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linux/drivers/uio/uio_hv_generic.c
Stephen Hemminger ce3d1536ac uio_hv_generic: fix subchannel ring mmap 
The fault method of handling subchannel ring, did not work correctly
(it only worked for the first page).

Since ring buffer is physically contiguous, using the vm helper
function is simpler and handles more cases.

Fixes: 37b96a4931 ("uio_hv_generic: support sub-channels")
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-23 12:43:48 +02:00

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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 DEBUG 1
#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 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);
struct hv_device *dev = channel->primary_channel->device_obj;
u16 q_idx = channel->offermsg.offer.sub_channel_index;
dev_dbg(&dev->device, "mmap channel %u pages %#lx at %#lx\n",
q_idx, vma_pages(vma), vma->vm_pgoff);
return vm_iomap_memory(vma, virt_to_phys(channel->ringbuffer_pages),
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);
}
}
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, dev->channel);
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);
ret = sysfs_create_bin_file(&dev->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);
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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