diff options
Diffstat (limited to 'drivers/uio/uio_hv_generic.c')
| -rw-r--r-- | drivers/uio/uio_hv_generic.c | 398 |
1 files changed, 398 insertions, 0 deletions
diff --git a/drivers/uio/uio_hv_generic.c b/drivers/uio/uio_hv_generic.c new file mode 100644 index 0000000000..20d9762331 --- /dev/null +++ b/drivers/uio/uio_hv_generic.c @@ -0,0 +1,398 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * uio_hv_generic - generic UIO driver for VMBus + * + * Copyright (c) 2013-2016 Brocade Communications Systems, Inc. + * Copyright (c) 2016, Microsoft Corporation. + * + * Since the driver does not declare any device ids, you must allocate + * id and bind the device to the driver yourself. For example: + * + * Associate Network GUID with UIO device + * # echo "f8615163-df3e-46c5-913f-f2d2f965ed0e" \ + * > /sys/bus/vmbus/drivers/uio_hv_generic/new_id + * Then rebind + * # echo -n "ed963694-e847-4b2a-85af-bc9cfc11d6f3" \ + * > /sys/bus/vmbus/drivers/hv_netvsc/unbind + * # echo -n "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 "0.02.1" +#define DRIVER_AUTHOR "Stephen Hemminger <sthemmin at microsoft.com>" +#define DRIVER_DESC "Generic UIO driver for VMBus devices" + +#define HV_RING_SIZE 512 /* pages */ +#define SEND_BUFFER_SIZE (16 * 1024 * 1024) +#define RECV_BUFFER_SIZE (31 * 1024 * 1024) + +/* + * 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, + RECV_BUF_MAP, + SEND_BUF_MAP +}; + +struct hv_uio_private_data { + struct uio_info info; + struct hv_device *device; + atomic_t refcnt; + + void *recv_buf; + struct vmbus_gpadl recv_gpadl; + char recv_name[32]; /* "recv_4294967295" */ + + void *send_buf; + struct vmbus_gpadl send_gpadl; + char send_name[32]; +}; + +/* + * 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 vmbus_channel *chan = context; + struct hv_device *hv_dev = chan->device_obj; + struct hv_uio_private_data *pdata = hv_get_drvdata(hv_dev); + + chan->inbound.ring_buffer->interrupt_mask = 1; + virt_mb(); + + uio_event_notify(&pdata->info); +} + +/* + * Callback from vmbus_event when channel is rescinded. + */ +static void hv_uio_rescind(struct vmbus_channel *channel) +{ + struct hv_device *hv_dev = channel->primary_channel->device_obj; + struct hv_uio_private_data *pdata = hv_get_drvdata(hv_dev); + + /* + * Turn off the interrupt file handle + * Next read for event will return -EIO + */ + pdata->info.irq = 0; + + /* Wake up reader */ + uio_event_notify(&pdata->info); +} + +/* Sysfs API to allow mmap of the ring buffers + * The ring buffer is allocated as contiguous memory by vmbus_open + */ +static int hv_uio_ring_mmap(struct file *filp, struct kobject *kobj, + struct bin_attribute *attr, + struct vm_area_struct *vma) +{ + struct vmbus_channel *channel + = container_of(kobj, struct vmbus_channel, kobj); + void *ring_buffer = page_address(channel->ringbuffer_page); + + if (channel->state != CHANNEL_OPENED_STATE) + return -ENODEV; + + return vm_iomap_memory(vma, virt_to_phys(ring_buffer), + channel->ringbuffer_pagecount << PAGE_SHIFT); +} + +static const struct bin_attribute ring_buffer_bin_attr = { + .attr = { + .name = "ring", + .mode = 0600, + }, + .size = 2 * HV_RING_SIZE * PAGE_SIZE, + .mmap = hv_uio_ring_mmap, +}; + +/* Callback from VMBUS subsystem when new channel created. */ +static void +hv_uio_new_channel(struct vmbus_channel *new_sc) +{ + struct hv_device *hv_dev = new_sc->primary_channel->device_obj; + struct device *device = &hv_dev->device; + const size_t ring_bytes = HV_RING_SIZE * PAGE_SIZE; + int ret; + + /* Create host communication ring */ + ret = vmbus_open(new_sc, ring_bytes, ring_bytes, NULL, 0, + hv_uio_channel_cb, new_sc); + if (ret) { + dev_err(device, "vmbus_open subchannel failed: %d\n", ret); + return; + } + + /* Disable interrupts on sub channel */ + new_sc->inbound.ring_buffer->interrupt_mask = 1; + set_channel_read_mode(new_sc, HV_CALL_ISR); + + ret = sysfs_create_bin_file(&new_sc->kobj, &ring_buffer_bin_attr); + if (ret) { + dev_err(device, "sysfs create ring bin file failed; %d\n", ret); + vmbus_close(new_sc); + } +} + +/* free the reserved buffers for send and receive */ +static void +hv_uio_cleanup(struct hv_device *dev, struct hv_uio_private_data *pdata) +{ + if (pdata->send_gpadl.gpadl_handle) { + vmbus_teardown_gpadl(dev->channel, &pdata->send_gpadl); + vfree(pdata->send_buf); + } + + if (pdata->recv_gpadl.gpadl_handle) { + vmbus_teardown_gpadl(dev->channel, &pdata->recv_gpadl); + vfree(pdata->recv_buf); + } +} + +/* VMBus primary channel is opened on first use */ +static int +hv_uio_open(struct uio_info *info, struct inode *inode) +{ + struct hv_uio_private_data *pdata + = container_of(info, struct hv_uio_private_data, info); + struct hv_device *dev = pdata->device; + int ret; + + if (atomic_inc_return(&pdata->refcnt) != 1) + return 0; + + vmbus_set_chn_rescind_callback(dev->channel, hv_uio_rescind); + vmbus_set_sc_create_callback(dev->channel, hv_uio_new_channel); + + ret = vmbus_connect_ring(dev->channel, + hv_uio_channel_cb, dev->channel); + if (ret == 0) + dev->channel->inbound.ring_buffer->interrupt_mask = 1; + else + atomic_dec(&pdata->refcnt); + + return ret; +} + +/* VMBus primary channel is closed on last close */ +static int +hv_uio_release(struct uio_info *info, struct inode *inode) +{ + struct hv_uio_private_data *pdata + = container_of(info, struct hv_uio_private_data, info); + struct hv_device *dev = pdata->device; + int ret = 0; + + if (atomic_dec_and_test(&pdata->refcnt)) + ret = vmbus_disconnect_ring(dev->channel); + + return ret; +} + +static int +hv_uio_probe(struct hv_device *dev, + const struct hv_vmbus_device_id *dev_id) +{ + struct vmbus_channel *channel = dev->channel; + struct hv_uio_private_data *pdata; + void *ring_buffer; + int ret; + + /* Communicating with host has to be via shared memory not hypercall */ + if (!channel->offermsg.monitor_allocated) { + dev_err(&dev->device, "vmbus channel requires hypercall\n"); + return -ENOTSUPP; + } + + pdata = devm_kzalloc(&dev->device, sizeof(*pdata), GFP_KERNEL); + if (!pdata) + return -ENOMEM; + + ret = vmbus_alloc_ring(channel, HV_RING_SIZE * PAGE_SIZE, + HV_RING_SIZE * PAGE_SIZE); + if (ret) + return ret; + + set_channel_read_mode(channel, HV_CALL_ISR); + + /* Fill general uio info */ + pdata->info.name = "uio_hv_generic"; + pdata->info.version = DRIVER_VERSION; + pdata->info.irqcontrol = hv_uio_irqcontrol; + pdata->info.open = hv_uio_open; + pdata->info.release = hv_uio_release; + pdata->info.irq = UIO_IRQ_CUSTOM; + atomic_set(&pdata->refcnt, 0); + + /* mem resources */ + pdata->info.mem[TXRX_RING_MAP].name = "txrx_rings"; + ring_buffer = page_address(channel->ringbuffer_page); + pdata->info.mem[TXRX_RING_MAP].addr + = (uintptr_t)virt_to_phys(ring_buffer); + pdata->info.mem[TXRX_RING_MAP].size + = channel->ringbuffer_pagecount << PAGE_SHIFT; + pdata->info.mem[TXRX_RING_MAP].memtype = UIO_MEM_IOVA; + + pdata->info.mem[INT_PAGE_MAP].name = "int_page"; + pdata->info.mem[INT_PAGE_MAP].addr + = (uintptr_t)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_page"; + pdata->info.mem[MON_PAGE_MAP].addr + = (uintptr_t)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->recv_buf = vzalloc(RECV_BUFFER_SIZE); + if (pdata->recv_buf == NULL) { + ret = -ENOMEM; + goto fail_free_ring; + } + + ret = vmbus_establish_gpadl(channel, pdata->recv_buf, + RECV_BUFFER_SIZE, &pdata->recv_gpadl); + if (ret) { + vfree(pdata->recv_buf); + goto fail_close; + } + + /* put Global Physical Address Label in name */ + snprintf(pdata->recv_name, sizeof(pdata->recv_name), + "recv:%u", pdata->recv_gpadl.gpadl_handle); + pdata->info.mem[RECV_BUF_MAP].name = pdata->recv_name; + pdata->info.mem[RECV_BUF_MAP].addr + = (uintptr_t)pdata->recv_buf; + pdata->info.mem[RECV_BUF_MAP].size = RECV_BUFFER_SIZE; + pdata->info.mem[RECV_BUF_MAP].memtype = UIO_MEM_VIRTUAL; + + pdata->send_buf = vzalloc(SEND_BUFFER_SIZE); + if (pdata->send_buf == NULL) { + ret = -ENOMEM; + goto fail_close; + } + + ret = vmbus_establish_gpadl(channel, pdata->send_buf, + SEND_BUFFER_SIZE, &pdata->send_gpadl); + if (ret) { + vfree(pdata->send_buf); + goto fail_close; + } + + snprintf(pdata->send_name, sizeof(pdata->send_name), + "send:%u", pdata->send_gpadl.gpadl_handle); + pdata->info.mem[SEND_BUF_MAP].name = pdata->send_name; + pdata->info.mem[SEND_BUF_MAP].addr + = (uintptr_t)pdata->send_buf; + pdata->info.mem[SEND_BUF_MAP].size = SEND_BUFFER_SIZE; + pdata->info.mem[SEND_BUF_MAP].memtype = UIO_MEM_VIRTUAL; + + 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; + } + + ret = sysfs_create_bin_file(&channel->kobj, &ring_buffer_bin_attr); + if (ret) + dev_notice(&dev->device, + "sysfs create ring bin file failed; %d\n", ret); + + hv_set_drvdata(dev, pdata); + + return 0; + +fail_close: + hv_uio_cleanup(dev, pdata); +fail_free_ring: + vmbus_free_ring(dev->channel); + + return ret; +} + +static void +hv_uio_remove(struct hv_device *dev) +{ + struct hv_uio_private_data *pdata = hv_get_drvdata(dev); + + if (!pdata) + return; + + sysfs_remove_bin_file(&dev->channel->kobj, &ring_buffer_bin_attr); + uio_unregister_device(&pdata->info); + hv_uio_cleanup(dev, pdata); + + vmbus_free_ring(dev->channel); +} + +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); 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