1 /*
2  * Copyright (c) 2014, NVIDIA CORPORATION. All rights reserved.
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a
5  * copy of this software and associated documentation files (the "Software"),
6  * to deal in the Software without restriction, including without limitation
7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8  * and/or sell copies of the Software, and to permit persons to whom the
9  * Software is furnished to do so, subject to the following conditions:
10  *
11  * The above copyright notice and this permission notice shall be included in
12  * all copies or substantial portions of the Software.
13  *
14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
17  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
18  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
19  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
20  * DEALINGS IN THE SOFTWARE.
21  */
22 #include "priv.h"
23 
24 #include <subdev/clk.h>
25 #include <subdev/timer.h>
26 #include <subdev/volt.h>
27 
28 #define BUSY_SLOT	0
29 #define CLK_SLOT	7
30 
31 struct gk20a_pmu_dvfs_data {
32 	int p_load_target;
33 	int p_load_max;
34 	int p_smooth;
35 	unsigned int avg_load;
36 };
37 
38 struct gk20a_pmu {
39 	struct nvkm_pmu base;
40 	struct nvkm_alarm alarm;
41 	struct gk20a_pmu_dvfs_data *data;
42 };
43 
44 struct gk20a_pmu_dvfs_dev_status {
45 	unsigned long total;
46 	unsigned long busy;
47 	int cur_state;
48 };
49 
50 static int
51 gk20a_pmu_dvfs_target(struct gk20a_pmu *pmu, int *state)
52 {
53 	struct nvkm_clk *clk = nvkm_clk(pmu);
54 
55 	return nvkm_clk_astate(clk, *state, 0, false);
56 }
57 
58 static int
59 gk20a_pmu_dvfs_get_cur_state(struct gk20a_pmu *pmu, int *state)
60 {
61 	struct nvkm_clk *clk = nvkm_clk(pmu);
62 
63 	*state = clk->pstate;
64 	return 0;
65 }
66 
67 static int
68 gk20a_pmu_dvfs_get_target_state(struct gk20a_pmu *pmu,
69 				int *state, int load)
70 {
71 	struct gk20a_pmu_dvfs_data *data = pmu->data;
72 	struct nvkm_clk *clk = nvkm_clk(pmu);
73 	int cur_level, level;
74 
75 	/* For GK20A, the performance level is directly mapped to pstate */
76 	level = cur_level = clk->pstate;
77 
78 	if (load > data->p_load_max) {
79 		level = min(clk->state_nr - 1, level + (clk->state_nr / 3));
80 	} else {
81 		level += ((load - data->p_load_target) * 10 /
82 				data->p_load_target) / 2;
83 		level = max(0, level);
84 		level = min(clk->state_nr - 1, level);
85 	}
86 
87 	nvkm_trace(&pmu->base.subdev, "cur level = %d, new level = %d\n",
88 		   cur_level, level);
89 
90 	*state = level;
91 
92 	if (level == cur_level)
93 		return 0;
94 	else
95 		return 1;
96 }
97 
98 static int
99 gk20a_pmu_dvfs_get_dev_status(struct gk20a_pmu *pmu,
100 			      struct gk20a_pmu_dvfs_dev_status *status)
101 {
102 	struct nvkm_device *device = pmu->base.subdev.device;
103 	status->busy = nvkm_rd32(device, 0x10a508 + (BUSY_SLOT * 0x10));
104 	status->total= nvkm_rd32(device, 0x10a508 + (CLK_SLOT * 0x10));
105 	return 0;
106 }
107 
108 static void
109 gk20a_pmu_dvfs_reset_dev_status(struct gk20a_pmu *pmu)
110 {
111 	struct nvkm_device *device = pmu->base.subdev.device;
112 	nvkm_wr32(device, 0x10a508 + (BUSY_SLOT * 0x10), 0x80000000);
113 	nvkm_wr32(device, 0x10a508 + (CLK_SLOT * 0x10), 0x80000000);
114 }
115 
116 static void
117 gk20a_pmu_dvfs_work(struct nvkm_alarm *alarm)
118 {
119 	struct gk20a_pmu *pmu =
120 		container_of(alarm, struct gk20a_pmu, alarm);
121 	struct gk20a_pmu_dvfs_data *data = pmu->data;
122 	struct gk20a_pmu_dvfs_dev_status status;
123 	struct nvkm_subdev *subdev = &pmu->base.subdev;
124 	struct nvkm_device *device = subdev->device;
125 	struct nvkm_clk *clk = device->clk;
126 	struct nvkm_volt *volt = device->volt;
127 	u32 utilization = 0;
128 	int state, ret;
129 
130 	/*
131 	 * The PMU is initialized before CLK and VOLT, so we have to make sure the
132 	 * CLK and VOLT are ready here.
133 	 */
134 	if (!clk || !volt)
135 		goto resched;
136 
137 	ret = gk20a_pmu_dvfs_get_dev_status(pmu, &status);
138 	if (ret) {
139 		nvkm_warn(subdev, "failed to get device status\n");
140 		goto resched;
141 	}
142 
143 	if (status.total)
144 		utilization = div_u64((u64)status.busy * 100, status.total);
145 
146 	data->avg_load = (data->p_smooth * data->avg_load) + utilization;
147 	data->avg_load /= data->p_smooth + 1;
148 	nvkm_trace(subdev, "utilization = %d %%, avg_load = %d %%\n",
149 		   utilization, data->avg_load);
150 
151 	ret = gk20a_pmu_dvfs_get_cur_state(pmu, &state);
152 	if (ret) {
153 		nvkm_warn(subdev, "failed to get current state\n");
154 		goto resched;
155 	}
156 
157 	if (gk20a_pmu_dvfs_get_target_state(pmu, &state, data->avg_load)) {
158 		nvkm_trace(subdev, "set new state to %d\n", state);
159 		gk20a_pmu_dvfs_target(pmu, &state);
160 	}
161 
162 resched:
163 	gk20a_pmu_dvfs_reset_dev_status(pmu);
164 	nvkm_timer_alarm(pmu, 100000000, alarm);
165 }
166 
167 static int
168 gk20a_pmu_fini(struct nvkm_object *object, bool suspend)
169 {
170 	struct gk20a_pmu *pmu = (void *)object;
171 
172 	nvkm_timer_alarm_cancel(pmu, &pmu->alarm);
173 
174 	return nvkm_subdev_fini_old(&pmu->base.subdev, suspend);
175 }
176 
177 static int
178 gk20a_pmu_init(struct nvkm_object *object)
179 {
180 	struct gk20a_pmu *pmu = (void *)object;
181 	struct nvkm_device *device = pmu->base.subdev.device;
182 	int ret;
183 
184 	ret = nvkm_subdev_init_old(&pmu->base.subdev);
185 	if (ret)
186 		return ret;
187 
188 	pmu->base.pgob = nvkm_pmu_pgob;
189 
190 	/* init pwr perf counter */
191 	nvkm_wr32(device, 0x10a504 + (BUSY_SLOT * 0x10), 0x00200001);
192 	nvkm_wr32(device, 0x10a50c + (BUSY_SLOT * 0x10), 0x00000002);
193 	nvkm_wr32(device, 0x10a50c + (CLK_SLOT * 0x10), 0x00000003);
194 
195 	nvkm_timer_alarm(pmu, 2000000000, &pmu->alarm);
196 	return ret;
197 }
198 
199 static struct gk20a_pmu_dvfs_data
200 gk20a_dvfs_data= {
201 	.p_load_target = 70,
202 	.p_load_max = 90,
203 	.p_smooth = 1,
204 };
205 
206 static int
207 gk20a_pmu_ctor(struct nvkm_object *parent, struct nvkm_object *engine,
208 	       struct nvkm_oclass *oclass, void *data, u32 size,
209 	       struct nvkm_object **pobject)
210 {
211 	struct gk20a_pmu *pmu;
212 	int ret;
213 
214 	ret = nvkm_pmu_create(parent, engine, oclass, &pmu);
215 	*pobject = nv_object(pmu);
216 	if (ret)
217 		return ret;
218 
219 	pmu->data = &gk20a_dvfs_data;
220 
221 	nvkm_alarm_init(&pmu->alarm, gk20a_pmu_dvfs_work);
222 	return 0;
223 }
224 
225 struct nvkm_oclass *
226 gk20a_pmu_oclass = &(struct nvkm_pmu_impl) {
227 	.base.handle = NV_SUBDEV(PMU, 0xea),
228 	.base.ofuncs = &(struct nvkm_ofuncs) {
229 		.ctor = gk20a_pmu_ctor,
230 		.dtor = _nvkm_pmu_dtor,
231 		.init = gk20a_pmu_init,
232 		.fini = gk20a_pmu_fini,
233 	},
234 }.base;
235