path: root/drivers/usb/usbip/vhci_hcd.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) 2003-2008 Takahiro Hirofuchi
 * Copyright (C) 2015-2016 Nobuo Iwata
 */

#include <linux/init.h>
#include <linux/file.h>
#include <linux/kernel.h>
#include <linux/kthread.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>

#include "usbip_common.h"
#include "vhci.h"

#define DRIVER_AUTHOR "Takahiro Hirofuchi"
#define DRIVER_DESC "USB/IP 'Virtual' Host Controller (VHCI) Driver"

/*
 * TODO
 *	- update root hub emulation
 *	- move the emulation code to userland ?
 *		porting to other operating systems
 *		minimize kernel code
 *	- add suspend/resume code
 *	- clean up everything
 */

/* See usb gadget dummy hcd */

static int vhci_hub_status(struct usb_hcd *hcd, char *buff);
static int vhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
			    u16 wIndex, char *buff, u16 wLength);
static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb,
			    gfp_t mem_flags);
static int vhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status);
static int vhci_start(struct usb_hcd *vhci_hcd);
static void vhci_stop(struct usb_hcd *hcd);
static int vhci_get_frame_number(struct usb_hcd *hcd);

static const char driver_name[] = "vhci_hcd";
static const char driver_desc[] = "USB/IP Virtual Host Controller";

int vhci_num_controllers = VHCI_NR_HCS;
struct vhci *vhcis;

static const char * const bit_desc[] = {
	"CONNECTION",		/*0*/
	"ENABLE",		/*1*/
	"SUSPEND",		/*2*/
	"OVER_CURRENT",		/*3*/
	"RESET",		/*4*/
	"L1",			/*5*/
	"R6",			/*6*/
	"R7",			/*7*/
	"POWER",		/*8*/
	"LOWSPEED",		/*9*/
	"HIGHSPEED",		/*10*/
	"PORT_TEST",		/*11*/
	"INDICATOR",		/*12*/
	"R13",			/*13*/
	"R14",			/*14*/
	"R15",			/*15*/
	"C_CONNECTION",		/*16*/
	"C_ENABLE",		/*17*/
	"C_SUSPEND",		/*18*/
	"C_OVER_CURRENT",	/*19*/
	"C_RESET",		/*20*/
	"C_L1",			/*21*/
	"R22",			/*22*/
	"R23",			/*23*/
	"R24",			/*24*/
	"R25",			/*25*/
	"R26",			/*26*/
	"R27",			/*27*/
	"R28",			/*28*/
	"R29",			/*29*/
	"R30",			/*30*/
	"R31",			/*31*/
};

static const char * const bit_desc_ss[] = {
	"CONNECTION",		/*0*/
	"ENABLE",		/*1*/
	"SUSPEND",		/*2*/
	"OVER_CURRENT",		/*3*/
	"RESET",		/*4*/
	"L1",			/*5*/
	"R6",			/*6*/
	"R7",			/*7*/
	"R8",			/*8*/
	"POWER",		/*9*/
	"HIGHSPEED",		/*10*/
	"PORT_TEST",		/*11*/
	"INDICATOR",		/*12*/
	"R13",			/*13*/
	"R14",			/*14*/
	"R15",			/*15*/
	"C_CONNECTION",		/*16*/
	"C_ENABLE",		/*17*/
	"C_SUSPEND",		/*18*/
	"C_OVER_CURRENT",	/*19*/
	"C_RESET",		/*20*/
	"C_BH_RESET",		/*21*/
	"C_LINK_STATE",		/*22*/
	"C_CONFIG_ERROR",	/*23*/
	"R24",			/*24*/
	"R25",			/*25*/
	"R26",			/*26*/
	"R27",			/*27*/
	"R28",			/*28*/
	"R29",			/*29*/
	"R30",			/*30*/
	"R31",			/*31*/
};

static void dump_port_status_diff(u32 prev_status, u32 new_status, bool usb3)
{
	int i = 0;
	u32 bit = 1;
	const char * const *desc = bit_desc;

	if (usb3)
		desc = bit_desc_ss;

	pr_debug("status prev -> new: %08x -> %08x\n", prev_status, new_status);
	while (bit) {
		u32 prev = prev_status & bit;
		u32 new = new_status & bit;
		char change;

		if (!prev && new)
			change = '+';
		else if (prev && !new)
			change = '-';
		else
			change = ' ';

		if (prev || new) {
			pr_debug(" %c%s\n", change, desc[i]);

			if (bit == 1) /* USB_PORT_STAT_CONNECTION */
				pr_debug(" %c%s\n", change, "USB_PORT_STAT_SPEED_5GBPS");
		}
		bit <<= 1;
		i++;
	}
	pr_debug("\n");
}

void rh_port_connect(struct vhci_device *vdev, enum usb_device_speed speed)
{
	struct vhci_hcd	*vhci_hcd = vdev_to_vhci_hcd(vdev);
	struct vhci *vhci = vhci_hcd->vhci;
	int		rhport = vdev->rhport;
	u32		status;
	unsigned long	flags;

	usbip_dbg_vhci_rh("rh_port_connect %d\n", rhport);

	spin_lock_irqsave(&vhci->lock, flags);

	status = vhci_hcd->port_status[rhport];

	status |= USB_PORT_STAT_CONNECTION | (1 << USB_PORT_FEAT_C_CONNECTION);

	switch (speed) {
	case USB_SPEED_HIGH:
		status |= USB_PORT_STAT_HIGH_SPEED;
		break;
	case USB_SPEED_LOW:
		status |= USB_PORT_STAT_LOW_SPEED;
		break;
	default:
		break;
	}

	vhci_hcd->port_status[rhport] = status;

	spin_unlock_irqrestore(&vhci->lock, flags);

	usb_hcd_poll_rh_status(vhci_hcd_to_hcd(vhci_hcd));
}

static void rh_port_disconnect(struct vhci_device *vdev)
{
	struct vhci_hcd	*vhci_hcd = vdev_to_vhci_hcd(vdev);
	struct vhci *vhci = vhci_hcd->vhci;
	int		rhport = vdev->rhport;
	u32		status;
	unsigned long	flags;

	usbip_dbg_vhci_rh("rh_port_disconnect %d\n", rhport);

	spin_lock_irqsave(&vhci->lock, flags);

	status = vhci_hcd->port_status[rhport];

	status &= ~USB_PORT_STAT_CONNECTION;
	status |= (1 << USB_PORT_FEAT_C_CONNECTION);

	vhci_hcd->port_status[rhport] = status;

	spin_unlock_irqrestore(&vhci->lock, flags);
	usb_hcd_poll_rh_status(vhci_hcd_to_hcd(vhci_hcd));
}

#define PORT_C_MASK				\
	((USB_PORT_STAT_C_CONNECTION		\
	  | USB_PORT_STAT_C_ENABLE		\
	  | USB_PORT_STAT_C_SUSPEND		\
	  | USB_PORT_STAT_C_OVERCURRENT		\
	  | USB_PORT_STAT_C_RESET) << 16)

/*
 * Returns 0 if the status hasn't changed, or the number of bytes in buf.
 * Ports are 0-indexed from the HCD point of view,
 * and 1-indexed from the USB core pointer of view.
 *
 * @buf: a bitmap to show which port status has been changed.
 *  bit  0: reserved
 *  bit  1: the status of port 0 has been changed.
 *  bit  2: the status of port 1 has been changed.
 *  ...
 */
static int vhci_hub_status(struct usb_hcd *hcd, char *buf)
{
	struct vhci_hcd	*vhci_hcd = hcd_to_vhci_hcd(hcd);
	struct vhci *vhci = vhci_hcd->vhci;
	int		retval = DIV_ROUND_UP(VHCI_HC_PORTS + 1, 8);
	int		rhport;
	int		changed = 0;
	unsigned long	flags;

	memset(buf, 0, retval);

	spin_lock_irqsave(&vhci->lock, flags);
	if (!HCD_HW_ACCESSIBLE(hcd)) {
		usbip_dbg_vhci_rh("hw accessible flag not on?\n");
		goto done;
	}

	/* check pseudo status register for each port */
	for (rhport = 0; rhport < VHCI_HC_PORTS; rhport++) {
		if ((vhci_hcd->port_status[rhport] & PORT_C_MASK)) {
			/* The status of a port has been changed, */
			usbip_dbg_vhci_rh("port %d status changed\n", rhport);

			buf[(rhport + 1) / 8] |= 1 << (rhport + 1) % 8;
			changed = 1;
		}
	}

	if ((hcd->state == HC_STATE_SUSPENDED) && (changed == 1))
		usb_hcd_resume_root_hub(hcd);

done:
	spin_unlock_irqrestore(&vhci->lock, flags);
	return changed ? retval : 0;
}

/* usb 3.0 root hub device descriptor */
static struct {
	struct usb_bos_descriptor bos;
	struct usb_ss_cap_descriptor ss_cap;
} __packed usb3_bos_desc = {

	.bos = {
		.bLength		= USB_DT_BOS_SIZE,
		.bDescriptorType	= USB_DT_BOS,
		.wTotalLength		= cpu_to_le16(sizeof(usb3_bos_desc)),
		.bNumDeviceCaps		= 1,
	},
	.ss_cap = {
		.bLength		= USB_DT_USB_SS_CAP_SIZE,
		.bDescriptorType	= USB_DT_DEVICE_CAPABILITY,
		.bDevCapabilityType	= USB_SS_CAP_TYPE,
		.wSpeedSupported	= cpu_to_le16(USB_5GBPS_OPERATION),
		.bFunctionalitySupport	= ilog2(USB_5GBPS_OPERATION),
	},
};

static inline void
ss_hub_descriptor(struct usb_hub_descriptor *desc)
{
	memset(desc, 0, sizeof *desc);
	desc->bDescriptorType = USB_DT_SS_HUB;
	desc->bDescLength = 12;
	desc->wHubCharacteristics = cpu_to_le16(
		HUB_CHAR_INDV_PORT_LPSM | HUB_CHAR_COMMON_OCPM);
	desc->bNbrPorts = VHCI_HC_PORTS;
	desc->u.ss.bHubHdrDecLat = 0x04; /* Worst case: 0.4 micro sec*/
	desc->u.ss.DeviceRemovable = 0xffff;
}

static inline void hub_descriptor(struct usb_hub_descriptor *desc)
{
	int width;

	memset(desc, 0, sizeof(*desc));
	desc->bDescriptorType = USB_DT_HUB;
	desc->wHubCharacteristics = cpu_to_le16(
		HUB_CHAR_INDV_PORT_LPSM | HUB_CHAR_COMMON_OCPM);

	desc->bNbrPorts = VHCI_HC_PORTS;
	BUILD_BUG_ON(VHCI_HC_PORTS > USB_MAXCHILDREN);
	width = desc->bNbrPorts / 8 + 1;
	desc->bDescLength = USB_DT_HUB_NONVAR_SIZE + 2 * width;
	memset(&desc->u.hs.DeviceRemovable[0], 0, width);
	memset(&