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