_bytes)
{
	if (state)
		state->in_flight_bytes = in_flight_bytes;
}

struct dmaengine_desc_callback {
	dma_async_tx_callback callback;
	dma_async_tx_callback_result callback_result;
	void *callback_param;
};

/**
 * dmaengine_desc_get_callback - get the passed in callback function
 * @tx: tx descriptor
 * @cb: temp struct to hold the callback info
 *
 * Fill the passed in cb struct with what's available in the passed in
 * tx descriptor struct
 * No locking is required.
 */
static inline void
dmaengine_desc_get_callback(struct dma_async_tx_descriptor *tx,
			    struct dmaengine_desc_callback *cb)
{
	cb->callback = tx->callback;
	cb->callback_result = tx->callback_result;
	cb->callback_param = tx->callback_param;
}

/**
 * dmaengine_desc_callback_invoke - call the callback function in cb struct
 * @cb: temp struct that is holding the callback info
 * @result: transaction result
 *
 * Call the callback function provided in the cb struct with the parameter
 * in the cb struct.
 * Locking is dependent on the driver.
 */
static inline void
dmaengine_desc_callback_invoke(struct dmaengine_desc_callback *cb,
			       const struct dmaengine_result *result)
{
	struct dmaengine_result dummy_result = {
		.result = DMA_TRANS_NOERROR,
		.residue = 0
	};

	if (cb->callback_result) {
		if (!result)
			result = &dummy_result;
		cb->callback_result(cb->callback_param, result);
	} else if (cb->callback) {
		cb->callback(cb->callback_param);
	}
}

/**
 * dmaengine_desc_get_callback_invoke - get the callback in tx descriptor and
 * 					then immediately call the callback.
 * @tx: dma async tx descriptor
 * @result: transaction result
 *
 * Call dmaengine_desc_get_callback() and dmaengine_desc_callback_invoke()
 * in a single function since no work is necessary in between for the driver.
 * Locking is dependent on the driver.
 */
static inline void
dmaengine_desc_get_callback_invoke(struct dma_async_tx_descriptor *tx,
				   const struct dmaengine_result *result)
{
	struct dmaengine_desc_callback cb;

	dmaengine_desc_get_callback(tx, &cb);
	dmaengine_desc_callback_invoke(&cb, result);
}

/**
 * dmaengine_desc_callback_valid - verify the callback is valid in cb
 * @cb: callback info struct
 *
 * Return a bool that verifies whether callback in cb is valid or not.
 * No locking is required.
 */
static inline bool
dmaengine_desc_callback_valid(struct dmaengine_desc_callback *cb)
{
	return cb->callback || cb->callback_result;
}

struct dma_chan *dma_get_slave_channel(struct dma_chan *chan);
struct dma_chan *dma_get_any_slave_channel(struct dma_device *device);

#ifdef CONFIG_DEBUG_FS
#include <linux/debugfs.h>

static inline struct dentry *
dmaengine_get_debugfs_root(struct dma_device *dma_dev) {
	return dma_dev->dbg_dev_root;
}
#else
struct dentry;
static inline struct dentry *
dmaengine_get_debugfs_root(struct dma_device *dma_dev)
{
	return NULL;
}
#endif /* CONFIG_DEBUG_FS */

#endif