1 /* 2 * Copyright (C) 2013 Red Hat 3 * Author: Rob Clark <robdclark@gmail.com> 4 * 5 * This program is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 as published by 7 * the Free Software Foundation. 8 * 9 * This program is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 12 * more details. 13 * 14 * You should have received a copy of the GNU General Public License along with 15 * this program. If not, see <http://www.gnu.org/licenses/>. 16 */ 17 18 /* For profiling, userspace can: 19 * 20 * tail -f /sys/kernel/debug/dri/<minor>/gpu 21 * 22 * This will enable performance counters/profiling to track the busy time 23 * and any gpu specific performance counters that are supported. 24 */ 25 26 #ifdef CONFIG_DEBUG_FS 27 28 #include <linux/debugfs.h> 29 30 #include "msm_drv.h" 31 #include "msm_gpu.h" 32 33 struct msm_perf_state { 34 struct drm_device *dev; 35 36 bool open; 37 int cnt; 38 struct mutex read_lock; 39 40 char buf[256]; 41 int buftot, bufpos; 42 43 unsigned long next_jiffies; 44 }; 45 46 #define SAMPLE_TIME (HZ/4) 47 48 /* wait for next sample time: */ 49 static int wait_sample(struct msm_perf_state *perf) 50 { 51 unsigned long start_jiffies = jiffies; 52 53 if (time_after(perf->next_jiffies, start_jiffies)) { 54 unsigned long remaining_jiffies = 55 perf->next_jiffies - start_jiffies; 56 int ret = schedule_timeout_interruptible(remaining_jiffies); 57 if (ret > 0) { 58 /* interrupted */ 59 return -ERESTARTSYS; 60 } 61 } 62 perf->next_jiffies += SAMPLE_TIME; 63 return 0; 64 } 65 66 static int refill_buf(struct msm_perf_state *perf) 67 { 68 struct msm_drm_private *priv = perf->dev->dev_private; 69 struct msm_gpu *gpu = priv->gpu; 70 char *ptr = perf->buf; 71 int rem = sizeof(perf->buf); 72 int i, n; 73 74 if ((perf->cnt++ % 32) == 0) { 75 /* Header line: */ 76 n = snprintf(ptr, rem, "%%BUSY"); 77 ptr += n; 78 rem -= n; 79 80 for (i = 0; i < gpu->num_perfcntrs; i++) { 81 const struct msm_gpu_perfcntr *perfcntr = &gpu->perfcntrs[i]; 82 n = snprintf(ptr, rem, "\t%s", perfcntr->name); 83 ptr += n; 84 rem -= n; 85 } 86 } else { 87 /* Sample line: */ 88 uint32_t activetime = 0, totaltime = 0; 89 uint32_t cntrs[5]; 90 uint32_t val; 91 int ret; 92 93 /* sleep until next sample time: */ 94 ret = wait_sample(perf); 95 if (ret) 96 return ret; 97 98 ret = msm_gpu_perfcntr_sample(gpu, &activetime, &totaltime, 99 ARRAY_SIZE(cntrs), cntrs); 100 if (ret < 0) 101 return ret; 102 103 val = totaltime ? 1000 * activetime / totaltime : 0; 104 n = snprintf(ptr, rem, "%3d.%d%%", val / 10, val % 10); 105 ptr += n; 106 rem -= n; 107 108 for (i = 0; i < ret; i++) { 109 /* cycle counters (I think).. convert to MHz.. */ 110 val = cntrs[i] / 10000; 111 n = snprintf(ptr, rem, "\t%5d.%02d", 112 val / 100, val % 100); 113 ptr += n; 114 rem -= n; 115 } 116 } 117 118 n = snprintf(ptr, rem, "\n"); 119 ptr += n; 120 rem -= n; 121 122 perf->bufpos = 0; 123 perf->buftot = ptr - perf->buf; 124 125 return 0; 126 } 127 128 static ssize_t perf_read(struct file *file, char __user *buf, 129 size_t sz, loff_t *ppos) 130 { 131 struct msm_perf_state *perf = file->private_data; 132 int n = 0, ret = 0; 133 134 mutex_lock(&perf->read_lock); 135 136 if (perf->bufpos >= perf->buftot) { 137 ret = refill_buf(perf); 138 if (ret) 139 goto out; 140 } 141 142 n = min((int)sz, perf->buftot - perf->bufpos); 143 if (copy_to_user(buf, &perf->buf[perf->bufpos], n)) { 144 ret = -EFAULT; 145 goto out; 146 } 147 148 perf->bufpos += n; 149 *ppos += n; 150 151 out: 152 mutex_unlock(&perf->read_lock); 153 if (ret) 154 return ret; 155 return n; 156 } 157 158 static int perf_open(struct inode *inode, struct file *file) 159 { 160 struct msm_perf_state *perf = inode->i_private; 161 struct drm_device *dev = perf->dev; 162 struct msm_drm_private *priv = dev->dev_private; 163 struct msm_gpu *gpu = priv->gpu; 164 int ret = 0; 165 166 mutex_lock(&dev->struct_mutex); 167 168 if (perf->open || !gpu) { 169 ret = -EBUSY; 170 goto out; 171 } 172 173 file->private_data = perf; 174 perf->open = true; 175 perf->cnt = 0; 176 perf->buftot = 0; 177 perf->bufpos = 0; 178 msm_gpu_perfcntr_start(gpu); 179 perf->next_jiffies = jiffies + SAMPLE_TIME; 180 181 out: 182 mutex_unlock(&dev->struct_mutex); 183 return ret; 184 } 185 186 static int perf_release(struct inode *inode, struct file *file) 187 { 188 struct msm_perf_state *perf = inode->i_private; 189 struct msm_drm_private *priv = perf->dev->dev_private; 190 msm_gpu_perfcntr_stop(priv->gpu); 191 perf->open = false; 192 return 0; 193 } 194 195 196 static const struct file_operations perf_debugfs_fops = { 197 .owner = THIS_MODULE, 198 .open = perf_open, 199 .read = perf_read, 200 .llseek = no_llseek, 201 .release = perf_release, 202 }; 203 204 int msm_perf_debugfs_init(struct drm_minor *minor) 205 { 206 struct msm_drm_private *priv = minor->dev->dev_private; 207 struct msm_perf_state *perf; 208 struct dentry *ent; 209 210 /* only create on first minor: */ 211 if (priv->perf) 212 return 0; 213 214 perf = kzalloc(sizeof(*perf), GFP_KERNEL); 215 if (!perf) 216 return -ENOMEM; 217 218 perf->dev = minor->dev; 219 220 mutex_init(&perf->read_lock); 221 priv->perf = perf; 222 223 ent = debugfs_create_file("perf", S_IFREG | S_IRUGO, 224 minor->debugfs_root, perf, &perf_debugfs_fops); 225 if (!ent) { 226 DRM_ERROR("Cannot create /sys/kernel/debug/dri/%pd/perf\n", 227 minor->debugfs_root); 228 goto fail; 229 } 230 231 return 0; 232 233 fail: 234 msm_perf_debugfs_cleanup(priv); 235 return -1; 236 } 237 238 void msm_perf_debugfs_cleanup(struct msm_drm_private *priv) 239 { 240 struct msm_perf_state *perf = priv->perf; 241 242 if (!perf) 243 return; 244 245 priv->perf = NULL; 246 247 mutex_destroy(&perf->read_lock); 248 249 kfree(perf); 250 } 251 252 #endif 253