diff options
Diffstat (limited to 'drivers/usb/host/ehci-q.c')
| -rw-r--r-- | drivers/usb/host/ehci-q.c | 1090 |
1 files changed, 1090 insertions, 0 deletions
diff --git a/drivers/usb/host/ehci-q.c b/drivers/usb/host/ehci-q.c new file mode 100644 index 00000000000..7df9b9af54f --- /dev/null +++ b/drivers/usb/host/ehci-q.c @@ -0,0 +1,1090 @@ +/* + * 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; +} + +/*-------------------------------------------------------------------------*/ + +static inline void +qh_update (struct ehci_hcd *ehci, struct ehci_qh *qh, struct ehci_qtd *qtd) +{ + /* writes to an active overlay are unsafe */ + BUG_ON(qh->qh_state != QH_STATE_IDLE); + + qh->hw_qtd_next = QTD_NEXT (qtd->qtd_dma); + qh->hw_alt_next = EHCI_LIST_END; + + /* Except for control endpoints, we make hardware maintain data + * toggle (like OHCI) ... here (re)initialize the toggle in the QH, + * and set the pseudo-toggle in udev. Only usb_clear_halt() will + * ever clear it. + */ + if (!(qh->hw_info1 & cpu_to_le32(1 << 14))) { + unsigned is_out, epnum; + + is_out = !(qtd->hw_token & cpu_to_le32(1 << 8)); + epnum = (le32_to_cpup(&qh->hw_info1) >> 8) & 0x0f; + if (unlikely (!usb_gettoggle (qh->dev, epnum, is_out))) { + qh->hw_token &= ~__constant_cpu_to_le32 (QTD_TOGGLE); + usb_settoggle (qh->dev, epnum, is_out, 1); + } + } + + /* 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); +} + +/* if it weren't for a common silicon quirk (writing the dummy into the qh + * overlay, so qh->hw_token wrongly becomes inactive/halted), only fault + * recovery (including urb dequeue) would need software changes to a QH... + */ +static void +qh_refresh (struct ehci_hcd *ehci, struct ehci_qh *qh) +{ + struct ehci_qtd *qtd; + + if (list_empty (&qh->qtd_list)) + qtd = qh->dummy; + else { + qtd = list_entry (qh->qtd_list.next, + struct ehci_qtd, qtd_list); + /* first qtd may already be partially processed */ + if (cpu_to_le32 (qtd->qtd_dma) == qh->hw_current) + qtd = NULL; + } + + if (qtd) + qh_update (ehci, qh, qtd); +} + +/*-------------------------------------------------------------------------*/ + +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); + + /* if async CSPLIT failed, try cleaning out the TT buffer */ + if (urb->status != -EPIPE + && urb->dev->tt && !usb_pipeint (urb->pipe) + && ((token & QTD_STS_MMF) != 0 + || QTD_CERR(token) == 0) + && (!ehci_is_TDI(ehci) + || urb->dev->tt->hub != + ehci_to_hcd(ehci)->self.root_hub)) { +#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) +__releases(ehci->lock) +__acquires(ehci->lock) +{ + if (likely (urb->hcpriv != NULL)) { + 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) */ + ehci_to_hcd(ehci)->self.bandwidth_int_reqs--; + } + qh_put (qh); + } + + spin_lock (&urb->lock); + urb->hcpriv = NULL; + 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); + +#ifdef EHCI_URB_TRACE + ehci_dbg (ehci, + "%s %s urb %p ep%d%s status %d len %d/%d\n", + __FUNCTION__, urb->dev->devpath, urb, + usb_pipeendpoint (urb->pipe), + usb_pipein (urb->pipe) ? "in" : "out", + urb->status, + urb->actual_length, urb->transfer_buffer_length); +#endif + + /* complete() can reenter this HCD */ + spin_unlock (&ehci->lock); + usb_hcd_giveback_urb (ehci_to_hcd(ehci), urb, regs); + spin_lock (&ehci->lock); +} + +static void start_unlink_async (struct ehci_hcd *ehci, struct ehci_qh *qh); +static void unlink_async (struct ehci_hcd *ehci, struct ehci_qh *qh); + +static void intr_deschedule (struct ehci_hcd *ehci, struct ehci_qh *qh); +static int qh_schedule (struct ehci_hcd *ehci, struct ehci_qh *qh); + +/* + * 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 = NULL, *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 = NULL; + } + + /* 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. + * that silicon quirk can kick in with this dummy too. + */ + } else if (IS_SHORT_READ (token) + && !(qtd->hw_alt_next & EHCI_LIST_END)) { + stopped = 1; + goto halt; + } + + /* stop scanning when we reach qtds the hc is using */ + } else if (likely (!stopped + && HC_IS_RUNNING (ehci_to_hcd(ehci)->state))) { + break; + + } else { + stopped = 1; + + if (unlikely (!HC_IS_RUNNING (ehci_to_hcd(ehci)->state))) + urb->status = -ESHUTDOWN; + + /* 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 != NULL)) { + 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; + + /* be sure the hardware's done with the qh before refreshing + * it after fault cleanup, or recovering from silicon wrongly + * overlaying the dummy qtd (which reduces DMA chatter). + */ + if (stopped != 0 || qh->hw_qtd_next == EHCI_LIST_END) { + switch (state) { + case QH_STATE_IDLE: + qh_refresh(ehci, qh); + break; + case QH_STATE_LINKED: + /* should be rare for periodic transfers, + * except maybe high bandwidth ... + */ + if (qh->period) { + intr_deschedule (ehci, qh); + (void) qh_schedule (ehci, qh); + } else + unlink_async (ehci, qh); + break; + /* otherwise, unlink already started */ + } + } + + 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 NULL; + 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; + + /* for zero length DATA stages, STATUS is always IN */ + 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 NULL; +} + +/*-------------------------------------------------------------------------*/ + +// 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. (2.7?) + + +/* + * 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; + + qh->period = urb->interval >> 3; + if (qh->period == 0 && urb->interval != 1) { + /* NOTE interval 2 or 4 uframes could work. + * But interval 1 scheduling is simpler, and + * includes high bandwidth. + */ + 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; + } + } + + /* support for tt scheduling, and access to toggles */ + qh->dev = usb_get_dev (urb->dev); + + /* 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; + + /* set the address of the TT; for TDI's integrated + * root hub tt, leave it zeroed. + */ + if (!ehci_is_TDI(ehci) + || urb->dev->tt->hub != + ehci_to_hcd(ehci)->self.root_hub) + 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 (qh); + return NULL; + } + + /* 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); + usb_settoggle (urb->dev, usb_pipeendpoint (urb->pipe), !is_input, 1); + qh_refresh (ehci, qh); + return qh; +} + +/*-------------------------------------------------------------------------*/ + +/* move qh (and its qtds) onto async queue; maybe enable queue. */ + +static void qh_link_async (struct ehci_hcd *ehci, struct ehci_qh *qh) +{ + __le32 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_to_hcd(ehci)->state = HC_STATE_RUNNING; + /* posted write need not be known to HC yet ... */ + } + } + + /* clear halt and/or toggle; and maybe recover from silicon quirk */ + if (qh->qh_state == QH_STATE_IDLE) + qh_refresh (ehci, qh); + + /* 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_cpu_to_le32(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 = NULL; + + qh = (struct ehci_qh *) *ptr; + if (unlikely (qh == NULL)) { + /* can't sleep here, we have ehci->lock... */ + qh = qh_make (ehci, urb, GFP_ATOMIC); + *ptr = qh; + } + if (likely (qh != NULL)) { + struct ehci_qtd *qtd; + + if (unlikely (list_empty (qtd_list))) + qtd = NULL; + else + qtd = list_entry (qtd_list->next, struct ehci_qtd, + qtd_list); + + /* control qh may need patching ... */ + if (unlikely (epnum == 0)) { + + /* usb_reset_device() briefly reverts to address 0 */ + if (usb_pipedevice (urb->pipe) == 0) + qh->hw_info1 &= ~QH_ADDR_MASK; + } + + /* just one way to queue requests: swap with the dummy qtd. + * only hc or qh_refresh() ever modify the overlay. + */ + if (likely (qtd != NULL)) { + struct ehci_qtd *dummy; + dma_addr_t dma; + __le32 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 usb_host_endpoint *ep, + struct urb *urb, + struct list_head *qtd_list, + int mem_flags +) { + struct ehci_qtd *qtd; + int epnum; + unsigned long flags; + struct ehci_qh *qh = NULL; + + qtd = list_entry (qtd_list->next, struct ehci_qtd, qtd_list); + epnum = ep->desc.bEndpointAddress; + +#ifdef EHCI_URB_TRACE + ehci_dbg (ehci, + "%s %s urb %p ep%d%s len %d, qtd %p [qh %p]\n", + __FUNCTION__, urb->dev->devpath, urb, + epnum & 0x0f, (epnum & USB_DIR_IN) ? "in" : "out", + urb->transfer_buffer_length, + qtd, ep->hcpriv); +#endif + + spin_lock_irqsave (&ehci->lock, flags); + qh = qh_append_tds (ehci, urb, qtd_list, epnum, &ep->hcpriv); + + /* 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 != NULL)) { + if (likely (qh->qh_state == QH_STATE_IDLE)) + qh_link_async (ehci, qh_get (qh)); + } + spin_unlock_irqrestore (&ehci->lock, flags); + if (unlikely (qh == NULL)) { + 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 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 = NULL; + qh_put (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 = NULL; + + qh_completions (ehci, qh, regs); + + if (!list_empty (&qh->qtd_list) + && HC_IS_RUNNING (ehci_to_hcd(ehci)->state)) + qh_link_async (ehci, qh); + else { + qh_put (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 (HC_IS_RUNNING (ehci_to_hcd(ehci)->state) + && ehci->async->qh_next.qh == NULL) + timer_action (ehci, TIMER_ASYNC_OFF); + } + + if (next) { + ehci->reclaim = NULL; + 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 + assert_spin_locked(&ehci->lock); + if (ehci->reclaim + || (qh->qh_state != QH_STATE_LINKED + && qh->qh_state != QH_STATE_UNLINK_WAIT) + ) + BUG (); +#endif + + /* stop async schedule right now? */ + if (unlikely (qh == ehci->async)) { + /* can't get here without STS_ASS set */ + if (ehci_to_hcd(ehci)->state != HC_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_to_hcd(ehci)->state == HC_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 != NULL)) { + 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 (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); +} |