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 #define DEBUG 1 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 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 struct hv_device *dev = channel->primary_channel->device_obj; 135 u16 q_idx = channel->offermsg.offer.sub_channel_index; 136 137 dev_dbg(&dev->device, "mmap channel %u pages %#lx at %#lx\n", 138 q_idx, vma_pages(vma), vma->vm_pgoff); 139 140 return vm_iomap_memory(vma, virt_to_phys(channel->ringbuffer_pages), 141 channel->ringbuffer_pagecount << PAGE_SHIFT); 142 } 143 144 static const struct bin_attribute ring_buffer_bin_attr = { 145 .attr = { 146 .name = "ring", 147 .mode = 0600, 148 }, 149 .size = 2 * HV_RING_SIZE * PAGE_SIZE, 150 .mmap = hv_uio_ring_mmap, 151 }; 152 153 /* Callback from VMBUS subsystem when new channel created. */ 154 static void 155 hv_uio_new_channel(struct vmbus_channel *new_sc) 156 { 157 struct hv_device *hv_dev = new_sc->primary_channel->device_obj; 158 struct device *device = &hv_dev->device; 159 const size_t ring_bytes = HV_RING_SIZE * PAGE_SIZE; 160 int ret; 161 162 /* Create host communication ring */ 163 ret = vmbus_open(new_sc, ring_bytes, ring_bytes, NULL, 0, 164 hv_uio_channel_cb, new_sc); 165 if (ret) { 166 dev_err(device, "vmbus_open subchannel failed: %d\n", ret); 167 return; 168 } 169 170 /* Disable interrupts on sub channel */ 171 new_sc->inbound.ring_buffer->interrupt_mask = 1; 172 set_channel_read_mode(new_sc, HV_CALL_ISR); 173 174 ret = sysfs_create_bin_file(&new_sc->kobj, &ring_buffer_bin_attr); 175 if (ret) { 176 dev_err(device, "sysfs create ring bin file failed; %d\n", ret); 177 vmbus_close(new_sc); 178 } 179 } 180 181 static void 182 hv_uio_cleanup(struct hv_device *dev, struct hv_uio_private_data *pdata) 183 { 184 if (pdata->send_gpadl) 185 vmbus_teardown_gpadl(dev->channel, pdata->send_gpadl); 186 vfree(pdata->send_buf); 187 188 if (pdata->recv_gpadl) 189 vmbus_teardown_gpadl(dev->channel, pdata->recv_gpadl); 190 vfree(pdata->recv_buf); 191 } 192 193 static int 194 hv_uio_probe(struct hv_device *dev, 195 const struct hv_vmbus_device_id *dev_id) 196 { 197 struct hv_uio_private_data *pdata; 198 int ret; 199 200 pdata = kzalloc(sizeof(*pdata), GFP_KERNEL); 201 if (!pdata) 202 return -ENOMEM; 203 204 ret = vmbus_open(dev->channel, HV_RING_SIZE * PAGE_SIZE, 205 HV_RING_SIZE * PAGE_SIZE, NULL, 0, 206 hv_uio_channel_cb, dev->channel); 207 if (ret) 208 goto fail; 209 210 /* Communicating with host has to be via shared memory not hypercall */ 211 if (!dev->channel->offermsg.monitor_allocated) { 212 dev_err(&dev->device, "vmbus channel requires hypercall\n"); 213 ret = -ENOTSUPP; 214 goto fail_close; 215 } 216 217 dev->channel->inbound.ring_buffer->interrupt_mask = 1; 218 set_channel_read_mode(dev->channel, HV_CALL_ISR); 219 220 /* Fill general uio info */ 221 pdata->info.name = "uio_hv_generic"; 222 pdata->info.version = DRIVER_VERSION; 223 pdata->info.irqcontrol = hv_uio_irqcontrol; 224 pdata->info.irq = UIO_IRQ_CUSTOM; 225 226 /* mem resources */ 227 pdata->info.mem[TXRX_RING_MAP].name = "txrx_rings"; 228 pdata->info.mem[TXRX_RING_MAP].addr 229 = (uintptr_t)dev->channel->ringbuffer_pages; 230 pdata->info.mem[TXRX_RING_MAP].size 231 = dev->channel->ringbuffer_pagecount << PAGE_SHIFT; 232 pdata->info.mem[TXRX_RING_MAP].memtype = UIO_MEM_LOGICAL; 233 234 pdata->info.mem[INT_PAGE_MAP].name = "int_page"; 235 pdata->info.mem[INT_PAGE_MAP].addr 236 = (uintptr_t)vmbus_connection.int_page; 237 pdata->info.mem[INT_PAGE_MAP].size = PAGE_SIZE; 238 pdata->info.mem[INT_PAGE_MAP].memtype = UIO_MEM_LOGICAL; 239 240 pdata->info.mem[MON_PAGE_MAP].name = "monitor_page"; 241 pdata->info.mem[MON_PAGE_MAP].addr 242 = (uintptr_t)vmbus_connection.monitor_pages[1]; 243 pdata->info.mem[MON_PAGE_MAP].size = PAGE_SIZE; 244 pdata->info.mem[MON_PAGE_MAP].memtype = UIO_MEM_LOGICAL; 245 246 pdata->recv_buf = vzalloc(RECV_BUFFER_SIZE); 247 if (pdata->recv_buf == NULL) { 248 ret = -ENOMEM; 249 goto fail_close; 250 } 251 252 ret = vmbus_establish_gpadl(dev->channel, pdata->recv_buf, 253 RECV_BUFFER_SIZE, &pdata->recv_gpadl); 254 if (ret) 255 goto fail_close; 256 257 /* put Global Physical Address Label in name */ 258 snprintf(pdata->recv_name, sizeof(pdata->recv_name), 259 "recv:%u", pdata->recv_gpadl); 260 pdata->info.mem[RECV_BUF_MAP].name = pdata->recv_name; 261 pdata->info.mem[RECV_BUF_MAP].addr 262 = (uintptr_t)pdata->recv_buf; 263 pdata->info.mem[RECV_BUF_MAP].size = RECV_BUFFER_SIZE; 264 pdata->info.mem[RECV_BUF_MAP].memtype = UIO_MEM_VIRTUAL; 265 266 267 pdata->send_buf = vzalloc(SEND_BUFFER_SIZE); 268 if (pdata->send_buf == NULL) { 269 ret = -ENOMEM; 270 goto fail_close; 271 } 272 273 ret = vmbus_establish_gpadl(dev->channel, pdata->send_buf, 274 SEND_BUFFER_SIZE, &pdata->send_gpadl); 275 if (ret) 276 goto fail_close; 277 278 snprintf(pdata->send_name, sizeof(pdata->send_name), 279 "send:%u", pdata->send_gpadl); 280 pdata->info.mem[SEND_BUF_MAP].name = pdata->send_name; 281 pdata->info.mem[SEND_BUF_MAP].addr 282 = (uintptr_t)pdata->send_buf; 283 pdata->info.mem[SEND_BUF_MAP].size = SEND_BUFFER_SIZE; 284 pdata->info.mem[SEND_BUF_MAP].memtype = UIO_MEM_VIRTUAL; 285 286 pdata->info.priv = pdata; 287 pdata->device = dev; 288 289 ret = uio_register_device(&dev->device, &pdata->info); 290 if (ret) { 291 dev_err(&dev->device, "hv_uio register failed\n"); 292 goto fail_close; 293 } 294 295 vmbus_set_chn_rescind_callback(dev->channel, hv_uio_rescind); 296 vmbus_set_sc_create_callback(dev->channel, hv_uio_new_channel); 297 298 ret = sysfs_create_bin_file(&dev->channel->kobj, &ring_buffer_bin_attr); 299 if (ret) 300 dev_notice(&dev->device, 301 "sysfs create ring bin file failed; %d\n", ret); 302 303 hv_set_drvdata(dev, pdata); 304 305 return 0; 306 307 fail_close: 308 hv_uio_cleanup(dev, pdata); 309 vmbus_close(dev->channel); 310 fail: 311 kfree(pdata); 312 313 return ret; 314 } 315 316 static int 317 hv_uio_remove(struct hv_device *dev) 318 { 319 struct hv_uio_private_data *pdata = hv_get_drvdata(dev); 320 321 if (!pdata) 322 return 0; 323 324 uio_unregister_device(&pdata->info); 325 hv_uio_cleanup(dev, pdata); 326 hv_set_drvdata(dev, NULL); 327 vmbus_close(dev->channel); 328 kfree(pdata); 329 return 0; 330 } 331 332 static struct hv_driver hv_uio_drv = { 333 .name = "uio_hv_generic", 334 .id_table = NULL, /* only dynamic id's */ 335 .probe = hv_uio_probe, 336 .remove = hv_uio_remove, 337 }; 338 339 static int __init 340 hyperv_module_init(void) 341 { 342 return vmbus_driver_register(&hv_uio_drv); 343 } 344 345 static void __exit 346 hyperv_module_exit(void) 347 { 348 vmbus_driver_unregister(&hv_uio_drv); 349 } 350 351 module_init(hyperv_module_init); 352 module_exit(hyperv_module_exit); 353 354 MODULE_VERSION(DRIVER_VERSION); 355 MODULE_LICENSE("GPL v2"); 356 MODULE_AUTHOR(DRIVER_AUTHOR); 357 MODULE_DESCRIPTION(DRIVER_DESC); 358