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d2912cb1 | 1 | /* SPDX-License-Identifier: GPL-2.0-only */ |
50437bff RK |
2 | /* |
3 | * Virtual DMA channel support for DMAengine | |
4 | * | |
5 | * Copyright (C) 2012 Russell King | |
50437bff RK |
6 | */ |
7 | #ifndef VIRT_DMA_H | |
8 | #define VIRT_DMA_H | |
9 | ||
10 | #include <linux/dmaengine.h> | |
11 | #include <linux/interrupt.h> | |
12 | ||
13 | #include "dmaengine.h" | |
14 | ||
15 | struct virt_dma_desc { | |
16 | struct dma_async_tx_descriptor tx; | |
09d5b702 | 17 | struct dmaengine_result tx_result; |
50437bff RK |
18 | /* protected by vc.lock */ |
19 | struct list_head node; | |
20 | }; | |
21 | ||
22 | struct virt_dma_chan { | |
23 | struct dma_chan chan; | |
24 | struct tasklet_struct task; | |
25 | void (*desc_free)(struct virt_dma_desc *); | |
26 | ||
27 | spinlock_t lock; | |
28 | ||
29 | /* protected by vc.lock */ | |
13bb26ae | 30 | struct list_head desc_allocated; |
50437bff RK |
31 | struct list_head desc_submitted; |
32 | struct list_head desc_issued; | |
33 | struct list_head desc_completed; | |
571fa740 RK |
34 | |
35 | struct virt_dma_desc *cyclic; | |
1c7f072d | 36 | struct virt_dma_desc *vd_terminated; |
50437bff RK |
37 | }; |
38 | ||
39 | static inline struct virt_dma_chan *to_virt_chan(struct dma_chan *chan) | |
40 | { | |
41 | return container_of(chan, struct virt_dma_chan, chan); | |
42 | } | |
43 | ||
44 | void vchan_dma_desc_free_list(struct virt_dma_chan *vc, struct list_head *head); | |
50437bff | 45 | void vchan_init(struct virt_dma_chan *vc, struct dma_device *dmadev); |
fe045874 | 46 | struct virt_dma_desc *vchan_find_desc(struct virt_dma_chan *, dma_cookie_t); |
02aa8486 BX |
47 | extern dma_cookie_t vchan_tx_submit(struct dma_async_tx_descriptor *); |
48 | extern int vchan_tx_desc_free(struct dma_async_tx_descriptor *); | |
50437bff RK |
49 | |
50 | /** | |
51 | * vchan_tx_prep - prepare a descriptor | |
28ca3e85 LPC |
52 | * @vc: virtual channel allocating this descriptor |
53 | * @vd: virtual descriptor to prepare | |
54 | * @tx_flags: flags argument passed in to prepare function | |
50437bff RK |
55 | */ |
56 | static inline struct dma_async_tx_descriptor *vchan_tx_prep(struct virt_dma_chan *vc, | |
57 | struct virt_dma_desc *vd, unsigned long tx_flags) | |
58 | { | |
13bb26ae | 59 | unsigned long flags; |
50437bff RK |
60 | |
61 | dma_async_tx_descriptor_init(&vd->tx, &vc->chan); | |
62 | vd->tx.flags = tx_flags; | |
63 | vd->tx.tx_submit = vchan_tx_submit; | |
13bb26ae RJ |
64 | vd->tx.desc_free = vchan_tx_desc_free; |
65 | ||
09d5b702 AA |
66 | vd->tx_result.result = DMA_TRANS_NOERROR; |
67 | vd->tx_result.residue = 0; | |
68 | ||
13bb26ae RJ |
69 | spin_lock_irqsave(&vc->lock, flags); |
70 | list_add_tail(&vd->node, &vc->desc_allocated); | |
71 | spin_unlock_irqrestore(&vc->lock, flags); | |
50437bff RK |
72 | |
73 | return &vd->tx; | |
74 | } | |
75 | ||
76 | /** | |
77 | * vchan_issue_pending - move submitted descriptors to issued list | |
28ca3e85 | 78 | * @vc: virtual channel to update |
50437bff RK |
79 | * |
80 | * vc.lock must be held by caller | |
81 | */ | |
82 | static inline bool vchan_issue_pending(struct virt_dma_chan *vc) | |
83 | { | |
84 | list_splice_tail_init(&vc->desc_submitted, &vc->desc_issued); | |
85 | return !list_empty(&vc->desc_issued); | |
86 | } | |
87 | ||
88 | /** | |
89 | * vchan_cookie_complete - report completion of a descriptor | |
28ca3e85 | 90 | * @vd: virtual descriptor to update |
50437bff RK |
91 | * |
92 | * vc.lock must be held by caller | |
93 | */ | |
94 | static inline void vchan_cookie_complete(struct virt_dma_desc *vd) | |
95 | { | |
96 | struct virt_dma_chan *vc = to_virt_chan(vd->tx.chan); | |
af58652a | 97 | dma_cookie_t cookie; |
50437bff | 98 | |
af58652a | 99 | cookie = vd->tx.cookie; |
50437bff RK |
100 | dma_cookie_complete(&vd->tx); |
101 | dev_vdbg(vc->chan.device->dev, "txd %p[%x]: marked complete\n", | |
af58652a | 102 | vd, cookie); |
50437bff RK |
103 | list_add_tail(&vd->node, &vc->desc_completed); |
104 | ||
105 | tasklet_schedule(&vc->task); | |
106 | } | |
107 | ||
6af149d2 PU |
108 | /** |
109 | * vchan_vdesc_fini - Free or reuse a descriptor | |
110 | * @vd: virtual descriptor to free/reuse | |
111 | */ | |
112 | static inline void vchan_vdesc_fini(struct virt_dma_desc *vd) | |
113 | { | |
114 | struct virt_dma_chan *vc = to_virt_chan(vd->tx.chan); | |
115 | ||
116 | if (dmaengine_desc_test_reuse(&vd->tx)) | |
117 | list_add(&vd->node, &vc->desc_allocated); | |
118 | else | |
119 | vc->desc_free(vd); | |
120 | } | |
121 | ||
571fa740 RK |
122 | /** |
123 | * vchan_cyclic_callback - report the completion of a period | |
28ca3e85 | 124 | * @vd: virtual descriptor |
571fa740 RK |
125 | */ |
126 | static inline void vchan_cyclic_callback(struct virt_dma_desc *vd) | |
127 | { | |
128 | struct virt_dma_chan *vc = to_virt_chan(vd->tx.chan); | |
129 | ||
130 | vc->cyclic = vd; | |
131 | tasklet_schedule(&vc->task); | |
132 | } | |
133 | ||
1c7f072d PU |
134 | /** |
135 | * vchan_terminate_vdesc - Disable pending cyclic callback | |
136 | * @vd: virtual descriptor to be terminated | |
137 | * | |
138 | * vc.lock must be held by caller | |
139 | */ | |
140 | static inline void vchan_terminate_vdesc(struct virt_dma_desc *vd) | |
141 | { | |
142 | struct virt_dma_chan *vc = to_virt_chan(vd->tx.chan); | |
143 | ||
144 | /* free up stuck descriptor */ | |
145 | if (vc->vd_terminated) | |
146 | vchan_vdesc_fini(vc->vd_terminated); | |
147 | ||
148 | vc->vd_terminated = vd; | |
149 | if (vc->cyclic == vd) | |
150 | vc->cyclic = NULL; | |
151 | } | |
152 | ||
50437bff RK |
153 | /** |
154 | * vchan_next_desc - peek at the next descriptor to be processed | |
28ca3e85 | 155 | * @vc: virtual channel to obtain descriptor from |
50437bff RK |
156 | * |
157 | * vc.lock must be held by caller | |
158 | */ | |
159 | static inline struct virt_dma_desc *vchan_next_desc(struct virt_dma_chan *vc) | |
160 | { | |
360af35b MY |
161 | return list_first_entry_or_null(&vc->desc_issued, |
162 | struct virt_dma_desc, node); | |
50437bff RK |
163 | } |
164 | ||
165 | /** | |
8c8fe97b | 166 | * vchan_get_all_descriptors - obtain all submitted and issued descriptors |
28ca3e85 LPC |
167 | * @vc: virtual channel to get descriptors from |
168 | * @head: list of descriptors found | |
50437bff RK |
169 | * |
170 | * vc.lock must be held by caller | |
171 | * | |
172 | * Removes all submitted and issued descriptors from internal lists, and | |
173 | * provides a list of all descriptors found | |
174 | */ | |
175 | static inline void vchan_get_all_descriptors(struct virt_dma_chan *vc, | |
176 | struct list_head *head) | |
177 | { | |
13bb26ae | 178 | list_splice_tail_init(&vc->desc_allocated, head); |
50437bff RK |
179 | list_splice_tail_init(&vc->desc_submitted, head); |
180 | list_splice_tail_init(&vc->desc_issued, head); | |
181 | list_splice_tail_init(&vc->desc_completed, head); | |
182 | } | |
183 | ||
184 | static inline void vchan_free_chan_resources(struct virt_dma_chan *vc) | |
185 | { | |
13bb26ae | 186 | struct virt_dma_desc *vd; |
50437bff RK |
187 | unsigned long flags; |
188 | LIST_HEAD(head); | |
189 | ||
190 | spin_lock_irqsave(&vc->lock, flags); | |
191 | vchan_get_all_descriptors(vc, &head); | |
13bb26ae RJ |
192 | list_for_each_entry(vd, &head, node) |
193 | dmaengine_desc_clear_reuse(&vd->tx); | |
50437bff RK |
194 | spin_unlock_irqrestore(&vc->lock, flags); |
195 | ||
196 | vchan_dma_desc_free_list(vc, &head); | |
197 | } | |
198 | ||
2ed08629 LPC |
199 | /** |
200 | * vchan_synchronize() - synchronize callback execution to the current context | |
201 | * @vc: virtual channel to synchronize | |
202 | * | |
203 | * Makes sure that all scheduled or active callbacks have finished running. For | |
204 | * proper operation the caller has to ensure that no new callbacks are scheduled | |
205 | * after the invocation of this function started. | |
1c7f072d | 206 | * Free up the terminated cyclic descriptor to prevent memory leakage. |
2ed08629 LPC |
207 | */ |
208 | static inline void vchan_synchronize(struct virt_dma_chan *vc) | |
209 | { | |
1c7f072d PU |
210 | unsigned long flags; |
211 | ||
2ed08629 | 212 | tasklet_kill(&vc->task); |
1c7f072d PU |
213 | |
214 | spin_lock_irqsave(&vc->lock, flags); | |
215 | if (vc->vd_terminated) { | |
216 | vchan_vdesc_fini(vc->vd_terminated); | |
217 | vc->vd_terminated = NULL; | |
218 | } | |
219 | spin_unlock_irqrestore(&vc->lock, flags); | |
2ed08629 LPC |
220 | } |
221 | ||
50437bff | 222 | #endif |