1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2020 HiSilicon Limited. 4 */ 5 6 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 7 8 #include <linux/debugfs.h> 9 #include <linux/delay.h> 10 #include <linux/device.h> 11 #include <linux/dma-mapping.h> 12 #include <linux/kernel.h> 13 #include <linux/kthread.h> 14 #include <linux/map_benchmark.h> 15 #include <linux/math64.h> 16 #include <linux/module.h> 17 #include <linux/pci.h> 18 #include <linux/platform_device.h> 19 #include <linux/slab.h> 20 #include <linux/timekeeping.h> 21 22 struct map_benchmark_data { 23 struct map_benchmark bparam; 24 struct device *dev; 25 struct dentry *debugfs; 26 enum dma_data_direction dir; 27 atomic64_t sum_map_100ns; 28 atomic64_t sum_unmap_100ns; 29 atomic64_t sum_sq_map; 30 atomic64_t sum_sq_unmap; 31 atomic64_t loops; 32 }; 33 34 static int map_benchmark_thread(void *data) 35 { 36 void *buf; 37 dma_addr_t dma_addr; 38 struct map_benchmark_data *map = data; 39 int npages = map->bparam.granule; 40 u64 size = npages * PAGE_SIZE; 41 int ret = 0; 42 43 buf = alloc_pages_exact(size, GFP_KERNEL); 44 if (!buf) 45 return -ENOMEM; 46 47 while (!kthread_should_stop()) { 48 u64 map_100ns, unmap_100ns, map_sq, unmap_sq; 49 ktime_t map_stime, map_etime, unmap_stime, unmap_etime; 50 ktime_t map_delta, unmap_delta; 51 52 /* 53 * for a non-coherent device, if we don't stain them in the 54 * cache, this will give an underestimate of the real-world 55 * overhead of BIDIRECTIONAL or TO_DEVICE mappings; 56 * 66 means evertything goes well! 66 is lucky. 57 */ 58 if (map->dir != DMA_FROM_DEVICE) 59 memset(buf, 0x66, size); 60 61 map_stime = ktime_get(); 62 dma_addr = dma_map_single(map->dev, buf, size, map->dir); 63 if (unlikely(dma_mapping_error(map->dev, dma_addr))) { 64 pr_err("dma_map_single failed on %s\n", 65 dev_name(map->dev)); 66 ret = -ENOMEM; 67 goto out; 68 } 69 map_etime = ktime_get(); 70 map_delta = ktime_sub(map_etime, map_stime); 71 72 /* Pretend DMA is transmitting */ 73 ndelay(map->bparam.dma_trans_ns); 74 75 unmap_stime = ktime_get(); 76 dma_unmap_single(map->dev, dma_addr, size, map->dir); 77 unmap_etime = ktime_get(); 78 unmap_delta = ktime_sub(unmap_etime, unmap_stime); 79 80 /* calculate sum and sum of squares */ 81 82 map_100ns = div64_ul(map_delta, 100); 83 unmap_100ns = div64_ul(unmap_delta, 100); 84 map_sq = map_100ns * map_100ns; 85 unmap_sq = unmap_100ns * unmap_100ns; 86 87 atomic64_add(map_100ns, &map->sum_map_100ns); 88 atomic64_add(unmap_100ns, &map->sum_unmap_100ns); 89 atomic64_add(map_sq, &map->sum_sq_map); 90 atomic64_add(unmap_sq, &map->sum_sq_unmap); 91 atomic64_inc(&map->loops); 92 } 93 94 out: 95 free_pages_exact(buf, size); 96 return ret; 97 } 98 99 static int do_map_benchmark(struct map_benchmark_data *map) 100 { 101 struct task_struct **tsk; 102 int threads = map->bparam.threads; 103 int node = map->bparam.node; 104 const cpumask_t *cpu_mask = cpumask_of_node(node); 105 u64 loops; 106 int ret = 0; 107 int i; 108 109 tsk = kmalloc_array(threads, sizeof(*tsk), GFP_KERNEL); 110 if (!tsk) 111 return -ENOMEM; 112 113 get_device(map->dev); 114 115 for (i = 0; i < threads; i++) { 116 tsk[i] = kthread_create_on_node(map_benchmark_thread, map, 117 map->bparam.node, "dma-map-benchmark/%d", i); 118 if (IS_ERR(tsk[i])) { 119 pr_err("create dma_map thread failed\n"); 120 ret = PTR_ERR(tsk[i]); 121 goto out; 122 } 123 124 if (node != NUMA_NO_NODE) 125 kthread_bind_mask(tsk[i], cpu_mask); 126 } 127 128 /* clear the old value in the previous benchmark */ 129 atomic64_set(&map->sum_map_100ns, 0); 130 atomic64_set(&map->sum_unmap_100ns, 0); 131 atomic64_set(&map->sum_sq_map, 0); 132 atomic64_set(&map->sum_sq_unmap, 0); 133 atomic64_set(&map->loops, 0); 134 135 for (i = 0; i < threads; i++) { 136 get_task_struct(tsk[i]); 137 wake_up_process(tsk[i]); 138 } 139 140 msleep_interruptible(map->bparam.seconds * 1000); 141 142 /* wait for the completion of benchmark threads */ 143 for (i = 0; i < threads; i++) { 144 ret = kthread_stop(tsk[i]); 145 if (ret) 146 goto out; 147 } 148 149 loops = atomic64_read(&map->loops); 150 if (likely(loops > 0)) { 151 u64 map_variance, unmap_variance; 152 u64 sum_map = atomic64_read(&map->sum_map_100ns); 153 u64 sum_unmap = atomic64_read(&map->sum_unmap_100ns); 154 u64 sum_sq_map = atomic64_read(&map->sum_sq_map); 155 u64 sum_sq_unmap = atomic64_read(&map->sum_sq_unmap); 156 157 /* average latency */ 158 map->bparam.avg_map_100ns = div64_u64(sum_map, loops); 159 map->bparam.avg_unmap_100ns = div64_u64(sum_unmap, loops); 160 161 /* standard deviation of latency */ 162 map_variance = div64_u64(sum_sq_map, loops) - 163 map->bparam.avg_map_100ns * 164 map->bparam.avg_map_100ns; 165 unmap_variance = div64_u64(sum_sq_unmap, loops) - 166 map->bparam.avg_unmap_100ns * 167 map->bparam.avg_unmap_100ns; 168 map->bparam.map_stddev = int_sqrt64(map_variance); 169 map->bparam.unmap_stddev = int_sqrt64(unmap_variance); 170 } 171 172 out: 173 for (i = 0; i < threads; i++) 174 put_task_struct(tsk[i]); 175 put_device(map->dev); 176 kfree(tsk); 177 return ret; 178 } 179 180 static long map_benchmark_ioctl(struct file *file, unsigned int cmd, 181 unsigned long arg) 182 { 183 struct map_benchmark_data *map = file->private_data; 184 void __user *argp = (void __user *)arg; 185 u64 old_dma_mask; 186 int ret; 187 188 if (copy_from_user(&map->bparam, argp, sizeof(map->bparam))) 189 return -EFAULT; 190 191 switch (cmd) { 192 case DMA_MAP_BENCHMARK: 193 if (map->bparam.threads == 0 || 194 map->bparam.threads > DMA_MAP_MAX_THREADS) { 195 pr_err("invalid thread number\n"); 196 return -EINVAL; 197 } 198 199 if (map->bparam.seconds == 0 || 200 map->bparam.seconds > DMA_MAP_MAX_SECONDS) { 201 pr_err("invalid duration seconds\n"); 202 return -EINVAL; 203 } 204 205 if (map->bparam.dma_trans_ns > DMA_MAP_MAX_TRANS_DELAY) { 206 pr_err("invalid transmission delay\n"); 207 return -EINVAL; 208 } 209 210 if (map->bparam.node != NUMA_NO_NODE && 211 !node_possible(map->bparam.node)) { 212 pr_err("invalid numa node\n"); 213 return -EINVAL; 214 } 215 216 if (map->bparam.granule < 1 || map->bparam.granule > 1024) { 217 pr_err("invalid granule size\n"); 218 return -EINVAL; 219 } 220 221 switch (map->bparam.dma_dir) { 222 case DMA_MAP_BIDIRECTIONAL: 223 map->dir = DMA_BIDIRECTIONAL; 224 break; 225 case DMA_MAP_FROM_DEVICE: 226 map->dir = DMA_FROM_DEVICE; 227 break; 228 case DMA_MAP_TO_DEVICE: 229 map->dir = DMA_TO_DEVICE; 230 break; 231 default: 232 pr_err("invalid DMA direction\n"); 233 return -EINVAL; 234 } 235 236 old_dma_mask = dma_get_mask(map->dev); 237 238 ret = dma_set_mask(map->dev, 239 DMA_BIT_MASK(map->bparam.dma_bits)); 240 if (ret) { 241 pr_err("failed to set dma_mask on device %s\n", 242 dev_name(map->dev)); 243 return -EINVAL; 244 } 245 246 ret = do_map_benchmark(map); 247 248 /* 249 * restore the original dma_mask as many devices' dma_mask are 250 * set by architectures, acpi, busses. When we bind them back 251 * to their original drivers, those drivers shouldn't see 252 * dma_mask changed by benchmark 253 */ 254 dma_set_mask(map->dev, old_dma_mask); 255 break; 256 default: 257 return -EINVAL; 258 } 259 260 if (copy_to_user(argp, &map->bparam, sizeof(map->bparam))) 261 return -EFAULT; 262 263 return ret; 264 } 265 266 static const struct file_operations map_benchmark_fops = { 267 .open = simple_open, 268 .unlocked_ioctl = map_benchmark_ioctl, 269 }; 270 271 static void map_benchmark_remove_debugfs(void *data) 272 { 273 struct map_benchmark_data *map = (struct map_benchmark_data *)data; 274 275 debugfs_remove(map->debugfs); 276 } 277 278 static int __map_benchmark_probe(struct device *dev) 279 { 280 struct dentry *entry; 281 struct map_benchmark_data *map; 282 int ret; 283 284 map = devm_kzalloc(dev, sizeof(*map), GFP_KERNEL); 285 if (!map) 286 return -ENOMEM; 287 map->dev = dev; 288 289 ret = devm_add_action(dev, map_benchmark_remove_debugfs, map); 290 if (ret) { 291 pr_err("Can't add debugfs remove action\n"); 292 return ret; 293 } 294 295 /* 296 * we only permit a device bound with this driver, 2nd probe 297 * will fail 298 */ 299 entry = debugfs_create_file("dma_map_benchmark", 0600, NULL, map, 300 &map_benchmark_fops); 301 if (IS_ERR(entry)) 302 return PTR_ERR(entry); 303 map->debugfs = entry; 304 305 return 0; 306 } 307 308 static int map_benchmark_platform_probe(struct platform_device *pdev) 309 { 310 return __map_benchmark_probe(&pdev->dev); 311 } 312 313 static struct platform_driver map_benchmark_platform_driver = { 314 .driver = { 315 .name = "dma_map_benchmark", 316 }, 317 .probe = map_benchmark_platform_probe, 318 }; 319 320 static int 321 map_benchmark_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) 322 { 323 return __map_benchmark_probe(&pdev->dev); 324 } 325 326 static struct pci_driver map_benchmark_pci_driver = { 327 .name = "dma_map_benchmark", 328 .probe = map_benchmark_pci_probe, 329 }; 330 331 static int __init map_benchmark_init(void) 332 { 333 int ret; 334 335 ret = pci_register_driver(&map_benchmark_pci_driver); 336 if (ret) 337 return ret; 338 339 ret = platform_driver_register(&map_benchmark_platform_driver); 340 if (ret) { 341 pci_unregister_driver(&map_benchmark_pci_driver); 342 return ret; 343 } 344 345 return 0; 346 } 347 348 static void __exit map_benchmark_cleanup(void) 349 { 350 platform_driver_unregister(&map_benchmark_platform_driver); 351 pci_unregister_driver(&map_benchmark_pci_driver); 352 } 353 354 module_init(map_benchmark_init); 355 module_exit(map_benchmark_cleanup); 356 357 MODULE_AUTHOR("Barry Song <song.bao.hua@hisilicon.com>"); 358 MODULE_DESCRIPTION("dma_map benchmark driver"); 359