drivers/uio/uio_hv_generic.c

   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
  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 hv_uio_private_data *pdata = context;
  98         struct hv_device *dev = pdata->device;
  99
 100         dev->channel->inbound.ring_buffer->interrupt_mask = 1;
 101         virt_mb();
 102
 103         uio_event_notify(&pdata->info);
 104 }
 105
 106 /*
 107  * Callback from vmbus_event when channel is rescinded.
 108  */
 109 static void hv_uio_rescind(struct vmbus_channel *channel)
 110 {
 111         struct hv_device *hv_dev = channel->primary_channel->device_obj;
 112         struct hv_uio_private_data *pdata = hv_get_drvdata(hv_dev);
 113
 114         /*
 115          * Turn off the interrupt file handle
 116          * Next read for event will return -EIO
 117          */
 118         pdata->info.irq = 0;
 119
 120         /* Wake up reader */
 121         uio_event_notify(&pdata->info);
 122 }
 123
 124 static void
 125 hv_uio_cleanup(struct hv_device *dev, struct hv_uio_private_data *pdata)
 126 {
 127         if (pdata->send_gpadl)
 128                 vmbus_teardown_gpadl(dev->channel, pdata->send_gpadl);
 129         vfree(pdata->send_buf);
 130
 131         if (pdata->recv_gpadl)
 132                 vmbus_teardown_gpadl(dev->channel, pdata->recv_gpadl);
 133         vfree(pdata->recv_buf);
 134 }
 135
 136 static int
 137 hv_uio_probe(struct hv_device *dev,
 138              const struct hv_vmbus_device_id *dev_id)
 139 {
 140         struct hv_uio_private_data *pdata;
 141         int ret;
 142
 143         pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
 144         if (!pdata)
 145                 return -ENOMEM;
 146
 147         ret = vmbus_open(dev->channel, HV_RING_SIZE * PAGE_SIZE,
 148                          HV_RING_SIZE * PAGE_SIZE, NULL, 0,
 149                          hv_uio_channel_cb, pdata);
 150         if (ret)
 151                 goto fail;
 152
 153         /* Communicating with host has to be via shared memory not hypercall */
 154         if (!dev->channel->offermsg.monitor_allocated) {
 155                 dev_err(&dev->device, "vmbus channel requires hypercall\n");
 156                 ret = -ENOTSUPP;
 157                 goto fail_close;
 158         }
 159
 160         dev->channel->inbound.ring_buffer->interrupt_mask = 1;
 161         set_channel_read_mode(dev->channel, HV_CALL_ISR);
 162
 163         /* Fill general uio info */
 164         pdata->info.name = "uio_hv_generic";
 165         pdata->info.version = DRIVER_VERSION;
 166         pdata->info.irqcontrol = hv_uio_irqcontrol;
 167         pdata->info.irq = UIO_IRQ_CUSTOM;
 168
 169         /* mem resources */
 170         pdata->info.mem[TXRX_RING_MAP].name = "txrx_rings";
 171         pdata->info.mem[TXRX_RING_MAP].addr
 172                 = (uintptr_t)dev->channel->ringbuffer_pages;
 173         pdata->info.mem[TXRX_RING_MAP].size
 174                 = dev->channel->ringbuffer_pagecount << PAGE_SHIFT;
 175         pdata->info.mem[TXRX_RING_MAP].memtype = UIO_MEM_LOGICAL;
 176
 177         pdata->info.mem[INT_PAGE_MAP].name = "int_page";
 178         pdata->info.mem[INT_PAGE_MAP].addr
 179                 = (uintptr_t)vmbus_connection.int_page;
 180         pdata->info.mem[INT_PAGE_MAP].size = PAGE_SIZE;
 181         pdata->info.mem[INT_PAGE_MAP].memtype = UIO_MEM_LOGICAL;
 182
 183         pdata->info.mem[MON_PAGE_MAP].name = "monitor_page";
 184         pdata->info.mem[MON_PAGE_MAP].addr
 185                 = (uintptr_t)vmbus_connection.monitor_pages[1];
 186         pdata->info.mem[MON_PAGE_MAP].size = PAGE_SIZE;
 187         pdata->info.mem[MON_PAGE_MAP].memtype = UIO_MEM_LOGICAL;
 188
 189         pdata->recv_buf = vzalloc(RECV_BUFFER_SIZE);
 190         if (pdata->recv_buf == NULL) {
 191                 ret = -ENOMEM;
 192                 goto fail_close;
 193         }
 194
 195         ret = vmbus_establish_gpadl(dev->channel, pdata->recv_buf,
 196                                     RECV_BUFFER_SIZE, &pdata->recv_gpadl);
 197         if (ret)
 198                 goto fail_close;
 199
 200         /* put Global Physical Address Label in name */
 201         snprintf(pdata->recv_name, sizeof(pdata->recv_name),
 202                  "recv:%u", pdata->recv_gpadl);
 203         pdata->info.mem[RECV_BUF_MAP].name = pdata->recv_name;
 204         pdata->info.mem[RECV_BUF_MAP].addr
 205                 = (uintptr_t)pdata->recv_buf;
 206         pdata->info.mem[RECV_BUF_MAP].size = RECV_BUFFER_SIZE;
 207         pdata->info.mem[RECV_BUF_MAP].memtype = UIO_MEM_VIRTUAL;
 208
 209
 210         pdata->send_buf = vzalloc(SEND_BUFFER_SIZE);
 211         if (pdata->send_buf == NULL) {
 212                 ret = -ENOMEM;
 213                 goto fail_close;
 214         }
 215
 216         ret = vmbus_establish_gpadl(dev->channel, pdata->send_buf,
 217                                     SEND_BUFFER_SIZE, &pdata->send_gpadl);
 218         if (ret)
 219                 goto fail_close;
 220
 221         snprintf(pdata->send_name, sizeof(pdata->send_name),
 222                  "send:%u", pdata->send_gpadl);
 223         pdata->info.mem[SEND_BUF_MAP].name = pdata->send_name;
 224         pdata->info.mem[SEND_BUF_MAP].addr
 225                 = (uintptr_t)pdata->send_buf;
 226         pdata->info.mem[SEND_BUF_MAP].size = SEND_BUFFER_SIZE;
 227         pdata->info.mem[SEND_BUF_MAP].memtype = UIO_MEM_VIRTUAL;
 228
 229         pdata->info.priv = pdata;
 230         pdata->device = dev;
 231
 232         ret = uio_register_device(&dev->device, &pdata->info);
 233         if (ret) {
 234                 dev_err(&dev->device, "hv_uio register failed\n");
 235                 goto fail_close;
 236         }
 237
 238         vmbus_set_chn_rescind_callback(dev->channel, hv_uio_rescind);
 239
 240         hv_set_drvdata(dev, pdata);
 241
 242         return 0;
 243
 244 fail_close:
 245         hv_uio_cleanup(dev, pdata);
 246         vmbus_close(dev->channel);
 247 fail:
 248         kfree(pdata);
 249
 250         return ret;
 251 }
 252
 253 static int
 254 hv_uio_remove(struct hv_device *dev)
 255 {
 256         struct hv_uio_private_data *pdata = hv_get_drvdata(dev);
 257
 258         if (!pdata)
 259                 return 0;
 260
 261         uio_unregister_device(&pdata->info);
 262         hv_uio_cleanup(dev, pdata);
 263         hv_set_drvdata(dev, NULL);
 264         vmbus_close(dev->channel);
 265         kfree(pdata);
 266         return 0;
 267 }
 268
 269 static struct hv_driver hv_uio_drv = {
 270         .name = "uio_hv_generic",
 271         .id_table = NULL, /* only dynamic id's */
 272         .probe = hv_uio_probe,
 273         .remove = hv_uio_remove,
 274 };
 275
 276 static int __init
 277 hyperv_module_init(void)
 278 {
 279         return vmbus_driver_register(&hv_uio_drv);
 280 }
 281
 282 static void __exit
 283 hyperv_module_exit(void)
 284 {
 285         vmbus_driver_unregister(&hv_uio_drv);
 286 }
 287
 288 module_init(hyperv_module_init);
 289 module_exit(hyperv_module_exit);
 290
 291 MODULE_VERSION(DRIVER_VERSION);
 292 MODULE_LICENSE("GPL v2");
 293 MODULE_AUTHOR(DRIVER_AUTHOR);
 294 MODULE_DESCRIPTION(DRIVER_DESC);