v4.19.13 snapshot.
diff --git a/drivers/usb/host/ehci-timer.c b/drivers/usb/host/ehci-timer.c
new file mode 100644
index 0000000..4fcebda
--- /dev/null
+++ b/drivers/usb/host/ehci-timer.c
@@ -0,0 +1,426 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2012 by Alan Stern
+ */
+
+/* This file is part of ehci-hcd.c */
+
+/*-------------------------------------------------------------------------*/
+
+/* Set a bit in the USBCMD register */
+static void ehci_set_command_bit(struct ehci_hcd *ehci, u32 bit)
+{
+ ehci->command |= bit;
+ ehci_writel(ehci, ehci->command, &ehci->regs->command);
+
+ /* unblock posted write */
+ ehci_readl(ehci, &ehci->regs->command);
+}
+
+/* Clear a bit in the USBCMD register */
+static void ehci_clear_command_bit(struct ehci_hcd *ehci, u32 bit)
+{
+ ehci->command &= ~bit;
+ ehci_writel(ehci, ehci->command, &ehci->regs->command);
+
+ /* unblock posted write */
+ ehci_readl(ehci, &ehci->regs->command);
+}
+
+/*-------------------------------------------------------------------------*/
+
+/*
+ * EHCI timer support... Now using hrtimers.
+ *
+ * Lots of different events are triggered from ehci->hrtimer. Whenever
+ * the timer routine runs, it checks each possible event; events that are
+ * currently enabled and whose expiration time has passed get handled.
+ * The set of enabled events is stored as a collection of bitflags in
+ * ehci->enabled_hrtimer_events, and they are numbered in order of
+ * increasing delay values (ranging between 1 ms and 100 ms).
+ *
+ * Rather than implementing a sorted list or tree of all pending events,
+ * we keep track only of the lowest-numbered pending event, in
+ * ehci->next_hrtimer_event. Whenever ehci->hrtimer gets restarted, its
+ * expiration time is set to the timeout value for this event.
+ *
+ * As a result, events might not get handled right away; the actual delay
+ * could be anywhere up to twice the requested delay. This doesn't
+ * matter, because none of the events are especially time-critical. The
+ * ones that matter most all have a delay of 1 ms, so they will be
+ * handled after 2 ms at most, which is okay. In addition to this, we
+ * allow for an expiration range of 1 ms.
+ */
+
+/*
+ * Delay lengths for the hrtimer event types.
+ * Keep this list sorted by delay length, in the same order as
+ * the event types indexed by enum ehci_hrtimer_event in ehci.h.
+ */
+static unsigned event_delays_ns[] = {
+ 1 * NSEC_PER_MSEC, /* EHCI_HRTIMER_POLL_ASS */
+ 1 * NSEC_PER_MSEC, /* EHCI_HRTIMER_POLL_PSS */
+ 1 * NSEC_PER_MSEC, /* EHCI_HRTIMER_POLL_DEAD */
+ 1125 * NSEC_PER_USEC, /* EHCI_HRTIMER_UNLINK_INTR */
+ 2 * NSEC_PER_MSEC, /* EHCI_HRTIMER_FREE_ITDS */
+ 2 * NSEC_PER_MSEC, /* EHCI_HRTIMER_ACTIVE_UNLINK */
+ 5 * NSEC_PER_MSEC, /* EHCI_HRTIMER_START_UNLINK_INTR */
+ 6 * NSEC_PER_MSEC, /* EHCI_HRTIMER_ASYNC_UNLINKS */
+ 10 * NSEC_PER_MSEC, /* EHCI_HRTIMER_IAA_WATCHDOG */
+ 10 * NSEC_PER_MSEC, /* EHCI_HRTIMER_DISABLE_PERIODIC */
+ 15 * NSEC_PER_MSEC, /* EHCI_HRTIMER_DISABLE_ASYNC */
+ 100 * NSEC_PER_MSEC, /* EHCI_HRTIMER_IO_WATCHDOG */
+};
+
+/* Enable a pending hrtimer event */
+static void ehci_enable_event(struct ehci_hcd *ehci, unsigned event,
+ bool resched)
+{
+ ktime_t *timeout = &ehci->hr_timeouts[event];
+
+ if (resched)
+ *timeout = ktime_add(ktime_get(), event_delays_ns[event]);
+ ehci->enabled_hrtimer_events |= (1 << event);
+
+ /* Track only the lowest-numbered pending event */
+ if (event < ehci->next_hrtimer_event) {
+ ehci->next_hrtimer_event = event;
+ hrtimer_start_range_ns(&ehci->hrtimer, *timeout,
+ NSEC_PER_MSEC, HRTIMER_MODE_ABS);
+ }
+}
+
+
+/* Poll the STS_ASS status bit; see when it agrees with CMD_ASE */
+static void ehci_poll_ASS(struct ehci_hcd *ehci)
+{
+ unsigned actual, want;
+
+ /* Don't enable anything if the controller isn't running (e.g., died) */
+ if (ehci->rh_state != EHCI_RH_RUNNING)
+ return;
+
+ want = (ehci->command & CMD_ASE) ? STS_ASS : 0;
+ actual = ehci_readl(ehci, &ehci->regs->status) & STS_ASS;
+
+ if (want != actual) {
+
+ /* Poll again later, but give up after about 2-4 ms */
+ if (ehci->ASS_poll_count++ < 2) {
+ ehci_enable_event(ehci, EHCI_HRTIMER_POLL_ASS, true);
+ return;
+ }
+ ehci_dbg(ehci, "Waited too long for the async schedule status (%x/%x), giving up\n",
+ want, actual);
+ }
+ ehci->ASS_poll_count = 0;
+
+ /* The status is up-to-date; restart or stop the schedule as needed */
+ if (want == 0) { /* Stopped */
+ if (ehci->async_count > 0)
+ ehci_set_command_bit(ehci, CMD_ASE);
+
+ } else { /* Running */
+ if (ehci->async_count == 0) {
+
+ /* Turn off the schedule after a while */
+ ehci_enable_event(ehci, EHCI_HRTIMER_DISABLE_ASYNC,
+ true);
+ }
+ }
+}
+
+/* Turn off the async schedule after a brief delay */
+static void ehci_disable_ASE(struct ehci_hcd *ehci)
+{
+ ehci_clear_command_bit(ehci, CMD_ASE);
+}
+
+
+/* Poll the STS_PSS status bit; see when it agrees with CMD_PSE */
+static void ehci_poll_PSS(struct ehci_hcd *ehci)
+{
+ unsigned actual, want;
+
+ /* Don't do anything if the controller isn't running (e.g., died) */
+ if (ehci->rh_state != EHCI_RH_RUNNING)
+ return;
+
+ want = (ehci->command & CMD_PSE) ? STS_PSS : 0;
+ actual = ehci_readl(ehci, &ehci->regs->status) & STS_PSS;
+
+ if (want != actual) {
+
+ /* Poll again later, but give up after about 2-4 ms */
+ if (ehci->PSS_poll_count++ < 2) {
+ ehci_enable_event(ehci, EHCI_HRTIMER_POLL_PSS, true);
+ return;
+ }
+ ehci_dbg(ehci, "Waited too long for the periodic schedule status (%x/%x), giving up\n",
+ want, actual);
+ }
+ ehci->PSS_poll_count = 0;
+
+ /* The status is up-to-date; restart or stop the schedule as needed */
+ if (want == 0) { /* Stopped */
+ if (ehci->periodic_count > 0)
+ ehci_set_command_bit(ehci, CMD_PSE);
+
+ } else { /* Running */
+ if (ehci->periodic_count == 0) {
+
+ /* Turn off the schedule after a while */
+ ehci_enable_event(ehci, EHCI_HRTIMER_DISABLE_PERIODIC,
+ true);
+ }
+ }
+}
+
+/* Turn off the periodic schedule after a brief delay */
+static void ehci_disable_PSE(struct ehci_hcd *ehci)
+{
+ ehci_clear_command_bit(ehci, CMD_PSE);
+}
+
+
+/* Poll the STS_HALT status bit; see when a dead controller stops */
+static void ehci_handle_controller_death(struct ehci_hcd *ehci)
+{
+ if (!(ehci_readl(ehci, &ehci->regs->status) & STS_HALT)) {
+
+ /* Give up after a few milliseconds */
+ if (ehci->died_poll_count++ < 5) {
+ /* Try again later */
+ ehci_enable_event(ehci, EHCI_HRTIMER_POLL_DEAD, true);
+ return;
+ }
+ ehci_warn(ehci, "Waited too long for the controller to stop, giving up\n");
+ }
+
+ /* Clean up the mess */
+ ehci->rh_state = EHCI_RH_HALTED;
+ ehci_writel(ehci, 0, &ehci->regs->configured_flag);
+ ehci_writel(ehci, 0, &ehci->regs->intr_enable);
+ ehci_work(ehci);
+ end_unlink_async(ehci);
+
+ /* Not in process context, so don't try to reset the controller */
+}
+
+/* start to unlink interrupt QHs */
+static void ehci_handle_start_intr_unlinks(struct ehci_hcd *ehci)
+{
+ bool stopped = (ehci->rh_state < EHCI_RH_RUNNING);
+
+ /*
+ * Process all the QHs on the intr_unlink list that were added
+ * before the current unlink cycle began. The list is in
+ * temporal order, so stop when we reach the first entry in the
+ * current cycle. But if the root hub isn't running then
+ * process all the QHs on the list.
+ */
+ while (!list_empty(&ehci->intr_unlink_wait)) {
+ struct ehci_qh *qh;
+
+ qh = list_first_entry(&ehci->intr_unlink_wait,
+ struct ehci_qh, unlink_node);
+ if (!stopped && (qh->unlink_cycle ==
+ ehci->intr_unlink_wait_cycle))
+ break;
+ list_del_init(&qh->unlink_node);
+ qh->unlink_reason |= QH_UNLINK_QUEUE_EMPTY;
+ start_unlink_intr(ehci, qh);
+ }
+
+ /* Handle remaining entries later */
+ if (!list_empty(&ehci->intr_unlink_wait)) {
+ ehci_enable_event(ehci, EHCI_HRTIMER_START_UNLINK_INTR, true);
+ ++ehci->intr_unlink_wait_cycle;
+ }
+}
+
+/* Handle unlinked interrupt QHs once they are gone from the hardware */
+static void ehci_handle_intr_unlinks(struct ehci_hcd *ehci)
+{
+ bool stopped = (ehci->rh_state < EHCI_RH_RUNNING);
+
+ /*
+ * Process all the QHs on the intr_unlink list that were added
+ * before the current unlink cycle began. The list is in
+ * temporal order, so stop when we reach the first entry in the
+ * current cycle. But if the root hub isn't running then
+ * process all the QHs on the list.
+ */
+ ehci->intr_unlinking = true;
+ while (!list_empty(&ehci->intr_unlink)) {
+ struct ehci_qh *qh;
+
+ qh = list_first_entry(&ehci->intr_unlink, struct ehci_qh,
+ unlink_node);
+ if (!stopped && qh->unlink_cycle == ehci->intr_unlink_cycle)
+ break;
+ list_del_init(&qh->unlink_node);
+ end_unlink_intr(ehci, qh);
+ }
+
+ /* Handle remaining entries later */
+ if (!list_empty(&ehci->intr_unlink)) {
+ ehci_enable_event(ehci, EHCI_HRTIMER_UNLINK_INTR, true);
+ ++ehci->intr_unlink_cycle;
+ }
+ ehci->intr_unlinking = false;
+}
+
+
+/* Start another free-iTDs/siTDs cycle */
+static void start_free_itds(struct ehci_hcd *ehci)
+{
+ if (!(ehci->enabled_hrtimer_events & BIT(EHCI_HRTIMER_FREE_ITDS))) {
+ ehci->last_itd_to_free = list_entry(
+ ehci->cached_itd_list.prev,
+ struct ehci_itd, itd_list);
+ ehci->last_sitd_to_free = list_entry(
+ ehci->cached_sitd_list.prev,
+ struct ehci_sitd, sitd_list);
+ ehci_enable_event(ehci, EHCI_HRTIMER_FREE_ITDS, true);
+ }
+}
+
+/* Wait for controller to stop using old iTDs and siTDs */
+static void end_free_itds(struct ehci_hcd *ehci)
+{
+ struct ehci_itd *itd, *n;
+ struct ehci_sitd *sitd, *sn;
+
+ if (ehci->rh_state < EHCI_RH_RUNNING) {
+ ehci->last_itd_to_free = NULL;
+ ehci->last_sitd_to_free = NULL;
+ }
+
+ list_for_each_entry_safe(itd, n, &ehci->cached_itd_list, itd_list) {
+ list_del(&itd->itd_list);
+ dma_pool_free(ehci->itd_pool, itd, itd->itd_dma);
+ if (itd == ehci->last_itd_to_free)
+ break;
+ }
+ list_for_each_entry_safe(sitd, sn, &ehci->cached_sitd_list, sitd_list) {
+ list_del(&sitd->sitd_list);
+ dma_pool_free(ehci->sitd_pool, sitd, sitd->sitd_dma);
+ if (sitd == ehci->last_sitd_to_free)
+ break;
+ }
+
+ if (!list_empty(&ehci->cached_itd_list) ||
+ !list_empty(&ehci->cached_sitd_list))
+ start_free_itds(ehci);
+}
+
+
+/* Handle lost (or very late) IAA interrupts */
+static void ehci_iaa_watchdog(struct ehci_hcd *ehci)
+{
+ u32 cmd, status;
+
+ /*
+ * Lost IAA irqs wedge things badly; seen first with a vt8235.
+ * So we need this watchdog, but must protect it against both
+ * (a) SMP races against real IAA firing and retriggering, and
+ * (b) clean HC shutdown, when IAA watchdog was pending.
+ */
+ if (!ehci->iaa_in_progress || ehci->rh_state != EHCI_RH_RUNNING)
+ return;
+
+ /* If we get here, IAA is *REALLY* late. It's barely
+ * conceivable that the system is so busy that CMD_IAAD
+ * is still legitimately set, so let's be sure it's
+ * clear before we read STS_IAA. (The HC should clear
+ * CMD_IAAD when it sets STS_IAA.)
+ */
+ cmd = ehci_readl(ehci, &ehci->regs->command);
+
+ /*
+ * If IAA is set here it either legitimately triggered
+ * after the watchdog timer expired (_way_ late, so we'll
+ * still count it as lost) ... or a silicon erratum:
+ * - VIA seems to set IAA without triggering the IRQ;
+ * - IAAD potentially cleared without setting IAA.
+ */
+ status = ehci_readl(ehci, &ehci->regs->status);
+ if ((status & STS_IAA) || !(cmd & CMD_IAAD)) {
+ COUNT(ehci->stats.lost_iaa);
+ ehci_writel(ehci, STS_IAA, &ehci->regs->status);
+ }
+
+ ehci_dbg(ehci, "IAA watchdog: status %x cmd %x\n", status, cmd);
+ end_iaa_cycle(ehci);
+}
+
+
+/* Enable the I/O watchdog, if appropriate */
+static void turn_on_io_watchdog(struct ehci_hcd *ehci)
+{
+ /* Not needed if the controller isn't running or it's already enabled */
+ if (ehci->rh_state != EHCI_RH_RUNNING ||
+ (ehci->enabled_hrtimer_events &
+ BIT(EHCI_HRTIMER_IO_WATCHDOG)))
+ return;
+
+ /*
+ * Isochronous transfers always need the watchdog.
+ * For other sorts we use it only if the flag is set.
+ */
+ if (ehci->isoc_count > 0 || (ehci->need_io_watchdog &&
+ ehci->async_count + ehci->intr_count > 0))
+ ehci_enable_event(ehci, EHCI_HRTIMER_IO_WATCHDOG, true);
+}
+
+
+/*
+ * Handler functions for the hrtimer event types.
+ * Keep this array in the same order as the event types indexed by
+ * enum ehci_hrtimer_event in ehci.h.
+ */
+static void (*event_handlers[])(struct ehci_hcd *) = {
+ ehci_poll_ASS, /* EHCI_HRTIMER_POLL_ASS */
+ ehci_poll_PSS, /* EHCI_HRTIMER_POLL_PSS */
+ ehci_handle_controller_death, /* EHCI_HRTIMER_POLL_DEAD */
+ ehci_handle_intr_unlinks, /* EHCI_HRTIMER_UNLINK_INTR */
+ end_free_itds, /* EHCI_HRTIMER_FREE_ITDS */
+ end_unlink_async, /* EHCI_HRTIMER_ACTIVE_UNLINK */
+ ehci_handle_start_intr_unlinks, /* EHCI_HRTIMER_START_UNLINK_INTR */
+ unlink_empty_async, /* EHCI_HRTIMER_ASYNC_UNLINKS */
+ ehci_iaa_watchdog, /* EHCI_HRTIMER_IAA_WATCHDOG */
+ ehci_disable_PSE, /* EHCI_HRTIMER_DISABLE_PERIODIC */
+ ehci_disable_ASE, /* EHCI_HRTIMER_DISABLE_ASYNC */
+ ehci_work, /* EHCI_HRTIMER_IO_WATCHDOG */
+};
+
+static enum hrtimer_restart ehci_hrtimer_func(struct hrtimer *t)
+{
+ struct ehci_hcd *ehci = container_of(t, struct ehci_hcd, hrtimer);
+ ktime_t now;
+ unsigned long events;
+ unsigned long flags;
+ unsigned e;
+
+ spin_lock_irqsave(&ehci->lock, flags);
+
+ events = ehci->enabled_hrtimer_events;
+ ehci->enabled_hrtimer_events = 0;
+ ehci->next_hrtimer_event = EHCI_HRTIMER_NO_EVENT;
+
+ /*
+ * Check each pending event. If its time has expired, handle
+ * the event; otherwise re-enable it.
+ */
+ now = ktime_get();
+ for_each_set_bit(e, &events, EHCI_HRTIMER_NUM_EVENTS) {
+ if (ktime_compare(now, ehci->hr_timeouts[e]) >= 0)
+ event_handlers[e](ehci);
+ else
+ ehci_enable_event(ehci, e, false);
+ }
+
+ spin_unlock_irqrestore(&ehci->lock, flags);
+ return HRTIMER_NORESTART;
+}