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/*
* Copyright (c) 2001-2002 by David Brownell
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*
* 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.
*/
/* this file is part of ehci-hcd.c */
/*-------------------------------------------------------------------------*/
/*
* EHCI hardware queue manipulation ... the core. QH/QTD manipulation.
*
* Control, bulk, and interrupt traffic all use "qh" lists. They list "qtd"
* entries describing USB transactions, max 16-20kB/entry (with 4kB-aligned
* buffers needed for the larger number). We use one QH per endpoint, queue
* multiple urbs (all three types) per endpoint. URBs may need several qtds.
*
* ISO traffic uses "ISO TD" (itd, and sitd) records, and (along with
* interrupts) needs careful scheduling. Performance improvements can be
* an ongoing challenge. That's in "ehci-sched.c".
*
* USB 1.1 devices are handled (a) by "companion" OHCI or UHCI root hubs,
* or otherwise through transaction translators (TTs) in USB 2.0 hubs using
* (b) special fields in qh entries or (c) split iso entries. TTs will
* buffer low/full speed data so the host collects it at high speed.
*/
/*-------------------------------------------------------------------------*/
/* fill a qtd, returning how much of the buffer we were able to queue up */
static int
qtd_fill (struct ehci_qtd *qtd, dma_addr_t buf, size_t len,
int token, int maxpacket)
{
int i, count;
u64 addr = buf;
/* one buffer entry per 4K ... first might be short or unaligned */
qtd->hw_buf [0] = cpu_to_le32 ((u32)addr);
qtd->hw_buf_hi [0] = cpu_to_le32 ((u32)(addr >> 32));
count = 0x1000 - (buf & 0x0fff); /* rest of that page */
if (likely (len < count)) /* ... iff needed */
count = len;
else {
buf += 0x1000;
buf &= ~0x0fff;
/* per-qtd limit: from 16K to 20K (best alignment) */
for (i = 1; count < len && i < 5; i++) {
addr = buf;
qtd->hw_buf [i] = cpu_to_le32 ((u32)addr);
qtd->hw_buf_hi [i] = cpu_to_le32 ((u32)(addr >> 32));
buf += 0x1000;
if ((count + 0x1000) < len)
count += 0x1000;
else
count = len;
}
/* short packets may only terminate transfers */
if (count != len)
count -= (count % maxpacket);
}
qtd->hw_token = cpu_to_le32 ((count << 16) | token);
qtd->length = count;
return count;
}
/*-------------------------------------------------------------------------*/
/* update halted (but potentially linked) qh */
static inline void
qh_update (struct ehci_hcd *ehci, struct ehci_qh *qh, struct ehci_qtd *qtd)
{
qh->hw_qtd_next = QTD_NEXT (qtd->qtd_dma);
qh->hw_alt_next = EHCI_LIST_END;
/* HC must see latest qtd and qh data before we clear ACTIVE+HALT */
wmb ();
qh->hw_token &= __constant_cpu_to_le32 (QTD_TOGGLE | QTD_STS_PING);
}
/*-------------------------------------------------------------------------*/
static void qtd_copy_status (
struct ehci_hcd *ehci,
struct urb *urb,
size_t length,
u32 token
)
{
/* count IN/OUT bytes, not SETUP (even short packets) */
if (likely (QTD_PID (token) != 2))
urb->actual_length += length - QTD_LENGTH (token);
/* don't modify error codes */
if (unlikely (urb->status != -EINPROGRESS))
return;
/* force cleanup after short read; not always an error */
if (unlikely (IS_SHORT_READ (token)))
urb->status = -EREMOTEIO;
/* serious "can't proceed" faults reported by the hardware */
if (token & QTD_STS_HALT) {
if (token & QTD_STS_BABBLE) {
/* FIXME "must" disable babbling device's port too */
urb->status = -EOVERFLOW;
} else if (token & QTD_STS_MMF) {
/* fs/ls interrupt xfer missed the complete-split */
urb->status = -EPROTO;
} else if (token & QTD_STS_DBE) {
urb->status = (QTD_PID (token) == 1) /* IN ? */
? -ENOSR /* hc couldn't read data */
: -ECOMM; /* hc couldn't write data */
} else if (token & QTD_STS_XACT) {
/* timeout, bad crc, wrong PID, etc; retried */
if (QTD_CERR (token))
urb->status = -EPIPE;
else {
ehci_dbg (ehci, "devpath %s ep%d%s 3strikes\n",
urb->dev->devpath,
usb_pipeendpoint (urb->pipe),
usb_pipein (urb->pipe) ? "in" : "out");
urb->status = -EPROTO;
}
/* CERR nonzero + no errors + halt --> stall */
} else if (QTD_CERR (token))
urb->status = -EPIPE;
else /* unknown */
urb->status = -EPROTO;
ehci_vdbg (ehci,
"dev%d ep%d%s qtd token %08x --> status %d\n",
usb_pipedevice (urb->pipe),
usb_pipeendpoint (urb->pipe),
usb_pipein (urb->pipe) ? "in" : "out",
token, urb->status);
/* stall indicates some recovery action is needed */
if (urb->status == -EPIPE) {
int pipe = urb->pipe;
if (!usb_pipecontrol (pipe))
usb_endpoint_halt (urb->dev,
usb_pipeendpoint (pipe),
usb_pipeout (pipe));
/* if async CSPLIT failed, try cleaning out the TT buffer */
} else if (urb->dev->tt && !usb_pipeint (urb->pipe)
&& QTD_CERR(token) == 0) {
#ifdef DEBUG
struct usb_device *tt = urb->dev->tt->hub;
dev_dbg (&tt->dev,
"clear tt buffer port %d, a%d ep%d t%08x\n",
urb->dev->ttport, urb->dev->devnum,
usb_pipeendpoint (urb->pipe), token);
#endif /* DEBUG */
usb_hub_tt_clear_buffer (urb->dev, urb->pipe);
}
}
}
static void
ehci_urb_done (struct ehci_hcd *ehci, struct urb *urb, struct pt_regs *regs)
{
if (likely (urb->hcpriv != 0)) {
struct ehci_qh *qh = (struct ehci_qh *) urb->hcpriv;
/* S-mask in a QH means it's an interrupt urb */
if ((qh->hw_info2 & __constant_cpu_to_le32 (0x00ff)) != 0) {
/* ... update hc-wide periodic stats (for usbfs) */
hcd_to_bus (&ehci->hcd)->bandwidth_int_reqs--;
}
qh_put (ehci, qh);
}
spin_lock (&urb->lock);
urb->hcpriv = 0;
switch (urb->status) {
case -EINPROGRESS: /* success */
urb->status = 0;
default: /* fault */
COUNT (ehci->stats.complete);
break;
case -EREMOTEIO: /* fault or normal */
if (!(urb->transfer_flags & URB_SHORT_NOT_OK))
urb->status = 0;
COUNT (ehci->stats.complete);
break;
case -ECONNRESET: /* canceled */
case -ENOENT:
COUNT (ehci->stats.unlink);
break;
}
spin_unlock (&urb->lock);
/* complete() can reenter this HCD */
spin_unlock (&ehci->lock);
usb_hcd_giveback_urb (&ehci->hcd, urb, regs);
spin_lock (&ehci->lock);
}
/*
* Process and free completed qtds for a qh, returning URBs to drivers.
* Chases up to qh->hw_current. Returns number of completions called,
* indicating how much "real" work we did.
*/
#define HALT_BIT __constant_cpu_to_le32(QTD_STS_HALT)
static unsigned
qh_completions (struct ehci_hcd *ehci, struct ehci_qh *qh, struct pt_regs *regs)
{
struct ehci_qtd *last = 0, *end = qh->dummy;
struct list_head *entry, *tmp;
int stopped;
unsigned count = 0;
int do_status = 0;
u8 state;
if (unlikely (list_empty (&qh->qtd_list)))
return count;
/* completions (or tasks on other cpus) must never clobber HALT
* till we've gone through and cleaned everything up, even when
* they add urbs to this qh's queue or mark them for unlinking.
*
* NOTE: unlinking expects to be done in queue order.
*/
state = qh->qh_state;
qh->qh_state = QH_STATE_COMPLETING;
stopped = (state == QH_STATE_IDLE);
/* remove de-activated QTDs from front of queue.
* after faults (including short reads), cleanup this urb
* then let the queue advance.
* if queue is stopped, handles unlinks.
*/
list_for_each_safe (entry, tmp, &qh->qtd_list) {
struct ehci_qtd *qtd;
struct urb *urb;
u32 token = 0;
qtd = list_entry (entry, struct ehci_qtd, qtd_list);
urb = qtd->urb;
/* clean up any state from previous QTD ...*/
if (last) {
if (likely (last->urb != urb)) {
ehci_urb_done (ehci, last->urb, regs);
count++;
}
ehci_qtd_free (ehci, last);
last = 0;
}
/* ignore urbs submitted during completions we reported */
if (qtd == end)
break;
/* hardware copies qtd out of qh overlay */
rmb ();
token = le32_to_cpu (qtd->hw_token);
/* always clean up qtds the hc de-activated */
if ((token & QTD_STS_ACTIVE) == 0) {
if ((token & QTD_STS_HALT) != 0) {
stopped = 1;
/* magic dummy for some short reads; qh won't advance */
} else if (IS_SHORT_READ (token)
&& (qh->hw_alt_next & QTD_MASK)
== ehci->async->hw_alt_next) {
stopped = 1;
goto halt;
}
/* stop scanning when we reach qtds the hc is using */
} else if (likely (!stopped
&& HCD_IS_RUNNING (ehci->hcd.state))) {
break;
} else {
stopped = 1;
/* ignore active urbs unless some previous qtd
* for the urb faulted (including short read) or
* its urb was canceled. we may patch qh or qtds.
*/
if (likely (urb->status == -EINPROGRESS))
continue;
/* issue status after short control reads */
if (unlikely (do_status != 0)
&& QTD_PID (token) == 0 /* OUT */) {
do_status = 0;
continue;
}
/* token in overlay may be most current */
if (state == QH_STATE_IDLE
&& cpu_to_le32 (qtd->qtd_dma)
== qh->hw_current)
token = le32_to_cpu (qh->hw_token);
/* force halt for unlinked or blocked qh, so we'll
* patch the qh later and so that completions can't
* activate it while we "know" it's stopped.
*/
if ((HALT_BIT & qh->hw_token) == 0) {
halt:
qh->hw_token |= HALT_BIT;
wmb ();
}
}
/* remove it from the queue */
spin_lock (&urb->lock);
qtd_copy_status (ehci, urb, qtd->length, token);
do_status = (urb->status == -EREMOTEIO)
&& usb_pipecontrol (urb->pipe);
spin_unlock (&urb->lock);
if (stopped && qtd->qtd_list.prev != &qh->qtd_list) {
last = list_entry (qtd->qtd_list.prev,
struct ehci_qtd, qtd_list);
last->hw_next = qtd->hw_next;
}
list_del (&qtd->qtd_list);
last = qtd;
}
/* last urb's completion might still need calling */
if (likely (last != 0)) {
ehci_urb_done (ehci, last->urb, regs);
count++;
ehci_qtd_free (ehci, last);
}
/* restore original state; caller must unlink or relink */
qh->qh_state = state;
/* update qh after fault cleanup */
if (unlikely (stopped != 0)
/* some EHCI 0.95 impls will overlay dummy qtds */
|| qh->hw_qtd_next == EHCI_LIST_END) {
if (list_empty (&qh->qtd_list))
end = qh->dummy;
else {
end = list_entry (qh->qtd_list.next,
struct ehci_qtd, qtd_list);
/* first qtd may already be partially processed */
if (cpu_to_le32 (end->qtd_dma) == qh->hw_current)
end = 0;
}
if (end)
qh_update (ehci, qh, end);
}
return count;
}
/*-------------------------------------------------------------------------*/
// high bandwidth multiplier, as encoded in highspeed endpoint descriptors
#define hb_mult(wMaxPacketSize) (1 + (((wMaxPacketSize) >> 11) & 0x03))
// ... and packet size, for any kind of endpoint descriptor
#define max_packet(wMaxPacketSize) ((wMaxPacketSize) & 0x07ff)
/*
* reverse of qh_urb_transaction: free a list of TDs.
* used for cleanup after errors, before HC sees an URB's TDs.
*/
static void qtd_list_free (
struct ehci_hcd *ehci,
struct urb *urb,
struct list_head *qtd_list
) {
struct list_head *entry, *temp;
list_for_each_safe (entry, temp, qtd_list) {
struct ehci_qtd *qtd;
qtd = list_entry (entry, struct ehci_qtd, qtd_list);
list_del (&qtd->qtd_list);
ehci_qtd_free (ehci, qtd);
}
}
/*
* create a list of filled qtds for this URB; won't link into qh.
*/
static struct list_head *
qh_urb_transaction (
struct ehci_hcd *ehci,
struct urb *urb,
struct list_head *head,
int flags
) {
struct ehci_qtd *qtd, *qtd_prev;
dma_addr_t buf;
int len, maxpacket;
int is_input;
u32 token;
/*
* URBs map to sequences of QTDs: one logical transaction
*/
qtd = ehci_qtd_alloc (ehci, flags);
if (unlikely (!qtd))
return 0;
list_add_tail (&qtd->qtd_list, head);
qtd->urb = urb;
token = QTD_STS_ACTIVE;
token |= (EHCI_TUNE_CERR << 10);
/* for split transactions, SplitXState initialized to zero */
len = urb->transfer_buffer_length;
is_input = usb_pipein (urb->pipe);
if (usb_pipecontrol (urb->pipe)) {
/* SETUP pid */
qtd_fill (qtd, urb->setup_dma, sizeof (struct usb_ctrlrequest),
token | (2 /* "setup" */ << 8), 8);
/* ... and always at least one more pid */
token ^= QTD_TOGGLE;
qtd_prev = qtd;
qtd = ehci_qtd_alloc (ehci, flags);
if (unlikely (!qtd))
goto cleanup;
qtd->urb = urb;
qtd_prev->hw_next = QTD_NEXT (qtd->qtd_dma);
list_add_tail (&qtd->qtd_list, head);
}
/*
* data transfer stage: buffer setup
*/
if (likely (len > 0))
buf = urb->transfer_dma;
else
buf = 0;
// FIXME this 'buf' check break some zlps...
if (!buf || is_input)
token |= (1 /* "in" */ << 8);
/* else it's already initted to "out" pid (0 << 8) */
maxpacket = max_packet(usb_maxpacket(urb->dev, urb->pipe, !is_input));
/*
* buffer gets wrapped in one or more qtds;
* last one may be "short" (including zero len)
* and may serve as a control status ack
*/
for (;;) {
int this_qtd_len;
this_qtd_len = qtd_fill (qtd, buf, len, token, maxpacket);
len -= this_qtd_len;
buf += this_qtd_len;
if (is_input)
qtd->hw_alt_next = ehci->async->hw_alt_next;
/* qh makes control packets use qtd toggle; maybe switch it */
if ((maxpacket & (this_qtd_len + (maxpacket - 1))) == 0)
token ^= QTD_TOGGLE;
if (likely (len <= 0))
break;
qtd_prev = qtd;
qtd = ehci_qtd_alloc (ehci, flags);
if (unlikely (!qtd))
goto cleanup;
qtd->urb = urb;
qtd_prev->hw_next = QTD_NEXT (qtd->qtd_dma);
list_add_tail (&qtd->qtd_list, head);
}
/* unless the bulk/interrupt caller wants a chance to clean
* up after short reads, hc should advance qh past this urb
*/
if (likely ((urb->transfer_flags & URB_SHORT_NOT_OK) == 0
|| usb_pipecontrol (urb->pipe)))
qtd->hw_alt_next = EHCI_LIST_END;
/*
* control requests may need a terminating data "status" ack;
* bulk ones may need a terminating short packet (zero length).
*/
if (likely (buf != 0)) {
int one_more = 0;
if (usb_pipecontrol (urb->pipe)) {
one_more = 1;
token ^= 0x0100; /* "in" <--> "out" */
token |= QTD_TOGGLE; /* force DATA1 */
} else if (usb_pipebulk (urb->pipe)
&& (urb->transfer_flags & URB_ZERO_PACKET)
&& !(urb->transfer_buffer_length % maxpacket)) {
one_more = 1;
}
if (one_more) {
qtd_prev = qtd;
qtd = ehci_qtd_alloc (ehci, flags);
if (unlikely (!qtd))
goto cleanup;
qtd->urb = urb;
qtd_prev->hw_next = QTD_NEXT (qtd->qtd_dma);
list_add_tail (&qtd->qtd_list, head);
/* never any data in such packets */
qtd_fill (qtd, 0, 0, token, 0);
}
}
/* by default, enable interrupt on urb completion */
if (likely (!(urb->transfer_flags & URB_NO_INTERRUPT)))
qtd->hw_token |= __constant_cpu_to_le32 (QTD_IOC);
return head;
cleanup:
qtd_list_free (ehci, urb, head);
return 0;
}
/*-------------------------------------------------------------------------*/
/*
* Hardware maintains data toggle (like OHCI) ... here we (re)initialize
* the hardware data toggle in the QH, and set the pseudo-toggle in udev
* so we can see if usb_clear_halt() was called. NOP for control, since
* we set up qh->hw_info1 to always use the QTD toggle bits.
*/
static inline void
clear_toggle (struct usb_device *udev, int ep, int is_out, struct ehci_qh *qh)
{
vdbg ("clear toggle, dev %d ep 0x%x-%s",
udev->devnum, ep, is_out ? "out" : "in");
qh->hw_token &= ~__constant_cpu_to_le32 (QTD_TOGGLE);
usb_settoggle (udev, ep, is_out, 1);
}
// Would be best to create all qh's from config descriptors,
// when each interface/altsetting is established. Unlink
// any previous qh and cancel its urbs first; endpoints are
// implicitly reset then (data toggle too).
// That'd mean updating how usbcore talks to HCDs. (2.5?)
/*
* Each QH holds a qtd list; a QH is used for everything except iso.
*
* For interrupt urbs, the scheduler must set the microframe scheduling
* mask(s) each time the QH gets scheduled. For highspeed, that's
* just one microframe in the s-mask. For split interrupt transactions
* there are additional complications: c-mask, maybe FSTNs.
*/
static struct ehci_qh *
qh_make (
struct ehci_hcd *ehci,
struct urb *urb,
int flags
) {
struct ehci_qh *qh = ehci_qh_alloc (ehci, flags);
u32 info1 = 0, info2 = 0;
int is_input, type;
int maxp = 0;
if (!qh)
return qh;
/*
* init endpoint/device data for this QH
*/
info1 |= usb_pipeendpoint (urb->pipe) << 8;
info1 |= usb_pipedevice (urb->pipe) << 0;
is_input = usb_pipein (urb->pipe);
type = usb_pipetype (urb->pipe);
maxp = usb_maxpacket (urb->dev, urb->pipe, !is_input);
/* Compute interrupt scheduling parameters just once, and save.
* - allowing for high bandwidth, how many nsec/uframe are used?
* - split transactions need a second CSPLIT uframe; same question
* - splits also need a schedule gap (for full/low speed I/O)
* - qh has a polling interval
*
* For control/bulk requests, the HC or TT handles these.
*/
if (type == PIPE_INTERRUPT) {
qh->usecs = usb_calc_bus_time (USB_SPEED_HIGH, is_input, 0,
hb_mult (maxp) * max_packet (maxp));
qh->start = NO_FRAME;
if (urb->dev->speed == USB_SPEED_HIGH) {
qh->c_usecs = 0;
qh->gap_uf = 0;
/* FIXME handle HS periods of less than 1 frame. */
qh->period = urb->interval >> 3;
if (qh->period < 1) {
dbg ("intr period %d uframes, NYET!",
urb->interval);
goto done;
}
} else {
/* gap is f(FS/LS transfer times) */
qh->gap_uf = 1 + usb_calc_bus_time (urb->dev->speed,
is_input, 0, maxp) / (125 * 1000);
/* FIXME this just approximates SPLIT/CSPLIT times */
if (is_input) { // SPLIT, gap, CSPLIT+DATA
qh->c_usecs = qh->usecs + HS_USECS (0);
qh->usecs = HS_USECS (1);
} else { // SPLIT+DATA, gap, CSPLIT
qh->usecs += HS_USECS (1);
qh->c_usecs = HS_USECS (0);
}
qh->period = urb->interval;
}
}
/* using TT? */
switch (urb->dev->speed) {
case USB_SPEED_LOW:
info1 |= (1 << 12); /* EPS "low" */
/* FALL THROUGH */
case USB_SPEED_FULL:
/* EPS 0 means "full" */
if (type != PIPE_INTERRUPT)
info1 |= (EHCI_TUNE_RL_TT << 28);
if (type == PIPE_CONTROL) {
info1 |= (1 << 27); /* for TT */
info1 |= 1 << 14; /* toggle from qtd */
}
info1 |= maxp << 16;
info2 |= (EHCI_TUNE_MULT_TT << 30);
info2 |= urb->dev->ttport << 23;
info2 |= urb->dev->tt->hub->devnum << 16;
/* NOTE: if (PIPE_INTERRUPT) { scheduler sets c-mask } */
break;
case USB_SPEED_HIGH: /* no TT involved */
info1 |= (2 << 12); /* EPS "high" */
if (type == PIPE_CONTROL) {
info1 |= (EHCI_TUNE_RL_HS << 28);
info1 |= 64 << 16; /* usb2 fixed maxpacket */
info1 |= 1 << 14; /* toggle from qtd */
info2 |= (EHCI_TUNE_MULT_HS << 30);
} else if (type == PIPE_BULK) {
info1 |= (EHCI_TUNE_RL_HS << 28);
info1 |= 512 << 16; /* usb2 fixed maxpacket */
info2 |= (EHCI_TUNE_MULT_HS << 30);
} else { /* PIPE_INTERRUPT */
info1 |= max_packet (maxp) << 16;
info2 |= hb_mult (maxp) << 30;
}
break;
default:
dbg ("bogus dev %p speed %d", urb->dev, urb->dev->speed);
done:
qh_put (ehci, qh);
return 0;
}
/* NOTE: if (PIPE_INTERRUPT) { scheduler sets s-mask } */
/* init as live, toggle clear, advance to dummy */
qh->qh_state = QH_STATE_IDLE;
qh->hw_info1 = cpu_to_le32 (info1);
qh->hw_info2 = cpu_to_le32 (info2);
qh_update (ehci, qh, qh->dummy);
usb_settoggle (urb->dev, usb_pipeendpoint (urb->pipe), !is_input, 1);
return qh;
}
#undef hb_mult
#undef hb_packet
/*-------------------------------------------------------------------------*/
/* move qh (and its qtds) onto async queue; maybe enable queue. */
static void qh_link_async (struct ehci_hcd *ehci, struct ehci_qh *qh)
{
u32 dma = QH_NEXT (qh->qh_dma);
struct ehci_qh *head;
/* (re)start the async schedule? */
head = ehci->async;
timer_action_done (ehci, TIMER_ASYNC_OFF);
if (!head->qh_next.qh) {
u32 cmd = readl (&ehci->regs->command);
if (!(cmd & CMD_ASE)) {
/* in case a clear of CMD_ASE didn't take yet */
(void) handshake (&ehci->regs->status, STS_ASS, 0, 150);
cmd |= CMD_ASE | CMD_RUN;
writel (cmd, &ehci->regs->command);
ehci->hcd.state = USB_STATE_RUNNING;
/* posted write need not be known to HC yet ... */
}
}
qh->hw_token &= ~HALT_BIT;
/* splice right after start */
qh->qh_next = head->qh_next;
qh->hw_next = head->hw_next;
wmb ();
head->qh_next.qh = qh;
head->hw_next = dma;
qh->qh_state = QH_STATE_LINKED;
/* qtd completions reported later by interrupt */
}
/*-------------------------------------------------------------------------*/
#define QH_ADDR_MASK __constant_le32_to_cpu(0x7f)
/*
* For control/bulk/interrupt, return QH with these TDs appended.
* Allocates and initializes the QH if necessary.
* Returns null if it can't allocate a QH it needs to.
* If the QH has TDs (urbs) already, that's great.
*/
static struct ehci_qh *qh_append_tds (
struct ehci_hcd *ehci,
struct urb *urb,
struct list_head *qtd_list,
int epnum,
void **ptr
)
{
struct ehci_qh *qh = 0;
qh = (struct ehci_qh *) *ptr;
if (unlikely (qh == 0)) {
/* can't sleep here, we have ehci->lock... */
qh = qh_make (ehci, urb, SLAB_ATOMIC);
*ptr = qh;
}
if (likely (qh != 0)) {
struct ehci_qtd *qtd;
if (unlikely (list_empty (qtd_list)))
qtd = 0;
else
qtd = list_entry (qtd_list->next, struct ehci_qtd,
qtd_list);
/* control qh may need patching after enumeration */
if (unlikely (epnum == 0)) {
/* set_address changes the address */
if ((qh->hw_info1 & QH_ADDR_MASK) == 0)
qh->hw_info1 |= cpu_to_le32 (
usb_pipedevice (urb->pipe));
/* for full speed, ep0 maxpacket can grow */
else if (!(qh->hw_info1
& __constant_cpu_to_le32 (0x3 << 12))) {
u32 info, max;
info = le32_to_cpu (qh->hw_info1);
max = urb->dev->descriptor.bMaxPacketSize0;
if (max > (0x07ff & (info >> 16))) {
info &= ~(0x07ff << 16);
info |= max << 16;
qh->hw_info1 = cpu_to_le32 (info);
}
}
/* usb_reset_device() briefly reverts to address 0 */
if (usb_pipedevice (urb->pipe) == 0)
qh->hw_info1 &= ~QH_ADDR_MASK;
}
/* usb_clear_halt() means qh data toggle gets reset */
if (unlikely (!usb_gettoggle (urb->dev,
(epnum & 0x0f), !(epnum & 0x10)))
&& !usb_pipecontrol (urb->pipe)) {
/* "never happens": drivers do stall cleanup right */
if (qh->qh_state != QH_STATE_IDLE
&& !list_empty (&qh->qtd_list)
&& qh->qh_state != QH_STATE_COMPLETING)
ehci_warn (ehci, "clear toggle dev%d "
"ep%d%s: not idle\n",
usb_pipedevice (urb->pipe),
epnum & 0x0f,
usb_pipein (urb->pipe)
? "in" : "out");
/* else we know this overlay write is safe */
clear_toggle (urb->dev,
epnum & 0x0f, !(epnum & 0x10), qh);
}
/* just one way to queue requests: swap with the dummy qtd.
* only hc or qh_completions() usually modify the overlay.
*/
if (likely (qtd != 0)) {
struct ehci_qtd *dummy;
dma_addr_t dma;
u32 token;
/* to avoid racing the HC, use the dummy td instead of
* the first td of our list (becomes new dummy). both
* tds stay deactivated until we're done, when the
* HC is allowed to fetch the old dummy (4.10.2).
*/
token = qtd->hw_token;
qtd->hw_token = HALT_BIT;
wmb ();
dummy = qh->dummy;
dma = dummy->qtd_dma;
*dummy = *qtd;
dummy->qtd_dma = dma;
list_del (&qtd->qtd_list);
list_add (&dummy->qtd_list, qtd_list);
__list_splice (qtd_list, qh->qtd_list.prev);
ehci_qtd_init (qtd, qtd->qtd_dma);
qh->dummy = qtd;
/* hc must see the new dummy at list end */
dma = qtd->qtd_dma;
qtd = list_entry (qh->qtd_list.prev,
struct ehci_qtd, qtd_list);
qtd->hw_next = QTD_NEXT (dma);
/* let the hc process these next qtds */
wmb ();
dummy->hw_token = token;
urb->hcpriv = qh_get (qh);
}
}
return qh;
}
/*-------------------------------------------------------------------------*/
static int
submit_async (
struct ehci_hcd *ehci,
struct urb *urb,
struct list_head *qtd_list,
int mem_flags
) {
struct ehci_qtd *qtd;
struct hcd_dev *dev;
int epnum;
unsigned long flags;
struct ehci_qh *qh = 0;
qtd = list_entry (qtd_list->next, struct ehci_qtd, qtd_list);
dev = (struct hcd_dev *)urb->dev->hcpriv;
epnum = usb_pipeendpoint (urb->pipe);
if (usb_pipein (urb->pipe) && !usb_pipecontrol (urb->pipe))
epnum |= 0x10;
ehci_vdbg (ehci, "submit_async urb %p len %d ep%d%s qtd %p [qh %p]\n",
urb, urb->transfer_buffer_length,
epnum & 0x0f, (epnum & 0x10) ? "in" : "out",
qtd, dev ? dev->ep [epnum] : (void *)~0);
spin_lock_irqsave (&ehci->lock, flags);
qh = qh_append_tds (ehci, urb, qtd_list, epnum, &dev->ep [epnum]);
/* Control/bulk operations through TTs don't need scheduling,
* the HC and TT handle it when the TT has a buffer ready.
*/
if (likely (qh != 0)) {
if (likely (qh->qh_state == QH_STATE_IDLE))
qh_link_async (ehci, qh_get (qh));
}
spin_unlock_irqrestore (&ehci->lock, flags);
if (unlikely (qh == 0)) {
qtd_list_free (ehci, urb, qtd_list);
return -ENOMEM;
}
return 0;
}
/*-------------------------------------------------------------------------*/
/* the async qh for the qtds being reclaimed are now unlinked from the HC */
static void start_unlink_async (struct ehci_hcd *ehci, struct ehci_qh *qh);
static void end_unlink_async (struct ehci_hcd *ehci, struct pt_regs *regs)
{
struct ehci_qh *qh = ehci->reclaim;
struct ehci_qh *next;
timer_action_done (ehci, TIMER_IAA_WATCHDOG);
// qh->hw_next = cpu_to_le32 (qh->qh_dma);
qh->qh_state = QH_STATE_IDLE;
qh->qh_next.qh = 0;
qh_put (ehci, qh); // refcount from reclaim
/* other unlink(s) may be pending (in QH_STATE_UNLINK_WAIT) */
next = qh->reclaim;
ehci->reclaim = next;
ehci->reclaim_ready = 0;
qh->reclaim = 0;
qh_completions (ehci, qh, regs);
if (!list_empty (&qh->qtd_list)
&& HCD_IS_RUNNING (ehci->hcd.state))
qh_link_async (ehci, qh);
else {
qh_put (ehci, qh); // refcount from async list
/* it's not free to turn the async schedule on/off; leave it
* active but idle for a while once it empties.
*/
if (HCD_IS_RUNNING (ehci->hcd.state)
&& ehci->async->qh_next.qh == 0)
timer_action (ehci, TIMER_ASYNC_OFF);
}
if (next) {
ehci->reclaim = 0;
start_unlink_async (ehci, next);
}
}
/* makes sure the async qh will become idle */
/* caller must own ehci->lock */
static void start_unlink_async (struct ehci_hcd *ehci, struct ehci_qh *qh)
{
int cmd = readl (&ehci->regs->command);
struct ehci_qh *prev;
#ifdef DEBUG
if (ehci->reclaim
|| (qh->qh_state != QH_STATE_LINKED
&& qh->qh_state != QH_STATE_UNLINK_WAIT)
#ifdef CONFIG_SMP
// this macro lies except on SMP compiles
|| !spin_is_locked (&ehci->lock)
#endif
)
BUG ();
#endif
/* stop async schedule right now? */
if (unlikely (qh == ehci->async)) {
/* can't get here without STS_ASS set */
if (ehci->hcd.state != USB_STATE_HALT) {
writel (cmd & ~CMD_ASE, &ehci->regs->command);
wmb ();
// handshake later, if we need to
}
timer_action_done (ehci, TIMER_ASYNC_OFF);
return;
}
qh->qh_state = QH_STATE_UNLINK;
ehci->reclaim = qh = qh_get (qh);
prev = ehci->async;
while (prev->qh_next.qh != qh)
prev = prev->qh_next.qh;
prev->hw_next = qh->hw_next;
prev->qh_next = qh->qh_next;
wmb ();
if (unlikely (ehci->hcd.state == USB_STATE_HALT)) {
/* if (unlikely (qh->reclaim != 0))
* this will recurse, probably not much
*/
end_unlink_async (ehci, NULL);
return;
}
ehci->reclaim_ready = 0;
cmd |= CMD_IAAD;
writel (cmd, &ehci->regs->command);
(void) readl (&ehci->regs->command);
timer_action (ehci, TIMER_IAA_WATCHDOG);
}
/*-------------------------------------------------------------------------*/
static void
scan_async (struct ehci_hcd *ehci, struct pt_regs *regs)
{
struct ehci_qh *qh;
enum ehci_timer_action action = TIMER_IO_WATCHDOG;
if (!++(ehci->stamp))
ehci->stamp++;
timer_action_done (ehci, TIMER_ASYNC_SHRINK);
rescan:
qh = ehci->async->qh_next.qh;
if (likely (qh != 0)) {
do {
/* clean any finished work for this qh */
if (!list_empty (&qh->qtd_list)
&& qh->stamp != ehci->stamp) {
int temp;
/* unlinks could happen here; completion
* reporting drops the lock. rescan using
* the latest schedule, but don't rescan
* qhs we already finished (no looping).
*/
qh = qh_get (qh);
qh->stamp = ehci->stamp;
temp = qh_completions (ehci, qh, regs);
qh_put (ehci, qh);
if (temp != 0) {
goto rescan;
}
}
/* unlink idle entries, reducing HC PCI usage as well
* as HCD schedule-scanning costs. delay for any qh
* we just scanned, there's a not-unusual case that it
* doesn't stay idle for long.
* (plus, avoids some kind of re-activation race.)
*/
if (list_empty (&qh->qtd_list)) {
if (qh->stamp == ehci->stamp)
action = TIMER_ASYNC_SHRINK;
else if (!ehci->reclaim
&& qh->qh_state == QH_STATE_LINKED)
start_unlink_async (ehci, qh);
}
qh = qh->qh_next.qh;
} while (qh);
}
if (action == TIMER_ASYNC_SHRINK)
timer_action (ehci, TIMER_ASYNC_SHRINK);
}