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bce5c2ea 1// SPDX-License-Identifier: GPL-2.0
95096f2f
SH
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 *
95096f2f
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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 *
42896968 11 * Associate Network GUID with UIO device
95096f2f 12 * # echo "f8615163-df3e-46c5-913f-f2d2f965ed0e" \
42896968
SH
13 * > /sys/bus/vmbus/drivers/uio_hv_generic/new_id
14 * Then rebind
15 * # echo -n "ed963694-e847-4b2a-85af-bc9cfc11d6f3" \
95096f2f 16 * > /sys/bus/vmbus/drivers/hv_netvsc/unbind
42896968 17 * # echo -n "ed963694-e847-4b2a-85af-bc9cfc11d6f3" \
95096f2f
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18 * > /sys/bus/vmbus/drivers/uio_hv_generic/bind
19 */
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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
108ddb8f 35#define DRIVER_VERSION "0.02.1"
95096f2f
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36#define DRIVER_AUTHOR "Stephen Hemminger <sthemmin at microsoft.com>"
37#define DRIVER_DESC "Generic UIO driver for VMBus devices"
38
e7d21464 39#define HV_RING_SIZE 512 /* pages */
108ddb8f
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40#define SEND_BUFFER_SIZE (16 * 1024 * 1024)
41#define RECV_BUFFER_SIZE (31 * 1024 * 1024)
e7d21464 42
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43/*
44 * List of resources to be mapped to user space
45 * can be extended up to MAX_UIO_MAPS(5) items
46 */
47enum hv_uio_map {
48 TXRX_RING_MAP = 0,
49 INT_PAGE_MAP,
50 MON_PAGE_MAP,
e7d21464
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51 RECV_BUF_MAP,
52 SEND_BUF_MAP
95096f2f
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53};
54
95096f2f
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55struct hv_uio_private_data {
56 struct uio_info info;
57 struct hv_device *device;
cdfa835c 58 atomic_t refcnt;
e7d21464
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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];
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67};
68
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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 */
78static int
79hv_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 */
93static void hv_uio_channel_cb(void *context)
94{
135db384
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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);
95096f2f 98
135db384 99 chan->inbound.ring_buffer->interrupt_mask = 1;
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100 virt_mb();
101
102 uio_event_notify(&pdata->info);
103}
104
ca3cda6f
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105/*
106 * Callback from vmbus_event when channel is rescinded.
107 */
108static 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}
e7d21464 122
ce3d1536
SH
123/* Sysfs API to allow mmap of the ring buffers
124 * The ring buffer is allocated as contiguous memory by vmbus_open
37b96a49 125 */
37b96a49
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126static 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);
52a42c2a 132 void *ring_buffer = page_address(channel->ringbuffer_page);
37b96a49 133
cdfa835c
SH
134 if (channel->state != CHANNEL_OPENED_STATE)
135 return -ENODEV;
37b96a49 136
52a42c2a 137 return vm_iomap_memory(vma, virt_to_phys(ring_buffer),
ce3d1536 138 channel->ringbuffer_pagecount << PAGE_SHIFT);
37b96a49
SH
139}
140
6e3d66b8 141static const struct bin_attribute ring_buffer_bin_attr = {
37b96a49
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142 .attr = {
143 .name = "ring",
144 .mode = 0600,
37b96a49 145 },
6e3d66b8 146 .size = 2 * HV_RING_SIZE * PAGE_SIZE,
37b96a49
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147 .mmap = hv_uio_ring_mmap,
148};
149
135db384 150/* Callback from VMBUS subsystem when new channel created. */
37b96a49
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151static void
152hv_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;
37b96a49
SH
156 const size_t ring_bytes = HV_RING_SIZE * PAGE_SIZE;
157 int ret;
158
159 /* Create host communication ring */
160 ret = vmbus_open(new_sc, ring_bytes, ring_bytes, NULL, 0,
135db384 161 hv_uio_channel_cb, new_sc);
37b96a49
SH
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(new_sc, HV_CALL_ISR);
170
171 ret = sysfs_create_bin_file(&new_sc->kobj, &ring_buffer_bin_attr);
172 if (ret) {
173 dev_err(device, "sysfs create ring bin file failed; %d\n", ret);
174 vmbus_close(new_sc);
175 }
176}
177
cdfa835c 178/* free the reserved buffers for send and receive */
e7d21464
SH
179static void
180hv_uio_cleanup(struct hv_device *dev, struct hv_uio_private_data *pdata)
181{
cdfa835c 182 if (pdata->send_gpadl) {
e7d21464 183 vmbus_teardown_gpadl(dev->channel, pdata->send_gpadl);
cdfa835c
SH
184 pdata->send_gpadl = 0;
185 vfree(pdata->send_buf);
186 }
e7d21464 187
cdfa835c 188 if (pdata->recv_gpadl) {
e7d21464 189 vmbus_teardown_gpadl(dev->channel, pdata->recv_gpadl);
cdfa835c
SH
190 pdata->recv_gpadl = 0;
191 vfree(pdata->recv_buf);
192 }
193}
194
195/* VMBus primary channel is opened on first use */
196static int
197hv_uio_open(struct uio_info *info, struct inode *inode)
198{
199 struct hv_uio_private_data *pdata
200 = container_of(info, struct hv_uio_private_data, info);
201 struct hv_device *dev = pdata->device;
202 int ret;
203
204 if (atomic_inc_return(&pdata->refcnt) != 1)
205 return 0;
206
5e3c420d
SH
207 vmbus_set_chn_rescind_callback(dev->channel, hv_uio_rescind);
208 vmbus_set_sc_create_callback(dev->channel, hv_uio_new_channel);
209
cdfa835c
SH
210 ret = vmbus_connect_ring(dev->channel,
211 hv_uio_channel_cb, dev->channel);
cdfa835c
SH
212 if (ret == 0)
213 dev->channel->inbound.ring_buffer->interrupt_mask = 1;
214 else
215 atomic_dec(&pdata->refcnt);
216
217 return ret;
218}
219
220/* VMBus primary channel is closed on last close */
221static int
222hv_uio_release(struct uio_info *info, struct inode *inode)
223{
224 struct hv_uio_private_data *pdata
225 = container_of(info, struct hv_uio_private_data, info);
226 struct hv_device *dev = pdata->device;
227 int ret = 0;
228
229 if (atomic_dec_and_test(&pdata->refcnt))
230 ret = vmbus_disconnect_ring(dev->channel);
231
232 return ret;
e7d21464
SH
233}
234
95096f2f
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235static int
236hv_uio_probe(struct hv_device *dev,
237 const struct hv_vmbus_device_id *dev_id)
238{
cdfa835c 239 struct vmbus_channel *channel = dev->channel;
95096f2f 240 struct hv_uio_private_data *pdata;
cdfa835c 241 void *ring_buffer;
95096f2f
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242 int ret;
243
cdfa835c
SH
244 /* Communicating with host has to be via shared memory not hypercall */
245 if (!channel->offermsg.monitor_allocated) {
246 dev_err(&dev->device, "vmbus channel requires hypercall\n");
247 return -ENOTSUPP;
248 }
249
74e71964 250 pdata = devm_kzalloc(&dev->device, sizeof(*pdata), GFP_KERNEL);
95096f2f
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251 if (!pdata)
252 return -ENOMEM;
253
cdfa835c
SH
254 ret = vmbus_alloc_ring(channel, HV_RING_SIZE * PAGE_SIZE,
255 HV_RING_SIZE * PAGE_SIZE);
95096f2f 256 if (ret)
74e71964 257 return ret;
95096f2f 258
cdfa835c 259 set_channel_read_mode(channel, HV_CALL_ISR);
95096f2f
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260
261 /* Fill general uio info */
262 pdata->info.name = "uio_hv_generic";
263 pdata->info.version = DRIVER_VERSION;
264 pdata->info.irqcontrol = hv_uio_irqcontrol;
cdfa835c
SH
265 pdata->info.open = hv_uio_open;
266 pdata->info.release = hv_uio_release;
95096f2f 267 pdata->info.irq = UIO_IRQ_CUSTOM;
cdfa835c 268 atomic_set(&pdata->refcnt, 0);
95096f2f
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269
270 /* mem resources */
271 pdata->info.mem[TXRX_RING_MAP].name = "txrx_rings";
cdfa835c 272 ring_buffer = page_address(channel->ringbuffer_page);
95096f2f 273 pdata->info.mem[TXRX_RING_MAP].addr
cdfa835c 274 = (uintptr_t)virt_to_phys(ring_buffer);
95096f2f 275 pdata->info.mem[TXRX_RING_MAP].size
cdfa835c 276 = channel->ringbuffer_pagecount << PAGE_SHIFT;
9da197f1 277 pdata->info.mem[TXRX_RING_MAP].memtype = UIO_MEM_IOVA;
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278
279 pdata->info.mem[INT_PAGE_MAP].name = "int_page";
9c40546c 280 pdata->info.mem[INT_PAGE_MAP].addr
72d14657 281 = (uintptr_t)vmbus_connection.int_page;
95096f2f
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282 pdata->info.mem[INT_PAGE_MAP].size = PAGE_SIZE;
283 pdata->info.mem[INT_PAGE_MAP].memtype = UIO_MEM_LOGICAL;
284
9c40546c
SH
285 pdata->info.mem[MON_PAGE_MAP].name = "monitor_page";
286 pdata->info.mem[MON_PAGE_MAP].addr
72d14657 287 = (uintptr_t)vmbus_connection.monitor_pages[1];
95096f2f
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288 pdata->info.mem[MON_PAGE_MAP].size = PAGE_SIZE;
289 pdata->info.mem[MON_PAGE_MAP].memtype = UIO_MEM_LOGICAL;
290
e7d21464
SH
291 pdata->recv_buf = vzalloc(RECV_BUFFER_SIZE);
292 if (pdata->recv_buf == NULL) {
293 ret = -ENOMEM;
294 goto fail_close;
295 }
296
cdfa835c 297 ret = vmbus_establish_gpadl(channel, pdata->recv_buf,
e7d21464
SH
298 RECV_BUFFER_SIZE, &pdata->recv_gpadl);
299 if (ret)
300 goto fail_close;
301
302 /* put Global Physical Address Label in name */
303 snprintf(pdata->recv_name, sizeof(pdata->recv_name),
304 "recv:%u", pdata->recv_gpadl);
305 pdata->info.mem[RECV_BUF_MAP].name = pdata->recv_name;
306 pdata->info.mem[RECV_BUF_MAP].addr
d6088e9a 307 = (uintptr_t)pdata->recv_buf;
e7d21464
SH
308 pdata->info.mem[RECV_BUF_MAP].size = RECV_BUFFER_SIZE;
309 pdata->info.mem[RECV_BUF_MAP].memtype = UIO_MEM_VIRTUAL;
310
e7d21464
SH
311 pdata->send_buf = vzalloc(SEND_BUFFER_SIZE);
312 if (pdata->send_buf == NULL) {
313 ret = -ENOMEM;
314 goto fail_close;
315 }
316
cdfa835c 317 ret = vmbus_establish_gpadl(channel, pdata->send_buf,
e7d21464
SH
318 SEND_BUFFER_SIZE, &pdata->send_gpadl);
319 if (ret)
320 goto fail_close;
321
322 snprintf(pdata->send_name, sizeof(pdata->send_name),
323 "send:%u", pdata->send_gpadl);
324 pdata->info.mem[SEND_BUF_MAP].name = pdata->send_name;
325 pdata->info.mem[SEND_BUF_MAP].addr
d6088e9a 326 = (uintptr_t)pdata->send_buf;
e7d21464
SH
327 pdata->info.mem[SEND_BUF_MAP].size = SEND_BUFFER_SIZE;
328 pdata->info.mem[SEND_BUF_MAP].memtype = UIO_MEM_VIRTUAL;
329
95096f2f
SH
330 pdata->info.priv = pdata;
331 pdata->device = dev;
332
333 ret = uio_register_device(&dev->device, &pdata->info);
334 if (ret) {
335 dev_err(&dev->device, "hv_uio register failed\n");
336 goto fail_close;
337 }
338
cdfa835c 339 ret = sysfs_create_bin_file(&channel->kobj, &ring_buffer_bin_attr);
9ab877a6
SH
340 if (ret)
341 dev_notice(&dev->device,
342 "sysfs create ring bin file failed; %d\n", ret);
343
95096f2f
SH
344 hv_set_drvdata(dev, pdata);
345
346 return 0;
347
348fail_close:
e7d21464 349 hv_uio_cleanup(dev, pdata);
95096f2f
SH
350
351 return ret;
352}
353
354static int
355hv_uio_remove(struct hv_device *dev)
356{
357 struct hv_uio_private_data *pdata = hv_get_drvdata(dev);
358
359 if (!pdata)
360 return 0;
361
7066c2f6 362 sysfs_remove_bin_file(&dev->channel->kobj, &ring_buffer_bin_attr);
95096f2f 363 uio_unregister_device(&pdata->info);
e7d21464 364 hv_uio_cleanup(dev, pdata);
cdfa835c
SH
365
366 vmbus_free_ring(dev->channel);
95096f2f
SH
367 return 0;
368}
369
370static struct hv_driver hv_uio_drv = {
371 .name = "uio_hv_generic",
372 .id_table = NULL, /* only dynamic id's */
373 .probe = hv_uio_probe,
374 .remove = hv_uio_remove,
375};
376
377static int __init
378hyperv_module_init(void)
379{
380 return vmbus_driver_register(&hv_uio_drv);
381}
382
383static void __exit
384hyperv_module_exit(void)
385{
386 vmbus_driver_unregister(&hv_uio_drv);
387}
388
389module_init(hyperv_module_init);
390module_exit(hyperv_module_exit);
391
392MODULE_VERSION(DRIVER_VERSION);
393MODULE_LICENSE("GPL v2");
394MODULE_AUTHOR(DRIVER_AUTHOR);
395MODULE_DESCRIPTION(DRIVER_DESC);