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OpenCloudOS-Kernel/drivers/uio/uio_hv_generic.c

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/*
* 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:
*
* 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 "0.02.0"
#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 (15 * 1024 * 1024)
#define RECV_BUFFER_SIZE (15 * 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;
void *recv_buf;
u32 recv_gpadl;
char recv_name[32]; /* "recv_4294967295" */
void *send_buf;
u32 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 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);
}
/*
* 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);
}
/*
* Handle fault when looking for sub channel ring buffer
* Subchannel ring buffer is same as resource 0 which is main ring buffer
* This is derived from uio_vma_fault
*/
static int hv_uio_vma_fault(struct vm_fault *vmf)
{
struct vm_area_struct *vma = vmf->vma;
void *ring_buffer = vma->vm_private_data;
struct page *page;
void *addr;
addr = ring_buffer + (vmf->pgoff << PAGE_SHIFT);
page = virt_to_page(addr);
get_page(page);
vmf->page = page;
return 0;
}
static const struct vm_operations_struct hv_uio_vm_ops = {
.fault = hv_uio_vma_fault,
};
/* Sysfs API to allow mmap of the ring buffers */
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);
unsigned long requested_pages, actual_pages;
if (vma->vm_end < vma->vm_start)
return -EINVAL;
/* only allow 0 for now */
if (vma->vm_pgoff > 0)
return -EINVAL;
requested_pages = vma_pages(vma);
actual_pages = 2 * HV_RING_SIZE;
if (requested_pages > actual_pages)
return -EINVAL;
vma->vm_private_data = channel->ringbuffer_pages;
vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
vma->vm_ops = &hv_uio_vm_ops;
return 0;
}
static struct bin_attribute ring_buffer_bin_attr __ro_after_init = {
.attr = {
.name = "ring",
.mode = 0600,
/* size is set at init time */
},
.mmap = hv_uio_ring_mmap,
};
/* Callback from VMBUS subystem 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;
struct hv_uio_private_data *pdata = hv_get_drvdata(hv_dev);
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, pdata);
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);
}
}
static void
hv_uio_cleanup(struct hv_device *dev, struct hv_uio_private_data *pdata)
{
if (pdata->send_gpadl)
vmbus_teardown_gpadl(dev->channel, pdata->send_gpadl);
vfree(pdata->send_buf);
if (pdata->recv_gpadl)
vmbus_teardown_gpadl(dev->channel, pdata->recv_gpadl);
vfree(pdata->recv_buf);
}
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;
/* Communicating with host has to be via shared memory not hypercall */
if (!dev->channel->offermsg.monitor_allocated) {
dev_err(&dev->device, "vmbus channel requires hypercall\n");
ret = -ENOTSUPP;
goto fail_close;
}
dev->channel->inbound.ring_buffer->interrupt_mask = 1;
set_channel_read_mode(dev->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.irq = UIO_IRQ_CUSTOM;
/* mem resources */
pdata->info.mem[TXRX_RING_MAP].name = "txrx_rings";
pdata->info.mem[TXRX_RING_MAP].addr
= (uintptr_t)dev->channel->ringbuffer_pages;
pdata->info.mem[TXRX_RING_MAP].size
= dev->channel->ringbuffer_pagecount << PAGE_SHIFT;
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
= (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_close;
}
ret = vmbus_establish_gpadl(dev->channel, pdata->recv_buf,
RECV_BUFFER_SIZE, &pdata->recv_gpadl);
if (ret)
goto fail_close;
/* put Global Physical Address Label in name */
snprintf(pdata->recv_name, sizeof(pdata->recv_name),
"recv:%u", pdata->recv_gpadl);
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(dev->channel, pdata->send_buf,
SEND_BUFFER_SIZE, &pdata->send_gpadl);
if (ret)
goto fail_close;
snprintf(pdata->send_name, sizeof(pdata->send_name),
"send:%u", pdata->send_gpadl);
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;
}
vmbus_set_chn_rescind_callback(dev->channel, hv_uio_rescind);
vmbus_set_sc_create_callback(dev->channel, hv_uio_new_channel);
hv_set_drvdata(dev, pdata);
return 0;
fail_close:
hv_uio_cleanup(dev, pdata);
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_uio_cleanup(dev, pdata);
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);
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