USB: xhci: Support xHCI host controllers and USB 3.0 devices.

This is the first of many patches to add support for USB 3.0 devices and
the hardware that implements the eXtensible Host Controller Interface
(xHCI) 0.95 specification.  This specification is not yet publicly
available, but companies can receive a copy by becoming an xHCI
Contributor (see http://www.intel.com/technology/usb/xhcispec.htm).

No xHCI hardware has made it onto the market yet, but these patches have
been tested under the Fresco Logic host controller prototype.

This patch adds the xHCI register sets, which are grouped into five sets:
 - Generic PCI registers
 - Host controller "capabilities" registers (cap_regs) short
 - Host controller "operational" registers (op_regs)
 - Host controller "runtime" registers (run_regs)
 - Host controller "doorbell" registers

These some of these registers may be virtualized if the Linux driver is
running under a VM.  Virtualization has not been tested for this patch.

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/host/xhci-dbg.c

@@ -0,0 +1,229 @@
+/*
+ * xHCI host controller driver
+ *
+ * Copyright (C) 2008 Intel Corp.
+ *
+ * Author: Sarah Sharp
+ * Some code borrowed from the Linux EHCI driver.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include "xhci.h"
+
+#define XHCI_INIT_VALUE 0x0
+
+/* Add verbose debugging later, just print everything for now */
+
+void xhci_dbg_regs(struct xhci_hcd *xhci)
+{
+	u32 temp;
+
+	xhci_dbg(xhci, "// xHCI capability registers at 0x%x:\n",
+			(unsigned int) xhci->cap_regs);
+	temp = xhci_readl(xhci, &xhci->cap_regs->hc_capbase);
+	xhci_dbg(xhci, "// @%x = 0x%x (CAPLENGTH AND HCIVERSION)\n",
+			(unsigned int) &xhci->cap_regs->hc_capbase,
+			(unsigned int) temp);
+	xhci_dbg(xhci, "//   CAPLENGTH: 0x%x\n",
+			(unsigned int) HC_LENGTH(temp));
+#if 0
+	xhci_dbg(xhci, "//   HCIVERSION: 0x%x\n",
+			(unsigned int) HC_VERSION(temp));
+#endif
+
+	xhci_dbg(xhci, "// xHCI operational registers at 0x%x:\n",
+			(unsigned int) xhci->op_regs);
+
+	temp = xhci_readl(xhci, &xhci->cap_regs->run_regs_off);
+	xhci_dbg(xhci, "// @%x = 0x%x RTSOFF\n",
+			(unsigned int) &xhci->cap_regs->run_regs_off,
+			(unsigned int) temp & RTSOFF_MASK);
+	xhci_dbg(xhci, "// xHCI runtime registers at 0x%x:\n",
+			(unsigned int) xhci->run_regs);
+
+	temp = xhci_readl(xhci, &xhci->cap_regs->db_off);
+	xhci_dbg(xhci, "// @%x = 0x%x DBOFF\n",
+			(unsigned int) &xhci->cap_regs->db_off, temp);
+}
+
+void xhci_print_cap_regs(struct xhci_hcd *xhci)
+{
+	u32 temp;
+
+	xhci_dbg(xhci, "xHCI capability registers at 0x%x:\n",
+			(unsigned int) xhci->cap_regs);
+
+	temp = xhci_readl(xhci, &xhci->cap_regs->hc_capbase);
+	xhci_dbg(xhci, "CAPLENGTH AND HCIVERSION 0x%x:\n",
+			(unsigned int) temp);
+	xhci_dbg(xhci, "CAPLENGTH: 0x%x\n",
+			(unsigned int) HC_LENGTH(temp));
+	xhci_dbg(xhci, "HCIVERSION: 0x%x\n",
+			(unsigned int) HC_VERSION(temp));
+
+	temp = xhci_readl(xhci, &xhci->cap_regs->hcs_params1);
+	xhci_dbg(xhci, "HCSPARAMS 1: 0x%x\n",
+			(unsigned int) temp);
+	xhci_dbg(xhci, "  Max device slots: %u\n",
+			(unsigned int) HCS_MAX_SLOTS(temp));
+	xhci_dbg(xhci, "  Max interrupters: %u\n",
+			(unsigned int) HCS_MAX_INTRS(temp));
+	xhci_dbg(xhci, "  Max ports: %u\n",
+			(unsigned int) HCS_MAX_PORTS(temp));
+
+	temp = xhci_readl(xhci, &xhci->cap_regs->hcs_params2);
+	xhci_dbg(xhci, "HCSPARAMS 2: 0x%x\n",
+			(unsigned int) temp);
+	xhci_dbg(xhci, "  Isoc scheduling threshold: %u\n",
+			(unsigned int) HCS_IST(temp));
+	xhci_dbg(xhci, "  Maximum allowed segments in event ring: %u\n",
+			(unsigned int) HCS_ERST_MAX(temp));
+
+	temp = xhci_readl(xhci, &xhci->cap_regs->hcs_params3);
+	xhci_dbg(xhci, "HCSPARAMS 3 0x%x:\n",
+			(unsigned int) temp);
+	xhci_dbg(xhci, "  Worst case U1 device exit latency: %u\n",
+			(unsigned int) HCS_U1_LATENCY(temp));
+	xhci_dbg(xhci, "  Worst case U2 device exit latency: %u\n",
+			(unsigned int) HCS_U2_LATENCY(temp));
+
+	temp = xhci_readl(xhci, &xhci->cap_regs->hcc_params);
+	xhci_dbg(xhci, "HCC PARAMS 0x%x:\n", (unsigned int) temp);
+	xhci_dbg(xhci, "  HC generates %s bit addresses\n",
+			HCC_64BIT_ADDR(temp) ? "64" : "32");
+	/* FIXME */
+	xhci_dbg(xhci, "  FIXME: more HCCPARAMS debugging\n");
+
+	temp = xhci_readl(xhci, &xhci->cap_regs->run_regs_off);
+	xhci_dbg(xhci, "RTSOFF 0x%x:\n", temp & RTSOFF_MASK);
+}
+
+void xhci_print_command_reg(struct xhci_hcd *xhci)
+{
+	u32 temp;
+
+	temp = xhci_readl(xhci, &xhci->op_regs->command);
+	xhci_dbg(xhci, "USBCMD 0x%x:\n", temp);
+	xhci_dbg(xhci, "  HC is %s\n",
+			(temp & CMD_RUN) ? "running" : "being stopped");
+	xhci_dbg(xhci, "  HC has %sfinished hard reset\n",
+			(temp & CMD_RESET) ? "not " : "");
+	xhci_dbg(xhci, "  Event Interrupts %s\n",
+			(temp & CMD_EIE) ? "enabled " : "disabled");
+	xhci_dbg(xhci, "  Host System Error Interrupts %s\n",
+			(temp & CMD_EIE) ? "enabled " : "disabled");
+	xhci_dbg(xhci, "  HC has %sfinished light reset\n",
+			(temp & CMD_LRESET) ? "not " : "");
+}
+
+void xhci_print_status(struct xhci_hcd *xhci)
+{
+	u32 temp;
+
+	temp = xhci_readl(xhci, &xhci->op_regs->status);
+	xhci_dbg(xhci, "USBSTS 0x%x:\n", temp);
+	xhci_dbg(xhci, "  Event ring is %sempty\n",
+			(temp & STS_EINT) ? "not " : "");
+	xhci_dbg(xhci, "  %sHost System Error\n",
+			(temp & STS_FATAL) ? "WARNING: " : "No ");
+	xhci_dbg(xhci, "  HC is %s\n",
+			(temp & STS_HALT) ? "halted" : "running");
+}
+
+void xhci_print_op_regs(struct xhci_hcd *xhci)
+{
+	xhci_dbg(xhci, "xHCI operational registers at 0x%x:\n",
+			(unsigned int) xhci->op_regs);
+	xhci_print_command_reg(xhci);
+	xhci_print_status(xhci);
+}
+
+void xhci_print_ir_set(struct xhci_hcd *xhci, struct intr_reg *ir_set, int set_num)
+{
+	void *addr;
+	u32 temp;
+
+	addr = &ir_set->irq_pending;
+	temp = xhci_readl(xhci, addr);
+	if (temp == XHCI_INIT_VALUE)
+		return;
+
+	xhci_dbg(xhci, "  0x%x: ir_set[%i]\n", (unsigned int) ir_set, set_num);
+
+	xhci_dbg(xhci, "  0x%x: ir_set.pending = 0x%x\n",
+			(unsigned int) addr, (unsigned int) temp);
+
+	addr = &ir_set->irq_control;
+	temp = xhci_readl(xhci, addr);
+	xhci_dbg(xhci, "  0x%x: ir_set.control = 0x%x\n",
+			(unsigned int) addr, (unsigned int) temp);
+
+	addr = &ir_set->erst_size;
+	temp = xhci_readl(xhci, addr);
+	xhci_dbg(xhci, "  0x%x: ir_set.erst_size = 0x%x\n",
+			(unsigned int) addr, (unsigned int) temp);
+
+	addr = &ir_set->rsvd;
+	temp = xhci_readl(xhci, addr);
+	if (temp != XHCI_INIT_VALUE)
+		xhci_dbg(xhci, "  WARN: 0x%x: ir_set.rsvd = 0x%x\n",
+				(unsigned int) addr, (unsigned int) temp);
+
+	addr = &ir_set->erst_base[0];
+	temp = xhci_readl(xhci, addr);
+	xhci_dbg(xhci, "  0x%x: ir_set.erst_base[0] = 0x%x\n",
+			(unsigned int) addr, (unsigned int) temp);
+
+	addr = &ir_set->erst_base[1];
+	temp = xhci_readl(xhci, addr);
+	xhci_dbg(xhci, "  0x%x: ir_set.erst_base[1] = 0x%x\n",
+			(unsigned int) addr, (unsigned int) temp);
+
+	addr = &ir_set->erst_dequeue[0];
+	temp = xhci_readl(xhci, addr);
+	xhci_dbg(xhci, "  0x%x: ir_set.erst_dequeue[0] = 0x%x\n",
+			(unsigned int) addr, (unsigned int) temp);
+
+	addr = &ir_set->erst_dequeue[1];
+	temp = xhci_readl(xhci, addr);
+	xhci_dbg(xhci, "  0x%x: ir_set.erst_dequeue[1] = 0x%x\n",
+			(unsigned int) addr, (unsigned int) temp);
+}
+
+void xhci_print_run_regs(struct xhci_hcd *xhci)
+{
+	u32 temp;
+	int i;
+
+	xhci_dbg(xhci, "xHCI runtime registers at 0x%x:\n",
+			(unsigned int) xhci->run_regs);
+	temp = xhci_readl(xhci, &xhci->run_regs->microframe_index);
+	xhci_dbg(xhci, "  0x%x: Microframe index = 0x%x\n",
+			(unsigned int) &xhci->run_regs->microframe_index,
+			(unsigned int) temp);
+	for (i = 0; i < 7; ++i) {
+		temp = xhci_readl(xhci, &xhci->run_regs->rsvd[i]);
+		if (temp != XHCI_INIT_VALUE)
+			xhci_dbg(xhci, "  WARN: 0x%x: Rsvd[%i] = 0x%x\n",
+					(unsigned int) &xhci->run_regs->rsvd[i],
+					i, (unsigned int) temp);
+	}
+}
+
+void xhci_print_registers(struct xhci_hcd *xhci)
+{
+	xhci_print_cap_regs(xhci);
+	xhci_print_op_regs(xhci);
+}

drivers/usb/host/xhci-ext-caps.h

@@ -0,0 +1,145 @@
+/*
+ * xHCI host controller driver
+ *
+ * Copyright (C) 2008 Intel Corp.
+ *
+ * Author: Sarah Sharp
+ * Some code borrowed from the Linux EHCI driver.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+/* Up to 16 microframes to halt an HC - one microframe is 125 microsectonds */
+#define XHCI_MAX_HALT_USEC	(16*125)
+/* HC not running - set to 1 when run/stop bit is cleared. */
+#define XHCI_STS_HALT		(1<<0)
+
+/* HCCPARAMS offset from PCI base address */
+#define XHCI_HCC_PARAMS_OFFSET	0x10
+/* HCCPARAMS contains the first extended capability pointer */
+#define XHCI_HCC_EXT_CAPS(p)	(((p)>>16)&0xffff)
+
+/* Command and Status registers offset from the Operational Registers address */
+#define XHCI_CMD_OFFSET		0x00
+#define XHCI_STS_OFFSET		0x04
+
+#define XHCI_MAX_EXT_CAPS		50
+
+/* Capability Register */
+/* bits 7:0 - how long is the Capabilities register */
+#define XHCI_HC_LENGTH(p)	(((p)>>00)&0x00ff)
+
+/* Extended capability register fields */
+#define XHCI_EXT_CAPS_ID(p)	(((p)>>0)&0xff)
+#define XHCI_EXT_CAPS_NEXT(p)	(((p)>>8)&0xff)
+#define	XHCI_EXT_CAPS_VAL(p)	((p)>>16)
+/* Extended capability IDs - ID 0 reserved */
+#define XHCI_EXT_CAPS_LEGACY	1
+#define XHCI_EXT_CAPS_PROTOCOL	2
+#define XHCI_EXT_CAPS_PM	3
+#define XHCI_EXT_CAPS_VIRT	4
+#define XHCI_EXT_CAPS_ROUTE	5
+/* IDs 6-9 reserved */
+#define XHCI_EXT_CAPS_DEBUG	10
+/* USB Legacy Support Capability - section 7.1.1 */
+#define XHCI_HC_BIOS_OWNED	(1 << 16)
+#define XHCI_HC_OS_OWNED	(1 << 24)
+
+/* USB Legacy Support Capability - section 7.1.1 */
+/* Add this offset, plus the value of xECP in HCCPARAMS to the base address */
+#define XHCI_LEGACY_SUPPORT_OFFSET	(0x00)
+
+/* USB Legacy Support Control and Status Register  - section 7.1.2 */
+/* Add this offset, plus the value of xECP in HCCPARAMS to the base address */
+#define XHCI_LEGACY_CONTROL_OFFSET	(0x04)
+/* bits 1:2, 5:12, and 17:19 need to be preserved; bits 21:28 should be zero */
+#define	XHCI_LEGACY_DISABLE_SMI		((0x3 << 1) + (0xff << 5) + (0x7 << 17))
+
+/* command register values to disable interrupts and halt the HC */
+/* start/stop HC execution - do not write unless HC is halted*/
+#define XHCI_CMD_RUN		(1 << 0)
+/* Event Interrupt Enable - get irq when EINT bit is set in USBSTS register */
+#define XHCI_CMD_EIE		(1 << 2)
+/* Host System Error Interrupt Enable - get irq when HSEIE bit set in USBSTS */
+#define XHCI_CMD_HSEIE		(1 << 3)
+/* Enable Wrap Event - '1' means xHC generates an event when MFINDEX wraps. */
+#define XHCI_CMD_EWE		(1 << 10)
+
+#define XHCI_IRQS		(XHCI_CMD_EIE | XHCI_CMD_HSEIE | XHCI_CMD_EWE)
+
+/* true: Controller Not Ready to accept doorbell or op reg writes after reset */
+#define XHCI_STS_CNR		(1 << 11)
+
+#include <linux/io.h>
+
+/**
+ * Return the next extended capability pointer register.
+ *
+ * @base	PCI register base address.
+ *
+ * @ext_offset	Offset of the 32-bit register that contains the extended
+ * capabilites pointer.  If searching for the first extended capability, pass
+ * in XHCI_HCC_PARAMS_OFFSET.  If searching for the next extended capability,
+ * pass in the offset of the current extended capability register.
+ *
+ * Returns 0 if there is no next extended capability register or returns the register offset
+ * from the PCI registers base address.
+ */
+static inline int xhci_find_next_cap_offset(void __iomem *base, int ext_offset)
+{
+	u32 next;
+
+	next = readl(base + ext_offset);
+
+	if (ext_offset == XHCI_HCC_PARAMS_OFFSET)
+		/* Find the first extended capability */
+		next = XHCI_HCC_EXT_CAPS(next);
+	else
+		/* Find the next extended capability */
+		next = XHCI_EXT_CAPS_NEXT(next);
+	if (!next)
+		return 0;
+	/*
+	 * Address calculation from offset of extended capabilities
+	 * (or HCCPARAMS) register - see section 5.3.6 and section 7.
+	 */
+	return ext_offset + (next << 2);
+}
+
+/**
+ * Find the offset of the extended capabilities with capability ID id.
+ *
+ * @base PCI MMIO registers base address.
+ * @ext_offset Offset from base of the first extended capability to look at,
+ * 		or the address of HCCPARAMS.
+ * @id Extended capability ID to search for.
+ *
+ * This uses an arbitrary limit of XHCI_MAX_EXT_CAPS extended capabilities
+ * to make sure that the list doesn't contain a loop.
+ */
+static inline int xhci_find_ext_cap_by_id(void __iomem *base, int ext_offset, int id)
+{
+	u32 val;
+	int limit = XHCI_MAX_EXT_CAPS;
+
+	while (ext_offset && limit > 0) {
+		val = readl(base + ext_offset);
+		if (XHCI_EXT_CAPS_ID(val) == id)
+			break;
+		ext_offset = xhci_find_next_cap_offset(base, ext_offset);
+		limit--;
+	}
+	if (limit > 0)
+		return ext_offset;
+	return 0;
+}

drivers/usb/host/xhci.h

@@ -0,0 +1,452 @@
+/*
+ * xHCI host controller driver
+ *
+ * Copyright (C) 2008 Intel Corp.
+ *
+ * Author: Sarah Sharp
+ * Some code borrowed from the Linux EHCI driver.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#ifndef __LINUX_XHCI_HCD_H
+#define __LINUX_XHCI_HCD_H
+
+#include <linux/usb.h>
+
+#include "../core/hcd.h"
+/* Code sharing between pci-quirks and xhci hcd */
+#include	"xhci-ext-caps.h"
+
+/* xHCI PCI Configuration Registers */
+#define XHCI_SBRN_OFFSET	(0x60)
+
+/*
+ * xHCI register interface.
+ * This corresponds to the eXtensible Host Controller Interface (xHCI)
+ * Revision 0.95 specification
+ *
+ * Registers should always be accessed with double word or quad word accesses.
+ *
+ * Some xHCI implementations may support 64-bit address pointers.  Registers
+ * with 64-bit address pointers should be written to with dword accesses by
+ * writing the low dword first (ptr[0]), then the high dword (ptr[1]) second.
+ * xHCI implementations that do not support 64-bit address pointers will ignore
+ * the high dword, and write order is irrelevant.
+ */
+
+/**
+ * struct xhci_cap_regs - xHCI Host Controller Capability Registers.
+ * @hc_capbase:		length of the capabilities register and HC version number
+ * @hcs_params1:	HCSPARAMS1 - Structural Parameters 1
+ * @hcs_params2:	HCSPARAMS2 - Structural Parameters 2
+ * @hcs_params3:	HCSPARAMS3 - Structural Parameters 3
+ * @hcc_params:		HCCPARAMS - Capability Parameters
+ * @db_off:		DBOFF - Doorbell array offset
+ * @run_regs_off:	RTSOFF - Runtime register space offset
+ */
+struct xhci_cap_regs {
+	u32	hc_capbase;
+	u32	hcs_params1;
+	u32	hcs_params2;
+	u32	hcs_params3;
+	u32	hcc_params;
+	u32	db_off;
+	u32	run_regs_off;
+	/* Reserved up to (CAPLENGTH - 0x1C) */
+} __attribute__ ((packed));
+
+/* hc_capbase bitmasks */
+/* bits 7:0 - how long is the Capabilities register */
+#define HC_LENGTH(p)		XHCI_HC_LENGTH(p)
+/* bits 31:16	*/
+#define HC_VERSION(p)		(((p) >> 16) & 0xffff)
+
+/* HCSPARAMS1 - hcs_params1 - bitmasks */
+/* bits 0:7, Max Device Slots */
+#define HCS_MAX_SLOTS(p)	(((p) >> 0) & 0xff)
+#define HCS_SLOTS_MASK		0xff
+/* bits 8:18, Max Interrupters */
+#define HCS_MAX_INTRS(p)	(((p) >> 8) & 0x7ff)
+/* bits 24:31, Max Ports - max value is 0x7F = 127 ports */
+#define HCS_MAX_PORTS(p)	(((p) >> 24) & 0x7f)
+
+/* HCSPARAMS2 - hcs_params2 - bitmasks */
+/* bits 0:3, frames or uframes that SW needs to queue transactions
+ * ahead of the HW to meet periodic deadlines */
+#define HCS_IST(p)		(((p) >> 0) & 0xf)
+/* bits 4:7, max number of Event Ring segments */
+#define HCS_ERST_MAX(p)		(((p) >> 4) & 0xf)
+/* bit 26 Scratchpad restore - for save/restore HW state - not used yet */
+/* bits 27:31 number of Scratchpad buffers SW must allocate for the HW */
+
+/* HCSPARAMS3 - hcs_params3 - bitmasks */
+/* bits 0:7, Max U1 to U0 latency for the roothub ports */
+#define HCS_U1_LATENCY(p)	(((p) >> 0) & 0xff)
+/* bits 16:31, Max U2 to U0 latency for the roothub ports */
+#define HCS_U2_LATENCY(p)	(((p) >> 16) & 0xffff)
+
+/* HCCPARAMS - hcc_params - bitmasks */
+/* true: HC can use 64-bit address pointers */
+#define HCC_64BIT_ADDR(p)	((p) & (1 << 0))
+/* true: HC can do bandwidth negotiation */
+#define HCC_BANDWIDTH_NEG(p)	((p) & (1 << 1))
+/* true: HC uses 64-byte Device Context structures
+ * FIXME 64-byte context structures aren't supported yet.
+ */
+#define HCC_64BYTE_CONTEXT(p)	((p) & (1 << 2))
+/* true: HC has port power switches */
+#define HCC_PPC(p)		((p) & (1 << 3))
+/* true: HC has port indicators */
+#define HCS_INDICATOR(p)	((p) & (1 << 4))
+/* true: HC has Light HC Reset Capability */
+#define HCC_LIGHT_RESET(p)	((p) & (1 << 5))
+/* true: HC supports latency tolerance messaging */
+#define HCC_LTC(p)		((p) & (1 << 6))
+/* true: no secondary Stream ID Support */
+#define HCC_NSS(p)		((p) & (1 << 7))
+/* Max size for Primary Stream Arrays - 2^(n+1), where n is bits 12:15 */
+#define HCC_MAX_PSA		(1 << ((((p) >> 12) & 0xf) + 1))
+/* Extended Capabilities pointer from PCI base - section 5.3.6 */
+#define HCC_EXT_CAPS(p)		XHCI_HCC_EXT_CAPS(p)
+
+/* db_off bitmask - bits 0:1 reserved */
+#define	DBOFF_MASK	(~0x3)
+
+/* run_regs_off bitmask - bits 0:4 reserved */
+#define	RTSOFF_MASK	(~0x1f)
+
+
+/* Number of registers per port */
+#define	NUM_PORT_REGS	4
+
+/**
+ * struct xhci_op_regs - xHCI Host Controller Operational Registers.
+ * @command:		USBCMD - xHC command register
+ * @status:		USBSTS - xHC status register
+ * @page_size:		This indicates the page size that the host controller
+ * 			supports.  If bit n is set, the HC supports a page size
+ * 			of 2^(n+12), up to a 128MB page size.
+ * 			4K is the minimum page size.
+ * @cmd_ring:		CRP - 64-bit Command Ring Pointer
+ * @dcbaa_ptr:		DCBAAP - 64-bit Device Context Base Address Array Pointer
+ * @config_reg:		CONFIG - Configure Register
+ * @port_status_base:	PORTSCn - base address for Port Status and Control
+ * 			Each port has a Port Status and Control register,
+ * 			followed by a Port Power Management Status and Control
+ * 			register, a Port Link Info register, and a reserved
+ * 			register.
+ * @port_power_base:	PORTPMSCn - base address for
+ * 			Port Power Management Status and Control
+ * @port_link_base:	PORTLIn - base address for Port Link Info (current
+ * 			Link PM state and control) for USB 2.1 and USB 3.0
+ * 			devices.
+ */
+struct xhci_op_regs {
+	u32	command;
+	u32	status;
+	u32	page_size;
+	u32	reserved1;
+	u32	reserved2;
+	u32	dev_notification;
+	u32	cmd_ring[2];
+	/* rsvd: offset 0x20-2F */
+	u32	reserved3[4];
+	u32	dcbaa_ptr[2];
+	u32	config_reg;
+	/* rsvd: offset 0x3C-3FF */
+	u32	reserved4[241];
+	/* port 1 registers, which serve as a base address for other ports */
+	u32	port_status_base;
+	u32	port_power_base;
+	u32	port_link_base;
+	u32	reserved5;
+	/* registers for ports 2-255 */
+	u32	reserved6[NUM_PORT_REGS*254];
+} __attribute__ ((packed));
+
+/* USBCMD - USB command - command bitmasks */
+/* start/stop HC execution - do not write unless HC is halted*/
+#define CMD_RUN		XHCI_CMD_RUN
+/* Reset HC - resets internal HC state machine and all registers (except
+ * PCI config regs).  HC does NOT drive a USB reset on the downstream ports.
+ * The xHCI driver must reinitialize the xHC after setting this bit.
+ */
+#define CMD_RESET	(1 << 1)
+/* Event Interrupt Enable - a '1' allows interrupts from the host controller */
+#define CMD_EIE		XHCI_CMD_EIE
+/* Host System Error Interrupt Enable - get out-of-band signal for HC errors */
+#define CMD_HSEIE	XHCI_CMD_HSEIE
+/* bits 4:6 are reserved (and should be preserved on writes). */
+/* light reset (port status stays unchanged) - reset completed when this is 0 */
+#define CMD_LRESET	(1 << 7)
+/* FIXME: ignoring host controller save/restore state for now. */
+#define CMD_CSS		(1 << 8)
+#define CMD_CRS		(1 << 9)
+/* Enable Wrap Event - '1' means xHC generates an event when MFINDEX wraps. */
+#define CMD_EWE		XHCI_CMD_EWE
+/* MFINDEX power management - '1' means xHC can stop MFINDEX counter if all root
+ * hubs are in U3 (selective suspend), disconnect, disabled, or powered-off.
+ * '0' means the xHC can power it off if all ports are in the disconnect,
+ * disabled, or powered-off state.
+ */
+#define CMD_PM_INDEX	(1 << 11)
+/* bits 12:31 are reserved (and should be preserved on writes). */
+
+/* USBSTS - USB status - status bitmasks */
+/* HC not running - set to 1 when run/stop bit is cleared. */
+#define STS_HALT	XHCI_STS_HALT
+/* serious error, e.g. PCI parity error.  The HC will clear the run/stop bit. */
+#define STS_FATAL	(1 << 2)
+/* event interrupt - clear this prior to clearing any IP flags in IR set*/
+#define STS_EINT	(1 << 3)
+/* port change detect */
+#define STS_PORT	(1 << 4)
+/* bits 5:7 reserved and zeroed */
+/* save state status - '1' means xHC is saving state */
+#define STS_SAVE	(1 << 8)
+/* restore state status - '1' means xHC is restoring state */
+#define STS_RESTORE	(1 << 9)
+/* true: save or restore error */
+#define STS_SRE		(1 << 10)
+/* true: Controller Not Ready to accept doorbell or op reg writes after reset */
+#define STS_CNR		XHCI_STS_CNR
+/* true: internal Host Controller Error - SW needs to reset and reinitialize */
+#define STS_HCE		(1 << 12)
+/* bits 13:31 reserved and should be preserved */
+
+/*
+ * DNCTRL - Device Notification Control Register - dev_notification bitmasks
+ * Generate a device notification event when the HC sees a transaction with a
+ * notification type that matches a bit set in this bit field.
+ */
+#define	DEV_NOTE_MASK		(0xffff)
+#define ENABLE_DEV_NOTE(x)	(1 << x)
+/* Most of the device notification types should only be used for debug.
+ * SW does need to pay attention to function wake notifications.
+ */
+#define	DEV_NOTE_FWAKE		ENABLE_DEV_NOTE(1)
+
+/* CONFIG - Configure Register - config_reg bitmasks */
+/* bits 0:7 - maximum number of device slots enabled (NumSlotsEn) */
+#define MAX_DEVS(p)	((p) & 0xff)
+/* bits 8:31 - reserved and should be preserved */
+
+/* PORTSC - Port Status and Control Register - port_status_base bitmasks */
+/* true: device connected */
+#define PORT_CONNECT	(1 << 0)
+/* true: port enabled */
+#define PORT_PE		(1 << 1)
+/* bit 2 reserved and zeroed */
+/* true: port has an over-current condition */
+#define PORT_OC		(1 << 3)
+/* true: port reset signaling asserted */
+#define PORT_RESET	(1 << 4)
+/* Port Link State - bits 5:8
+ * A read gives the current link PM state of the port,
+ * a write with Link State Write Strobe set sets the link state.
+ */
+/* true: port has power (see HCC_PPC) */
+#define PORT_POWER	(1 << 9)
+/* bits 10:13 indicate device speed:
+ * 0 - undefined speed - port hasn't be initialized by a reset yet
+ * 1 - full speed
+ * 2 - low speed
+ * 3 - high speed
+ * 4 - super speed
+ * 5-15 reserved
+ */
+#define DEV_SPEED_MASK		(0xf<<10)
+#define DEV_UNDEFSPEED(p)	(((p) & DEV_SPEED_MASK) == (0x0<<10))
+#define DEV_FULLSPEED(p)	(((p) & DEV_SPEED_MASK) == (0x1<<10))
+#define DEV_LOWSPEED(p)		(((p) & DEV_SPEED_MASK) == (0x2<<10))
+#define DEV_HIGHSPEED(p)	(((p) & DEV_SPEED_MASK) == (0x3<<10))
+#define DEV_SUPERSPEED(p)	(((p) & DEV_SPEED_MASK) == (0x4<<10))
+/* Port Indicator Control */
+#define PORT_LED_OFF	(0 << 14)
+#define PORT_LED_AMBER	(1 << 14)
+#define PORT_LED_GREEN	(2 << 14)
+#define PORT_LED_MASK	(3 << 14)
+/* Port Link State Write Strobe - set this when changing link state */
+#define PORT_LINK_STROBE	(1 << 16)
+/* true: connect status change */
+#define PORT_CSC	(1 << 17)
+/* true: port enable change */
+#define PORT_PEC	(1 << 18)
+/* true: warm reset for a USB 3.0 device is done.  A "hot" reset puts the port
+ * into an enabled state, and the device into the default state.  A "warm" reset
+ * also resets the link, forcing the device through the link training sequence.
+ * SW can also look at the Port Reset register to see when warm reset is done.
+ */
+#define PORT_WRC	(1 << 19)
+/* true: over-current change */
+#define PORT_OCC	(1 << 20)
+/* true: reset change - 1 to 0 transition of PORT_RESET */
+#define PORT_RC		(1 << 21)
+/* port link status change - set on some port link state transitions:
+ *  Transition				Reason
+ *  ------------------------------------------------------------------------------
+ *  - U3 to Resume			Wakeup signaling from a device
+ *  - Resume to Recovery to U0		USB 3.0 device resume
+ *  - Resume to U0			USB 2.0 device resume
+ *  - U3 to Recovery to U0		Software resume of USB 3.0 device complete
+ *  - U3 to U0				Software resume of USB 2.0 device complete
+ *  - U2 to U0				L1 resume of USB 2.1 device complete
+ *  - U0 to U0 (???)			L1 entry rejection by USB 2.1 device
+ *  - U0 to disabled			L1 entry error with USB 2.1 device
+ *  - Any state to inactive		Error on USB 3.0 port
+ */
+#define PORT_PLC	(1 << 22)
+/* port configure error change - port failed to configure its link partner */
+#define PORT_CEC	(1 << 23)
+/* bit 24 reserved */
+/* wake on connect (enable) */
+#define PORT_WKCONN_E	(1 << 25)
+/* wake on disconnect (enable) */
+#define PORT_WKDISC_E	(1 << 26)
+/* wake on over-current (enable) */
+#define PORT_WKOC_E	(1 << 27)
+/* bits 28:29 reserved */
+/* true: device is removable - for USB 3.0 roothub emulation */
+#define PORT_DEV_REMOVE	(1 << 30)
+/* Initiate a warm port reset - complete when PORT_WRC is '1' */
+#define PORT_WR		(1 << 31)
+
+/* Port Power Management Status and Control - port_power_base bitmasks */
+/* Inactivity timer value for transitions into U1, in microseconds.
+ * Timeout can be up to 127us.  0xFF means an infinite timeout.
+ */
+#define PORT_U1_TIMEOUT(p)	((p) & 0xff)
+/* Inactivity timer value for transitions into U2 */
+#define PORT_U2_TIMEOUT(p)	(((p) & 0xff) << 8)
+/* Bits 24:31 for port testing */
+
+
+/**
+ * struct intr_reg - Interrupt Register Set
+ * @irq_pending:	IMAN - Interrupt Management Register.  Used to enable
+ *			interrupts and check for pending interrupts.
+ * @irq_control:	IMOD - Interrupt Moderation Register.
+ * 			Used to throttle interrupts.
+ * @erst_size:		Number of segments in the Event Ring Segment Table (ERST).
+ * @erst_base:		ERST base address.
+ * @erst_dequeue:	Event ring dequeue pointer.
+ *
+ * Each interrupter (defined by a MSI-X vector) has an event ring and an Event
+ * Ring Segment Table (ERST) associated with it.  The event ring is comprised of
+ * multiple segments of the same size.  The HC places events on the ring and
+ * "updates the Cycle bit in the TRBs to indicate to software the current
+ * position of the Enqueue Pointer." The HCD (Linux) processes those events and
+ * updates the dequeue pointer.
+ */
+struct intr_reg {
+	u32	irq_pending;
+	u32	irq_control;
+	u32	erst_size;
+	u32	rsvd;
+	u32	erst_base[2];
+	u32	erst_dequeue[2];
+} __attribute__ ((packed));
+
+#define	ER_IRQ_PENDING(p)	((p) & 0x1)
+#define	ER_IRQ_ENABLE(p)	((p) | 0x2)
+/* Preserve bits 16:31 of erst_size */
+#define	ERST_SIZE_MASK	(0xffff<<16)
+
+/**
+ * struct xhci_run_regs
+ * @microframe_index:
+ * 		MFINDEX - current microframe number
+ *
+ * Section 5.5 Host Controller Runtime Registers:
+ * "Software should read and write these registers using only Dword (32 bit)
+ * or larger accesses"
+ */
+struct xhci_run_regs {
+	u32	microframe_index;
+	u32	rsvd[7];
+	struct intr_reg	ir_set[128];
+} __attribute__ ((packed));
+
+
+/* There is one ehci_hci structure per controller */
+struct xhci_hcd {
+	/* glue to PCI and HCD framework */
+	struct xhci_cap_regs __iomem *cap_regs;
+	struct xhci_op_regs __iomem *op_regs;
+	struct xhci_run_regs __iomem *run_regs;
+
+	/* Cached register copies of read-only HC data */
+	__u32		hcs_params1;
+	__u32		hcs_params2;
+	__u32		hcs_params3;
+	__u32		hcc_params;
+
+	spinlock_t	lock;
+
+	/* packed release number */
+	u8		sbrn;
+	u16		hci_version;
+	u8		max_slots;
+	u8		max_interrupters;
+	u8		max_ports;
+	u8		isoc_threshold;
+	int		event_ring_max;
+	int		addr_64;
+	int		page_size;
+};
+
+/* convert between an HCD pointer and the corresponding EHCI_HCD */
+static inline struct xhci_hcd *hcd_to_xhci(struct usb_hcd *hcd)
+{
+	return (struct xhci_hcd *) (hcd->hcd_priv);
+}
+
+static inline struct usb_hcd *xhci_to_hcd(struct xhci_hcd *xhci)
+{
+	return container_of((void *) xhci, struct usb_hcd, hcd_priv);
+}
+
+#ifdef CONFIG_USB_XHCI_HCD_DEBUGGING
+#define XHCI_DEBUG	1
+#else
+#define XHCI_DEBUG	0
+#endif
+
+#define xhci_dbg(xhci, fmt, args...) \
+	do { if (XHCI_DEBUG) dev_dbg(xhci_to_hcd(xhci)->self.controller , fmt , ## args); } while (0)
+#define xhci_info(xhci, fmt, args...) \
+	do { if (XHCI_DEBUG) dev_info(xhci_to_hcd(xhci)->self.controller , fmt , ## args); } while (0)
+#define xhci_err(xhci, fmt, args...) \
+	dev_err(xhci_to_hcd(xhci)->self.controller , fmt , ## args)
+#define xhci_warn(xhci, fmt, args...) \
+	dev_warn(xhci_to_hcd(xhci)->self.controller , fmt , ## args)
+
+/* TODO: copied from ehci.h - can be refactored? */
+/* xHCI spec says all registers are little endian */
+static inline unsigned int xhci_readl(const struct xhci_hcd *xhci,
+		__u32 __iomem *regs)
+{
+	return readl(regs);
+}
+static inline void xhci_writel(const struct xhci_hcd *xhci,
+		const unsigned int val, __u32 __iomem *regs)
+{
+	if (!in_interrupt())
+		xhci_dbg(xhci, "`MEM_WRITE_DWORD(3'b000, 32'h%0x, 32'h%0x, 4'hf);\n",
+				(unsigned int) regs, val);
+	writel(val, regs);
+}
+
+#endif /* __LINUX_XHCI_HCD_H */