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-rw-r--r--drivers/uio/uio_hv_generic.c398
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);