uhci-hcd.c

h内核

/*
 * Universal Host Controller Interface driver for USB.
 *
 * Maintainer: Alan Stern <[e-mail]>
 *
 * (C) Copyright 1999 Linus Torvalds
 * (C) Copyright 1999-2002 Johannes Erdfelt, [e-mail]
 * (C) Copyright 1999 Randy Dunlap
 * (C) Copyright 1999 Georg Acher, [e-mail]
 * (C) Copyright 1999 Deti Fliegl, [e-mail]
 * (C) Copyright 1999 Thomas Sailer, [e-mail]
 * (C) Copyright 1999 Roman Weissgaerber, [e-mail]
 * (C) Copyright 2000 Yggdrasil Computing, Inc. (port of new PCI interface
 *               support from usb-ohci.c by Adam Richter, [e-mail]).
 * (C) Copyright 1999 Gregory P. Smith (from usb-ohci.c)
 * (C) Copyright 2004 Alan Stern, [e-mail]
 *
 * Intel documents this fairly well, and as far as I know there
 * are no royalties or anything like that, but even so there are
 * people who decided that they want to do the same thing in a
 * completely different way.
 *
 * WARNING! The USB documentation is downright evil. Most of it
 * is just crap, written by a committee. You're better off ignoring
 * most of it, the important stuff is:
 *  - the low-level protocol (fairly simple but lots of small details)
 *  - working around the horridness of the rest
 */

#include <linux/config.h>
#ifdef CONFIG_USB_DEBUG
#define DEBUG
#else
#undef DEBUG
#endif
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/ioport.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/smp_lock.h>
#include <linux/errno.h>
#include <linux/unistd.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/debugfs.h>
#include <linux/pm.h>
#include <linux/dmapool.h>
#include <linux/dma-mapping.h>
#include <linux/usb.h>
#include <linux/bitops.h>

#include <asm/uaccess.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/system.h>

#include "../core/hcd.h"
#include "uhci-hcd.h"

/*
 * Version Information
 */
#define DRIVER_VERSION "v2.2"
#define DRIVER_AUTHOR "Linus 'Frodo Rabbit' Torvalds, Johannes Erdfelt, \
Randy Dunlap, Georg Acher, Deti Fliegl, Thomas Sailer, Roman Weissgaerber, \
Alan Stern"
#define DRIVER_DESC "USB Universal Host Controller Interface driver"

/*
 * debug = 0, no debugging messages
 * debug = 1, dump failed URB's except for stalls
 * debug = 2, dump all failed URB's (including stalls)
 *            show all queues in /debug/uhci/[pci_addr]
 * debug = 3, show all TD's in URB's when dumping
 */
#ifdef DEBUG
static int debug = 1;
#else
static int debug = 0;
#endif
module_param(debug, int, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(debug, "Debug level");
static char *errbuf;
#define ERRBUF_LEN    (32 * 1024)

#include "uhci-hub.c"
#include "uhci-debug.c"

static kmem_cache_t *uhci_up_cachep;	/* urb_priv */

static unsigned int uhci_get_current_frame_number(struct uhci_hcd *uhci);
static int uhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb);
static void uhci_unlink_generic(struct uhci_hcd *uhci, struct urb *urb);
static void uhci_remove_pending_urbps(struct uhci_hcd *uhci);
static void uhci_finish_completion(struct usb_hcd *hcd, struct pt_regs *regs);
static void uhci_free_pending_qhs(struct uhci_hcd *uhci);
static void uhci_free_pending_tds(struct uhci_hcd *uhci);

static void hc_state_transitions(struct uhci_hcd *uhci);

/* If a transfer is still active after this much time, turn off FSBR */
#define IDLE_TIMEOUT	msecs_to_jiffies(50)
#define FSBR_DELAY	msecs_to_jiffies(50)

/* When we timeout an idle transfer for FSBR, we'll switch it over to */
/* depth first traversal. We'll do it in groups of this number of TD's */
/* to make sure it doesn't hog all of the bandwidth */
#define DEPTH_INTERVAL 5

/*
 * Technically, updating td->status here is a race, but it's not really a
 * problem. The worst that can happen is that we set the IOC bit again
 * generating a spurious interrupt. We could fix this by creating another
 * QH and leaving the IOC bit always set, but then we would have to play
 * games with the FSBR code to make sure we get the correct order in all
 * the cases. I don't think it's worth the effort
 */
static inline void uhci_set_next_interrupt(struct uhci_hcd *uhci)
{
	uhci->term_td->status |= cpu_to_le32(TD_CTRL_IOC); 
}

static inline void uhci_clear_next_interrupt(struct uhci_hcd *uhci)
{
	uhci->term_td->status &= ~cpu_to_le32(TD_CTRL_IOC);
}

static inline void uhci_moveto_complete(struct uhci_hcd *uhci, 
					struct urb_priv *urbp)
{
	list_move_tail(&urbp->urb_list, &uhci->complete_list);
}

static struct uhci_td *uhci_alloc_td(struct uhci_hcd *uhci, struct usb_device *dev)
{
	dma_addr_t dma_handle;
	struct uhci_td *td;

	td = dma_pool_alloc(uhci->td_pool, GFP_ATOMIC, &dma_handle);
	if (!td)
		return NULL;

	td->dma_handle = dma_handle;

	td->link = UHCI_PTR_TERM;
	td->buffer = 0;

	td->frame = -1;
	td->dev = dev;

	INIT_LIST_HEAD(&td->list);
	INIT_LIST_HEAD(&td->remove_list);
	INIT_LIST_HEAD(&td->fl_list);

	usb_get_dev(dev);

	return td;
}

static inline void uhci_fill_td(struct uhci_td *td, u32 status,
		u32 token, u32 buffer)
{
	td->status = cpu_to_le32(status);
	td->token = cpu_to_le32(token);
	td->buffer = cpu_to_le32(buffer);
}

/*
 * We insert Isochronous URB's directly into the frame list at the beginning
 */
static void uhci_insert_td_frame_list(struct uhci_hcd *uhci, struct uhci_td *td, unsigned framenum)
{
	framenum &= (UHCI_NUMFRAMES - 1);

	td->frame = framenum;

	/* Is there a TD already mapped there? */
	if (uhci->fl->frame_cpu[framenum]) {
		struct uhci_td *ftd, *ltd;

		ftd = uhci->fl->frame_cpu[framenum];
		ltd = list_entry(ftd->fl_list.prev, struct uhci_td, fl_list);

		list_add_tail(&td->fl_list, &ftd->fl_list);

		td->link = ltd->link;
		wmb();
		ltd->link = cpu_to_le32(td->dma_handle);
	} else {
		td->link = uhci->fl->frame[framenum];
		wmb();
		uhci->fl->frame[framenum] = cpu_to_le32(td->dma_handle);
		uhci->fl->frame_cpu[framenum] = td;
	}
}

static void uhci_remove_td(struct uhci_hcd *uhci, struct uhci_td *td)
{
	/* If it's not inserted, don't remove it */
	if (td->frame == -1 && list_empty(&td->fl_list))
		return;

	if (td->frame != -1 && uhci->fl->frame_cpu[td->frame] == td) {
		if (list_empty(&td->fl_list)) {
			uhci->fl->frame[td->frame] = td->link;
			uhci->fl->frame_cpu[td->frame] = NULL;
		} else {
			struct uhci_td *ntd;

			ntd = list_entry(td->fl_list.next, struct uhci_td, fl_list);
			uhci->fl->frame[td->frame] = cpu_to_le32(ntd->dma_handle);
			uhci->fl->frame_cpu[td->frame] = ntd;
		}
	} else {
		struct uhci_td *ptd;

		ptd = list_entry(td->fl_list.prev, struct uhci_td, fl_list);
		ptd->link = td->link;
	}

	wmb();
	td->link = UHCI_PTR_TERM;

	list_del_init(&td->fl_list);
	td->frame = -1;
}

/*
 * Inserts a td list into qh.
 */
static void uhci_insert_tds_in_qh(struct uhci_qh *qh, struct urb *urb, __le32 breadth)
{
	struct urb_priv *urbp = (struct urb_priv *)urb->hcpriv;
	struct uhci_td *td;
	__le32 *plink;

	/* Ordering isn't important here yet since the QH hasn't been */
	/* inserted into the schedule yet */
	plink = &qh->element;
	list_for_each_entry(td, &urbp->td_list, list) {
		*plink = cpu_to_le32(td->dma_handle) | breadth;
		plink = &td->link;
	}
	*plink = UHCI_PTR_TERM;
}

static void uhci_free_td(struct uhci_hcd *uhci, struct uhci_td *td)
{
	if (!list_empty(&td->list))
		dev_warn(uhci_dev(uhci), "td %p still in list!\n", td);
	if (!list_empty(&td->remove_list))
		dev_warn(uhci_dev(uhci), "td %p still in remove_list!\n", td);
	if (!list_empty(&td->fl_list))
		dev_warn(uhci_dev(uhci), "td %p still in fl_list!\n", td);

	if (td->dev)
		usb_put_dev(td->dev);

	dma_pool_free(uhci->td_pool, td, td->dma_handle);
}

static struct uhci_qh *uhci_alloc_qh(struct uhci_hcd *uhci, struct usb_device *dev)
{
	dma_addr_t dma_handle;
	struct uhci_qh *qh;

	qh = dma_pool_alloc(uhci->qh_pool, GFP_ATOMIC, &dma_handle);
	if (!qh)
		return NULL;

	qh->dma_handle = dma_handle;

	qh->element = UHCI_PTR_TERM;
	qh->link = UHCI_PTR_TERM;

	qh->dev = dev;
	qh->urbp = NULL;

	INIT_LIST_HEAD(&qh->list);
	INIT_LIST_HEAD(&qh->remove_list);

	usb_get_dev(dev);

	return qh;
}

static void uhci_free_qh(struct uhci_hcd *uhci, struct uhci_qh *qh)
{
	if (!list_empty(&qh->list))
		dev_warn(uhci_dev(uhci), "qh %p list not empty!\n", qh);
	if (!list_empty(&qh->remove_list))
		dev_warn(uhci_dev(uhci), "qh %p still in remove_list!\n", qh);

	if (qh->dev)
		usb_put_dev(qh->dev);

	dma_pool_free(uhci->qh_pool, qh, qh->dma_handle);
}

/*
 * Append this urb's qh after the last qh in skelqh->list
 *
 * Note that urb_priv.queue_list doesn't have a separate queue head;
 * it's a ring with every element "live".
 */
static void uhci_insert_qh(struct uhci_hcd *uhci, struct uhci_qh *skelqh, struct urb *urb)
{
	struct urb_priv *urbp = (struct urb_priv *)urb->hcpriv;
	struct urb_priv *turbp;
	struct uhci_qh *lqh;

	/* Grab the last QH */
	lqh = list_entry(skelqh->list.prev, struct uhci_qh, list);

	/* Point to the next skelqh */
	urbp->qh->link = lqh->link;
	wmb();				/* Ordering is important */

	/*
	 * Patch QHs for previous endpoint's queued URBs?  HC goes
	 * here next, not to the next skelqh it now points to.
	 *
	 *    lqh --> td ... --> qh ... --> td --> qh ... --> td
	 *     |                 |                 |
	 *     v                 v                 v
	 *     +<----------------+-----------------+
	 *     v
	 *    newqh --> td ... --> td
	 *     |
	 *     v
	 *    ...
	 *
	 * The HC could see (and use!) any of these as we write them.
	 */
	lqh->link = cpu_to_le32(urbp->qh->dma_handle) | UHCI_PTR_QH;
	if (lqh->urbp) {
		list_for_each_entry(turbp, &lqh->urbp->queue_list, queue_list)
			turbp->qh->link = lqh->link;
	}

	list_add_tail(&urbp->qh->list, &skelqh->list);
}

/*
 * Start removal of QH from schedule; it finishes next frame.
 * TDs should be unlinked before this is called.
 */
static void uhci_remove_qh(struct uhci_hcd *uhci, struct uhci_qh *qh)
{
	struct uhci_qh *pqh;
	__le32 newlink;
	unsigned int age;

	if (!qh)
		return;

	/*
	 * Only go through the hoops if it's actually linked in
	 */
	if (!list_empty(&qh->list)) {

		/* If our queue is nonempty, make the next URB the head */
		if (!list_empty(&qh->urbp->queue_list)) {
			struct urb_priv *nurbp;

			nurbp = list_entry(qh->urbp->queue_list.next,
					struct urb_priv, queue_list);
			nurbp->queued = 0;
			list_add(&nurbp->qh->list, &qh->list);
			newlink = cpu_to_le32(nurbp->qh->dma_handle) | UHCI_PTR_QH;
		} else
			newlink = qh->link;

		/* Fix up the previous QH's queue to link to either
		 * the new head of this queue or the start of the
		 * next endpoint's queue. */
		pqh = list_entry(qh->list.prev, struct uhci_qh, list);
		pqh->link = newlink;
		if (pqh->urbp) {
			struct urb_priv *turbp;

			list_for_each_entry(turbp, &pqh->urbp->queue_list,
					queue_list)
				turbp->qh->link = newlink;
		}
		wmb();

		/* Leave qh->link in case the HC is on the QH now, it will */
		/* continue the rest of the schedule */
		qh->element = UHCI_PTR_TERM;

		list_del_init(&qh->list);
	}

	list_del_init(&qh->urbp->queue_list);
	qh->urbp = NULL;

	age = uhci_get_current_frame_number(uhci);
	if (age != uhci->qh_remove_age) {
		uhci_free_pending_qhs(uhci);
		uhci->qh_remove_age = age;
	}

	/* Check to see if the remove list is empty. Set the IOC bit */
	/* to force an interrupt so we can remove the QH */
	if (list_empty(&uhci->qh_remove_list))
		uhci_set_next_interrupt(uhci);

	list_add(&qh->remove_list, &uhci->qh_remove_list);
}

static int uhci_fixup_toggle(struct urb *urb, unsigned int toggle)
{
	struct urb_priv *urbp = (struct urb_priv *)urb->hcpriv;
	struct uhci_td *td;

	list_for_each_entry(td, &urbp->td_list, list) {
		if (toggle)
			td->token |= cpu_to_le32(TD_TOKEN_TOGGLE);
		else
			td->token &= ~cpu_to_le32(TD_TOKEN_TOGGLE);

		toggle ^= 1;
	}

	return toggle;
}

/* This function will append one URB's QH to another URB's QH. This is for */
/* queuing interrupt, control or bulk transfers */
static void uhci_append_queued_urb(struct uhci_hcd *uhci, struct urb *eurb, struct urb *urb)
{
	struct urb_priv *eurbp, *urbp, *furbp, *lurbp;
	struct uhci_td *lltd;

	eurbp = eurb->hcpriv;
	urbp = urb->hcpriv;

	/* Find the first URB in the queue */
	furbp = eurbp;
	if (eurbp->queued) {
		list_for_each_entry(furbp, &eurbp->queue_list, queue_list)
			if (!furbp->queued)
				break;
	}

	lurbp = list_entry(furbp->queue_list.prev, struct urb_priv, queue_list);

	lltd = list_entry(lurbp->td_list.prev, struct uhci_td, list);

	/* Control transfers always start with toggle 0 */
	if (!usb_pipecontrol(urb->pipe))
		usb_settoggle(urb->dev, usb_pipeendpoint(urb->pipe),
				usb_pipeout(urb->pipe),
				uhci_fixup_toggle(urb,
					uhci_toggle(td_token(lltd)) ^ 1));

	/* All qh's in the queue need to link to the next queue */
	urbp->qh->link = eurbp->qh->link;

	wmb();			/* Make sure we flush everything */

	lltd->link = cpu_to_le32(urbp->qh->dma_handle) | UHCI_PTR_QH;

	list_add_tail(&urbp->queue_list, &furbp->queue_list);

	urbp->queued = 1;
}

static void uhci_delete_queued_urb(struct uhci_hcd *uhci, struct urb *urb)
{
	struct urb_priv *urbp, *nurbp, *purbp, *turbp;
	struct uhci_td *pltd;
	unsigned int toggle;

	urbp = urb->hcpriv;

	if (list_empty(&urbp->queue_list))
		return;