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 HV_RING_SIZE 512 /* pages */ 40 #define SEND_BUFFER_SIZE (16 * 1024 * 1024) 41 #define RECV_BUFFER_SIZE (31 * 1024 * 1024) 42 43 /* 44 * List of resources to be mapped to user space 45 * can be extended up to MAX_UIO_MAPS(5) items 46 */ 47 enum hv_uio_map { 48 TXRX_RING_MAP = 0, 49 INT_PAGE_MAP, 50 MON_PAGE_MAP, 51 RECV_BUF_MAP, 52 SEND_BUF_MAP 53 }; 54 55 struct hv_uio_private_data { 56 struct uio_info info; 57 struct hv_device *device; 58 atomic_t refcnt; 59 60 void *recv_buf; 61 struct vmbus_gpadl recv_gpadl; 62 char recv_name[32]; /* "recv_4294967295" */ 63 64 void *send_buf; 65 struct vmbus_gpadl send_gpadl; 66 char send_name[32]; 67 }; 68 69 /* 70 * This is the irqcontrol callback to be registered to uio_info. 71 * It can be used to disable/enable interrupt from user space processes. 72 * 73 * @param info 74 * pointer to uio_info. 75 * @param irq_state 76 * state value. 1 to enable interrupt, 0 to disable interrupt. 77 */ 78 static int 79 hv_uio_irqcontrol(struct uio_info *info, s32 irq_state) 80 { 81 struct hv_uio_private_data *pdata = info->priv; 82 struct hv_device *dev = pdata->device; 83 84 dev->channel->inbound.ring_buffer->interrupt_mask = !irq_state; 85 virt_mb(); 86 87 return 0; 88 } 89 90 /* 91 * Callback from vmbus_event when something is in inbound ring. 92 */ 93 static void hv_uio_channel_cb(void *context) 94 { 95 struct vmbus_channel *chan = context; 96 struct hv_device *hv_dev = chan->device_obj; 97 struct hv_uio_private_data *pdata = hv_get_drvdata(hv_dev); 98 99 chan->inbound.ring_buffer->interrupt_mask = 1; 100 virt_mb(); 101 102 uio_event_notify(&pdata->info); 103 } 104 105 /* 106 * Callback from vmbus_event when channel is rescinded. 107 */ 108 static void hv_uio_rescind(struct vmbus_channel *channel) 109 { 110 struct hv_device *hv_dev = channel->primary_channel->device_obj; 111 struct hv_uio_private_data *pdata = hv_get_drvdata(hv_dev); 112 113 /* 114 * Turn off the interrupt file handle 115 * Next read for event will return -EIO 116 */ 117 pdata->info.irq = 0; 118 119 /* Wake up reader */ 120 uio_event_notify(&pdata->info); 121 } 122 123 /* Sysfs API to allow mmap of the ring buffers 124 * The ring buffer is allocated as contiguous memory by vmbus_open 125 */ 126 static int hv_uio_ring_mmap(struct file *filp, struct kobject *kobj, 127 struct bin_attribute *attr, 128 struct vm_area_struct *vma) 129 { 130 struct vmbus_channel *channel 131 = container_of(kobj, struct vmbus_channel, kobj); 132 void *ring_buffer = page_address(channel->ringbuffer_page); 133 134 if (channel->state != CHANNEL_OPENED_STATE) 135 return -ENODEV; 136 137 return vm_iomap_memory(vma, virt_to_phys(ring_buffer), 138 channel->ringbuffer_pagecount << PAGE_SHIFT); 139 } 140 141 static const struct bin_attribute ring_buffer_bin_attr = { 142 .attr = { 143 .name = "ring", 144 .mode = 0600, 145 }, 146 .size = 2 * HV_RING_SIZE * PAGE_SIZE, 147 .mmap = hv_uio_ring_mmap, 148 }; 149 150 /* Callback from VMBUS subsystem when new channel created. */ 151 static void 152 hv_uio_new_channel(struct vmbus_channel *new_sc) 153 { 154 struct hv_device *hv_dev = new_sc->primary_channel->device_obj; 155 struct device *device = &hv_dev->device; 156 const size_t ring_bytes = HV_RING_SIZE * PAGE_SIZE; 157 int ret; 158 159 /* Create host communication ring */ 160 ret = vmbus_open(new_sc, ring_bytes, ring_bytes, NULL, 0, 161 hv_uio_channel_cb, new_sc); 162 if (ret) { 163 dev_err(device, "vmbus_open subchannel failed: %d\n", ret); 164 return; 165 } 166 167 /* Disable interrupts on sub channel */ 168 new_sc->inbound.ring_buffer->interrupt_mask = 1; 169 set_channel_read_mode(new_sc, HV_CALL_ISR); 170 171 ret = sysfs_create_bin_file(&new_sc->kobj, &ring_buffer_bin_attr); 172 if (ret) { 173 dev_err(device, "sysfs create ring bin file failed; %d\n", ret); 174 vmbus_close(new_sc); 175 } 176 } 177 178 /* free the reserved buffers for send and receive */ 179 static void 180 hv_uio_cleanup(struct hv_device *dev, struct hv_uio_private_data *pdata) 181 { 182 if (pdata->send_gpadl.gpadl_handle) { 183 vmbus_teardown_gpadl(dev->channel, &pdata->send_gpadl); 184 vfree(pdata->send_buf); 185 } 186 187 if (pdata->recv_gpadl.gpadl_handle) { 188 vmbus_teardown_gpadl(dev->channel, &pdata->recv_gpadl); 189 vfree(pdata->recv_buf); 190 } 191 } 192 193 /* VMBus primary channel is opened on first use */ 194 static int 195 hv_uio_open(struct uio_info *info, struct inode *inode) 196 { 197 struct hv_uio_private_data *pdata 198 = container_of(info, struct hv_uio_private_data, info); 199 struct hv_device *dev = pdata->device; 200 int ret; 201 202 if (atomic_inc_return(&pdata->refcnt) != 1) 203 return 0; 204 205 vmbus_set_chn_rescind_callback(dev->channel, hv_uio_rescind); 206 vmbus_set_sc_create_callback(dev->channel, hv_uio_new_channel); 207 208 ret = vmbus_connect_ring(dev->channel, 209 hv_uio_channel_cb, dev->channel); 210 if (ret == 0) 211 dev->channel->inbound.ring_buffer->interrupt_mask = 1; 212 else 213 atomic_dec(&pdata->refcnt); 214 215 return ret; 216 } 217 218 /* VMBus primary channel is closed on last close */ 219 static int 220 hv_uio_release(struct uio_info *info, struct inode *inode) 221 { 222 struct hv_uio_private_data *pdata 223 = container_of(info, struct hv_uio_private_data, info); 224 struct hv_device *dev = pdata->device; 225 int ret = 0; 226 227 if (atomic_dec_and_test(&pdata->refcnt)) 228 ret = vmbus_disconnect_ring(dev->channel); 229 230 return ret; 231 } 232 233 static int 234 hv_uio_probe(struct hv_device *dev, 235 const struct hv_vmbus_device_id *dev_id) 236 { 237 struct vmbus_channel *channel = dev->channel; 238 struct hv_uio_private_data *pdata; 239 void *ring_buffer; 240 int ret; 241 242 /* Communicating with host has to be via shared memory not hypercall */ 243 if (!channel->offermsg.monitor_allocated) { 244 dev_err(&dev->device, "vmbus channel requires hypercall\n"); 245 return -ENOTSUPP; 246 } 247 248 pdata = devm_kzalloc(&dev->device, sizeof(*pdata), GFP_KERNEL); 249 if (!pdata) 250 return -ENOMEM; 251 252 ret = vmbus_alloc_ring(channel, HV_RING_SIZE * PAGE_SIZE, 253 HV_RING_SIZE * PAGE_SIZE); 254 if (ret) 255 return ret; 256 257 set_channel_read_mode(channel, HV_CALL_ISR); 258 259 /* Fill general uio info */ 260 pdata->info.name = "uio_hv_generic"; 261 pdata->info.version = DRIVER_VERSION; 262 pdata->info.irqcontrol = hv_uio_irqcontrol; 263 pdata->info.open = hv_uio_open; 264 pdata->info.release = hv_uio_release; 265 pdata->info.irq = UIO_IRQ_CUSTOM; 266 atomic_set(&pdata->refcnt, 0); 267 268 /* mem resources */ 269 pdata->info.mem[TXRX_RING_MAP].name = "txrx_rings"; 270 ring_buffer = page_address(channel->ringbuffer_page); 271 pdata->info.mem[TXRX_RING_MAP].addr 272 = (uintptr_t)virt_to_phys(ring_buffer); 273 pdata->info.mem[TXRX_RING_MAP].size 274 = channel->ringbuffer_pagecount << PAGE_SHIFT; 275 pdata->info.mem[TXRX_RING_MAP].memtype = UIO_MEM_IOVA; 276 277 pdata->info.mem[INT_PAGE_MAP].name = "int_page"; 278 pdata->info.mem[INT_PAGE_MAP].addr 279 = (uintptr_t)vmbus_connection.int_page; 280 pdata->info.mem[INT_PAGE_MAP].size = PAGE_SIZE; 281 pdata->info.mem[INT_PAGE_MAP].memtype = UIO_MEM_LOGICAL; 282 283 pdata->info.mem[MON_PAGE_MAP].name = "monitor_page"; 284 pdata->info.mem[MON_PAGE_MAP].addr 285 = (uintptr_t)vmbus_connection.monitor_pages[1]; 286 pdata->info.mem[MON_PAGE_MAP].size = PAGE_SIZE; 287 pdata->info.mem[MON_PAGE_MAP].memtype = UIO_MEM_LOGICAL; 288 289 pdata->recv_buf = vzalloc(RECV_BUFFER_SIZE); 290 if (pdata->recv_buf == NULL) { 291 ret = -ENOMEM; 292 goto fail_free_ring; 293 } 294 295 ret = vmbus_establish_gpadl(channel, pdata->recv_buf, 296 RECV_BUFFER_SIZE, &pdata->recv_gpadl); 297 if (ret) { 298 vfree(pdata->recv_buf); 299 goto fail_close; 300 } 301 302 /* put Global Physical Address Label in name */ 303 snprintf(pdata->recv_name, sizeof(pdata->recv_name), 304 "recv:%u", pdata->recv_gpadl.gpadl_handle); 305 pdata->info.mem[RECV_BUF_MAP].name = pdata->recv_name; 306 pdata->info.mem[RECV_BUF_MAP].addr 307 = (uintptr_t)pdata->recv_buf; 308 pdata->info.mem[RECV_BUF_MAP].size = RECV_BUFFER_SIZE; 309 pdata->info.mem[RECV_BUF_MAP].memtype = UIO_MEM_VIRTUAL; 310 311 pdata->send_buf = vzalloc(SEND_BUFFER_SIZE); 312 if (pdata->send_buf == NULL) { 313 ret = -ENOMEM; 314 goto fail_close; 315 } 316 317 ret = vmbus_establish_gpadl(channel, pdata->send_buf, 318 SEND_BUFFER_SIZE, &pdata->send_gpadl); 319 if (ret) { 320 vfree(pdata->send_buf); 321 goto fail_close; 322 } 323 324 snprintf(pdata->send_name, sizeof(pdata->send_name), 325 "send:%u", pdata->send_gpadl.gpadl_handle); 326 pdata->info.mem[SEND_BUF_MAP].name = pdata->send_name; 327 pdata->info.mem[SEND_BUF_MAP].addr 328 = (uintptr_t)pdata->send_buf; 329 pdata->info.mem[SEND_BUF_MAP].size = SEND_BUFFER_SIZE; 330 pdata->info.mem[SEND_BUF_MAP].memtype = UIO_MEM_VIRTUAL; 331 332 pdata->info.priv = pdata; 333 pdata->device = dev; 334 335 ret = uio_register_device(&dev->device, &pdata->info); 336 if (ret) { 337 dev_err(&dev->device, "hv_uio register failed\n"); 338 goto fail_close; 339 } 340 341 ret = sysfs_create_bin_file(&channel->kobj, &ring_buffer_bin_attr); 342 if (ret) 343 dev_notice(&dev->device, 344 "sysfs create ring bin file failed; %d\n", ret); 345 346 hv_set_drvdata(dev, pdata); 347 348 return 0; 349 350 fail_close: 351 hv_uio_cleanup(dev, pdata); 352 fail_free_ring: 353 vmbus_free_ring(dev->channel); 354 355 return ret; 356 } 357 358 static void 359 hv_uio_remove(struct hv_device *dev) 360 { 361 struct hv_uio_private_data *pdata = hv_get_drvdata(dev); 362 363 if (!pdata) 364 return; 365 366 sysfs_remove_bin_file(&dev->channel->kobj, &ring_buffer_bin_attr); 367 uio_unregister_device(&pdata->info); 368 hv_uio_cleanup(dev, pdata); 369 370 vmbus_free_ring(dev->channel); 371 } 372 373 static struct hv_driver hv_uio_drv = { 374 .name = "uio_hv_generic", 375 .id_table = NULL, /* only dynamic id's */ 376 .probe = hv_uio_probe, 377 .remove = hv_uio_remove, 378 }; 379 380 static int __init 381 hyperv_module_init(void) 382 { 383 return vmbus_driver_register(&hv_uio_drv); 384 } 385 386 static void __exit 387 hyperv_module_exit(void) 388 { 389 vmbus_driver_unregister(&hv_uio_drv); 390 } 391 392 module_init(hyperv_module_init); 393 module_exit(hyperv_module_exit); 394 395 MODULE_VERSION(DRIVER_VERSION); 396 MODULE_LICENSE("GPL v2"); 397 MODULE_AUTHOR(DRIVER_AUTHOR); 398 MODULE_DESCRIPTION(DRIVER_DESC); 399