diff options
Diffstat (limited to 'drivers/uio/uio_hv_generic.c')
| -rw-r--r-- | drivers/uio/uio_hv_generic.c | 218 |
1 files changed, 218 insertions, 0 deletions
diff --git a/drivers/uio/uio_hv_generic.c b/drivers/uio/uio_hv_generic.c new file mode 100644 index 000000000000..50958f167305 --- /dev/null +++ b/drivers/uio/uio_hv_generic.c @@ -0,0 +1,218 @@ +/* + * uio_hv_generic - generic UIO driver for VMBus + * + * Copyright (c) 2013-2016 Brocade Communications Systems, Inc. + * Copyright (c) 2016, Microsoft Corporation. + * + * + * This work is licensed under the terms of the GNU GPL, version 2. + * + * Since the driver does not declare any device ids, you must allocate + * id and bind the device to the driver yourself. For example: + * + * # echo "f8615163-df3e-46c5-913f-f2d2f965ed0e" \ + * > /sys/bus/vmbus/drivers/uio_hv_generic + * # echo -n vmbus-ed963694-e847-4b2a-85af-bc9cfc11d6f3 \ + * > /sys/bus/vmbus/drivers/hv_netvsc/unbind + * # echo -n vmbus-ed963694-e847-4b2a-85af-bc9cfc11d6f3 \ + * > /sys/bus/vmbus/drivers/uio_hv_generic/bind + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/device.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/uio_driver.h> +#include <linux/netdevice.h> +#include <linux/if_ether.h> +#include <linux/skbuff.h> +#include <linux/hyperv.h> +#include <linux/vmalloc.h> +#include <linux/slab.h> + +#include "../hv/hyperv_vmbus.h" + +#define DRIVER_VERSION "0.02.0" +#define DRIVER_AUTHOR "Stephen Hemminger <sthemmin at microsoft.com>" +#define DRIVER_DESC "Generic UIO driver for VMBus devices" + +/* + * List of resources to be mapped to user space + * can be extended up to MAX_UIO_MAPS(5) items + */ +enum hv_uio_map { + TXRX_RING_MAP = 0, + INT_PAGE_MAP, + MON_PAGE_MAP, +}; + +#define HV_RING_SIZE 512 + +struct hv_uio_private_data { + struct uio_info info; + struct hv_device *device; +}; + +static int +hv_uio_mmap(struct uio_info *info, struct vm_area_struct *vma) +{ + int mi; + + if (vma->vm_pgoff >= MAX_UIO_MAPS) + return -EINVAL; + + if (info->mem[vma->vm_pgoff].size == 0) + return -EINVAL; + + mi = (int)vma->vm_pgoff; + + return remap_pfn_range(vma, vma->vm_start, + info->mem[mi].addr >> PAGE_SHIFT, + vma->vm_end - vma->vm_start, vma->vm_page_prot); +} + +/* + * This is the irqcontrol callback to be registered to uio_info. + * It can be used to disable/enable interrupt from user space processes. + * + * @param info + * pointer to uio_info. + * @param irq_state + * state value. 1 to enable interrupt, 0 to disable interrupt. + */ +static int +hv_uio_irqcontrol(struct uio_info *info, s32 irq_state) +{ + struct hv_uio_private_data *pdata = info->priv; + struct hv_device *dev = pdata->device; + + dev->channel->inbound.ring_buffer->interrupt_mask = !irq_state; + virt_mb(); + + return 0; +} + +/* + * Callback from vmbus_event when something is in inbound ring. + */ +static void hv_uio_channel_cb(void *context) +{ + struct hv_uio_private_data *pdata = context; + struct hv_device *dev = pdata->device; + + dev->channel->inbound.ring_buffer->interrupt_mask = 1; + virt_mb(); + + uio_event_notify(&pdata->info); +} + +static int +hv_uio_probe(struct hv_device *dev, + const struct hv_vmbus_device_id *dev_id) +{ + struct hv_uio_private_data *pdata; + int ret; + + pdata = kzalloc(sizeof(*pdata), GFP_KERNEL); + if (!pdata) + return -ENOMEM; + + ret = vmbus_open(dev->channel, HV_RING_SIZE * PAGE_SIZE, + HV_RING_SIZE * PAGE_SIZE, NULL, 0, + hv_uio_channel_cb, pdata); + if (ret) + goto fail; + + dev->channel->inbound.ring_buffer->interrupt_mask = 1; + dev->channel->batched_reading = false; + + /* Fill general uio info */ + pdata->info.name = "uio_hv_generic"; + pdata->info.version = DRIVER_VERSION; + pdata->info.irqcontrol = hv_uio_irqcontrol; + pdata->info.mmap = hv_uio_mmap; + pdata->info.irq = UIO_IRQ_CUSTOM; + + /* mem resources */ + pdata->info.mem[TXRX_RING_MAP].name = "txrx_rings"; + pdata->info.mem[TXRX_RING_MAP].addr + = virt_to_phys(dev->channel->ringbuffer_pages); + pdata->info.mem[TXRX_RING_MAP].size + = dev->channel->ringbuffer_pagecount * PAGE_SIZE; + pdata->info.mem[TXRX_RING_MAP].memtype = UIO_MEM_LOGICAL; + + pdata->info.mem[INT_PAGE_MAP].name = "int_page"; + pdata->info.mem[INT_PAGE_MAP].addr = + virt_to_phys(vmbus_connection.int_page); + pdata->info.mem[INT_PAGE_MAP].size = PAGE_SIZE; + pdata->info.mem[INT_PAGE_MAP].memtype = UIO_MEM_LOGICAL; + + pdata->info.mem[MON_PAGE_MAP].name = "monitor_pages"; + pdata->info.mem[MON_PAGE_MAP].addr = + virt_to_phys(vmbus_connection.monitor_pages[1]); + pdata->info.mem[MON_PAGE_MAP].size = PAGE_SIZE; + pdata->info.mem[MON_PAGE_MAP].memtype = UIO_MEM_LOGICAL; + + pdata->info.priv = pdata; + pdata->device = dev; + + ret = uio_register_device(&dev->device, &pdata->info); + if (ret) { + dev_err(&dev->device, "hv_uio register failed\n"); + goto fail_close; + } + + hv_set_drvdata(dev, pdata); + + return 0; + +fail_close: + vmbus_close(dev->channel); +fail: + kfree(pdata); + + return ret; +} + +static int +hv_uio_remove(struct hv_device *dev) +{ + struct hv_uio_private_data *pdata = hv_get_drvdata(dev); + + if (!pdata) + return 0; + + uio_unregister_device(&pdata->info); + hv_set_drvdata(dev, NULL); + vmbus_close(dev->channel); + kfree(pdata); + return 0; +} + +static struct hv_driver hv_uio_drv = { + .name = "uio_hv_generic", + .id_table = NULL, /* only dynamic id's */ + .probe = hv_uio_probe, + .remove = hv_uio_remove, +}; + +static int __init +hyperv_module_init(void) +{ + return vmbus_driver_register(&hv_uio_drv); +} + +static void __exit +hyperv_module_exit(void) +{ + vmbus_driver_unregister(&hv_uio_drv); +} + +module_init(hyperv_module_init); +module_exit(hyperv_module_exit); + +MODULE_VERSION(DRIVER_VERSION); +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR(DRIVER_AUTHOR); +MODULE_DESCRIPTION(DRIVER_DESC); |