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
hv_uio_irqcontrol(struct uio_info * info,s32 irq_state)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 */
hv_uio_channel_cb(void * context)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 */
hv_uio_rescind(struct vmbus_channel * channel)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 */
hv_uio_ring_mmap(struct file * filp,struct kobject * kobj,struct bin_attribute * attr,struct vm_area_struct * vma)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
hv_uio_new_channel(struct vmbus_channel * new_sc)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
hv_uio_cleanup(struct hv_device * dev,struct hv_uio_private_data * pdata)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
hv_uio_probe(struct hv_device * dev,const struct hv_vmbus_device_id * dev_id)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
hv_uio_remove(struct hv_device * dev)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
hyperv_module_init(void)338 hyperv_module_init(void)
339 {
340 return vmbus_driver_register(&hv_uio_drv);
341 }
342
343 static void __exit
hyperv_module_exit(void)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
