1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * The contents of this file are private to DMA engine drivers, and is not
4 * part of the API to be used by DMA engine users.
5 */
6#ifndef DMAENGINE_H
7#define DMAENGINE_H
8
9#include <linux/bug.h>
10#include <linux/dmaengine.h>
11
12/**
13 * dma_cookie_init - initialize the cookies for a DMA channel
14 * @chan: dma channel to initialize
15 */
16static inline void dma_cookie_init(struct dma_chan *chan)
17{
18 chan->cookie = DMA_MIN_COOKIE;
19 chan->completed_cookie = DMA_MIN_COOKIE;
20}
21
22/**
23 * dma_cookie_assign - assign a DMA engine cookie to the descriptor
24 * @tx: descriptor needing cookie
25 *
26 * Assign a unique non-zero per-channel cookie to the descriptor.
27 * Note: caller is expected to hold a lock to prevent concurrency.
28 */
29static inline dma_cookie_t dma_cookie_assign(struct dma_async_tx_descriptor *tx)
30{
31 struct dma_chan *chan = tx->chan;
32 dma_cookie_t cookie;
33
34 cookie = chan->cookie + 1;
35 if (cookie < DMA_MIN_COOKIE)
36 cookie = DMA_MIN_COOKIE;
37 tx->cookie = chan->cookie = cookie;
38
39 return cookie;
40}
41
42/**
43 * dma_cookie_complete - complete a descriptor
44 * @tx: descriptor to complete
45 *
46 * Mark this descriptor complete by updating the channels completed
47 * cookie marker. Zero the descriptors cookie to prevent accidental
48 * repeated completions.
49 *
50 * Note: caller is expected to hold a lock to prevent concurrency.
51 */
52static inline void dma_cookie_complete(struct dma_async_tx_descriptor *tx)
53{
54 BUG_ON(tx->cookie < DMA_MIN_COOKIE);
55 tx->chan->completed_cookie = tx->cookie;
56 tx->cookie = 0;
57}
58
59/**
60 * dma_cookie_status - report cookie status
61 * @chan: dma channel
62 * @cookie: cookie we are interested in
63 * @state: dma_tx_state structure to return last/used cookies
64 *
65 * Report the status of the cookie, filling in the state structure if
66 * non-NULL. No locking is required.
67 */
68static inline enum dma_status dma_cookie_status(struct dma_chan *chan,
69 dma_cookie_t cookie, struct dma_tx_state *state)
70{
71 dma_cookie_t used, complete;
72
73 used = chan->cookie;
74 complete = chan->completed_cookie;
75 barrier();
76 if (state) {
77 state->last = complete;
78 state->used = used;
79 state->residue = 0;
80 state->in_flight_bytes = 0;
81 }
82 return dma_async_is_complete(cookie, last_complete: complete, last_used: used);
83}
84
85static inline void dma_set_residue(struct dma_tx_state *state, u32 residue)
86{
87 if (state)
88 state->residue = residue;
89}
90
91static inline void dma_set_in_flight_bytes(struct dma_tx_state *state,
92 u32 in_flight_bytes)
93{
94 if (state)
95 state->in_flight_bytes = in_flight_bytes;
96}
97
98struct dmaengine_desc_callback {
99 dma_async_tx_callback callback;
100 dma_async_tx_callback_result callback_result;
101 void *callback_param;
102};
103
104/**
105 * dmaengine_desc_get_callback - get the passed in callback function
106 * @tx: tx descriptor
107 * @cb: temp struct to hold the callback info
108 *
109 * Fill the passed in cb struct with what's available in the passed in
110 * tx descriptor struct
111 * No locking is required.
112 */
113static inline void
114dmaengine_desc_get_callback(struct dma_async_tx_descriptor *tx,
115 struct dmaengine_desc_callback *cb)
116{
117 cb->callback = tx->callback;
118 cb->callback_result = tx->callback_result;
119 cb->callback_param = tx->callback_param;
120}
121
122/**
123 * dmaengine_desc_callback_invoke - call the callback function in cb struct
124 * @cb: temp struct that is holding the callback info
125 * @result: transaction result
126 *
127 * Call the callback function provided in the cb struct with the parameter
128 * in the cb struct.
129 * Locking is dependent on the driver.
130 */
131static inline void
132dmaengine_desc_callback_invoke(struct dmaengine_desc_callback *cb,
133 const struct dmaengine_result *result)
134{
135 struct dmaengine_result dummy_result = {
136 .result = DMA_TRANS_NOERROR,
137 .residue = 0
138 };
139
140 if (cb->callback_result) {
141 if (!result)
142 result = &dummy_result;
143 cb->callback_result(cb->callback_param, result);
144 } else if (cb->callback) {
145 cb->callback(cb->callback_param);
146 }
147}
148
149/**
150 * dmaengine_desc_get_callback_invoke - get the callback in tx descriptor and
151 * then immediately call the callback.
152 * @tx: dma async tx descriptor
153 * @result: transaction result
154 *
155 * Call dmaengine_desc_get_callback() and dmaengine_desc_callback_invoke()
156 * in a single function since no work is necessary in between for the driver.
157 * Locking is dependent on the driver.
158 */
159static inline void
160dmaengine_desc_get_callback_invoke(struct dma_async_tx_descriptor *tx,
161 const struct dmaengine_result *result)
162{
163 struct dmaengine_desc_callback cb;
164
165 dmaengine_desc_get_callback(tx, cb: &cb);
166 dmaengine_desc_callback_invoke(cb: &cb, result);
167}
168
169/**
170 * dmaengine_desc_callback_valid - verify the callback is valid in cb
171 * @cb: callback info struct
172 *
173 * Return a bool that verifies whether callback in cb is valid or not.
174 * No locking is required.
175 */
176static inline bool
177dmaengine_desc_callback_valid(struct dmaengine_desc_callback *cb)
178{
179 return cb->callback || cb->callback_result;
180}
181
182struct dma_chan *dma_get_slave_channel(struct dma_chan *chan);
183struct dma_chan *dma_get_any_slave_channel(struct dma_device *device);
184
185#ifdef CONFIG_DEBUG_FS
186#include <linux/debugfs.h>
187
188static inline struct dentry *
189dmaengine_get_debugfs_root(struct dma_device *dma_dev) {
190 return dma_dev->dbg_dev_root;
191}
192#else
193struct dentry;
194static inline struct dentry *
195dmaengine_get_debugfs_root(struct dma_device *dma_dev)
196{
197 return NULL;
198}
199#endif /* CONFIG_DEBUG_FS */
200
201#endif
202