xref: /linux/drivers/gpu/drm/xe/xe_gt_idle.c (revision ae22a94997b8a03dcb3c922857c203246711f9d4)
1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright © 2023 Intel Corporation
4  */
5 
6 #include <drm/drm_managed.h>
7 
8 #include "xe_device.h"
9 #include "xe_gt.h"
10 #include "xe_gt_idle.h"
11 #include "xe_gt_sysfs.h"
12 #include "xe_guc_pc.h"
13 #include "regs/xe_gt_regs.h"
14 #include "xe_mmio.h"
15 
16 /**
17  * DOC: Xe GT Idle
18  *
19  * Contains functions that init GT idle features like C6
20  *
21  * device/gt#/gtidle/name - name of the state
22  * device/gt#/gtidle/idle_residency_ms - Provides residency of the idle state in ms
23  * device/gt#/gtidle/idle_status - Provides current idle state
24  */
25 
26 static struct xe_gt_idle *dev_to_gtidle(struct device *dev)
27 {
28 	struct kobject *kobj = &dev->kobj;
29 
30 	return &kobj_to_gt(kobj->parent)->gtidle;
31 }
32 
33 static struct xe_gt *gtidle_to_gt(struct xe_gt_idle *gtidle)
34 {
35 	return container_of(gtidle, struct xe_gt, gtidle);
36 }
37 
38 static struct xe_guc_pc *gtidle_to_pc(struct xe_gt_idle *gtidle)
39 {
40 	return &gtidle_to_gt(gtidle)->uc.guc.pc;
41 }
42 
43 static const char *gt_idle_state_to_string(enum xe_gt_idle_state state)
44 {
45 	switch (state) {
46 	case GT_IDLE_C0:
47 		return "gt-c0";
48 	case GT_IDLE_C6:
49 		return "gt-c6";
50 	default:
51 		return "unknown";
52 	}
53 }
54 
55 static u64 get_residency_ms(struct xe_gt_idle *gtidle, u64 cur_residency)
56 {
57 	u64 delta, overflow_residency, prev_residency;
58 
59 	overflow_residency = BIT_ULL(32);
60 
61 	/*
62 	 * Counter wrap handling
63 	 * Store previous hw counter values for counter wrap-around handling
64 	 * Relying on sufficient frequency of queries otherwise counters can still wrap.
65 	 */
66 	prev_residency = gtidle->prev_residency;
67 	gtidle->prev_residency = cur_residency;
68 
69 	/* delta */
70 	if (cur_residency >= prev_residency)
71 		delta = cur_residency - prev_residency;
72 	else
73 		delta = cur_residency + (overflow_residency - prev_residency);
74 
75 	/* Add delta to extended raw driver copy of idle residency */
76 	cur_residency = gtidle->cur_residency + delta;
77 	gtidle->cur_residency = cur_residency;
78 
79 	/* residency multiplier in ns, convert to ms */
80 	cur_residency = mul_u64_u32_div(cur_residency, gtidle->residency_multiplier, 1e6);
81 
82 	return cur_residency;
83 }
84 
85 static ssize_t name_show(struct device *dev,
86 			 struct device_attribute *attr, char *buff)
87 {
88 	struct xe_gt_idle *gtidle = dev_to_gtidle(dev);
89 
90 	return sysfs_emit(buff, "%s\n", gtidle->name);
91 }
92 static DEVICE_ATTR_RO(name);
93 
94 static ssize_t idle_status_show(struct device *dev,
95 				struct device_attribute *attr, char *buff)
96 {
97 	struct xe_gt_idle *gtidle = dev_to_gtidle(dev);
98 	struct xe_guc_pc *pc = gtidle_to_pc(gtidle);
99 	enum xe_gt_idle_state state;
100 
101 	state = gtidle->idle_status(pc);
102 
103 	return sysfs_emit(buff, "%s\n", gt_idle_state_to_string(state));
104 }
105 static DEVICE_ATTR_RO(idle_status);
106 
107 static ssize_t idle_residency_ms_show(struct device *dev,
108 				      struct device_attribute *attr, char *buff)
109 {
110 	struct xe_gt_idle *gtidle = dev_to_gtidle(dev);
111 	struct xe_guc_pc *pc = gtidle_to_pc(gtidle);
112 	u64 residency;
113 
114 	residency = gtidle->idle_residency(pc);
115 	return sysfs_emit(buff, "%llu\n", get_residency_ms(gtidle, residency));
116 }
117 static DEVICE_ATTR_RO(idle_residency_ms);
118 
119 static const struct attribute *gt_idle_attrs[] = {
120 	&dev_attr_name.attr,
121 	&dev_attr_idle_status.attr,
122 	&dev_attr_idle_residency_ms.attr,
123 	NULL,
124 };
125 
126 static void gt_idle_sysfs_fini(struct drm_device *drm, void *arg)
127 {
128 	struct kobject *kobj = arg;
129 
130 	sysfs_remove_files(kobj, gt_idle_attrs);
131 	kobject_put(kobj);
132 }
133 
134 void xe_gt_idle_sysfs_init(struct xe_gt_idle *gtidle)
135 {
136 	struct xe_gt *gt = gtidle_to_gt(gtidle);
137 	struct xe_device *xe = gt_to_xe(gt);
138 	struct kobject *kobj;
139 	int err;
140 
141 	kobj = kobject_create_and_add("gtidle", gt->sysfs);
142 	if (!kobj) {
143 		drm_warn(&xe->drm, "%s failed, err: %d\n", __func__, -ENOMEM);
144 		return;
145 	}
146 
147 	if (xe_gt_is_media_type(gt)) {
148 		sprintf(gtidle->name, "gt%d-mc", gt->info.id);
149 		gtidle->idle_residency = xe_guc_pc_mc6_residency;
150 	} else {
151 		sprintf(gtidle->name, "gt%d-rc", gt->info.id);
152 		gtidle->idle_residency = xe_guc_pc_rc6_residency;
153 	}
154 
155 	/* Multiplier for Residency counter in units of 1.28us */
156 	gtidle->residency_multiplier = 1280;
157 	gtidle->idle_status = xe_guc_pc_c_status;
158 
159 	err = sysfs_create_files(kobj, gt_idle_attrs);
160 	if (err) {
161 		kobject_put(kobj);
162 		drm_warn(&xe->drm, "failed to register gtidle sysfs, err: %d\n", err);
163 		return;
164 	}
165 
166 	err = drmm_add_action_or_reset(&xe->drm, gt_idle_sysfs_fini, kobj);
167 	if (err)
168 		drm_warn(&xe->drm, "%s: drmm_add_action_or_reset failed, err: %d\n",
169 			 __func__, err);
170 }
171 
172 void xe_gt_idle_enable_c6(struct xe_gt *gt)
173 {
174 	xe_device_assert_mem_access(gt_to_xe(gt));
175 	xe_force_wake_assert_held(gt_to_fw(gt), XE_FW_GT);
176 
177 	/* Units of 1280 ns for a total of 5s */
178 	xe_mmio_write32(gt, RC_IDLE_HYSTERSIS, 0x3B9ACA);
179 	/* Enable RC6 */
180 	xe_mmio_write32(gt, RC_CONTROL,
181 			RC_CTL_HW_ENABLE | RC_CTL_TO_MODE | RC_CTL_RC6_ENABLE);
182 }
183 
184 void xe_gt_idle_disable_c6(struct xe_gt *gt)
185 {
186 	xe_device_assert_mem_access(gt_to_xe(gt));
187 	xe_force_wake_assert_held(gt_to_fw(gt), XE_FORCEWAKE_ALL);
188 
189 	xe_mmio_write32(gt, PG_ENABLE, 0);
190 	xe_mmio_write32(gt, RC_CONTROL, 0);
191 	xe_mmio_write32(gt, RC_STATE, 0);
192 }
193