xref: /linux/drivers/gpu/host1x/hw/syncpt_hw.c (revision 93df8a1ed6231727c5db94a80b1a6bd5ee67cec3)
1 /*
2  * Tegra host1x Syncpoints
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 #include <linux/io.h>
20 
21 #include "../dev.h"
22 #include "../syncpt.h"
23 
24 /*
25  * Write the current syncpoint value back to hw.
26  */
27 static void syncpt_restore(struct host1x_syncpt *sp)
28 {
29 	struct host1x *host = sp->host;
30 	int min = host1x_syncpt_read_min(sp);
31 	host1x_sync_writel(host, min, HOST1X_SYNC_SYNCPT(sp->id));
32 }
33 
34 /*
35  * Write the current waitbase value back to hw.
36  */
37 static void syncpt_restore_wait_base(struct host1x_syncpt *sp)
38 {
39 	struct host1x *host = sp->host;
40 	host1x_sync_writel(host, sp->base_val,
41 			   HOST1X_SYNC_SYNCPT_BASE(sp->id));
42 }
43 
44 /*
45  * Read waitbase value from hw.
46  */
47 static void syncpt_read_wait_base(struct host1x_syncpt *sp)
48 {
49 	struct host1x *host = sp->host;
50 	sp->base_val =
51 		host1x_sync_readl(host, HOST1X_SYNC_SYNCPT_BASE(sp->id));
52 }
53 
54 /*
55  * Updates the last value read from hardware.
56  */
57 static u32 syncpt_load(struct host1x_syncpt *sp)
58 {
59 	struct host1x *host = sp->host;
60 	u32 old, live;
61 
62 	/* Loop in case there's a race writing to min_val */
63 	do {
64 		old = host1x_syncpt_read_min(sp);
65 		live = host1x_sync_readl(host, HOST1X_SYNC_SYNCPT(sp->id));
66 	} while ((u32)atomic_cmpxchg(&sp->min_val, old, live) != old);
67 
68 	if (!host1x_syncpt_check_max(sp, live))
69 		dev_err(host->dev, "%s failed: id=%u, min=%d, max=%d\n",
70 			__func__, sp->id, host1x_syncpt_read_min(sp),
71 			host1x_syncpt_read_max(sp));
72 
73 	return live;
74 }
75 
76 /*
77  * Write a cpu syncpoint increment to the hardware, without touching
78  * the cache.
79  */
80 static int syncpt_cpu_incr(struct host1x_syncpt *sp)
81 {
82 	struct host1x *host = sp->host;
83 	u32 reg_offset = sp->id / 32;
84 
85 	if (!host1x_syncpt_client_managed(sp) &&
86 	    host1x_syncpt_idle(sp))
87 		return -EINVAL;
88 	host1x_sync_writel(host, BIT_MASK(sp->id),
89 			   HOST1X_SYNC_SYNCPT_CPU_INCR(reg_offset));
90 	wmb();
91 
92 	return 0;
93 }
94 
95 /* remove a wait pointed to by patch_addr */
96 static int syncpt_patch_wait(struct host1x_syncpt *sp, void *patch_addr)
97 {
98 	u32 override = host1x_class_host_wait_syncpt(
99 		HOST1X_SYNCPT_RESERVED, 0);
100 
101 	*((u32 *)patch_addr) = override;
102 	return 0;
103 }
104 
105 static const struct host1x_syncpt_ops host1x_syncpt_ops = {
106 	.restore = syncpt_restore,
107 	.restore_wait_base = syncpt_restore_wait_base,
108 	.load_wait_base = syncpt_read_wait_base,
109 	.load = syncpt_load,
110 	.cpu_incr = syncpt_cpu_incr,
111 	.patch_wait = syncpt_patch_wait,
112 };
113