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 DEBUG 1 21 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 22 23 #include <linux/device.h> 24 #include <linux/kernel.h> 25 #include <linux/module.h> 26 #include <linux/uio_driver.h> 27 #include <linux/netdevice.h> 28 #include <linux/if_ether.h> 29 #include <linux/skbuff.h> 30 #include <linux/hyperv.h> 31 #include <linux/vmalloc.h> 32 #include <linux/slab.h> 33 34 #include "../hv/hyperv_vmbus.h" 35 36 #define DRIVER_VERSION "0.02.0" 37 #define DRIVER_AUTHOR "Stephen Hemminger <sthemmin at microsoft.com>" 38 #define DRIVER_DESC "Generic UIO driver for VMBus devices" 39 40 #define HV_RING_SIZE 512 /* pages */ 41 #define SEND_BUFFER_SIZE (15 * 1024 * 1024) 42 #define RECV_BUFFER_SIZE (15 * 1024 * 1024) 43 44 /* 45 * List of resources to be mapped to user space 46 * can be extended up to MAX_UIO_MAPS(5) items 47 */ 48 enum hv_uio_map { 49 TXRX_RING_MAP = 0, 50 INT_PAGE_MAP, 51 MON_PAGE_MAP, 52 RECV_BUF_MAP, 53 SEND_BUF_MAP 54 }; 55 56 struct hv_uio_private_data { 57 struct uio_info info; 58 struct hv_device *device; 59 60 void *recv_buf; 61 u32 recv_gpadl; 62 char recv_name[32]; /* "recv_4294967295" */ 63 64 void *send_buf; 65 u32 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 struct hv_device *dev = channel->primary_channel->device_obj; 133 u16 q_idx = channel->offermsg.offer.sub_channel_index; 134 135 dev_dbg(&dev->device, "mmap channel %u pages %#lx at %#lx\n", 136 q_idx, vma_pages(vma), vma->vm_pgoff); 137 138 return vm_iomap_memory(vma, virt_to_phys(channel->ringbuffer_pages), 139 channel->ringbuffer_pagecount << PAGE_SHIFT); 140 } 141 142 static const struct bin_attribute ring_buffer_bin_attr = { 143 .attr = { 144 .name = "ring", 145 .mode = 0600, 146 }, 147 .size = 2 * HV_RING_SIZE * PAGE_SIZE, 148 .mmap = hv_uio_ring_mmap, 149 }; 150 151 /* Callback from VMBUS subsystem when new channel created. */ 152 static void 153 hv_uio_new_channel(struct vmbus_channel *new_sc) 154 { 155 struct hv_device *hv_dev = new_sc->primary_channel->device_obj; 156 struct device *device = &hv_dev->device; 157 const size_t ring_bytes = HV_RING_SIZE * PAGE_SIZE; 158 int ret; 159 160 /* Create host communication ring */ 161 ret = vmbus_open(new_sc, ring_bytes, ring_bytes, NULL, 0, 162 hv_uio_channel_cb, new_sc); 163 if (ret) { 164 dev_err(device, "vmbus_open subchannel failed: %d\n", ret); 165 return; 166 } 167 168 /* Disable interrupts on sub channel */ 169 new_sc->inbound.ring_buffer->interrupt_mask = 1; 170 set_channel_read_mode(new_sc, HV_CALL_ISR); 171 172 ret = sysfs_create_bin_file(&new_sc->kobj, &ring_buffer_bin_attr); 173 if (ret) { 174 dev_err(device, "sysfs create ring bin file failed; %d\n", ret); 175 vmbus_close(new_sc); 176 } 177 } 178 179 static void 180 hv_uio_cleanup(struct hv_device *dev, struct hv_uio_private_data *pdata) 181 { 182 if (pdata->send_gpadl) 183 vmbus_teardown_gpadl(dev->channel, pdata->send_gpadl); 184 vfree(pdata->send_buf); 185 186 if (pdata->recv_gpadl) 187 vmbus_teardown_gpadl(dev->channel, pdata->recv_gpadl); 188 vfree(pdata->recv_buf); 189 } 190 191 static int 192 hv_uio_probe(struct hv_device *dev, 193 const struct hv_vmbus_device_id *dev_id) 194 { 195 struct hv_uio_private_data *pdata; 196 int ret; 197 198 pdata = kzalloc(sizeof(*pdata), GFP_KERNEL); 199 if (!pdata) 200 return -ENOMEM; 201 202 ret = vmbus_open(dev->channel, HV_RING_SIZE * PAGE_SIZE, 203 HV_RING_SIZE * PAGE_SIZE, NULL, 0, 204 hv_uio_channel_cb, dev->channel); 205 if (ret) 206 goto fail; 207 208 /* Communicating with host has to be via shared memory not hypercall */ 209 if (!dev->channel->offermsg.monitor_allocated) { 210 dev_err(&dev->device, "vmbus channel requires hypercall\n"); 211 ret = -ENOTSUPP; 212 goto fail_close; 213 } 214 215 dev->channel->inbound.ring_buffer->interrupt_mask = 1; 216 set_channel_read_mode(dev->channel, HV_CALL_ISR); 217 218 /* Fill general uio info */ 219 pdata->info.name = "uio_hv_generic"; 220 pdata->info.version = DRIVER_VERSION; 221 pdata->info.irqcontrol = hv_uio_irqcontrol; 222 pdata->info.irq = UIO_IRQ_CUSTOM; 223 224 /* mem resources */ 225 pdata->info.mem[TXRX_RING_MAP].name = "txrx_rings"; 226 pdata->info.mem[TXRX_RING_MAP].addr 227 = (uintptr_t)dev->channel->ringbuffer_pages; 228 pdata->info.mem[TXRX_RING_MAP].size 229 = dev->channel->ringbuffer_pagecount << PAGE_SHIFT; 230 pdata->info.mem[TXRX_RING_MAP].memtype = UIO_MEM_LOGICAL; 231 232 pdata->info.mem[INT_PAGE_MAP].name = "int_page"; 233 pdata->info.mem[INT_PAGE_MAP].addr 234 = (uintptr_t)vmbus_connection.int_page; 235 pdata->info.mem[INT_PAGE_MAP].size = PAGE_SIZE; 236 pdata->info.mem[INT_PAGE_MAP].memtype = UIO_MEM_LOGICAL; 237 238 pdata->info.mem[MON_PAGE_MAP].name = "monitor_page"; 239 pdata->info.mem[MON_PAGE_MAP].addr 240 = (uintptr_t)vmbus_connection.monitor_pages[1]; 241 pdata->info.mem[MON_PAGE_MAP].size = PAGE_SIZE; 242 pdata->info.mem[MON_PAGE_MAP].memtype = UIO_MEM_LOGICAL; 243 244 pdata->recv_buf = vzalloc(RECV_BUFFER_SIZE); 245 if (pdata->recv_buf == NULL) { 246 ret = -ENOMEM; 247 goto fail_close; 248 } 249 250 ret = vmbus_establish_gpadl(dev->channel, pdata->recv_buf, 251 RECV_BUFFER_SIZE, &pdata->recv_gpadl); 252 if (ret) 253 goto fail_close; 254 255 /* put Global Physical Address Label in name */ 256 snprintf(pdata->recv_name, sizeof(pdata->recv_name), 257 "recv:%u", pdata->recv_gpadl); 258 pdata->info.mem[RECV_BUF_MAP].name = pdata->recv_name; 259 pdata->info.mem[RECV_BUF_MAP].addr 260 = (uintptr_t)pdata->recv_buf; 261 pdata->info.mem[RECV_BUF_MAP].size = RECV_BUFFER_SIZE; 262 pdata->info.mem[RECV_BUF_MAP].memtype = UIO_MEM_VIRTUAL; 263 264 265 pdata->send_buf = vzalloc(SEND_BUFFER_SIZE); 266 if (pdata->send_buf == NULL) { 267 ret = -ENOMEM; 268 goto fail_close; 269 } 270 271 ret = vmbus_establish_gpadl(dev->channel, pdata->send_buf, 272 SEND_BUFFER_SIZE, &pdata->send_gpadl); 273 if (ret) 274 goto fail_close; 275 276 snprintf(pdata->send_name, sizeof(pdata->send_name), 277 "send:%u", pdata->send_gpadl); 278 pdata->info.mem[SEND_BUF_MAP].name = pdata->send_name; 279 pdata->info.mem[SEND_BUF_MAP].addr 280 = (uintptr_t)pdata->send_buf; 281 pdata->info.mem[SEND_BUF_MAP].size = SEND_BUFFER_SIZE; 282 pdata->info.mem[SEND_BUF_MAP].memtype = UIO_MEM_VIRTUAL; 283 284 pdata->info.priv = pdata; 285 pdata->device = dev; 286 287 ret = uio_register_device(&dev->device, &pdata->info); 288 if (ret) { 289 dev_err(&dev->device, "hv_uio register failed\n"); 290 goto fail_close; 291 } 292 293 vmbus_set_chn_rescind_callback(dev->channel, hv_uio_rescind); 294 vmbus_set_sc_create_callback(dev->channel, hv_uio_new_channel); 295 296 ret = sysfs_create_bin_file(&dev->channel->kobj, &ring_buffer_bin_attr); 297 if (ret) 298 dev_notice(&dev->device, 299 "sysfs create ring bin file failed; %d\n", ret); 300 301 hv_set_drvdata(dev, pdata); 302 303 return 0; 304 305 fail_close: 306 hv_uio_cleanup(dev, pdata); 307 vmbus_close(dev->channel); 308 fail: 309 kfree(pdata); 310 311 return ret; 312 } 313 314 static int 315 hv_uio_remove(struct hv_device *dev) 316 { 317 struct hv_uio_private_data *pdata = hv_get_drvdata(dev); 318 319 if (!pdata) 320 return 0; 321 322 uio_unregister_device(&pdata->info); 323 hv_uio_cleanup(dev, pdata); 324 hv_set_drvdata(dev, NULL); 325 vmbus_close(dev->channel); 326 kfree(pdata); 327 return 0; 328 } 329 330 static struct hv_driver hv_uio_drv = { 331 .name = "uio_hv_generic", 332 .id_table = NULL, /* only dynamic id's */ 333 .probe = hv_uio_probe, 334 .remove = hv_uio_remove, 335 }; 336 337 static int __init 338 hyperv_module_init(void) 339 { 340 return vmbus_driver_register(&hv_uio_drv); 341 } 342 343 static void __exit 344 hyperv_module_exit(void) 345 { 346 vmbus_driver_unregister(&hv_uio_drv); 347 } 348 349 module_init(hyperv_module_init); 350 module_exit(hyperv_module_exit); 351 352 MODULE_VERSION(DRIVER_VERSION); 353 MODULE_LICENSE("GPL v2"); 354 MODULE_AUTHOR(DRIVER_AUTHOR); 355 MODULE_DESCRIPTION(DRIVER_DESC); 356