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kernel_samsung_a34x-permissive/drivers/usb/host/ehci-sched.c

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Import A346BXXU1AWB9 kernel source Android 13
2024-04-28 06:49:01 -07:00
// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (c) 2001-2004 by David Brownell
* Copyright (c) 2003 Michal Sojka, for high-speed iso transfers
*/
/* this file is part of ehci-hcd.c */
/*-------------------------------------------------------------------------*/
/*
* EHCI scheduled transaction support: interrupt, iso, split iso
* These are called "periodic" transactions in the EHCI spec.
*
* Note that for interrupt transfers, the QH/QTD manipulation is shared
* with the "asynchronous" transaction support (control/bulk transfers).
* The only real difference is in how interrupt transfers are scheduled.
*
* For ISO, we make an "iso_stream" head to serve the same role as a QH.
* It keeps track of every ITD (or SITD) that's linked, and holds enough
* pre-calculated schedule data to make appending to the queue be quick.
*/
static int ehci_get_frame(struct usb_hcd *hcd);
/*
* periodic_next_shadow - return "next" pointer on shadow list
* @periodic: host pointer to qh/itd/sitd
* @tag: hardware tag for type of this record
*/
static union ehci_shadow *
periodic_next_shadow(struct ehci_hcd *ehci, union ehci_shadow *periodic,
__hc32 tag)
{
switch (hc32_to_cpu(ehci, tag)) {
case Q_TYPE_QH:
return &periodic->qh->qh_next;
case Q_TYPE_FSTN:
return &periodic->fstn->fstn_next;
case Q_TYPE_ITD:
return &periodic->itd->itd_next;
/* case Q_TYPE_SITD: */
default:
return &periodic->sitd->sitd_next;
}
}
static __hc32 *
shadow_next_periodic(struct ehci_hcd *ehci, union ehci_shadow *periodic,
__hc32 tag)
{
switch (hc32_to_cpu(ehci, tag)) {
/* our ehci_shadow.qh is actually software part */
case Q_TYPE_QH:
return &periodic->qh->hw->hw_next;
/* others are hw parts */
default:
return periodic->hw_next;
}
}
/* caller must hold ehci->lock */
static void periodic_unlink(struct ehci_hcd *ehci, unsigned frame, void *ptr)
{
union ehci_shadow *prev_p = &ehci->pshadow[frame];
__hc32 *hw_p = &ehci->periodic[frame];
union ehci_shadow here = *prev_p;
/* find predecessor of "ptr"; hw and shadow lists are in sync */
while (here.ptr && here.ptr != ptr) {
prev_p = periodic_next_shadow(ehci, prev_p,
Q_NEXT_TYPE(ehci, *hw_p));
hw_p = shadow_next_periodic(ehci, &here,
Q_NEXT_TYPE(ehci, *hw_p));
here = *prev_p;
}
/* an interrupt entry (at list end) could have been shared */
if (!here.ptr)
return;
/* update shadow and hardware lists ... the old "next" pointers
* from ptr may still be in use, the caller updates them.
*/
*prev_p = *periodic_next_shadow(ehci, &here,
Q_NEXT_TYPE(ehci, *hw_p));
if (!ehci->use_dummy_qh ||
*shadow_next_periodic(ehci, &here, Q_NEXT_TYPE(ehci, *hw_p))
!= EHCI_LIST_END(ehci))
*hw_p = *shadow_next_periodic(ehci, &here,
Q_NEXT_TYPE(ehci, *hw_p));
else
*hw_p = cpu_to_hc32(ehci, ehci->dummy->qh_dma);
}
/*-------------------------------------------------------------------------*/
/* Bandwidth and TT management */
/* Find the TT data structure for this device; create it if necessary */
static struct ehci_tt *find_tt(struct usb_device *udev)
{
struct usb_tt *utt = udev->tt;
struct ehci_tt *tt, **tt_index, **ptt;
unsigned port;
bool allocated_index = false;
if (!utt)
return NULL; /* Not below a TT */
/*
* Find/create our data structure.
* For hubs with a single TT, we get it directly.
* For hubs with multiple TTs, there's an extra level of pointers.
*/
tt_index = NULL;
if (utt->multi) {
tt_index = utt->hcpriv;
if (!tt_index) { /* Create the index array */
tt_index = kcalloc(utt->hub->maxchild,
sizeof(*tt_index),
GFP_ATOMIC);
if (!tt_index)
return ERR_PTR(-ENOMEM);
utt->hcpriv = tt_index;
allocated_index = true;
}
port = udev->ttport - 1;
ptt = &tt_index[port];
} else {
port = 0;
ptt = (struct ehci_tt **) &utt->hcpriv;
}
tt = *ptt;
if (!tt) { /* Create the ehci_tt */
struct ehci_hcd *ehci =
hcd_to_ehci(bus_to_hcd(udev->bus));
tt = kzalloc(sizeof(*tt), GFP_ATOMIC);
if (!tt) {
if (allocated_index) {
utt->hcpriv = NULL;
kfree(tt_index);
}
return ERR_PTR(-ENOMEM);
}
list_add_tail(&tt->tt_list, &ehci->tt_list);
INIT_LIST_HEAD(&tt->ps_list);
tt->usb_tt = utt;
tt->tt_port = port;
*ptt = tt;
}
return tt;
}
/* Release the TT above udev, if it's not in use */
static void drop_tt(struct usb_device *udev)
{
struct usb_tt *utt = udev->tt;
struct ehci_tt *tt, **tt_index, **ptt;
int cnt, i;
if (!utt || !utt->hcpriv)
return; /* Not below a TT, or never allocated */
cnt = 0;
if (utt->multi) {
tt_index = utt->hcpriv;
ptt = &tt_index[udev->ttport - 1];
/* How many entries are left in tt_index? */
for (i = 0; i < utt->hub->maxchild; ++i)
cnt += !!tt_index[i];
} else {
tt_index = NULL;
ptt = (struct ehci_tt **) &utt->hcpriv;
}
tt = *ptt;
if (!tt || !list_empty(&tt->ps_list))
return; /* never allocated, or still in use */
list_del(&tt->tt_list);
*ptt = NULL;
kfree(tt);
if (cnt == 1) {
utt->hcpriv = NULL;
kfree(tt_index);
}
}
static void bandwidth_dbg(struct ehci_hcd *ehci, int sign, char *type,
struct ehci_per_sched *ps)
{
dev_dbg(&ps->udev->dev,
"ep %02x: %s %s @ %u+%u (%u.%u+%u) [%u/%u us] mask %04x\n",
ps->ep->desc.bEndpointAddress,
(sign >= 0 ? "reserve" : "release"), type,
(ps->bw_phase << 3) + ps->phase_uf, ps->bw_uperiod,
ps->phase, ps->phase_uf, ps->period,
ps->usecs, ps->c_usecs, ps->cs_mask);
}
static void reserve_release_intr_bandwidth(struct ehci_hcd *ehci,
struct ehci_qh *qh, int sign)
{
unsigned start_uf;
unsigned i, j, m;
int usecs = qh->ps.usecs;
int c_usecs = qh->ps.c_usecs;
int tt_usecs = qh->ps.tt_usecs;
struct ehci_tt *tt;
if (qh->ps.phase == NO_FRAME) /* Bandwidth wasn't reserved */
return;
start_uf = qh->ps.bw_phase << 3;
bandwidth_dbg(ehci, sign, "intr", &qh->ps);
if (sign < 0) { /* Release bandwidth */
usecs = -usecs;
c_usecs = -c_usecs;
tt_usecs = -tt_usecs;
}
/* Entire transaction (high speed) or start-split (full/low speed) */
for (i = start_uf + qh->ps.phase_uf; i < EHCI_BANDWIDTH_SIZE;
i += qh->ps.bw_uperiod)
ehci->bandwidth[i] += usecs;
/* Complete-split (full/low speed) */
if (qh->ps.c_usecs) {
/* NOTE: adjustments needed for FSTN */
for (i = start_uf; i < EHCI_BANDWIDTH_SIZE;
i += qh->ps.bw_uperiod) {
for ((j = 2, m = 1 << (j+8)); j < 8; (++j, m <<= 1)) {
if (qh->ps.cs_mask & m)
ehci->bandwidth[i+j] += c_usecs;
}
}
}
/* FS/LS bus bandwidth */
if (tt_usecs) {
tt = find_tt(qh->ps.udev);
if (sign > 0)
list_add_tail(&qh->ps.ps_list, &tt->ps_list);
else
list_del(&qh->ps.ps_list);
for (i = start_uf >> 3; i < EHCI_BANDWIDTH_FRAMES;
i += qh->ps.bw_period)
tt->bandwidth[i] += tt_usecs;
}
}
/*-------------------------------------------------------------------------*/
static void compute_tt_budget(u8 budget_table[EHCI_BANDWIDTH_SIZE],
struct ehci_tt *tt)
{
struct ehci_per_sched *ps;
unsigned uframe, uf, x;
u8 *budget_line;
if (!tt)
return;
memset(budget_table, 0, EHCI_BANDWIDTH_SIZE);
/* Add up the contributions from all the endpoints using this TT */
list_for_each_entry(ps, &tt->ps_list, ps_list) {
for (uframe = ps->bw_phase << 3; uframe < EHCI_BANDWIDTH_SIZE;
uframe += ps->bw_uperiod) {
budget_line = &budget_table[uframe];
x = ps->tt_usecs;
/* propagate the time forward */
for (uf = ps->phase_uf; uf < 8; ++uf) {
x += budget_line[uf];
/* Each microframe lasts 125 us */
if (x <= 125) {
budget_line[uf] = x;
break;
}
budget_line[uf] = 125;
x -= 125;
}
}
}
}
static int __maybe_unused same_tt(struct usb_device *dev1,
struct usb_device *dev2)
{
if (!dev1->tt || !dev2->tt)
return 0;
if (dev1->tt != dev2->tt)
return 0;
if (dev1->tt->multi)
return dev1->ttport == dev2->ttport;
else
return 1;
}
#ifdef CONFIG_USB_EHCI_TT_NEWSCHED
/* Which uframe does the low/fullspeed transfer start in?
*
* The parameter is the mask of ssplits in "H-frame" terms
* and this returns the transfer start uframe in "B-frame" terms,
* which allows both to match, e.g. a ssplit in "H-frame" uframe 0
* will cause a transfer in "B-frame" uframe 0. "B-frames" lag
* "H-frames" by 1 uframe. See the EHCI spec sec 4.5 and figure 4.7.
*/
static inline unsigned char tt_start_uframe(struct ehci_hcd *ehci, __hc32 mask)
{
unsigned char smask = hc32_to_cpu(ehci, mask) & QH_SMASK;
if (!smask) {
ehci_err(ehci, "invalid empty smask!\n");
/* uframe 7 can't have bw so this will indicate failure */
return 7;
}
return ffs(smask) - 1;
}
static const unsigned char
max_tt_usecs[] = { 125, 125, 125, 125, 125, 125, 30, 0 };
/* carryover low/fullspeed bandwidth that crosses uframe boundries */
static inline void carryover_tt_bandwidth(unsigned short tt_usecs[8])
{
int i;
for (i = 0; i < 7; i++) {
if (max_tt_usecs[i] < tt_usecs[i]) {
tt_usecs[i+1] += tt_usecs[i] - max_tt_usecs[i];
tt_usecs[i] = max_tt_usecs[i];
}
}
}
/*
* Return true if the device's tt's downstream bus is available for a
* periodic transfer of the specified length (usecs), starting at the
* specified frame/uframe. Note that (as summarized in section 11.19
* of the usb 2.0 spec) TTs can buffer multiple transactions for each
* uframe.
*
* The uframe parameter is when the fullspeed/lowspeed transfer
* should be executed in "B-frame" terms, which is the same as the
* highspeed ssplit's uframe (which is in "H-frame" terms). For example
* a ssplit in "H-frame" 0 causes a transfer in "B-frame" 0.
* See the EHCI spec sec 4.5 and fig 4.7.
*
* This checks if the full/lowspeed bus, at the specified starting uframe,
* has the specified bandwidth available, according to rules listed
* in USB 2.0 spec section 11.18.1 fig 11-60.
*
* This does not check if the transfer would exceed the max ssplit
* limit of 16, specified in USB 2.0 spec section 11.18.4 requirement #4,
* since proper scheduling limits ssplits to less than 16 per uframe.
*/
static int tt_available(
struct ehci_hcd *ehci,
struct ehci_per_sched *ps,
struct ehci_tt *tt,
unsigned frame,
unsigned uframe
)
{
unsigned period = ps->bw_period;
unsigned usecs = ps->tt_usecs;
if ((period == 0) || (uframe >= 7)) /* error */
return 0;
for (frame &= period - 1; frame < EHCI_BANDWIDTH_FRAMES;
frame += period) {
unsigned i, uf;
unsigned short tt_usecs[8];
if (tt->bandwidth[frame] + usecs > 900)
return 0;
uf = frame << 3;
for (i = 0; i < 8; (++i, ++uf))
tt_usecs[i] = ehci->tt_budget[uf];
if (max_tt_usecs[uframe] <= tt_usecs[uframe])
return 0;
/* special case for isoc transfers larger than 125us:
* the first and each subsequent fully used uframe
* must be empty, so as to not illegally delay
* already scheduled transactions
*/
if (usecs > 125) {
int ufs = (usecs / 125);
for (i = uframe; i < (uframe + ufs) && i < 8; i++)
if (tt_usecs[i] > 0)
return 0;
}
tt_usecs[uframe] += usecs;
carryover_tt_bandwidth(tt_usecs);
/* fail if the carryover pushed bw past the last uframe's limit */
if (max_tt_usecs[7] < tt_usecs[7])
return 0;
}
return 1;
}
#else
/* return true iff the device's transaction translator is available
* for a periodic transfer starting at the specified frame, using
* all the uframes in the mask.
*/
static int tt_no_collision(
struct ehci_hcd *ehci,
unsigned period,
struct usb_device *dev,
unsigned frame,
u32 uf_mask
)
{
if (period == 0) /* error */
return 0;
/* note bandwidth wastage: split never follows csplit
* (different dev or endpoint) until the next uframe.
* calling convention doesn't make that distinction.
*/
for (; frame < ehci->periodic_size; frame += period) {
union ehci_shadow here;
__hc32 type;
struct ehci_qh_hw *hw;
here = ehci->pshadow[frame];
type = Q_NEXT_TYPE(ehci, ehci->periodic[frame]);
while (here.ptr) {
switch (hc32_to_cpu(ehci, type)) {
case Q_TYPE_ITD:
type = Q_NEXT_TYPE(ehci, here.itd->hw_next);
here = here.itd->itd_next;
continue;
case Q_TYPE_QH:
hw = here.qh->hw;
if (same_tt(dev, here.qh->ps.udev)) {
u32 mask;
mask = hc32_to_cpu(ehci,
hw->hw_info2);
/* "knows" no gap is needed */
mask |= mask >> 8;
if (mask & uf_mask)
break;
}
type = Q_NEXT_TYPE(ehci, hw->hw_next);
here = here.qh->qh_next;
continue;
case Q_TYPE_SITD:
if (same_tt(dev, here.sitd->urb->dev)) {
u16 mask;
mask = hc32_to_cpu(ehci, here.sitd
->hw_uframe);
/* FIXME assumes no gap for IN! */
mask |= mask >> 8;
if (mask & uf_mask)
break;
}
type = Q_NEXT_TYPE(ehci, here.sitd->hw_next);
here = here.sitd->sitd_next;
continue;
/* case Q_TYPE_FSTN: */
default:
ehci_dbg(ehci,
"periodic frame %d bogus type %d\n",
frame, type);
}
/* collision or error */
return 0;
}
}
/* no collision */
return 1;
}
#endif /* CONFIG_USB_EHCI_TT_NEWSCHED */
/*-------------------------------------------------------------------------*/
static void enable_periodic(struct ehci_hcd *ehci)
{
if (ehci->periodic_count++)
return;
/* Stop waiting to turn off the periodic schedule */
ehci->enabled_hrtimer_events &= ~BIT(EHCI_HRTIMER_DISABLE_PERIODIC);
/* Don't start the schedule until PSS is 0 */
ehci_poll_PSS(ehci);
turn_on_io_watchdog(ehci);
}
static void disable_periodic(struct ehci_hcd *ehci)
{
if (--ehci->periodic_count)
return;
/* Don't turn off the schedule until PSS is 1 */
ehci_poll_PSS(ehci);
}
/*-------------------------------------------------------------------------*/
/* periodic schedule slots have iso tds (normal or split) first, then a
* sparse tree for active interrupt transfers.
*
* this just links in a qh; caller guarantees uframe masks are set right.
* no FSTN support (yet; ehci 0.96+)
*/
static void qh_link_periodic(struct ehci_hcd *ehci, struct ehci_qh *qh)
{
unsigned i;
unsigned period = qh->ps.period;
dev_dbg(&qh->ps.udev->dev,
"link qh%d-%04x/%p start %d [%d/%d us]\n",
period, hc32_to_cpup(ehci, &qh->hw->hw_info2)
& (QH_CMASK | QH_SMASK),
qh, qh->ps.phase, qh->ps.usecs, qh->ps.c_usecs);
/* high bandwidth, or otherwise every microframe */
if (period == 0)
period = 1;
for (i = qh->ps.phase; i < ehci->periodic_size; i += period) {
union ehci_shadow *prev = &ehci->pshadow[i];
__hc32 *hw_p = &ehci->periodic[i];
union ehci_shadow here = *prev;
__hc32 type = 0;
/* skip the iso nodes at list head */
while (here.ptr) {
type = Q_NEXT_TYPE(ehci, *hw_p);
if (type == cpu_to_hc32(ehci, Q_TYPE_QH))
break;
prev = periodic_next_shadow(ehci, prev, type);
hw_p = shadow_next_periodic(ehci, &here, type);
here = *prev;
}
/* sorting each branch by period (slow-->fast)
* enables sharing interior tree nodes
*/
while (here.ptr && qh != here.qh) {
if (qh->ps.period > here.qh->ps.period)
break;
prev = &here.qh->qh_next;
hw_p = &here.qh->hw->hw_next;
here = *prev;
}
/* link in this qh, unless some earlier pass did that */
if (qh != here.qh) {
qh->qh_next = here;
if (here.qh)
qh->hw->hw_next = *hw_p;
wmb();
prev->qh = qh;
*hw_p = QH_NEXT(ehci, qh->qh_dma);
}
}
qh->qh_state = QH_STATE_LINKED;
qh->xacterrs = 0;
qh->unlink_reason = 0;
/* update per-qh bandwidth for debugfs */
ehci_to_hcd(ehci)->self.bandwidth_allocated += qh->ps.bw_period
? ((qh->ps.usecs + qh->ps.c_usecs) / qh->ps.bw_period)
: (qh->ps.usecs * 8);
list_add(&qh->intr_node, &ehci->intr_qh_list);
/* maybe enable periodic schedule processing */
++ehci->intr_count;
enable_periodic(ehci);
}
static void qh_unlink_periodic(struct ehci_hcd *ehci, struct ehci_qh *qh)
{
unsigned i;
unsigned period;
/*
* If qh is for a low/full-speed device, simply unlinking it
* could interfere with an ongoing split transaction. To unlink
* it safely would require setting the QH_INACTIVATE bit and
* waiting at least one frame, as described in EHCI 4.12.2.5.
*
* We won't bother with any of this. Instead, we assume that the
* only reason for unlinking an interrupt QH while the current URB
* is still active is to dequeue all the URBs (flush the whole
* endpoint queue).
*
* If rebalancing the periodic schedule is ever implemented, this
* approach will no longer be valid.
*/
/* high bandwidth, or otherwise part of every microframe */
period = qh->ps.period ? : 1;
for (i = qh->ps.phase; i < ehci->periodic_size; i += period)
periodic_unlink(ehci, i, qh);
/* update per-qh bandwidth for debugfs */
ehci_to_hcd(ehci)->self.bandwidth_allocated -= qh->ps.bw_period
? ((qh->ps.usecs + qh->ps.c_usecs) / qh->ps.bw_period)
: (qh->ps.usecs * 8);
dev_dbg(&qh->ps.udev->dev,
"unlink qh%d-%04x/%p start %d [%d/%d us]\n",
qh->ps.period,
hc32_to_cpup(ehci, &qh->hw->hw_info2) & (QH_CMASK | QH_SMASK),
qh, qh->ps.phase, qh->ps.usecs, qh->ps.c_usecs);
/* qh->qh_next still "live" to HC */
qh->qh_state = QH_STATE_UNLINK;
qh->qh_next.ptr = NULL;
if (ehci->qh_scan_next == qh)
ehci->qh_scan_next = list_entry(qh->intr_node.next,
struct ehci_qh, intr_node);
list_del(&qh->intr_node);
}
static void cancel_unlink_wait_intr(struct ehci_hcd *ehci, struct ehci_qh *qh)
{
if (qh->qh_state != QH_STATE_LINKED ||
list_empty(&qh->unlink_node))
return;
list_del_init(&qh->unlink_node);
/*
* TODO: disable the event of EHCI_HRTIMER_START_UNLINK_INTR for
* avoiding unnecessary CPU wakeup
*/
}
static void start_unlink_intr(struct ehci_hcd *ehci, struct ehci_qh *qh)
{
/* If the QH isn't linked then there's nothing we can do. */
if (qh->qh_state != QH_STATE_LINKED)
return;
/* if the qh is waiting for unlink, cancel it now */
cancel_unlink_wait_intr(ehci, qh);
qh_unlink_periodic(ehci, qh);
/* Make sure the unlinks are visible before starting the timer */
wmb();
/*
* The EHCI spec doesn't say how long it takes the controller to
* stop accessing an unlinked interrupt QH. The timer delay is
* 9 uframes; presumably that will be long enough.
*/
qh->unlink_cycle = ehci->intr_unlink_cycle;
/* New entries go at the end of the intr_unlink list */
list_add_tail(&qh->unlink_node, &ehci->intr_unlink);
if (ehci->intr_unlinking)
; /* Avoid recursive calls */
else if (ehci->rh_state < EHCI_RH_RUNNING)
ehci_handle_intr_unlinks(ehci);
else if (ehci->intr_unlink.next == &qh->unlink_node) {
ehci_enable_event(ehci, EHCI_HRTIMER_UNLINK_INTR, true);
++ehci->intr_unlink_cycle;
}
}
/*
* It is common only one intr URB is scheduled on one qh, and
* given complete() is run in tasklet context, introduce a bit
* delay to avoid unlink qh too early.
*/
static void start_unlink_intr_wait(struct ehci_hcd *ehci,
struct ehci_qh *qh)
{
qh->unlink_cycle = ehci->intr_unlink_wait_cycle;
/* New entries go at the end of the intr_unlink_wait list */
list_add_tail(&qh->unlink_node, &ehci->intr_unlink_wait);
if (ehci->rh_state < EHCI_RH_RUNNING)
ehci_handle_start_intr_unlinks(ehci);
else if (ehci->intr_unlink_wait.next == &qh->unlink_node) {
ehci_enable_event(ehci, EHCI_HRTIMER_START_UNLINK_INTR, true);
++ehci->intr_unlink_wait_cycle;
}
}
static void end_unlink_intr(struct ehci_hcd *ehci, struct ehci_qh *qh)
{
struct ehci_qh_hw *hw = qh->hw;
int rc;
qh->qh_state = QH_STATE_IDLE;
hw->hw_next = EHCI_LIST_END(ehci);
if (!list_empty(&qh->qtd_list))
qh_completions(ehci, qh);
/* reschedule QH iff another request is queued */
if (!list_empty(&qh->qtd_list) && ehci->rh_state == EHCI_RH_RUNNING) {
rc = qh_schedule(ehci, qh);
if (rc == 0) {
qh_refresh(ehci, qh);
qh_link_periodic(ehci, qh);
}
/* An error here likely indicates handshake failure
* or no space left in the schedule. Neither fault
* should happen often ...
*
* FIXME kill the now-dysfunctional queued urbs
*/
else {
ehci_err(ehci, "can't reschedule qh %p, err %d\n",
qh, rc);
}
}
/* maybe turn off periodic schedule */
--ehci->intr_count;
disable_periodic(ehci);
}
/*-------------------------------------------------------------------------*/
static int check_period(
struct ehci_hcd *ehci,
unsigned frame,
unsigned uframe,
unsigned uperiod,
unsigned usecs
) {
/* complete split running into next frame?
* given FSTN support, we could sometimes check...
*/
if (uframe >= 8)
return 0;
/* convert "usecs we need" to "max already claimed" */
usecs = ehci->uframe_periodic_max - usecs;
for (uframe += frame << 3; uframe < EHCI_BANDWIDTH_SIZE;
uframe += uperiod) {
if (ehci->bandwidth[uframe] > usecs)
return 0;
}
/* success! */
return 1;
}
static int check_intr_schedule(
struct ehci_hcd *ehci,
unsigned frame,
unsigned uframe,
struct ehci_qh *qh,
unsigned *c_maskp,
struct ehci_tt *tt
)
{
int retval = -ENOSPC;
u8 mask = 0;
if (qh->ps.c_usecs && uframe >= 6) /* FSTN territory? */
goto done;
if (!check_period(ehci, frame, uframe, qh->ps.bw_uperiod, qh->ps.usecs))
goto done;
if (!qh->ps.c_usecs) {
retval = 0;
*c_maskp = 0;
goto done;
}
#ifdef CONFIG_USB_EHCI_TT_NEWSCHED
if (tt_available(ehci, &qh->ps, tt, frame, uframe)) {
unsigned i;
/* TODO : this may need FSTN for SSPLIT in uframe 5. */
for (i = uframe+2; i < 8 && i <= uframe+4; i++)
if (!check_period(ehci, frame, i,
qh->ps.bw_uperiod, qh->ps.c_usecs))
goto done;
else
mask |= 1 << i;
retval = 0;
*c_maskp = mask;
}
#else
/* Make sure this tt's buffer is also available for CSPLITs.
* We pessimize a bit; probably the typical full speed case
* doesn't need the second CSPLIT.
*
* NOTE: both SPLIT and CSPLIT could be checked in just
* one smart pass...
*/
mask = 0x03 << (uframe + qh->gap_uf);
*c_maskp = mask;
mask |= 1 << uframe;
if (tt_no_collision(ehci, qh->ps.bw_period, qh->ps.udev, frame, mask)) {
if (!check_period(ehci, frame, uframe + qh->gap_uf + 1,
qh->ps.bw_uperiod, qh->ps.c_usecs))
goto done;
if (!check_period(ehci, frame, uframe + qh->gap_uf,
qh->ps.bw_uperiod, qh->ps.c_usecs))
goto done;
retval = 0;
}
#endif
done:
return retval;
}
/* "first fit" scheduling policy used the first time through,
* or when the previous schedule slot can't be re-used.
*/
static int qh_schedule(struct ehci_hcd *ehci, struct ehci_qh *qh)
{
int status = 0;
unsigned uframe;
unsigned c_mask;
struct ehci_qh_hw *hw = qh->hw;
struct ehci_tt *tt;
hw->hw_next = EHCI_LIST_END(ehci);
/* reuse the previous schedule slots, if we can */
if (qh->ps.phase != NO_FRAME) {
ehci_dbg(ehci, "reused qh %p schedule\n", qh);
return 0;
}
uframe = 0;
c_mask = 0;
tt = find_tt(qh->ps.udev);
if (IS_ERR(tt)) {
status = PTR_ERR(tt);
goto done;
}
compute_tt_budget(ehci->tt_budget, tt);
/* else scan the schedule to find a group of slots such that all
* uframes have enough periodic bandwidth available.
*/
/* "normal" case, uframing flexible except with splits */
if (qh->ps.bw_period) {
int i;
unsigned frame;
for (i = qh->ps.bw_period; i > 0; --i) {
frame = ++ehci->random_frame & (qh->ps.bw_period - 1);
for (uframe = 0; uframe < 8; uframe++) {
status = check_intr_schedule(ehci,
frame, uframe, qh, &c_mask, tt);
if (status == 0)
goto got_it;
}
}
/* qh->ps.bw_period == 0 means every uframe */
} else {
status = check_intr_schedule(ehci, 0, 0, qh, &c_mask, tt);
}
if (status)
goto done;
got_it:
qh->ps.phase = (qh->ps.period ? ehci->random_frame &
(qh->ps.period - 1) : 0);
qh->ps.bw_phase = qh->ps.phase & (qh->ps.bw_period - 1);
qh->ps.phase_uf = uframe;
qh->ps.cs_mask = qh->ps.period ?
(c_mask << 8) | (1 << uframe) :
QH_SMASK;
/* reset S-frame and (maybe) C-frame masks */
hw->hw_info2 &= cpu_to_hc32(ehci, ~(QH_CMASK | QH_SMASK));
hw->hw_info2 |= cpu_to_hc32(ehci, qh->ps.cs_mask);
reserve_release_intr_bandwidth(ehci, qh, 1);
done:
return status;
}
static int intr_submit(
struct ehci_hcd *ehci,
struct urb *urb,
struct list_head *qtd_list,
gfp_t mem_flags
) {
unsigned epnum;
unsigned long flags;
struct ehci_qh *qh;
int status;
struct list_head empty;
/* get endpoint and transfer/schedule data */
epnum = urb->ep->desc.bEndpointAddress;
spin_lock_irqsave(&ehci->lock, flags);
if (unlikely(!HCD_HW_ACCESSIBLE(ehci_to_hcd(ehci)))) {
status = -ESHUTDOWN;
goto done_not_linked;
}
status = usb_hcd_link_urb_to_ep(ehci_to_hcd(ehci), urb);
if (unlikely(status))
goto done_not_linked;
/* get qh and force any scheduling errors */
INIT_LIST_HEAD(&empty);
qh = qh_append_tds(ehci, urb, &empty, epnum, &urb->ep->hcpriv);
if (qh == NULL) {
status = -ENOMEM;
goto done;
}
if (qh->qh_state == QH_STATE_IDLE) {
status = qh_schedule(ehci, qh);
if (status)
goto done;
}
/* then queue the urb's tds to the qh */
qh = qh_append_tds(ehci, urb, qtd_list, epnum, &urb->ep->hcpriv);
BUG_ON(qh == NULL);
/* stuff into the periodic schedule */
if (qh->qh_state == QH_STATE_IDLE) {
qh_refresh(ehci, qh);
qh_link_periodic(ehci, qh);
} else {
/* cancel unlink wait for the qh */
cancel_unlink_wait_intr(ehci, qh);
}
/* ... update usbfs periodic stats */
ehci_to_hcd(ehci)->self.bandwidth_int_reqs++;
done:
if (unlikely(status))
usb_hcd_unlink_urb_from_ep(ehci_to_hcd(ehci), urb);
done_not_linked:
spin_unlock_irqrestore(&ehci->lock, flags);
if (status)
qtd_list_free(ehci, urb, qtd_list);
return status;
}
static void scan_intr(struct ehci_hcd *ehci)
{
struct ehci_qh *qh;
list_for_each_entry_safe(qh, ehci->qh_scan_next, &ehci->intr_qh_list,
intr_node) {
/* clean any finished work for this qh */
if (!list_empty(&qh->qtd_list)) {
int temp;
/*
* Unlinks could happen here; completion reporting
* drops the lock. That's why ehci->qh_scan_next
* always holds the next qh to scan; if the next qh
* gets unlinked then ehci->qh_scan_next is adjusted
* in qh_unlink_periodic().
*/
temp = qh_completions(ehci, qh);
if (unlikely(temp))
start_unlink_intr(ehci, qh);
else if (unlikely(list_empty(&qh->qtd_list) &&
qh->qh_state == QH_STATE_LINKED))
start_unlink_intr_wait(ehci, qh);
}
}
}
/*-------------------------------------------------------------------------*/
/* ehci_iso_stream ops work with both ITD and SITD */
static struct ehci_iso_stream *
iso_stream_alloc(gfp_t mem_flags)
{
struct ehci_iso_stream *stream;
stream = kzalloc(sizeof(*stream), mem_flags);
if (likely(stream != NULL)) {
INIT_LIST_HEAD(&stream->td_list);
INIT_LIST_HEAD(&stream->free_list);
stream->next_uframe = NO_FRAME;
stream->ps.phase = NO_FRAME;
}
return stream;
}
static void
iso_stream_init(
struct ehci_hcd *ehci,
struct ehci_iso_stream *stream,
struct urb *urb
)
{
static const u8 smask_out[] = { 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f };
struct usb_device *dev = urb->dev;
u32 buf1;
unsigned epnum, maxp;
int is_input;
unsigned tmp;
/*
* this might be a "high bandwidth" highspeed endpoint,
* as encoded in the ep descriptor's wMaxPacket field
*/
epnum = usb_pipeendpoint(urb->pipe);
is_input = usb_pipein(urb->pipe) ? USB_DIR_IN : 0;
maxp = usb_endpoint_maxp(&urb->ep->desc);
buf1 = is_input ? 1 << 11 : 0;
/* knows about ITD vs SITD */
if (dev->speed == USB_SPEED_HIGH) {
unsigned multi = usb_endpoint_maxp_mult(&urb->ep->desc);
stream->highspeed = 1;
buf1 |= maxp;
maxp *= multi;
stream->buf0 = cpu_to_hc32(ehci, (epnum << 8) | dev->devnum);
stream->buf1 = cpu_to_hc32(ehci, buf1);
stream->buf2 = cpu_to_hc32(ehci, multi);
/* usbfs wants to report the average usecs per frame tied up
* when transfers on this endpoint are scheduled ...
*/
stream->ps.usecs = HS_USECS_ISO(maxp);
/* period for bandwidth allocation */
tmp = min_t(unsigned, EHCI_BANDWIDTH_SIZE,
1 << (urb->ep->desc.bInterval - 1));
/* Allow urb->interval to override */
stream->ps.bw_uperiod = min_t(unsigned, tmp, urb->interval);
stream->uperiod = urb->interval;
stream->ps.period = urb->interval >> 3;
stream->bandwidth = stream->ps.usecs * 8 /
stream->ps.bw_uperiod;
} else {
u32 addr;
int think_time;
int hs_transfers;
addr = dev->ttport << 24;
if (!ehci_is_TDI(ehci)
|| (dev->tt->hub !=
ehci_to_hcd(ehci)->self.root_hub))
addr |= dev->tt->hub->devnum << 16;
addr |= epnum << 8;
addr |= dev->devnum;
stream->ps.usecs = HS_USECS_ISO(maxp);
think_time = dev->tt->think_time;
stream->ps.tt_usecs = NS_TO_US(think_time + usb_calc_bus_time(
dev->speed, is_input, 1, maxp));
hs_transfers = max(1u, (maxp + 187) / 188);
if (is_input) {
u32 tmp;
addr |= 1 << 31;
stream->ps.c_usecs = stream->ps.usecs;
stream->ps.usecs = HS_USECS_ISO(1);
stream->ps.cs_mask = 1;
/* c-mask as specified in USB 2.0 11.18.4 3.c */
tmp = (1 << (hs_transfers + 2)) - 1;
stream->ps.cs_mask |= tmp << (8 + 2);
} else
stream->ps.cs_mask = smask_out[hs_transfers - 1];
/* period for bandwidth allocation */
tmp = min_t(unsigned, EHCI_BANDWIDTH_FRAMES,
1 << (urb->ep->desc.bInterval - 1));
/* Allow urb->interval to override */
stream->ps.bw_period = min_t(unsigned, tmp, urb->interval);
stream->ps.bw_uperiod = stream->ps.bw_period << 3;
stream->ps.period = urb->interval;
stream->uperiod = urb->interval << 3;
stream->bandwidth = (stream->ps.usecs + stream->ps.c_usecs) /
stream->ps.bw_period;
/* stream->splits gets created from cs_mask later */
stream->address = cpu_to_hc32(ehci, addr);
}
stream->ps.udev = dev;
stream->ps.ep = urb->ep;
stream->bEndpointAddress = is_input | epnum;
stream->maxp = maxp;
}
static struct ehci_iso_stream *
iso_stream_find(struct ehci_hcd *ehci, struct urb *urb)
{
unsigned epnum;
struct ehci_iso_stream *stream;
struct usb_host_endpoint *ep;
unsigned long flags;
epnum = usb_pipeendpoint (urb->pipe);
if (usb_pipein(urb->pipe))
ep = urb->dev->ep_in[epnum];
else
ep = urb->dev->ep_out[epnum];
spin_lock_irqsave(&ehci->lock, flags);
stream = ep->hcpriv;
if (unlikely(stream == NULL)) {
stream = iso_stream_alloc(GFP_ATOMIC);
if (likely(stream != NULL)) {
ep->hcpriv = stream;
iso_stream_init(ehci, stream, urb);
}
/* if dev->ep [epnum] is a QH, hw is set */
} else if (unlikely(stream->hw != NULL)) {
ehci_dbg(ehci, "dev %s ep%d%s, not iso??\n",
urb->dev->devpath, epnum,
usb_pipein(urb->pipe) ? "in" : "out");
stream = NULL;
}
spin_unlock_irqrestore(&ehci->lock, flags);
return stream;
}
/*-------------------------------------------------------------------------*/
/* ehci_iso_sched ops can be ITD-only or SITD-only */
static struct ehci_iso_sched *
iso_sched_alloc(unsigned packets, gfp_t mem_flags)
{
struct ehci_iso_sched *iso_sched;
int size = sizeof(*iso_sched);
size += packets * sizeof(struct ehci_iso_packet);
iso_sched = kzalloc(size, mem_flags);
if (likely(iso_sched != NULL))
INIT_LIST_HEAD(&iso_sched->td_list);
return iso_sched;
}
static inline void
itd_sched_init(
struct ehci_hcd *ehci,
struct ehci_iso_sched *iso_sched,
struct ehci_iso_stream *stream,
struct urb *urb
)
{
unsigned i;
dma_addr_t dma = urb->transfer_dma;
/* how many uframes are needed for these transfers */
iso_sched->span = urb->number_of_packets * stream->uperiod;
/* figure out per-uframe itd fields that we'll need later
* when we fit new itds into the schedule.
*/
for (i = 0; i < urb->number_of_packets; i++) {
struct ehci_iso_packet *uframe = &iso_sched->packet[i];
unsigned length;
dma_addr_t buf;
u32 trans;
length = urb->iso_frame_desc[i].length;
buf = dma + urb->iso_frame_desc[i].offset;
trans = EHCI_ISOC_ACTIVE;
trans |= buf & 0x0fff;
if (unlikely(((i + 1) == urb->number_of_packets))
&& !(urb->transfer_flags & URB_NO_INTERRUPT))
trans |= EHCI_ITD_IOC;
trans |= length << 16;
uframe->transaction = cpu_to_hc32(ehci, trans);
/* might need to cross a buffer page within a uframe */
uframe->bufp = (buf & ~(u64)0x0fff);
buf += length;
if (unlikely((uframe->bufp != (buf & ~(u64)0x0fff))))
uframe->cross = 1;
}
}
static void
iso_sched_free(
struct ehci_iso_stream *stream,
struct ehci_iso_sched *iso_sched
)
{
if (!iso_sched)
return;
/* caller must hold ehci->lock! */
list_splice(&iso_sched->td_list, &stream->free_list);
kfree(iso_sched);
}
static int
itd_urb_transaction(
struct ehci_iso_stream *stream,
struct ehci_hcd *ehci,
struct urb *urb,
gfp_t mem_flags
)
{
struct ehci_itd *itd;
dma_addr_t itd_dma;
int i;
unsigned num_itds;
struct ehci_iso_sched *sched;
unsigned long flags;
sched = iso_sched_alloc(urb->number_of_packets, mem_flags);
if (unlikely(sched == NULL))
return -ENOMEM;
itd_sched_init(ehci, sched, stream, urb);
if (urb->interval < 8)
num_itds = 1 + (sched->span + 7) / 8;
else
num_itds = urb->number_of_packets;
/* allocate/init ITDs */
spin_lock_irqsave(&ehci->lock, flags);
for (i = 0; i < num_itds; i++) {
/*
* Use iTDs from the free list, but not iTDs that may
* still be in use by the hardware.
*/
if (likely(!list_empty(&stream->free_list))) {
itd = list_first_entry(&stream->free_list,
struct ehci_itd, itd_list);
if (itd->frame == ehci->now_frame)
goto alloc_itd;
list_del(&itd->itd_list);
itd_dma = itd->itd_dma;
} else {
alloc_itd:
spin_unlock_irqrestore(&ehci->lock, flags);
itd = dma_pool_alloc(ehci->itd_pool, mem_flags,
&itd_dma);
spin_lock_irqsave(&ehci->lock, flags);
if (!itd) {
iso_sched_free(stream, sched);
spin_unlock_irqrestore(&ehci->lock, flags);
return -ENOMEM;
}
}
memset(itd, 0, sizeof(*itd));
itd->itd_dma = itd_dma;
itd->frame = NO_FRAME;
list_add(&itd->itd_list, &sched->td_list);
}
spin_unlock_irqrestore(&ehci->lock, flags);
/* temporarily store schedule info in hcpriv */
urb->hcpriv = sched;
urb->error_count = 0;
return 0;
}
/*-------------------------------------------------------------------------*/
static void reserve_release_iso_bandwidth(struct ehci_hcd *ehci,
struct ehci_iso_stream *stream, int sign)
{
unsigned uframe;
unsigned i, j;
unsigned s_mask, c_mask, m;
int usecs = stream->ps.usecs;
int c_usecs = stream->ps.c_usecs;
int tt_usecs = stream->ps.tt_usecs;
struct ehci_tt *tt;
if (stream->ps.phase == NO_FRAME) /* Bandwidth wasn't reserved */
return;
uframe = stream->ps.bw_phase << 3;
bandwidth_dbg(ehci, sign, "iso", &stream->ps);
if (sign < 0) { /* Release bandwidth */
usecs = -usecs;
c_usecs = -c_usecs;
tt_usecs = -tt_usecs;
}
if (!stream->splits) { /* High speed */
for (i = uframe + stream->ps.phase_uf; i < EHCI_BANDWIDTH_SIZE;
i += stream->ps.bw_uperiod)
ehci->bandwidth[i] += usecs;
} else { /* Full speed */
s_mask = stream->ps.cs_mask;
c_mask = s_mask >> 8;
/* NOTE: adjustment needed for frame overflow */
for (i = uframe; i < EHCI_BANDWIDTH_SIZE;
i += stream->ps.bw_uperiod) {
for ((j = stream->ps.phase_uf, m = 1 << j); j < 8;
(++j, m <<= 1)) {
if (s_mask & m)
ehci->bandwidth[i+j] += usecs;
else if (c_mask & m)
ehci->bandwidth[i+j] += c_usecs;
}
}
tt = find_tt(stream->ps.udev);
if (sign > 0)
list_add_tail(&stream->ps.ps_list, &tt->ps_list);
else
list_del(&stream->ps.ps_list);
for (i = uframe >> 3; i < EHCI_BANDWIDTH_FRAMES;
i += stream->ps.bw_period)
tt->bandwidth[i] += tt_usecs;
}
}
static inline int
itd_slot_ok(
struct ehci_hcd *ehci,
struct ehci_iso_stream *stream,
unsigned uframe
)
{
unsigned usecs;
/* convert "usecs we need" to "max already claimed" */
usecs = ehci->uframe_periodic_max - stream->ps.usecs;
for (uframe &= stream->ps.bw_uperiod - 1; uframe < EHCI_BANDWIDTH_SIZE;
uframe += stream->ps.bw_uperiod) {
if (ehci->bandwidth[uframe] > usecs)
return 0;
}
return 1;
}
static inline int
sitd_slot_ok(
struct ehci_hcd *ehci,
struct ehci_iso_stream *stream,
unsigned uframe,
struct ehci_iso_sched *sched,
struct ehci_tt *tt
)
{
unsigned mask, tmp;
unsigned frame, uf;
mask = stream->ps.cs_mask << (uframe & 7);
/* for OUT, don't wrap SSPLIT into H-microframe 7 */
if (((stream->ps.cs_mask & 0xff) << (uframe & 7)) >= (1 << 7))
return 0;
/* for IN, don't wrap CSPLIT into the next frame */
if (mask & ~0xffff)
return 0;
/* check bandwidth */
uframe &= stream->ps.bw_uperiod - 1;
frame = uframe >> 3;
#ifdef CONFIG_USB_EHCI_TT_NEWSCHED
/* The tt's fullspeed bus bandwidth must be available.
* tt_available scheduling guarantees 10+% for control/bulk.
*/
uf = uframe & 7;
if (!tt_available(ehci, &stream->ps, tt, frame, uf))
return 0;
#else
/* tt must be idle for start(s), any gap, and csplit.
* assume scheduling slop leaves 10+% for control/bulk.
*/
if (!tt_no_collision(ehci, stream->ps.bw_period,
stream->ps.udev, frame, mask))
return 0;
#endif
do {
unsigned max_used;
unsigned i;
/* check starts (OUT uses more than one) */
uf = uframe;
max_used = ehci->uframe_periodic_max - stream->ps.usecs;
for (tmp = stream->ps.cs_mask & 0xff; tmp; tmp >>= 1, uf++) {
if (ehci->bandwidth[uf] > max_used)
return 0;
}
/* for IN, check CSPLIT */
if (stream->ps.c_usecs) {
max_used = ehci->uframe_periodic_max -
stream->ps.c_usecs;
uf = uframe & ~7;
tmp = 1 << (2+8);
for (i = (uframe & 7) + 2; i < 8; (++i, tmp <<= 1)) {
if ((stream->ps.cs_mask & tmp) == 0)
continue;
if (ehci->bandwidth[uf+i] > max_used)
return 0;
}
}
uframe += stream->ps.bw_uperiod;
} while (uframe < EHCI_BANDWIDTH_SIZE);
stream->ps.cs_mask <<= uframe & 7;
stream->splits = cpu_to_hc32(ehci, stream->ps.cs_mask);
return 1;
}
/*
* This scheduler plans almost as far into the future as it has actual
* periodic schedule slots. (Affected by TUNE_FLS, which defaults to
* "as small as possible" to be cache-friendlier.) That limits the size
* transfers you can stream reliably; avoid more than 64 msec per urb.
* Also avoid queue depths of less than ehci's worst irq latency (affected
* by the per-urb URB_NO_INTERRUPT hint, the log2_irq_thresh module parameter,
* and other factors); or more than about 230 msec total (for portability,
* given EHCI_TUNE_FLS and the slop). Or, write a smarter scheduler!
*/
static int
iso_stream_schedule(
struct ehci_hcd *ehci,
struct urb *urb,
struct ehci_iso_stream *stream
)
{
u32 now, base, next, start, period, span, now2;
u32 wrap = 0, skip = 0;
int status = 0;
unsigned mod = ehci->periodic_size << 3;
struct ehci_iso_sched *sched = urb->hcpriv;
bool empty = list_empty(&stream->td_list);
bool new_stream = false;
period = stream->uperiod;
span = sched->span;
if (!stream->highspeed)
span <<= 3;
/* Start a new isochronous stream? */
if (unlikely(empty && !hcd_periodic_completion_in_progress(
ehci_to_hcd(ehci), urb->ep))) {
/* Schedule the endpoint */
if (stream->ps.phase == NO_FRAME) {
int done = 0;
struct ehci_tt *tt = find_tt(stream->ps.udev);
if (IS_ERR(tt)) {
status = PTR_ERR(tt);
goto fail;
}
compute_tt_budget(ehci->tt_budget, tt);
start = ((-(++ehci->random_frame)) << 3) & (period - 1);
/* find a uframe slot with enough bandwidth.
* Early uframes are more precious because full-speed
* iso IN transfers can't use late uframes,
* and therefore they should be allocated last.
*/
next = start;
start += period;
do {
start--;
/* check schedule: enough space? */
if (stream->highspeed) {
if (itd_slot_ok(ehci, stream, start))
done = 1;
} else {
if ((start % 8) >= 6)
continue;
if (sitd_slot_ok(ehci, stream, start,
sched, tt))
done = 1;
}
} while (start > next && !done);
/* no room in the schedule */
if (!done) {
ehci_dbg(ehci, "iso sched full %p", urb);
status = -ENOSPC;
goto fail;
}
stream->ps.phase = (start >> 3) &
(stream->ps.period - 1);
stream->ps.bw_phase = stream->ps.phase &
(stream->ps.bw_period - 1);
stream->ps.phase_uf = start & 7;
reserve_release_iso_bandwidth(ehci, stream, 1);
}
/* New stream is already scheduled; use the upcoming slot */
else {
start = (stream->ps.phase << 3) + stream->ps.phase_uf;
}
stream->next_uframe = start;
new_stream = true;
}
now = ehci_read_frame_index(ehci) & (mod - 1);
/* Take the isochronous scheduling threshold into account */
if (ehci->i_thresh)
next = now + ehci->i_thresh; /* uframe cache */
else
next = (now + 2 + 7) & ~0x07; /* full frame cache */
/* If needed, initialize last_iso_frame so that this URB will be seen */
if (ehci->isoc_count == 0)
ehci->last_iso_frame = now >> 3;
/*
* Use ehci->last_iso_frame as the base. There can't be any
* TDs scheduled for earlier than that.
*/
base = ehci->last_iso_frame << 3;
next = (next - base) & (mod - 1);
start = (stream->next_uframe - base) & (mod - 1);
if (unlikely(new_stream))
goto do_ASAP;
/*
* Typical case: reuse current schedule, stream may still be active.
* Hopefully there are no gaps from the host falling behind
* (irq delays etc). If there are, the behavior depends on
* whether URB_ISO_ASAP is set.
*/
now2 = (now - base) & (mod - 1);
/* Is the schedule about to wrap around? */
if (unlikely(!empty && start < period)) {
ehci_dbg(ehci, "request %p would overflow (%u-%u < %u mod %u)\n",
urb, stream->next_uframe, base, period, mod);
status = -EFBIG;
goto fail;
}
/* Is the next packet scheduled after the base time? */
if (likely(!empty || start <= now2 + period)) {
/* URB_ISO_ASAP: make sure that start >= next */
if (unlikely(start < next &&
(urb->transfer_flags & URB_ISO_ASAP)))
goto do_ASAP;
/* Otherwise use start, if it's not in the past */
if (likely(start >= now2))
goto use_start;
/* Otherwise we got an underrun while the queue was empty */
} else {
if (urb->transfer_flags & URB_ISO_ASAP)
goto do_ASAP;
wrap = mod;
now2 += mod;
}
/* How many uframes and packets do we need to skip? */
skip = (now2 - start + period - 1) & -period;
if (skip >= span) { /* Entirely in the past? */
ehci_dbg(ehci, "iso underrun %p (%u+%u < %u) [%u]\n",
urb, start + base, span - period, now2 + base,
base);
/* Try to keep the last TD intact for scanning later */
skip = span - period;
/* Will it come before the current scan position? */
if (empty) {
skip = span; /* Skip the entire URB */
status = 1; /* and give it back immediately */
iso_sched_free(stream, sched);
sched = NULL;
}
}
urb->error_count = skip / period;
if (sched)
sched->first_packet = urb->error_count;
goto use_start;
do_ASAP:
/* Use the first slot after "next" */
start = next + ((start - next) & (period - 1));
use_start:
/* Tried to schedule too far into the future? */
if (unlikely(start + span - period >= mod + wrap)) {
ehci_dbg(ehci, "request %p would overflow (%u+%u >= %u)\n",
urb, start, span - period, mod + wrap);
status = -EFBIG;
goto fail;
}
start += base;
stream->next_uframe = (start + skip) & (mod - 1);
/* report high speed start in uframes; full speed, in frames */
urb->start_frame = start & (mod - 1);
if (!stream->highspeed)
urb->start_frame >>= 3;
return status;
fail:
iso_sched_free(stream, sched);
urb->hcpriv = NULL;
return status;
}
/*-------------------------------------------------------------------------*/
static inline void
itd_init(struct ehci_hcd *ehci, struct ehci_iso_stream *stream,
struct ehci_itd *itd)
{
int i;
/* it's been recently zeroed */
itd->hw_next = EHCI_LIST_END(ehci);
itd->hw_bufp[0] = stream->buf0;
itd->hw_bufp[1] = stream->buf1;
itd->hw_bufp[2] = stream->buf2;
for (i = 0; i < 8; i++)
itd->index[i] = -1;
/* All other fields are filled when scheduling */
}
static inline void
itd_patch(
struct ehci_hcd *ehci,
struct ehci_itd *itd,
struct ehci_iso_sched *iso_sched,
unsigned index,
u16 uframe
)
{
struct ehci_iso_packet *uf = &iso_sched->packet[index];
unsigned pg = itd->pg;
/* BUG_ON(pg == 6 && uf->cross); */
uframe &= 0x07;
itd->index[uframe] = index;
itd->hw_transaction[uframe] = uf->transaction;
itd->hw_transaction[uframe] |= cpu_to_hc32(ehci, pg << 12);
itd->hw_bufp[pg] |= cpu_to_hc32(ehci, uf->bufp & ~(u32)0);
itd->hw_bufp_hi[pg] |= cpu_to_hc32(ehci, (u32)(uf->bufp >> 32));
/* iso_frame_desc[].offset must be strictly increasing */
if (unlikely(uf->cross)) {
u64 bufp = uf->bufp + 4096;
itd->pg = ++pg;
itd->hw_bufp[pg] |= cpu_to_hc32(ehci, bufp & ~(u32)0);
itd->hw_bufp_hi[pg] |= cpu_to_hc32(ehci, (u32)(bufp >> 32));
}
}
static inline void
itd_link(struct ehci_hcd *ehci, unsigned frame, struct ehci_itd *itd)
{
union ehci_shadow *prev = &ehci->pshadow[frame];
__hc32 *hw_p = &ehci->periodic[frame];
union ehci_shadow here = *prev;
__hc32 type = 0;
/* skip any iso nodes which might belong to previous microframes */
while (here.ptr) {
type = Q_NEXT_TYPE(ehci, *hw_p);
if (type == cpu_to_hc32(ehci, Q_TYPE_QH))
break;
prev = periodic_next_shadow(ehci, prev, type);
hw_p = shadow_next_periodic(ehci, &here, type);
here = *prev;
}
itd->itd_next = here;
itd->hw_next = *hw_p;
prev->itd = itd;
itd->frame = frame;
wmb();
*hw_p = cpu_to_hc32(ehci, itd->itd_dma | Q_TYPE_ITD);
}
/* fit urb's itds into the selected schedule slot; activate as needed */
static void itd_link_urb(
struct ehci_hcd *ehci,
struct urb *urb,
unsigned mod,
struct ehci_iso_stream *stream
)
{
int packet;
unsigned next_uframe, uframe, frame;
struct ehci_iso_sched *iso_sched = urb->hcpriv;
struct ehci_itd *itd;
next_uframe = stream->next_uframe & (mod - 1);
if (unlikely(list_empty(&stream->td_list)))
ehci_to_hcd(ehci)->self.bandwidth_allocated
+= stream->bandwidth;
if (ehci_to_hcd(ehci)->self.bandwidth_isoc_reqs == 0) {
if (ehci->amd_pll_fix == 1)
usb_amd_quirk_pll_disable();
}
ehci_to_hcd(ehci)->self.bandwidth_isoc_reqs++;
/* fill iTDs uframe by uframe */
for (packet = iso_sched->first_packet, itd = NULL;
packet < urb->number_of_packets;) {
if (itd == NULL) {
/* ASSERT: we have all necessary itds */
/* BUG_ON(list_empty(&iso_sched->td_list)); */
/* ASSERT: no itds for this endpoint in this uframe */
itd = list_entry(iso_sched->td_list.next,
struct ehci_itd, itd_list);
list_move_tail(&itd->itd_list, &stream->td_list);
itd->stream = stream;
itd->urb = urb;
itd_init(ehci, stream, itd);
}
uframe = next_uframe & 0x07;
frame = next_uframe >> 3;
itd_patch(ehci, itd, iso_sched, packet, uframe);
next_uframe += stream->uperiod;
next_uframe &= mod - 1;
packet++;
/* link completed itds into the schedule */
if (((next_uframe >> 3) != frame)
|| packet == urb->number_of_packets) {
itd_link(ehci, frame & (ehci->periodic_size - 1), itd);
itd = NULL;
}
}
stream->next_uframe = next_uframe;
/* don't need that schedule data any more */
iso_sched_free(stream, iso_sched);
urb->hcpriv = stream;
++ehci->isoc_count;
enable_periodic(ehci);
}
#define ISO_ERRS (EHCI_ISOC_BUF_ERR | EHCI_ISOC_BABBLE | EHCI_ISOC_XACTERR)
/* Process and recycle a completed ITD. Return true iff its urb completed,
* and hence its completion callback probably added things to the hardware
* schedule.
*
* Note that we carefully avoid recycling this descriptor until after any
* completion callback runs, so that it won't be reused quickly. That is,
* assuming (a) no more than two urbs per frame on this endpoint, and also
* (b) only this endpoint's completions submit URBs. It seems some silicon
* corrupts things if you reuse completed descriptors very quickly...
*/
static bool itd_complete(struct ehci_hcd *ehci, struct ehci_itd *itd)
{
struct urb *urb = itd->urb;
struct usb_iso_packet_descriptor *desc;
u32 t;
unsigned uframe;
int urb_index = -1;
struct ehci_iso_stream *stream = itd->stream;
bool retval = false;
/* for each uframe with a packet */
for (uframe = 0; uframe < 8; uframe++) {
if (likely(itd->index[uframe] == -1))
continue;
urb_index = itd->index[uframe];
desc = &urb->iso_frame_desc[urb_index];
t = hc32_to_cpup(ehci, &itd->hw_transaction[uframe]);
itd->hw_transaction[uframe] = 0;
/* report transfer status */
if (unlikely(t & ISO_ERRS)) {
urb->error_count++;
if (t & EHCI_ISOC_BUF_ERR)
desc->status = usb_pipein(urb->pipe)
? -ENOSR /* hc couldn't read */
: -ECOMM; /* hc couldn't write */
else if (t & EHCI_ISOC_BABBLE)
desc->status = -EOVERFLOW;
else /* (t & EHCI_ISOC_XACTERR) */
desc->status = -EPROTO;
/* HC need not update length with this error */
if (!(t & EHCI_ISOC_BABBLE)) {
desc->actual_length = EHCI_ITD_LENGTH(t);
urb->actual_length += desc->actual_length;
}
} else if (likely((t & EHCI_ISOC_ACTIVE) == 0)) {
desc->status = 0;
desc->actual_length = EHCI_ITD_LENGTH(t);
urb->actual_length += desc->actual_length;
} else {
/* URB was too late */
urb->error_count++;
}
}
/* handle completion now? */
if (likely((urb_index + 1) != urb->number_of_packets))
goto done;
/*
* ASSERT: it's really the last itd for this urb
* list_for_each_entry (itd, &stream->td_list, itd_list)
* BUG_ON(itd->urb == urb);
*/
/* give urb back to the driver; completion often (re)submits */
ehci_urb_done(ehci, urb, 0);
retval = true;
urb = NULL;
--ehci->isoc_count;
disable_periodic(ehci);
ehci_to_hcd(ehci)->self.bandwidth_isoc_reqs--;
if (ehci_to_hcd(ehci)->self.bandwidth_isoc_reqs == 0) {
if (ehci->amd_pll_fix == 1)
usb_amd_quirk_pll_enable();
}
if (unlikely(list_is_singular(&stream->td_list)))
ehci_to_hcd(ehci)->self.bandwidth_allocated
-= stream->bandwidth;
done:
itd->urb = NULL;
/* Add to the end of the free list for later reuse */
list_move_tail(&itd->itd_list, &stream->free_list);
/* Recycle the iTDs when the pipeline is empty (ep no longer in use) */
if (list_empty(&stream->td_list)) {
list_splice_tail_init(&stream->free_list,
&ehci->cached_itd_list);
start_free_itds(ehci);
}
return retval;
}
/*-------------------------------------------------------------------------*/
static int itd_submit(struct ehci_hcd *ehci, struct urb *urb,
gfp_t mem_flags)
{
int status = -EINVAL;
unsigned long flags;
struct ehci_iso_stream *stream;
/* Get iso_stream head */
stream = iso_stream_find(ehci, urb);
if (unlikely(stream == NULL)) {
ehci_dbg(ehci, "can't get iso stream\n");
return -ENOMEM;
}
if (unlikely(urb->interval != stream->uperiod)) {
ehci_dbg(ehci, "can't change iso interval %d --> %d\n",
stream->uperiod, urb->interval);
goto done;
}
#ifdef EHCI_URB_TRACE
ehci_dbg(ehci,
"%s %s urb %p ep%d%s len %d, %d pkts %d uframes [%p]\n",
__func__, urb->dev->devpath, urb,
usb_pipeendpoint(urb->pipe),
usb_pipein(urb->pipe) ? "in" : "out",
urb->transfer_buffer_length,
urb->number_of_packets, urb->interval,
stream);
#endif
/* allocate ITDs w/o locking anything */
status = itd_urb_transaction(stream, ehci, urb, mem_flags);
if (unlikely(status < 0)) {
ehci_dbg(ehci, "can't init itds\n");
goto done;
}
/* schedule ... need to lock */
spin_lock_irqsave(&ehci->lock, flags);
if (unlikely(!HCD_HW_ACCESSIBLE(ehci_to_hcd(ehci)))) {
status = -ESHUTDOWN;
goto done_not_linked;
}
status = usb_hcd_link_urb_to_ep(ehci_to_hcd(ehci), urb);
if (unlikely(status))
goto done_not_linked;
status = iso_stream_schedule(ehci, urb, stream);
if (likely(status == 0)) {
itd_link_urb(ehci, urb, ehci->periodic_size << 3, stream);
} else if (status > 0) {
status = 0;
ehci_urb_done(ehci, urb, 0);
} else {
usb_hcd_unlink_urb_from_ep(ehci_to_hcd(ehci), urb);
}
done_not_linked:
spin_unlock_irqrestore(&ehci->lock, flags);
done:
return status;
}
/*-------------------------------------------------------------------------*/
/*
* "Split ISO TDs" ... used for USB 1.1 devices going through the
* TTs in USB 2.0 hubs. These need microframe scheduling.
*/
static inline void
sitd_sched_init(
struct ehci_hcd *ehci,
struct ehci_iso_sched *iso_sched,
struct ehci_iso_stream *stream,
struct urb *urb
)
{
unsigned i;
dma_addr_t dma = urb->transfer_dma;
/* how many frames are needed for these transfers */
iso_sched->span = urb->number_of_packets * stream->ps.period;
/* figure out per-frame sitd fields that we'll need later
* when we fit new sitds into the schedule.
*/
for (i = 0; i < urb->number_of_packets; i++) {
struct ehci_iso_packet *packet = &iso_sched->packet[i];
unsigned length;
dma_addr_t buf;
u32 trans;
length = urb->iso_frame_desc[i].length & 0x03ff;
buf = dma + urb->iso_frame_desc[i].offset;
trans = SITD_STS_ACTIVE;
if (((i + 1) == urb->number_of_packets)
&& !(urb->transfer_flags & URB_NO_INTERRUPT))
trans |= SITD_IOC;
trans |= length << 16;
packet->transaction = cpu_to_hc32(ehci, trans);
/* might need to cross a buffer page within a td */
packet->bufp = buf;
packet->buf1 = (buf + length) & ~0x0fff;
if (packet->buf1 != (buf & ~(u64)0x0fff))
packet->cross = 1;
/* OUT uses multiple start-splits */
if (stream->bEndpointAddress & USB_DIR_IN)
continue;
length = (length + 187) / 188;
if (length > 1) /* BEGIN vs ALL */
length |= 1 << 3;
packet->buf1 |= length;
}
}
static int
sitd_urb_transaction(
struct ehci_iso_stream *stream,
struct ehci_hcd *ehci,
struct urb *urb,
gfp_t mem_flags
)
{
struct ehci_sitd *sitd;
dma_addr_t sitd_dma;
int i;
struct ehci_iso_sched *iso_sched;
unsigned long flags;
iso_sched = iso_sched_alloc(urb->number_of_packets, mem_flags);
if (iso_sched == NULL)
return -ENOMEM;
sitd_sched_init(ehci, iso_sched, stream, urb);
/* allocate/init sITDs */
spin_lock_irqsave(&ehci->lock, flags);
for (i = 0; i < urb->number_of_packets; i++) {
/* NOTE: for now, we don't try to handle wraparound cases
* for IN (using sitd->hw_backpointer, like a FSTN), which
* means we never need two sitds for full speed packets.
*/
/*
* Use siTDs from the free list, but not siTDs that may
* still be in use by the hardware.
*/
if (likely(!list_empty(&stream->free_list))) {
sitd = list_first_entry(&stream->free_list,
struct ehci_sitd, sitd_list);
if (sitd->frame == ehci->now_frame)
goto alloc_sitd;
list_del(&sitd->sitd_list);
sitd_dma = sitd->sitd_dma;
} else {
alloc_sitd:
spin_unlock_irqrestore(&ehci->lock, flags);
sitd = dma_pool_alloc(ehci->sitd_pool, mem_flags,
&sitd_dma);
spin_lock_irqsave(&ehci->lock, flags);
if (!sitd) {
iso_sched_free(stream, iso_sched);
spin_unlock_irqrestore(&ehci->lock, flags);
return -ENOMEM;
}
}
memset(sitd, 0, sizeof(*sitd));
sitd->sitd_dma = sitd_dma;
sitd->frame = NO_FRAME;
list_add(&sitd->sitd_list, &iso_sched->td_list);
}
/* temporarily store schedule info in hcpriv */
urb->hcpriv = iso_sched;
urb->error_count = 0;
spin_unlock_irqrestore(&ehci->lock, flags);
return 0;
}
/*-------------------------------------------------------------------------*/
static inline void
sitd_patch(
struct ehci_hcd *ehci,
struct ehci_iso_stream *stream,
struct ehci_sitd *sitd,
struct ehci_iso_sched *iso_sched,
unsigned index
)
{
struct ehci_iso_packet *uf = &iso_sched->packet[index];
u64 bufp;
sitd->hw_next = EHCI_LIST_END(ehci);
sitd->hw_fullspeed_ep = stream->address;
sitd->hw_uframe = stream->splits;
sitd->hw_results = uf->transaction;
sitd->hw_backpointer = EHCI_LIST_END(ehci);
bufp = uf->bufp;
sitd->hw_buf[0] = cpu_to_hc32(ehci, bufp);
sitd->hw_buf_hi[0] = cpu_to_hc32(ehci, bufp >> 32);
sitd->hw_buf[1] = cpu_to_hc32(ehci, uf->buf1);
if (uf->cross)
bufp += 4096;
sitd->hw_buf_hi[1] = cpu_to_hc32(ehci, bufp >> 32);
sitd->index = index;
}
static inline void
sitd_link(struct ehci_hcd *ehci, unsigned frame, struct ehci_sitd *sitd)
{
/* note: sitd ordering could matter (CSPLIT then SSPLIT) */
sitd->sitd_next = ehci->pshadow[frame];
sitd->hw_next = ehci->periodic[frame];
ehci->pshadow[frame].sitd = sitd;
sitd->frame = frame;
wmb();
ehci->periodic[frame] = cpu_to_hc32(ehci, sitd->sitd_dma | Q_TYPE_SITD);
}
/* fit urb's sitds into the selected schedule slot; activate as needed */
static void sitd_link_urb(
struct ehci_hcd *ehci,
struct urb *urb,
unsigned mod,
struct ehci_iso_stream *stream
)
{
int packet;
unsigned next_uframe;
struct ehci_iso_sched *sched = urb->hcpriv;
struct ehci_sitd *sitd;
next_uframe = stream->next_uframe;
if (list_empty(&stream->td_list))
/* usbfs ignores TT bandwidth */
ehci_to_hcd(ehci)->self.bandwidth_allocated
+= stream->bandwidth;
if (ehci_to_hcd(ehci)->self.bandwidth_isoc_reqs == 0) {
if (ehci->amd_pll_fix == 1)
usb_amd_quirk_pll_disable();
}
ehci_to_hcd(ehci)->self.bandwidth_isoc_reqs++;
/* fill sITDs frame by frame */
for (packet = sched->first_packet, sitd = NULL;
packet < urb->number_of_packets;
packet++) {
/* ASSERT: we have all necessary sitds */
BUG_ON(list_empty(&sched->td_list));
/* ASSERT: no itds for this endpoint in this frame */
sitd = list_entry(sched->td_list.next,
struct ehci_sitd, sitd_list);
list_move_tail(&sitd->sitd_list, &stream->td_list);
sitd->stream = stream;
sitd->urb = urb;
sitd_patch(ehci, stream, sitd, sched, packet);
sitd_link(ehci, (next_uframe >> 3) & (ehci->periodic_size - 1),
sitd);
next_uframe += stream->uperiod;
}
stream->next_uframe = next_uframe & (mod - 1);
/* don't need that schedule data any more */
iso_sched_free(stream, sched);
urb->hcpriv = stream;
++ehci->isoc_count;
enable_periodic(ehci);
}
/*-------------------------------------------------------------------------*/
#define SITD_ERRS (SITD_STS_ERR | SITD_STS_DBE | SITD_STS_BABBLE \
| SITD_STS_XACT | SITD_STS_MMF)
/* Process and recycle a completed SITD. Return true iff its urb completed,
* and hence its completion callback probably added things to the hardware
* schedule.
*
* Note that we carefully avoid recycling this descriptor until after any
* completion callback runs, so that it won't be reused quickly. That is,
* assuming (a) no more than two urbs per frame on this endpoint, and also
* (b) only this endpoint's completions submit URBs. It seems some silicon
* corrupts things if you reuse completed descriptors very quickly...
*/
static bool sitd_complete(struct ehci_hcd *ehci, struct ehci_sitd *sitd)
{
struct urb *urb = sitd->urb;
struct usb_iso_packet_descriptor *desc;
u32 t;
int urb_index;
struct ehci_iso_stream *stream = sitd->stream;
bool retval = false;
urb_index = sitd->index;
desc = &urb->iso_frame_desc[urb_index];
t = hc32_to_cpup(ehci, &sitd->hw_results);
/* report transfer status */
if (unlikely(t & SITD_ERRS)) {
urb->error_count++;
if (t & SITD_STS_DBE)
desc->status = usb_pipein(urb->pipe)
? -ENOSR /* hc couldn't read */
: -ECOMM; /* hc couldn't write */
else if (t & SITD_STS_BABBLE)
desc->status = -EOVERFLOW;
else /* XACT, MMF, etc */
desc->status = -EPROTO;
} else if (unlikely(t & SITD_STS_ACTIVE)) {
/* URB was too late */
urb->error_count++;
} else {
desc->status = 0;
desc->actual_length = desc->length - SITD_LENGTH(t);
urb->actual_length += desc->actual_length;
}
/* handle completion now? */
if ((urb_index + 1) != urb->number_of_packets)
goto done;
/*
* ASSERT: it's really the last sitd for this urb
* list_for_each_entry (sitd, &stream->td_list, sitd_list)
* BUG_ON(sitd->urb == urb);
*/
/* give urb back to the driver; completion often (re)submits */
ehci_urb_done(ehci, urb, 0);
retval = true;
urb = NULL;
--ehci->isoc_count;
disable_periodic(ehci);
ehci_to_hcd(ehci)->self.bandwidth_isoc_reqs--;
if (ehci_to_hcd(ehci)->self.bandwidth_isoc_reqs == 0) {
if (ehci->amd_pll_fix == 1)
usb_amd_quirk_pll_enable();
}
if (list_is_singular(&stream->td_list))
ehci_to_hcd(ehci)->self.bandwidth_allocated
-= stream->bandwidth;
done:
sitd->urb = NULL;
/* Add to the end of the free list for later reuse */
list_move_tail(&sitd->sitd_list, &stream->free_list);
/* Recycle the siTDs when the pipeline is empty (ep no longer in use) */
if (list_empty(&stream->td_list)) {
list_splice_tail_init(&stream->free_list,
&ehci->cached_sitd_list);
start_free_itds(ehci);
}
return retval;
}
static int sitd_submit(struct ehci_hcd *ehci, struct urb *urb,
gfp_t mem_flags)
{
int status = -EINVAL;
unsigned long flags;
struct ehci_iso_stream *stream;
/* Get iso_stream head */
stream = iso_stream_find(ehci, urb);
if (stream == NULL) {
ehci_dbg(ehci, "can't get iso stream\n");
return -ENOMEM;
}
if (urb->interval != stream->ps.period) {
ehci_dbg(ehci, "can't change iso interval %d --> %d\n",
stream->ps.period, urb->interval);
goto done;
}
#ifdef EHCI_URB_TRACE
ehci_dbg(ehci,
"submit %p dev%s ep%d%s-iso len %d\n",
urb, urb->dev->devpath,
usb_pipeendpoint(urb->pipe),
usb_pipein(urb->pipe) ? "in" : "out",
urb->transfer_buffer_length);
#endif
/* allocate SITDs */
status = sitd_urb_transaction(stream, ehci, urb, mem_flags);
if (status < 0) {
ehci_dbg(ehci, "can't init sitds\n");
goto done;
}
/* schedule ... need to lock */
spin_lock_irqsave(&ehci->lock, flags);
if (unlikely(!HCD_HW_ACCESSIBLE(ehci_to_hcd(ehci)))) {
status = -ESHUTDOWN;
goto done_not_linked;
}
status = usb_hcd_link_urb_to_ep(ehci_to_hcd(ehci), urb);
if (unlikely(status))
goto done_not_linked;
status = iso_stream_schedule(ehci, urb, stream);
if (likely(status == 0)) {
sitd_link_urb(ehci, urb, ehci->periodic_size << 3, stream);
} else if (status > 0) {
status = 0;
ehci_urb_done(ehci, urb, 0);
} else {
usb_hcd_unlink_urb_from_ep(ehci_to_hcd(ehci), urb);
}
done_not_linked:
spin_unlock_irqrestore(&ehci->lock, flags);
done:
return status;
}
/*-------------------------------------------------------------------------*/
static void scan_isoc(struct ehci_hcd *ehci)
{
unsigned uf, now_frame, frame;
unsigned fmask = ehci->periodic_size - 1;
bool modified, live;
union ehci_shadow q, *q_p;
__hc32 type, *hw_p;
/*
* When running, scan from last scan point up to "now"
* else clean up by scanning everything that's left.
* Touches as few pages as possible: cache-friendly.
*/
if (ehci->rh_state >= EHCI_RH_RUNNING) {
uf = ehci_read_frame_index(ehci);
now_frame = (uf >> 3) & fmask;
live = true;
} else {
now_frame = (ehci->last_iso_frame - 1) & fmask;
live = false;
}
ehci->now_frame = now_frame;
frame = ehci->last_iso_frame;
restart:
/* Scan each element in frame's queue for completions */
q_p = &ehci->pshadow[frame];
hw_p = &ehci->periodic[frame];
q.ptr = q_p->ptr;
type = Q_NEXT_TYPE(ehci, *hw_p);
modified = false;
while (q.ptr != NULL) {
switch (hc32_to_cpu(ehci, type)) {
case Q_TYPE_ITD:
/*
* If this ITD is still active, leave it for
* later processing ... check the next entry.
* No need to check for activity unless the
* frame is current.
*/
if (frame == now_frame && live) {
rmb();
for (uf = 0; uf < 8; uf++) {
if (q.itd->hw_transaction[uf] &
ITD_ACTIVE(ehci))
break;
}
if (uf < 8) {
q_p = &q.itd->itd_next;
hw_p = &q.itd->hw_next;
type = Q_NEXT_TYPE(ehci,
q.itd->hw_next);
q = *q_p;
break;
}
}
/*
* Take finished ITDs out of the schedule
* and process them: recycle, maybe report
* URB completion. HC won't cache the
* pointer for much longer, if at all.
*/
*q_p = q.itd->itd_next;
if (!ehci->use_dummy_qh ||
q.itd->hw_next != EHCI_LIST_END(ehci))
*hw_p = q.itd->hw_next;
else
*hw_p = cpu_to_hc32(ehci, ehci->dummy->qh_dma);
type = Q_NEXT_TYPE(ehci, q.itd->hw_next);
wmb();
modified = itd_complete(ehci, q.itd);
q = *q_p;
break;
case Q_TYPE_SITD:
/*
* If this SITD is still active, leave it for
* later processing ... check the next entry.
* No need to check for activity unless the
* frame is current.
*/
if (((frame == now_frame) ||
(((frame + 1) & fmask) == now_frame))
&& live
&& (q.sitd->hw_results & SITD_ACTIVE(ehci))) {
q_p = &q.sitd->sitd_next;
hw_p = &q.sitd->hw_next;
type = Q_NEXT_TYPE(ehci, q.sitd->hw_next);
q = *q_p;
break;
}
/*
* Take finished SITDs out of the schedule
* and process them: recycle, maybe report
* URB completion.
*/
*q_p = q.sitd->sitd_next;
if (!ehci->use_dummy_qh ||
q.sitd->hw_next != EHCI_LIST_END(ehci))
*hw_p = q.sitd->hw_next;
else
*hw_p = cpu_to_hc32(ehci, ehci->dummy->qh_dma);
type = Q_NEXT_TYPE(ehci, q.sitd->hw_next);
wmb();
modified = sitd_complete(ehci, q.sitd);
q = *q_p;
break;
default:
ehci_dbg(ehci, "corrupt type %d frame %d shadow %p\n",
type, frame, q.ptr);
/* BUG(); */
/* FALL THROUGH */
case Q_TYPE_QH:
case Q_TYPE_FSTN:
/* End of the iTDs and siTDs */
q.ptr = NULL;
break;
}
/* Assume completion callbacks modify the queue */
if (unlikely(modified && ehci->isoc_count > 0))
goto restart;
}
/* Stop when we have reached the current frame */
if (frame == now_frame)
return;
/* The last frame may still have active siTDs */
ehci->last_iso_frame = frame;
frame = (frame + 1) & fmask;
goto restart;
}
Reference in a new issue Copy permalink