1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * uio_hv_generic - generic UIO driver for VMBus 4 * 5 * Copyright (c) 2013-2016 Brocade Communications Systems, Inc. 6 * Copyright (c) 2016, Microsoft Corporation. 7 * 8 * Since the driver does not declare any device ids, you must allocate 9 * id and bind the device to the driver yourself. For example: 10 * 11 * Associate Network GUID with UIO device 12 * # echo "f8615163-df3e-46c5-913f-f2d2f965ed0e" \ 13 * > /sys/bus/vmbus/drivers/uio_hv_generic/new_id 14 * Then rebind 15 * # echo -n "ed963694-e847-4b2a-85af-bc9cfc11d6f3" \ 16 * > /sys/bus/vmbus/drivers/hv_netvsc/unbind 17 * # echo -n "ed963694-e847-4b2a-85af-bc9cfc11d6f3" \ 18 * > /sys/bus/vmbus/drivers/uio_hv_generic/bind 19 */ 20 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 21 22 #include <linux/device.h> 23 #include <linux/kernel.h> 24 #include <linux/module.h> 25 #include <linux/uio_driver.h> 26 #include <linux/netdevice.h> 27 #include <linux/if_ether.h> 28 #include <linux/skbuff.h> 29 #include <linux/hyperv.h> 30 #include <linux/vmalloc.h> 31 #include <linux/slab.h> 32 33 #include "../hv/hyperv_vmbus.h" 34 35 #define DRIVER_VERSION "0.02.1" 36 #define DRIVER_AUTHOR "Stephen Hemminger <sthemmin at microsoft.com>" 37 #define DRIVER_DESC "Generic UIO driver for VMBus devices" 38 39 #define SEND_BUFFER_SIZE (16 * 1024 * 1024) 40 #define RECV_BUFFER_SIZE (31 * 1024 * 1024) 41 42 /* 43 * List of resources to be mapped to user space 44 * can be extended up to MAX_UIO_MAPS(5) items 45 */ 46 enum hv_uio_map { 47 TXRX_RING_MAP = 0, 48 INT_PAGE_MAP, 49 MON_PAGE_MAP, 50 RECV_BUF_MAP, 51 SEND_BUF_MAP 52 }; 53 54 struct hv_uio_private_data { 55 struct uio_info info; 56 struct hv_device *device; 57 atomic_t refcnt; 58 59 void *recv_buf; 60 struct vmbus_gpadl recv_gpadl; 61 char recv_name[32]; /* "recv_4294967295" */ 62 63 void *send_buf; 64 struct vmbus_gpadl send_gpadl; 65 char send_name[32]; 66 }; 67 68 /* 69 * This is the irqcontrol callback to be registered to uio_info. 70 * It can be used to disable/enable interrupt from user space processes. 71 * 72 * @param info 73 * pointer to uio_info. 74 * @param irq_state 75 * state value. 1 to enable interrupt, 0 to disable interrupt. 76 */ 77 static int 78 hv_uio_irqcontrol(struct uio_info *info, s32 irq_state) 79 { 80 struct hv_uio_private_data *pdata = info->priv; 81 struct hv_device *dev = pdata->device; 82 83 dev->channel->inbound.ring_buffer->interrupt_mask = !irq_state; 84 virt_mb(); 85 86 if (!dev->channel->offermsg.monitor_allocated && irq_state) 87 vmbus_setevent(dev->channel); 88 89 return 0; 90 } 91 92 /* 93 * Callback from vmbus_event when something is in inbound ring. 94 */ 95 static void hv_uio_channel_cb(void *context) 96 { 97 struct vmbus_channel *chan = context; 98 struct hv_device *hv_dev = chan->device_obj; 99 struct hv_uio_private_data *pdata = hv_get_drvdata(hv_dev); 100 101 chan->inbound.ring_buffer->interrupt_mask = 1; 102 virt_mb(); 103 104 uio_event_notify(&pdata->info); 105 } 106 107 /* 108 * Callback from vmbus_event when channel is rescinded. 109 */ 110 static void hv_uio_rescind(struct vmbus_channel *channel) 111 { 112 struct hv_device *hv_dev = channel->primary_channel->device_obj; 113 struct hv_uio_private_data *pdata = hv_get_drvdata(hv_dev); 114 115 /* 116 * Turn off the interrupt file handle 117 * Next read for event will return -EIO 118 */ 119 pdata->info.irq = 0; 120 121 /* Wake up reader */ 122 uio_event_notify(&pdata->info); 123 } 124 125 /* Sysfs API to allow mmap of the ring buffers 126 * The ring buffer is allocated as contiguous memory by vmbus_open 127 */ 128 static int hv_uio_ring_mmap(struct file *filp, struct kobject *kobj, 129 struct bin_attribute *attr, 130 struct vm_area_struct *vma) 131 { 132 struct vmbus_channel *channel 133 = container_of(kobj, struct vmbus_channel, kobj); 134 void *ring_buffer = page_address(channel->ringbuffer_page); 135 136 if (channel->state != CHANNEL_OPENED_STATE) 137 return -ENODEV; 138 139 return vm_iomap_memory(vma, virt_to_phys(ring_buffer), 140 channel->ringbuffer_pagecount << PAGE_SHIFT); 141 } 142 143 static const struct bin_attribute ring_buffer_bin_attr = { 144 .attr = { 145 .name = "ring", 146 .mode = 0600, 147 }, 148 .size = 2 * SZ_2M, 149 .mmap = hv_uio_ring_mmap, 150 }; 151 152 /* Callback from VMBUS subsystem when new channel created. */ 153 static void 154 hv_uio_new_channel(struct vmbus_channel *new_sc) 155 { 156 struct hv_device *hv_dev = new_sc->primary_channel->device_obj; 157 struct device *device = &hv_dev->device; 158 const size_t ring_bytes = SZ_2M; 159 int ret; 160 161 /* Create host communication ring */ 162 ret = vmbus_open(new_sc, ring_bytes, ring_bytes, NULL, 0, 163 hv_uio_channel_cb, new_sc); 164 if (ret) { 165 dev_err(device, "vmbus_open subchannel failed: %d\n", ret); 166 return; 167 } 168 169 /* Disable interrupts on sub channel */ 170 new_sc->inbound.ring_buffer->interrupt_mask = 1; 171 set_channel_read_mode(new_sc, HV_CALL_ISR); 172 173 ret = sysfs_create_bin_file(&new_sc->kobj, &ring_buffer_bin_attr); 174 if (ret) { 175 dev_err(device, "sysfs create ring bin file failed; %d\n", ret); 176 vmbus_close(new_sc); 177 } 178 } 179 180 /* free the reserved buffers for send and receive */ 181 static void 182 hv_uio_cleanup(struct hv_device *dev, struct hv_uio_private_data *pdata) 183 { 184 if (pdata->send_gpadl.gpadl_handle) { 185 vmbus_teardown_gpadl(dev->channel, &pdata->send_gpadl); 186 if (!pdata->send_gpadl.decrypted) 187 vfree(pdata->send_buf); 188 } 189 190 if (pdata->recv_gpadl.gpadl_handle) { 191 vmbus_teardown_gpadl(dev->channel, &pdata->recv_gpadl); 192 if (!pdata->recv_gpadl.decrypted) 193 vfree(pdata->recv_buf); 194 } 195 } 196 197 /* VMBus primary channel is opened on first use */ 198 static int 199 hv_uio_open(struct uio_info *info, struct inode *inode) 200 { 201 struct hv_uio_private_data *pdata 202 = container_of(info, struct hv_uio_private_data, info); 203 struct hv_device *dev = pdata->device; 204 int ret; 205 206 if (atomic_inc_return(&pdata->refcnt) != 1) 207 return 0; 208 209 vmbus_set_chn_rescind_callback(dev->channel, hv_uio_rescind); 210 vmbus_set_sc_create_callback(dev->channel, hv_uio_new_channel); 211 212 ret = vmbus_connect_ring(dev->channel, 213 hv_uio_channel_cb, dev->channel); 214 if (ret == 0) 215 dev->channel->inbound.ring_buffer->interrupt_mask = 1; 216 else 217 atomic_dec(&pdata->refcnt); 218 219 return ret; 220 } 221 222 /* VMBus primary channel is closed on last close */ 223 static int 224 hv_uio_release(struct uio_info *info, struct inode *inode) 225 { 226 struct hv_uio_private_data *pdata 227 = container_of(info, struct hv_uio_private_data, info); 228 struct hv_device *dev = pdata->device; 229 int ret = 0; 230 231 if (atomic_dec_and_test(&pdata->refcnt)) 232 ret = vmbus_disconnect_ring(dev->channel); 233 234 return ret; 235 } 236 237 static int 238 hv_uio_probe(struct hv_device *dev, 239 const struct hv_vmbus_device_id *dev_id) 240 { 241 struct vmbus_channel *channel = dev->channel; 242 struct hv_uio_private_data *pdata; 243 void *ring_buffer; 244 int ret; 245 size_t ring_size = hv_dev_ring_size(channel); 246 247 if (!ring_size) 248 ring_size = SZ_2M; 249 250 pdata = devm_kzalloc(&dev->device, sizeof(*pdata), GFP_KERNEL); 251 if (!pdata) 252 return -ENOMEM; 253 254 ret = vmbus_alloc_ring(channel, ring_size, ring_size); 255 if (ret) 256 return ret; 257 258 set_channel_read_mode(channel, HV_CALL_ISR); 259 260 /* Fill general uio info */ 261 pdata->info.name = "uio_hv_generic"; 262 pdata->info.version = DRIVER_VERSION; 263 pdata->info.irqcontrol = hv_uio_irqcontrol; 264 pdata->info.open = hv_uio_open; 265 pdata->info.release = hv_uio_release; 266 pdata->info.irq = UIO_IRQ_CUSTOM; 267 atomic_set(&pdata->refcnt, 0); 268 269 /* mem resources */ 270 pdata->info.mem[TXRX_RING_MAP].name = "txrx_rings"; 271 ring_buffer = page_address(channel->ringbuffer_page); 272 pdata->info.mem[TXRX_RING_MAP].addr 273 = (uintptr_t)virt_to_phys(ring_buffer); 274 pdata->info.mem[TXRX_RING_MAP].size 275 = channel->ringbuffer_pagecount << PAGE_SHIFT; 276 pdata->info.mem[TXRX_RING_MAP].memtype = UIO_MEM_IOVA; 277 278 pdata->info.mem[INT_PAGE_MAP].name = "int_page"; 279 pdata->info.mem[INT_PAGE_MAP].addr 280 = (uintptr_t)vmbus_connection.int_page; 281 pdata->info.mem[INT_PAGE_MAP].size = PAGE_SIZE; 282 pdata->info.mem[INT_PAGE_MAP].memtype = UIO_MEM_LOGICAL; 283 284 pdata->info.mem[MON_PAGE_MAP].name = "monitor_page"; 285 pdata->info.mem[MON_PAGE_MAP].addr 286 = (uintptr_t)vmbus_connection.monitor_pages[1]; 287 pdata->info.mem[MON_PAGE_MAP].size = PAGE_SIZE; 288 pdata->info.mem[MON_PAGE_MAP].memtype = UIO_MEM_LOGICAL; 289 290 pdata->recv_buf = vzalloc(RECV_BUFFER_SIZE); 291 if (pdata->recv_buf == NULL) { 292 ret = -ENOMEM; 293 goto fail_free_ring; 294 } 295 296 ret = vmbus_establish_gpadl(channel, pdata->recv_buf, 297 RECV_BUFFER_SIZE, &pdata->recv_gpadl); 298 if (ret) { 299 if (!pdata->recv_gpadl.decrypted) 300 vfree(pdata->recv_buf); 301 goto fail_close; 302 } 303 304 /* put Global Physical Address Label in name */ 305 snprintf(pdata->recv_name, sizeof(pdata->recv_name), 306 "recv:%u", pdata->recv_gpadl.gpadl_handle); 307 pdata->info.mem[RECV_BUF_MAP].name = pdata->recv_name; 308 pdata->info.mem[RECV_BUF_MAP].addr 309 = (uintptr_t)pdata->recv_buf; 310 pdata->info.mem[RECV_BUF_MAP].size = RECV_BUFFER_SIZE; 311 pdata->info.mem[RECV_BUF_MAP].memtype = UIO_MEM_VIRTUAL; 312 313 pdata->send_buf = vzalloc(SEND_BUFFER_SIZE); 314 if (pdata->send_buf == NULL) { 315 ret = -ENOMEM; 316 goto fail_close; 317 } 318 319 ret = vmbus_establish_gpadl(channel, pdata->send_buf, 320 SEND_BUFFER_SIZE, &pdata->send_gpadl); 321 if (ret) { 322 if (!pdata->send_gpadl.decrypted) 323 vfree(pdata->send_buf); 324 goto fail_close; 325 } 326 327 snprintf(pdata->send_name, sizeof(pdata->send_name), 328 "send:%u", pdata->send_gpadl.gpadl_handle); 329 pdata->info.mem[SEND_BUF_MAP].name = pdata->send_name; 330 pdata->info.mem[SEND_BUF_MAP].addr 331 = (uintptr_t)pdata->send_buf; 332 pdata->info.mem[SEND_BUF_MAP].size = SEND_BUFFER_SIZE; 333 pdata->info.mem[SEND_BUF_MAP].memtype = UIO_MEM_VIRTUAL; 334 335 pdata->info.priv = pdata; 336 pdata->device = dev; 337 338 ret = uio_register_device(&dev->device, &pdata->info); 339 if (ret) { 340 dev_err(&dev->device, "hv_uio register failed\n"); 341 goto fail_close; 342 } 343 344 ret = sysfs_create_bin_file(&channel->kobj, &ring_buffer_bin_attr); 345 if (ret) 346 dev_notice(&dev->device, 347 "sysfs create ring bin file failed; %d\n", ret); 348 349 hv_set_drvdata(dev, pdata); 350 351 return 0; 352 353 fail_close: 354 hv_uio_cleanup(dev, pdata); 355 fail_free_ring: 356 vmbus_free_ring(dev->channel); 357 358 return ret; 359 } 360 361 static void 362 hv_uio_remove(struct hv_device *dev) 363 { 364 struct hv_uio_private_data *pdata = hv_get_drvdata(dev); 365 366 if (!pdata) 367 return; 368 369 sysfs_remove_bin_file(&dev->channel->kobj, &ring_buffer_bin_attr); 370 uio_unregister_device(&pdata->info); 371 hv_uio_cleanup(dev, pdata); 372 373 vmbus_free_ring(dev->channel); 374 } 375 376 static struct hv_driver hv_uio_drv = { 377 .name = "uio_hv_generic", 378 .id_table = NULL, /* only dynamic id's */ 379 .probe = hv_uio_probe, 380 .remove = hv_uio_remove, 381 }; 382 383 static int __init 384 hyperv_module_init(void) 385 { 386 return vmbus_driver_register(&hv_uio_drv); 387 } 388 389 static void __exit 390 hyperv_module_exit(void) 391 { 392 vmbus_driver_unregister(&hv_uio_drv); 393 } 394 395 module_init(hyperv_module_init); 396 module_exit(hyperv_module_exit); 397 398 MODULE_VERSION(DRIVER_VERSION); 399 MODULE_LICENSE("GPL v2"); 400 MODULE_AUTHOR(DRIVER_AUTHOR); 401 MODULE_DESCRIPTION(DRIVER_DESC); 402