xref: /openbmc/linux/drivers/gpu/host1x/cdma.h (revision bc5aa3a0)
1 /*
2  * Tegra host1x Command DMA
3  *
4  * Copyright (c) 2010-2013, NVIDIA Corporation.
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms and conditions of the GNU General Public License,
8  * version 2, as published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope it will be useful, but WITHOUT
11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
13  * more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
17  */
18 
19 #ifndef __HOST1X_CDMA_H
20 #define __HOST1X_CDMA_H
21 
22 #include <linux/sched.h>
23 #include <linux/semaphore.h>
24 #include <linux/list.h>
25 
26 struct host1x_syncpt;
27 struct host1x_userctx_timeout;
28 struct host1x_job;
29 
30 /*
31  * cdma
32  *
33  * This is in charge of a host command DMA channel.
34  * Sends ops to a push buffer, and takes responsibility for unpinning
35  * (& possibly freeing) of memory after those ops have completed.
36  * Producer:
37  *	begin
38  *		push - send ops to the push buffer
39  *	end - start command DMA and enqueue handles to be unpinned
40  * Consumer:
41  *	update - call to update sync queue and push buffer, unpin memory
42  */
43 
44 struct push_buffer {
45 	void *mapped;			/* mapped pushbuffer memory */
46 	dma_addr_t phys;		/* physical address of pushbuffer */
47 	u32 fence;			/* index we've written */
48 	u32 pos;			/* index to write to */
49 	u32 size_bytes;
50 };
51 
52 struct buffer_timeout {
53 	struct delayed_work wq;		/* work queue */
54 	bool initialized;		/* timer one-time setup flag */
55 	struct host1x_syncpt *syncpt;	/* buffer completion syncpt */
56 	u32 syncpt_val;			/* syncpt value when completed */
57 	ktime_t start_ktime;		/* starting time */
58 	/* context timeout information */
59 	int client;
60 };
61 
62 enum cdma_event {
63 	CDMA_EVENT_NONE,		/* not waiting for any event */
64 	CDMA_EVENT_SYNC_QUEUE_EMPTY,	/* wait for empty sync queue */
65 	CDMA_EVENT_PUSH_BUFFER_SPACE	/* wait for space in push buffer */
66 };
67 
68 struct host1x_cdma {
69 	struct mutex lock;		/* controls access to shared state */
70 	struct semaphore sem;		/* signalled when event occurs */
71 	enum cdma_event event;		/* event that sem is waiting for */
72 	unsigned int slots_used;	/* pb slots used in current submit */
73 	unsigned int slots_free;	/* pb slots free in current submit */
74 	unsigned int first_get;		/* DMAGET value, where submit begins */
75 	unsigned int last_pos;		/* last value written to DMAPUT */
76 	struct push_buffer push_buffer;	/* channel's push buffer */
77 	struct list_head sync_queue;	/* job queue */
78 	struct buffer_timeout timeout;	/* channel's timeout state/wq */
79 	bool running;
80 	bool torndown;
81 };
82 
83 #define cdma_to_channel(cdma) container_of(cdma, struct host1x_channel, cdma)
84 #define cdma_to_host1x(cdma) dev_get_drvdata(cdma_to_channel(cdma)->dev->parent)
85 #define pb_to_cdma(pb) container_of(pb, struct host1x_cdma, push_buffer)
86 
87 int host1x_cdma_init(struct host1x_cdma *cdma);
88 int host1x_cdma_deinit(struct host1x_cdma *cdma);
89 void host1x_cdma_stop(struct host1x_cdma *cdma);
90 int host1x_cdma_begin(struct host1x_cdma *cdma, struct host1x_job *job);
91 void host1x_cdma_push(struct host1x_cdma *cdma, u32 op1, u32 op2);
92 void host1x_cdma_end(struct host1x_cdma *cdma, struct host1x_job *job);
93 void host1x_cdma_update(struct host1x_cdma *cdma);
94 void host1x_cdma_peek(struct host1x_cdma *cdma, u32 dmaget, int slot,
95 		      u32 *out);
96 unsigned int host1x_cdma_wait_locked(struct host1x_cdma *cdma,
97 				     enum cdma_event event);
98 void host1x_cdma_update_sync_queue(struct host1x_cdma *cdma,
99 				   struct device *dev);
100 #endif
101