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(dev: hv_dev); |
98 | |
99 | chan->inbound.ring_buffer->interrupt_mask = 1; |
100 | virt_mb(); |
101 | |
102 | uio_event_notify(info: &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(dev: 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(info: &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(address: ring_buffer), |
138 | len: 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(channel: new_sc, send_ringbuffersize: ring_bytes, recv_ringbuffersize: ring_bytes, NULL, userdatalen: 0, |
161 | onchannel_callback: hv_uio_channel_cb, context: 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(c: new_sc, mode: HV_CALL_ISR); |
170 | |
171 | ret = sysfs_create_bin_file(kobj: &new_sc->kobj, attr: &ring_buffer_bin_attr); |
172 | if (ret) { |
173 | dev_err(device, "sysfs create ring bin file failed; %d\n" , ret); |
174 | vmbus_close(channel: 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(channel: dev->channel, gpadl: &pdata->send_gpadl); |
184 | vfree(addr: pdata->send_buf); |
185 | } |
186 | |
187 | if (pdata->recv_gpadl.gpadl_handle) { |
188 | vmbus_teardown_gpadl(channel: dev->channel, gpadl: &pdata->recv_gpadl); |
189 | vfree(addr: 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(v: &pdata->refcnt) != 1) |
203 | return 0; |
204 | |
205 | vmbus_set_chn_rescind_callback(channel: dev->channel, chn_rescind_cb: hv_uio_rescind); |
206 | vmbus_set_sc_create_callback(primary_channel: dev->channel, sc_cr_cb: hv_uio_new_channel); |
207 | |
208 | ret = vmbus_connect_ring(channel: dev->channel, |
209 | onchannel_callback: hv_uio_channel_cb, context: dev->channel); |
210 | if (ret == 0) |
211 | dev->channel->inbound.ring_buffer->interrupt_mask = 1; |
212 | else |
213 | atomic_dec(v: &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(v: &pdata->refcnt)) |
228 | ret = vmbus_disconnect_ring(channel: 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: &dev->device, size: 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(c: channel, mode: 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(v: &pdata->refcnt, i: 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(address: 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, kbuffer: pdata->recv_buf, |
296 | RECV_BUFFER_SIZE, gpadl: &pdata->recv_gpadl); |
297 | if (ret) { |
298 | vfree(addr: pdata->recv_buf); |
299 | goto fail_close; |
300 | } |
301 | |
302 | /* put Global Physical Address Label in name */ |
303 | snprintf(buf: pdata->recv_name, size: sizeof(pdata->recv_name), |
304 | fmt: "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, kbuffer: pdata->send_buf, |
318 | SEND_BUFFER_SIZE, gpadl: &pdata->send_gpadl); |
319 | if (ret) { |
320 | vfree(addr: pdata->send_buf); |
321 | goto fail_close; |
322 | } |
323 | |
324 | snprintf(buf: pdata->send_name, size: sizeof(pdata->send_name), |
325 | fmt: "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(kobj: &channel->kobj, attr: &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, data: pdata); |
347 | |
348 | return 0; |
349 | |
350 | fail_close: |
351 | hv_uio_cleanup(dev, pdata); |
352 | fail_free_ring: |
353 | vmbus_free_ring(channel: 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(kobj: &dev->channel->kobj, attr: &ring_buffer_bin_attr); |
367 | uio_unregister_device(info: &pdata->info); |
368 | hv_uio_cleanup(dev, pdata); |
369 | |
370 | vmbus_free_ring(channel: 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_driver: &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 | |