1 /* 2 * uio_hv_generic - generic UIO driver for VMBus 3 * 4 * Copyright (c) 2013-2016 Brocade Communications Systems, Inc. 5 * Copyright (c) 2016, Microsoft Corporation. 6 * 7 * 8 * This work is licensed under the terms of the GNU GPL, version 2. 9 * 10 * Since the driver does not declare any device ids, you must allocate 11 * id and bind the device to the driver yourself. For example: 12 * 13 * Associate Network GUID with UIO device 14 * # echo "f8615163-df3e-46c5-913f-f2d2f965ed0e" \ 15 * > /sys/bus/vmbus/drivers/uio_hv_generic/new_id 16 * Then rebind 17 * # echo -n "ed963694-e847-4b2a-85af-bc9cfc11d6f3" \ 18 * > /sys/bus/vmbus/drivers/hv_netvsc/unbind 19 * # echo -n "ed963694-e847-4b2a-85af-bc9cfc11d6f3" \ 20 * > /sys/bus/vmbus/drivers/uio_hv_generic/bind 21 */ 22 23 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 24 25 #include <linux/device.h> 26 #include <linux/kernel.h> 27 #include <linux/module.h> 28 #include <linux/uio_driver.h> 29 #include <linux/netdevice.h> 30 #include <linux/if_ether.h> 31 #include <linux/skbuff.h> 32 #include <linux/hyperv.h> 33 #include <linux/vmalloc.h> 34 #include <linux/slab.h> 35 36 #include "../hv/hyperv_vmbus.h" 37 38 #define DRIVER_VERSION "0.02.0" 39 #define DRIVER_AUTHOR "Stephen Hemminger <sthemmin at microsoft.com>" 40 #define DRIVER_DESC "Generic UIO driver for VMBus devices" 41 42 #define HV_RING_SIZE 512 /* pages */ 43 #define SEND_BUFFER_SIZE (15 * 1024 * 1024) 44 #define RECV_BUFFER_SIZE (15 * 1024 * 1024) 45 46 /* 47 * List of resources to be mapped to user space 48 * can be extended up to MAX_UIO_MAPS(5) items 49 */ 50 enum hv_uio_map { 51 TXRX_RING_MAP = 0, 52 INT_PAGE_MAP, 53 MON_PAGE_MAP, 54 RECV_BUF_MAP, 55 SEND_BUF_MAP 56 }; 57 58 struct hv_uio_private_data { 59 struct uio_info info; 60 struct hv_device *device; 61 62 void *recv_buf; 63 u32 recv_gpadl; 64 char recv_name[32]; /* "recv_4294967295" */ 65 66 void *send_buf; 67 u32 send_gpadl; 68 char send_name[32]; 69 }; 70 71 /* 72 * This is the irqcontrol callback to be registered to uio_info. 73 * It can be used to disable/enable interrupt from user space processes. 74 * 75 * @param info 76 * pointer to uio_info. 77 * @param irq_state 78 * state value. 1 to enable interrupt, 0 to disable interrupt. 79 */ 80 static int 81 hv_uio_irqcontrol(struct uio_info *info, s32 irq_state) 82 { 83 struct hv_uio_private_data *pdata = info->priv; 84 struct hv_device *dev = pdata->device; 85 86 dev->channel->inbound.ring_buffer->interrupt_mask = !irq_state; 87 virt_mb(); 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 hv_uio_private_data *pdata = context; 98 struct hv_device *dev = pdata->device; 99 100 dev->channel->inbound.ring_buffer->interrupt_mask = 1; 101 virt_mb(); 102 103 uio_event_notify(&pdata->info); 104 } 105 106 /* 107 * Callback from vmbus_event when channel is rescinded. 108 */ 109 static void hv_uio_rescind(struct vmbus_channel *channel) 110 { 111 struct hv_device *hv_dev = channel->primary_channel->device_obj; 112 struct hv_uio_private_data *pdata = hv_get_drvdata(hv_dev); 113 114 /* 115 * Turn off the interrupt file handle 116 * Next read for event will return -EIO 117 */ 118 pdata->info.irq = 0; 119 120 /* Wake up reader */ 121 uio_event_notify(&pdata->info); 122 } 123 124 /* 125 * Handle fault when looking for sub channel ring buffer 126 * Subchannel ring buffer is same as resource 0 which is main ring buffer 127 * This is derived from uio_vma_fault 128 */ 129 static int hv_uio_vma_fault(struct vm_fault *vmf) 130 { 131 struct vm_area_struct *vma = vmf->vma; 132 void *ring_buffer = vma->vm_private_data; 133 struct page *page; 134 void *addr; 135 136 addr = ring_buffer + (vmf->pgoff << PAGE_SHIFT); 137 page = virt_to_page(addr); 138 get_page(page); 139 vmf->page = page; 140 return 0; 141 } 142 143 static const struct vm_operations_struct hv_uio_vm_ops = { 144 .fault = hv_uio_vma_fault, 145 }; 146 147 /* Sysfs API to allow mmap of the ring buffers */ 148 static int hv_uio_ring_mmap(struct file *filp, struct kobject *kobj, 149 struct bin_attribute *attr, 150 struct vm_area_struct *vma) 151 { 152 struct vmbus_channel *channel 153 = container_of(kobj, struct vmbus_channel, kobj); 154 unsigned long requested_pages, actual_pages; 155 156 if (vma->vm_end < vma->vm_start) 157 return -EINVAL; 158 159 /* only allow 0 for now */ 160 if (vma->vm_pgoff > 0) 161 return -EINVAL; 162 163 requested_pages = vma_pages(vma); 164 actual_pages = 2 * HV_RING_SIZE; 165 if (requested_pages > actual_pages) 166 return -EINVAL; 167 168 vma->vm_private_data = channel->ringbuffer_pages; 169 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP; 170 vma->vm_ops = &hv_uio_vm_ops; 171 return 0; 172 } 173 174 static struct bin_attribute ring_buffer_bin_attr __ro_after_init = { 175 .attr = { 176 .name = "ring", 177 .mode = 0600, 178 /* size is set at init time */ 179 }, 180 .mmap = hv_uio_ring_mmap, 181 }; 182 183 /* Callback from VMBUS subystem when new channel created. */ 184 static void 185 hv_uio_new_channel(struct vmbus_channel *new_sc) 186 { 187 struct hv_device *hv_dev = new_sc->primary_channel->device_obj; 188 struct device *device = &hv_dev->device; 189 struct hv_uio_private_data *pdata = hv_get_drvdata(hv_dev); 190 const size_t ring_bytes = HV_RING_SIZE * PAGE_SIZE; 191 int ret; 192 193 /* Create host communication ring */ 194 ret = vmbus_open(new_sc, ring_bytes, ring_bytes, NULL, 0, 195 hv_uio_channel_cb, pdata); 196 if (ret) { 197 dev_err(device, "vmbus_open subchannel failed: %d\n", ret); 198 return; 199 } 200 201 /* Disable interrupts on sub channel */ 202 new_sc->inbound.ring_buffer->interrupt_mask = 1; 203 set_channel_read_mode(new_sc, HV_CALL_ISR); 204 205 ret = sysfs_create_bin_file(&new_sc->kobj, &ring_buffer_bin_attr); 206 if (ret) { 207 dev_err(device, "sysfs create ring bin file failed; %d\n", ret); 208 vmbus_close(new_sc); 209 } 210 } 211 212 static void 213 hv_uio_cleanup(struct hv_device *dev, struct hv_uio_private_data *pdata) 214 { 215 if (pdata->send_gpadl) 216 vmbus_teardown_gpadl(dev->channel, pdata->send_gpadl); 217 vfree(pdata->send_buf); 218 219 if (pdata->recv_gpadl) 220 vmbus_teardown_gpadl(dev->channel, pdata->recv_gpadl); 221 vfree(pdata->recv_buf); 222 } 223 224 static int 225 hv_uio_probe(struct hv_device *dev, 226 const struct hv_vmbus_device_id *dev_id) 227 { 228 struct hv_uio_private_data *pdata; 229 int ret; 230 231 pdata = kzalloc(sizeof(*pdata), GFP_KERNEL); 232 if (!pdata) 233 return -ENOMEM; 234 235 ret = vmbus_open(dev->channel, HV_RING_SIZE * PAGE_SIZE, 236 HV_RING_SIZE * PAGE_SIZE, NULL, 0, 237 hv_uio_channel_cb, pdata); 238 if (ret) 239 goto fail; 240 241 /* Communicating with host has to be via shared memory not hypercall */ 242 if (!dev->channel->offermsg.monitor_allocated) { 243 dev_err(&dev->device, "vmbus channel requires hypercall\n"); 244 ret = -ENOTSUPP; 245 goto fail_close; 246 } 247 248 dev->channel->inbound.ring_buffer->interrupt_mask = 1; 249 set_channel_read_mode(dev->channel, HV_CALL_ISR); 250 251 /* Fill general uio info */ 252 pdata->info.name = "uio_hv_generic"; 253 pdata->info.version = DRIVER_VERSION; 254 pdata->info.irqcontrol = hv_uio_irqcontrol; 255 pdata->info.irq = UIO_IRQ_CUSTOM; 256 257 /* mem resources */ 258 pdata->info.mem[TXRX_RING_MAP].name = "txrx_rings"; 259 pdata->info.mem[TXRX_RING_MAP].addr 260 = (uintptr_t)dev->channel->ringbuffer_pages; 261 pdata->info.mem[TXRX_RING_MAP].size 262 = dev->channel->ringbuffer_pagecount << PAGE_SHIFT; 263 pdata->info.mem[TXRX_RING_MAP].memtype = UIO_MEM_LOGICAL; 264 265 pdata->info.mem[INT_PAGE_MAP].name = "int_page"; 266 pdata->info.mem[INT_PAGE_MAP].addr 267 = (uintptr_t)vmbus_connection.int_page; 268 pdata->info.mem[INT_PAGE_MAP].size = PAGE_SIZE; 269 pdata->info.mem[INT_PAGE_MAP].memtype = UIO_MEM_LOGICAL; 270 271 pdata->info.mem[MON_PAGE_MAP].name = "monitor_page"; 272 pdata->info.mem[MON_PAGE_MAP].addr 273 = (uintptr_t)vmbus_connection.monitor_pages[1]; 274 pdata->info.mem[MON_PAGE_MAP].size = PAGE_SIZE; 275 pdata->info.mem[MON_PAGE_MAP].memtype = UIO_MEM_LOGICAL; 276 277 pdata->recv_buf = vzalloc(RECV_BUFFER_SIZE); 278 if (pdata->recv_buf == NULL) { 279 ret = -ENOMEM; 280 goto fail_close; 281 } 282 283 ret = vmbus_establish_gpadl(dev->channel, pdata->recv_buf, 284 RECV_BUFFER_SIZE, &pdata->recv_gpadl); 285 if (ret) 286 goto fail_close; 287 288 /* put Global Physical Address Label in name */ 289 snprintf(pdata->recv_name, sizeof(pdata->recv_name), 290 "recv:%u", pdata->recv_gpadl); 291 pdata->info.mem[RECV_BUF_MAP].name = pdata->recv_name; 292 pdata->info.mem[RECV_BUF_MAP].addr 293 = (uintptr_t)pdata->recv_buf; 294 pdata->info.mem[RECV_BUF_MAP].size = RECV_BUFFER_SIZE; 295 pdata->info.mem[RECV_BUF_MAP].memtype = UIO_MEM_VIRTUAL; 296 297 298 pdata->send_buf = vzalloc(SEND_BUFFER_SIZE); 299 if (pdata->send_buf == NULL) { 300 ret = -ENOMEM; 301 goto fail_close; 302 } 303 304 ret = vmbus_establish_gpadl(dev->channel, pdata->send_buf, 305 SEND_BUFFER_SIZE, &pdata->send_gpadl); 306 if (ret) 307 goto fail_close; 308 309 snprintf(pdata->send_name, sizeof(pdata->send_name), 310 "send:%u", pdata->send_gpadl); 311 pdata->info.mem[SEND_BUF_MAP].name = pdata->send_name; 312 pdata->info.mem[SEND_BUF_MAP].addr 313 = (uintptr_t)pdata->send_buf; 314 pdata->info.mem[SEND_BUF_MAP].size = SEND_BUFFER_SIZE; 315 pdata->info.mem[SEND_BUF_MAP].memtype = UIO_MEM_VIRTUAL; 316 317 pdata->info.priv = pdata; 318 pdata->device = dev; 319 320 ret = uio_register_device(&dev->device, &pdata->info); 321 if (ret) { 322 dev_err(&dev->device, "hv_uio register failed\n"); 323 goto fail_close; 324 } 325 326 vmbus_set_chn_rescind_callback(dev->channel, hv_uio_rescind); 327 vmbus_set_sc_create_callback(dev->channel, hv_uio_new_channel); 328 329 hv_set_drvdata(dev, pdata); 330 331 return 0; 332 333 fail_close: 334 hv_uio_cleanup(dev, pdata); 335 vmbus_close(dev->channel); 336 fail: 337 kfree(pdata); 338 339 return ret; 340 } 341 342 static int 343 hv_uio_remove(struct hv_device *dev) 344 { 345 struct hv_uio_private_data *pdata = hv_get_drvdata(dev); 346 347 if (!pdata) 348 return 0; 349 350 uio_unregister_device(&pdata->info); 351 hv_uio_cleanup(dev, pdata); 352 hv_set_drvdata(dev, NULL); 353 vmbus_close(dev->channel); 354 kfree(pdata); 355 return 0; 356 } 357 358 static struct hv_driver hv_uio_drv = { 359 .name = "uio_hv_generic", 360 .id_table = NULL, /* only dynamic id's */ 361 .probe = hv_uio_probe, 362 .remove = hv_uio_remove, 363 }; 364 365 static int __init 366 hyperv_module_init(void) 367 { 368 return vmbus_driver_register(&hv_uio_drv); 369 } 370 371 static void __exit 372 hyperv_module_exit(void) 373 { 374 vmbus_driver_unregister(&hv_uio_drv); 375 } 376 377 module_init(hyperv_module_init); 378 module_exit(hyperv_module_exit); 379 380 MODULE_VERSION(DRIVER_VERSION); 381 MODULE_LICENSE("GPL v2"); 382 MODULE_AUTHOR(DRIVER_AUTHOR); 383 MODULE_DESCRIPTION(DRIVER_DESC); 384