misc: mic: Add data structures for the VOP driver

This patch adds VOP driver data structures used in subsequent
patches. These data structures are refactored from similar data
structures used in the virtio parts of previous MIC host and card
drivers.
Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Signed-off-by: Sudeep Dutt <sudeep.dutt@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/misc/mic/vop/vop_main.h

+/*
+ * Intel MIC Platform Software Stack (MPSS)
+ *
+ * Copyright(c) 2016 Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * The full GNU General Public License is included in this distribution in
+ * the file called "COPYING".
+ *
+ * Intel Virtio Over PCIe (VOP) driver.
+ *
+ */
+#ifndef _VOP_MAIN_H_
+#define _VOP_MAIN_H_
+
+#include <linux/vringh.h>
+#include <linux/virtio_config.h>
+#include <linux/virtio.h>
+#include <linux/miscdevice.h>
+
+#include <linux/mic_common.h>
+#include "../common/mic_dev.h"
+
+#include "../bus/vop_bus.h"
+
+/*
+ * Note on endianness.
+ * 1. Host can be both BE or LE
+ * 2. Guest/card is LE. Host uses le_to_cpu to access desc/avail
+ *    rings and ioreadXX/iowriteXX to access used ring.
+ * 3. Device page exposed by host to guest contains LE values. Guest
+ *    accesses these using ioreadXX/iowriteXX etc. This way in general we
+ *    obey the virtio spec according to which guest works with native
+ *    endianness and host is aware of guest endianness and does all
+ *    required endianness conversion.
+ * 4. Data provided from user space to guest (in ADD_DEVICE and
+ *    CONFIG_CHANGE ioctl's) is not interpreted by the driver and should be
+ *    in guest endianness.
+ */
+
+/*
+ * vop_info - Allocated per invocation of VOP probe
+ *
+ * @vpdev: VOP device
+ * @hotplug_work: Handle virtio device creation, deletion and configuration
+ * @cookie: Cookie received upon requesting a virtio configuration interrupt
+ * @h2c_config_db: The doorbell used by the peer to indicate a config change
+ * @vdev_list: List of "active" virtio devices injected in the peer node
+ * @vop_mutex: Synchronize access to the device page as well as serialize
+ *             creation/deletion of virtio devices on the peer node
+ * @dp: Peer device page information
+ * @dbg: Debugfs entry
+ * @dma_ch: The DMA channel used by this transport for data transfers.
+ * @name: Name for this transport used in misc device creation.
+ * @miscdev: The misc device registered.
+ */
+struct vop_info {
+	struct vop_device *vpdev;
+	struct work_struct hotplug_work;
+	struct mic_irq *cookie;
+	int h2c_config_db;
+	struct list_head vdev_list;
+	struct mutex vop_mutex;
+	void __iomem *dp;
+	struct dentry *dbg;
+	struct dma_chan *dma_ch;
+	char name[16];
+	struct miscdevice miscdev;
+};
+
+/**
+ * struct vop_vringh - Virtio ring host information.
+ *
+ * @vring: The VOP vring used for setting up user space mappings.
+ * @vrh: The host VRINGH used for accessing the card vrings.
+ * @riov: The VRINGH read kernel IOV.
+ * @wiov: The VRINGH write kernel IOV.
+ * @head: The VRINGH head index address passed to vringh_getdesc_kern(..).
+ * @vr_mutex: Mutex for synchronizing access to the VRING.
+ * @buf: Temporary kernel buffer used to copy in/out data
+ * from/to the card via DMA.
+ * @buf_da: dma address of buf.
+ * @vdev: Back pointer to VOP virtio device for vringh_notify(..).
+ */
+struct vop_vringh {
+	struct mic_vring vring;
+	struct vringh vrh;
+	struct vringh_kiov riov;
+	struct vringh_kiov wiov;
+	u16 head;
+	struct mutex vr_mutex;
+	void *buf;
+	dma_addr_t buf_da;
+	struct vop_vdev *vdev;
+};
+
+/**
+ * struct vop_vdev - Host information for a card Virtio device.
+ *
+ * @virtio_id - Virtio device id.
+ * @waitq - Waitqueue to allow ring3 apps to poll.
+ * @vpdev - pointer to VOP bus device.
+ * @poll_wake - Used for waking up threads blocked in poll.
+ * @out_bytes - Debug stats for number of bytes copied from host to card.
+ * @in_bytes - Debug stats for number of bytes copied from card to host.
+ * @out_bytes_dma - Debug stats for number of bytes copied from host to card
+ * using DMA.
+ * @in_bytes_dma - Debug stats for number of bytes copied from card to host
+ * using DMA.
+ * @tx_len_unaligned - Debug stats for number of bytes copied to the card where
+ * the transfer length did not have the required DMA alignment.
+ * @tx_dst_unaligned - Debug stats for number of bytes copied where the
+ * destination address on the card did not have the required DMA alignment.
+ * @vvr - Store per VRING data structures.
+ * @virtio_bh_work - Work struct used to schedule virtio bottom half handling.
+ * @dd - Virtio device descriptor.
+ * @dc - Virtio device control fields.
+ * @list - List of Virtio devices.
+ * @virtio_db - The doorbell used by the card to interrupt the host.
+ * @virtio_cookie - The cookie returned while requesting interrupts.
+ * @vi: Transport information.
+ * @vdev_mutex: Mutex synchronizing virtio device injection,
+ *              removal and data transfers.
+ * @destroy: Track if a virtio device is being destroyed.
+ * @deleted: The virtio device has been deleted.
+ */
+struct vop_vdev {
+	int virtio_id;
+	wait_queue_head_t waitq;
+	struct vop_device *vpdev;
+	int poll_wake;
+	unsigned long out_bytes;
+	unsigned long in_bytes;
+	unsigned long out_bytes_dma;
+	unsigned long in_bytes_dma;
+	unsigned long tx_len_unaligned;
+	unsigned long tx_dst_unaligned;
+	unsigned long rx_dst_unaligned;
+	struct vop_vringh vvr[MIC_MAX_VRINGS];
+	struct work_struct virtio_bh_work;
+	struct mic_device_desc *dd;
+	struct mic_device_ctrl *dc;
+	struct list_head list;
+	int virtio_db;
+	struct mic_irq *virtio_cookie;
+	struct vop_info *vi;
+	struct mutex vdev_mutex;
+	struct completion destroy;
+	bool deleted;
+};
+
+/* Helper API to check if a virtio device is running */
+static inline bool vop_vdevup(struct vop_vdev *vdev)
+{
+	return !!vdev->dd->status;
+}
+
+void vop_init_debugfs(struct vop_info *vi);
+void vop_exit_debugfs(struct vop_info *vi);
+int vop_host_init(struct vop_info *vi);
+void vop_host_uninit(struct vop_info *vi);
+#endif