xref: /linux/drivers/gpu/host1x/hw/syncpt_hw.c (revision 856e7c4b619af622d56b3b454f7bec32a170ac99)
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 	u32 min = host1x_syncpt_read_min(sp);
30 	struct host1x *host = sp->host;
31 
32 	host1x_sync_writel(host, min, HOST1X_SYNC_SYNCPT(sp->id));
33 }
34 
35 /*
36  * Write the current waitbase value back to hw.
37  */
38 static void syncpt_restore_wait_base(struct host1x_syncpt *sp)
39 {
40 	struct host1x *host = sp->host;
41 
42 	host1x_sync_writel(host, sp->base_val,
43 			   HOST1X_SYNC_SYNCPT_BASE(sp->id));
44 }
45 
46 /*
47  * Read waitbase value from hw.
48  */
49 static void syncpt_read_wait_base(struct host1x_syncpt *sp)
50 {
51 	struct host1x *host = sp->host;
52 
53 	sp->base_val =
54 		host1x_sync_readl(host, HOST1X_SYNC_SYNCPT_BASE(sp->id));
55 }
56 
57 /*
58  * Updates the last value read from hardware.
59  */
60 static u32 syncpt_load(struct host1x_syncpt *sp)
61 {
62 	struct host1x *host = sp->host;
63 	u32 old, live;
64 
65 	/* Loop in case there's a race writing to min_val */
66 	do {
67 		old = host1x_syncpt_read_min(sp);
68 		live = host1x_sync_readl(host, HOST1X_SYNC_SYNCPT(sp->id));
69 	} while ((u32)atomic_cmpxchg(&sp->min_val, old, live) != old);
70 
71 	if (!host1x_syncpt_check_max(sp, live))
72 		dev_err(host->dev, "%s failed: id=%u, min=%d, max=%d\n",
73 			__func__, sp->id, host1x_syncpt_read_min(sp),
74 			host1x_syncpt_read_max(sp));
75 
76 	return live;
77 }
78 
79 /*
80  * Write a cpu syncpoint increment to the hardware, without touching
81  * the cache.
82  */
83 static int syncpt_cpu_incr(struct host1x_syncpt *sp)
84 {
85 	struct host1x *host = sp->host;
86 	u32 reg_offset = sp->id / 32;
87 
88 	if (!host1x_syncpt_client_managed(sp) &&
89 	    host1x_syncpt_idle(sp))
90 		return -EINVAL;
91 
92 	host1x_sync_writel(host, BIT(sp->id % 32),
93 			   HOST1X_SYNC_SYNCPT_CPU_INCR(reg_offset));
94 	wmb();
95 
96 	return 0;
97 }
98 
99 /**
100  * syncpt_assign_to_channel() - Assign syncpoint to channel
101  * @sp: syncpoint
102  * @ch: channel
103  *
104  * On chips with the syncpoint protection feature (Tegra186+), assign @sp to
105  * @ch, preventing other channels from incrementing the syncpoints. If @ch is
106  * NULL, unassigns the syncpoint.
107  *
108  * On older chips, do nothing.
109  */
110 static void syncpt_assign_to_channel(struct host1x_syncpt *sp,
111 				  struct host1x_channel *ch)
112 {
113 #if HOST1X_HW >= 6
114 	struct host1x *host = sp->host;
115 
116 	if (!host->hv_regs)
117 		return;
118 
119 	host1x_sync_writel(host,
120 			   HOST1X_SYNC_SYNCPT_CH_APP_CH(ch ? ch->id : 0xff),
121 			   HOST1X_SYNC_SYNCPT_CH_APP(sp->id));
122 #endif
123 }
124 
125 /**
126  * syncpt_enable_protection() - Enable syncpoint protection
127  * @host: host1x instance
128  *
129  * On chips with the syncpoint protection feature (Tegra186+), enable this
130  * feature. On older chips, do nothing.
131  */
132 static void syncpt_enable_protection(struct host1x *host)
133 {
134 #if HOST1X_HW >= 6
135 	if (!host->hv_regs)
136 		return;
137 
138 	host1x_hypervisor_writel(host, HOST1X_HV_SYNCPT_PROT_EN_CH_EN,
139 				 HOST1X_HV_SYNCPT_PROT_EN);
140 #endif
141 }
142 
143 static const struct host1x_syncpt_ops host1x_syncpt_ops = {
144 	.restore = syncpt_restore,
145 	.restore_wait_base = syncpt_restore_wait_base,
146 	.load_wait_base = syncpt_read_wait_base,
147 	.load = syncpt_load,
148 	.cpu_incr = syncpt_cpu_incr,
149 	.assign_to_channel = syncpt_assign_to_channel,
150 	.enable_protection = syncpt_enable_protection,
151 };
152