/* * Copyright (C) 2001-2004 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_hcd *ehci, 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_hc32(ehci, (u32)addr); qtd->hw_buf_hi[0] = cpu_to_hc32(ehci, (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_hc32(ehci, (u32)addr); qtd->hw_buf_hi[i] = cpu_to_hc32(ehci, (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_hc32(ehci, (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) { struct ehci_qh_hw *hw = qh->hw; /* writes to an active overlay are unsafe */ BUG_ON(qh->qh_state != QH_STATE_IDLE); hw->hw_qtd_next = QTD_NEXT(ehci, qtd->qtd_dma); hw->hw_alt_next = EHCI_LIST_END(ehci); /* 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 (!(hw->hw_info1 & cpu_to_hc32(ehci, 1 << 14))) { unsigned is_out, epnum; is_out = qh->is_out; epnum = (hc32_to_cpup(ehci, &hw->hw_info1) >> 8) & 0x0f; if (unlikely (!usb_gettoggle (qh->dev, epnum, is_out))) { hw->hw_token &= ~cpu_to_hc32(ehci, QTD_TOGGLE); usb_settoggle (qh->dev, epnum, is_out, 1); } } /* HC must see latest qtd and qh data before we clear ACTIVE+HALT */ wmb (); hw->hw_token &= cpu_to_hc32(ehci, 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_hc32(ehci, qtd->qtd_dma) == qh->hw->hw_current) qtd = NULL; } if (qtd) qh_update (ehci, qh, qtd); } /*-------------------------------------------------------------------------*/ static void qh_link_async(struct ehci_hcd *ehci, struct ehci_qh *qh); static void ehci_clear_tt_buffer_complete(struct usb_hcd *hcd, struct usb_host_endpoint *ep) { struct ehci_hcd *ehci = hcd_to_ehci(hcd); struct ehci_qh *qh = ep->hcpriv; unsigned long flags; spin_lock_irqsave(&ehci->lock, flags); qh->clearing_tt = 0; if (qh->qh_state == QH_STATE_IDLE && !list_empty(&qh->qtd_list) && HC_IS_RUNNING(hcd->state)) qh_link_async(ehci, qh); spin_unlock_irqrestore(&ehci->lock, flags); } static void ehci_clear_tt_buffer(struct ehci_hcd *ehci, struct ehci_qh *qh, struct urb *urb, u32 token) { /* If an async split transaction gets an error or is unlinked, * the TT buffer may be left in an indeterminate state. We * have to clear the TT buffer. * * Note: this routine is never called for Isochronous transfers. */ if (urb->dev->tt && !usb_pipeint(urb->pipe) && !qh->clearing_tt) { #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 */ if (!ehci_is_TDI(ehci) || urb->dev->tt->hub != ehci_to_hcd(ehci)->self.root_hub) { if (usb_hub_clear_tt_buffer(urb) == 0) qh->clearing_tt = 1; } else { /* REVISIT ARC-derived cores don't clear the root * hub TT buffer in this way... */ } } } static int qtd_copy_status ( struct ehci_hcd *ehci, struct urb *urb, size_t length, u32 token ) { int status = -EINPROGRESS; /* 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->unlinked)) return status; /* force cleanup after short read; not always an error */ if (unlikely (IS_SHORT_READ (token))) 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 */ status = -EOVERFLOW; /* CERR nonzero + halt --> stall */ } else if (QTD_CERR(token)) { status = -EPIPE; /* In theory, more than one of the following bits can be set * since they are sticky and the transaction is retried. * Which to test first is rather arbitrary. */ } else if (token & QTD_STS_MMF) { /* fs/ls interrupt xfer missed the complete-split */ status = -EPROTO; } else if (token & QTD_STS_DBE) { 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 */ ehci_dbg(ehci, "devpath %s ep%d%s 3strikes\n", urb->dev->devpath, usb_pipeendpoint(urb->pipe), usb_pipein(urb->pipe) ? "in" : "out"); status = -EPROTO; } else { /* unknown */ 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, status); } return status; } static void ehci_urb_done(struct ehci_hcd *ehci, struct urb *urb, int status) __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->hw_info2 & cpu_to_hc32(ehci, QH_SMASK)) != 0) { /* ... update hc-wide periodic stats (for usbfs) */ ehci_to_hcd(ehci)->self.bandwidth_int_reqs--; } qh_put (qh); } if (unlikely(urb->unlinked)) { COUNT(ehci->stats.unlink); } else { /* report non-error and short read status as zero */ if (status == -EINPROGRESS || status == -EREMOTEIO) status = 0; COUNT(ehci->stats.complete); } #ifdef EHCI_URB_TRACE ehci_dbg (ehci, "%s %s urb %p ep%d%s status %d len %d/%d\n", __func__, urb->dev->devpath, urb, usb_pipeendpoint (urb->pipe), usb_pipein (urb->pipe) ? "in" : "out", status, urb->actual_length, urb->transfer_buffer_length); #endif /* complete() can reenter this HCD */ usb_hcd_unlink_urb_from_ep(ehci_to_hcd(ehci), urb); spin_unlock (&ehci->lock); usb_hcd_giveback_urb(ehci_to_hcd(ehci), urb, status); 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 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. */ static unsigned qh_completions (struct ehci_hcd *ehci, struct ehci_qh *qh) { struct ehci_qtd *last, *end = qh->dummy; struct list_head *entry, *tmp; int last_status; int stopped; unsigned count = 0; u8 state; struct ehci_qh_hw *hw = qh->hw; 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. * * It's a bug for qh->qh_state to be anything other than * QH_STATE_IDLE, unless our caller is scan_async() or * scan_periodic(). */ state = qh->qh_state; qh->qh_state = QH_STATE_COMPLETING; stopped = (state == QH_STATE_IDLE); rescan: last = NULL; last_status = -EINPROGRESS; qh->needs_rescan = 0; /* 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, last_status); count++; last_status = -EINPROGRESS; } 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 = hc32_to_cpu(ehci, qtd->hw_token); /* always clean up qtds the hc de-activated */ retry_xacterr: if ((token & QTD_STS_ACTIVE) == 0) { /* on STALL, error, and short reads this urb must * complete and all its qtds must be recycled. */ if ((token & QTD_STS_HALT) != 0) { /* retry transaction errors until we * reach the software xacterr limit */ if ((token & QTD_STS_XACT) && QTD_CERR(token) == 0 && ++qh->xacterrs < QH_XACTERR_MAX && !urb->unlinked) { ehci_dbg(ehci, "detected XactErr len %zu/%zu retry %d\n", qtd->length - QTD_LENGTH(token), qtd->length, qh->xacterrs); /* reset the token in the qtd and the * qh overlay (which still contains * the qtd) so that we pick up from * where we left off */ token &= ~QTD_STS_HALT; token |= QTD_STS_ACTIVE | (EHCI_TUNE_CERR << 10); qtd->hw_token = cpu_to_hc32(ehci, token); wmb(); hw->hw_token = cpu_to_hc32(ehci, token); goto retry_xacterr; } stopped = 1; /* magic dummy for some short reads; qh won't advance. * that silicon quirk can kick in with this dummy too. * * other short reads won't stop the queue, including * control transfers (status stage handles that) or * most other single-qtd reads ... the queue stops if * URB_SHORT_NOT_OK was set so the driver submitting * the urbs could clean it up. */ } else if (IS_SHORT_READ (token) && !(qtd->hw_alt_next & EHCI_LIST_END(ehci))) { stopped = 1; } /* stop scanning when we reach qtds the hc is using */ } else if (likely (!stopped && HC_IS_RUNNING (ehci_to_hcd(ehci)->state))) { break; /* scan the whole queue for unlinks whenever it stops */ } else { stopped = 1; /* cancel everything if we halt, suspend, etc */ if (!HC_IS_RUNNING(ehci_to_hcd(ehci)->state)) last_status = -ESHUTDOWN; /* this qtd is active; skip it unless a previous qtd * for its urb faulted, or its urb was canceled. */ else if (last_status == -EINPROGRESS && !urb->unlinked) continue; /* qh unlinked; token in overlay may be most current */ if (state == QH_STATE_IDLE && cpu_to_hc32(ehci, qtd->qtd_dma) == hw->hw_current) { token = hc32_to_cpu(ehci, hw->hw_token); /* An unlink may leave an incomplete * async transaction in the TT buffer. * We have to clear it. */ ehci_clear_tt_buffer(ehci, qh, urb, token); } } /* unless we already know the urb's status, collect qtd status * and update count of bytes transferred. in common short read * cases with only one data qtd (including control transfers), * queue processing won't halt. but with two or more qtds (for * example, with a 32 KB transfer), when the first qtd gets a * short read the second must be removed by hand. */ if (last_status == -EINPROGRESS) { last_status = qtd_copy_status(ehci, urb, qtd->length, token); if (last_status == -EREMOTEIO && (qtd->hw_alt_next & EHCI_LIST_END(ehci))) last_status = -EINPROGRESS; /* As part of low/full-speed endpoint-halt processing * we must clear the TT buffer (11.17.5). */ if (unlikely(last_status != -EINPROGRESS && last_status != -EREMOTEIO)) { /* The TT's in some hubs malfunction when they * receive this request following a STALL (they * stop sending isochronous packets). Since a * STALL can't leave the TT buffer in a busy * state (if you believe Figures 11-48 - 11-51 * in the USB 2.0 spec), we won't clear the TT * buffer in this case. Strictly speaking this * is a violation of the spec. */ if (last_status != -EPIPE) ehci_clear_tt_buffer(ehci, qh, urb, token); } } /* if we're removing something not at the queue head, * patch the hardware queue pointer. */ 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; } /* remove qtd; it's recycled after possible urb completion */ list_del (&qtd->qtd_list); last = qtd; /* reinit the xacterr counter for the next qtd */ qh->xacterrs = 0; } /* last urb's completion might still need calling */ if (likely (last != NULL)) { ehci_urb_done(ehci, last->urb, last_status); count++; ehci_qtd_free (ehci, last); } /* Do we need to rescan for URBs dequeued during a giveback? */ if (unlikely(qh->needs_rescan)) { /* If the QH is already unlinked, do the rescan now. */ if (state == QH_STATE_IDLE) goto rescan; /* Otherwise we have to wait until the QH is fully unlinked. * Our caller will start an unlink if qh->needs_rescan is * set. But if an unlink has already started, nothing needs * to be done. */ if (state != QH_STATE_LINKED) qh->needs_rescan = 0; } /* 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 || hw->hw_qtd_next == EHCI_LIST_END(ehci)) { switch (state) { case QH_STATE_IDLE: qh_refresh(ehci, qh); break; case QH_STATE_LINKED: /* We won't refresh a QH that's linked (after the HC * stopped the queue). That avoids a race: * - HC reads first part of QH; * - CPU updates that first part and the token; * - HC reads rest of that QH, including token * Result: HC gets an inconsistent image, and then * DMAs to/from the wrong memory (corrupting it). * * That should be rare for interrupt transfers, * except maybe high bandwidth ... */ /* Tell the caller to start an unlink */ qh->needs_rescan = 1; 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, gfp_t flags ) { struct ehci_qtd *qtd, *qtd_prev; dma_addr_t buf; int len, this_sg_len, maxpacket; int is_input; u32 token; int i; struct scatterlist *sg; /* * 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(ehci, 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(ehci, qtd->qtd_dma); list_add_tail (&qtd->qtd_list, head); /* for zero length DATA stages, STATUS is always IN */ if (len == 0) token |= (1 /* "in" */ << 8); } /* * data transfer stage: buffer setup */ i = urb->num_sgs; if (len > 0 && i > 0) { sg = urb->sg; buf = sg_dma_address(sg); /* urb->transfer_buffer_length may be smaller than the * size of the scatterlist (or vice versa) */ this_sg_len = min_t(int, sg_dma_len(sg), len); } else { sg = NULL; buf = urb->transfer_dma; this_sg_len = len; } if (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(ehci, qtd, buf, this_sg_len, token, maxpacket); this_sg_len -= this_qtd_len; len -= this_qtd_len; buf += this_qtd_len; /* * short reads advance to a "magic" dummy instead of the next * qtd ... that forces the queue to stop, for manual cleanup. * (this will usually be overridden later.) */ if (is_input) qtd->hw_alt_next = ehci->async->hw->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(this_sg_len <= 0)) { if (--i <= 0 || len <= 0) break; sg = sg_next(sg); buf = sg_dma_address(sg); this_sg_len = min_t(int, sg_dma_len(sg), len); } qtd_prev = qtd; qtd = ehci_qtd_alloc (ehci, flags); if (unlikely (!qtd)) goto cleanup; qtd->urb = urb; qtd_prev->hw_next = QTD_NEXT(ehci, qtd->qtd_dma); list_add_tail (&qtd->qtd_list, head); } /* * unless the caller requires manual cleanup after short reads, * have the alt_next mechanism keep the queue running after the * last data qtd (the only one, for control and most other cases). */ if (likely ((urb->transfer_flags & URB_SHORT_NOT_OK) == 0 || usb_pipecontrol (urb->pipe))) qtd->hw_alt_next = EHCI_LIST_END(ehci); /* * control requests may need a terminating data "status" ack; * bulk ones may need a terminating short packet (zero length). */ if (likely (urb->transfer_buffer_length != 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(ehci, qtd->qtd_dma); list_add_tail (&qtd->qtd_list, head); /* never any data in such packets */ qtd_fill(ehci, qtd, 0, 0, token, 0); } } /* by default, enable interrupt on urb completion */ if (likely (!(urb->transfer_flags & URB_NO_INTERRUPT))) qtd->hw_token |= cpu_to_hc32(ehci, 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, gfp_t flags ) { struct ehci_qh *qh = ehci_qh_alloc (ehci, flags); u32 info1 = 0, info2 = 0; int is_input, type; int maxp = 0; struct usb_tt *tt = urb->dev->tt; struct ehci_qh_hw *hw; 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); /* 1024 byte maxpacket is a hardware ceiling. High bandwidth * acts like up to 3KB, but is built from smaller packets. */ if (max_packet(maxp) > 1024) { ehci_dbg(ehci, "bogus qh maxpacket %d\n", max_packet(maxp)); goto done; } /* 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 = NS_TO_US(usb_calc_bus_time(USB_SPEED_HIGH, is_input, 0, hb_mult(maxp) * max_packet(maxp))); qh->start = NO_FRAME; qh->stamp = ehci->periodic_stamp; 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. */ urb->interval = 1; } else if (qh->period > ehci->periodic_size) { qh->period = ehci->periodic_size; urb->interval = qh->period << 3; } } else { int think_time; /* 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); } think_time = tt ? tt->think_time : 0; qh->tt_usecs = NS_TO_US (think_time + usb_calc_bus_time (urb->dev->speed, is_input, 0, max_packet (maxp))); qh->period = urb->interval; if (qh->period > ehci->periodic_size) { qh->period = ehci->periodic_size; urb->interval = qh->period; } } } /* support for tt scheduling, and access to toggles */ qh->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); /* Some Freescale processors have an erratum in which the * port number in the queue head was 0..N-1 instead of 1..N. */ if (ehci_has_fsl_portno_bug(ehci)) info2 |= (urb->dev->ttport-1) << 23; else info2 |= urb->dev->ttport << 23; /* set the address of the TT; for TDI's integrated * root hub tt, leave it zeroed. */ if (tt && tt->hub != ehci_to_hcd(ehci)->self.root_hub) info2 |= 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); /* The USB spec says that high speed bulk endpoints * always use 512 byte maxpacket. But some device * vendors decided to ignore that, and MSFT is happy * to help them do so. So now people expect to use * such nonconformant devices with Linux too; sigh. */ info1 |= max_packet(maxp) << 16; 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; hw = qh->hw; hw->hw_info1 = cpu_to_hc32(ehci, info1); hw->hw_info2 = cpu_to_hc32(ehci, info2); qh->is_out = !is_input; 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) { __hc32 dma = QH_NEXT(ehci, qh->qh_dma); struct ehci_qh *head; /* Don't link a QH if there's a Clear-TT-Buffer pending */ if (unlikely(qh->clearing_tt)) return; WARN_ON(qh->qh_state != QH_STATE_IDLE); /* (re)start the async schedule? */ head = ehci->async; timer_action_done (ehci, TIMER_ASYNC_OFF); if (!head->qh_next.qh) { u32 cmd = ehci_readl(ehci, &ehci->regs->command); if (!(cmd & CMD_ASE)) { /* in case a clear of CMD_ASE didn't take yet */ (void)handshake(ehci, &ehci->regs->status, STS_ASS, 0, 150); cmd |= CMD_ASE | CMD_RUN; ehci_writel(ehci, 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 */ qh_refresh(ehci, qh); /* splice right after start */ qh->qh_next = head->qh_next; qh->hw->hw_next = head->hw->hw_next; wmb (); head->qh_next.qh = qh; head->hw->hw_next = dma; /* * flush qh descriptor into memory immediately, * see comments in qh_append_tds. */ ehci_sync_mem(); qh_get(qh); qh->xacterrs = 0; qh->qh_state = QH_STATE_LINKED; /* qtd completions reported later by interrupt */ } /*-------------------------------------------------------------------------*/ /* * 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; __hc32 qh_addr_mask = cpu_to_hc32(ehci, 0x7f); 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->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; __hc32 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(ehci); 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_tail(qtd_list, &qh->qtd_list); ehci_qtd_init(ehci, 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(ehci, dma); /* let the hc process these next qtds */ wmb (); dummy->hw_token = token; /* * Writing to dma coherent buffer on ARM may * be delayed to reach memory, so HC may not see * hw_token of dummy qtd in time, which can cause * the qtd transaction to be executed very late, * and degrade performance a lot. ehci_sync_mem * is added to flush 'token' immediatelly into * memory, so that ehci can execute the transaction * ASAP. */ ehci_sync_mem(); urb->hcpriv = qh_get (qh); } } return qh; } /*-------------------------------------------------------------------------*/ static int submit_async ( struct ehci_hcd *ehci, struct urb *urb, struct list_head *qtd_list, gfp_t mem_flags ) { int epnum; unsigned long flags; struct ehci_qh *qh = NULL; int rc; epnum = urb->ep->desc.bEndpointAddress; #ifdef EHCI_URB_TRACE { struct ehci_qtd *qtd; qtd = list_entry(qtd_list->next, struct ehci_qtd, qtd_list); ehci_dbg(ehci, "%s %s urb %p ep%d%s len %d, qtd %p [qh %p]\n", __func__, urb->dev->devpath, urb, epnum & 0x0f, (epnum & USB_DIR_IN) ? "in" : "out", urb->transfer_buffer_length, qtd, urb->ep->hcpriv); } #endif spin_lock_irqsave (&ehci->lock, flags); if (unlikely(!HCD_HW_ACCESSIBLE(ehci_to_hcd(ehci)))) { rc = -ESHUTDOWN; goto done; } rc = usb_hcd_link_urb_to_ep(ehci_to_hcd(ehci), urb); if (unlikely(rc)) goto done; qh = qh_append_tds(ehci, urb, qtd_list, epnum, &urb->ep->hcpriv); if (unlikely(qh == NULL)) { usb_hcd_unlink_urb_from_ep(ehci_to_hcd(ehci), urb); rc = -ENOMEM; goto done; } /* 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->qh_state == QH_STATE_IDLE)) qh_link_async(ehci, qh); done: spin_unlock_irqrestore (&ehci->lock, flags); if (unlikely (qh == NULL)) qtd_list_free (ehci, urb, qtd_list); return rc; } /*-------------------------------------------------------------------------*/ /* the async qh for the qtds being reclaimed are now unlinked from the HC */ static void end_unlink_async (struct ehci_hcd *ehci) { struct ehci_qh *qh = ehci->reclaim; struct ehci_qh *next; iaa_watchdog_done(ehci); // qh->hw_next = cpu_to_hc32(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; qh->reclaim = NULL; qh_completions (ehci, qh); if (!list_empty (&qh->qtd_list) && HC_IS_RUNNING (ehci_to_hcd(ehci)->state)) qh_link_async (ehci, qh); else { /* 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); } qh_put(qh); /* refcount from async list */ if (next) { ehci->reclaim = NULL; start_unlink_async (ehci, next); } if (ehci->has_synopsys_hc_bug) ehci_writel(ehci, (u32) ehci->async->qh_dma, &ehci->regs->async_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 = ehci_readl(ehci, &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 && !ehci->reclaim) { /* ... and CMD_IAAD clear */ ehci_writel(ehci, 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->hw_next = qh->hw->hw_next; prev->qh_next = qh->qh_next; if (ehci->qh_scan_next == qh) ehci->qh_scan_next = qh->qh_next.qh; wmb (); /* If the controller isn't running, we don't have to wait for it */ if (unlikely(!HC_IS_RUNNING(ehci_to_hcd(ehci)->state))) { /* if (unlikely (qh->reclaim != 0)) * this will recurse, probably not much */ end_unlink_async (ehci); return; } cmd |= CMD_IAAD; ehci_writel(ehci, cmd, &ehci->regs->command); (void)ehci_readl(ehci, &ehci->regs->command); iaa_watchdog_start(ehci); } /*-------------------------------------------------------------------------*/ static void scan_async (struct ehci_hcd *ehci) { bool stopped; struct ehci_qh *qh; enum ehci_timer_action action = TIMER_IO_WATCHDOG; timer_action_done (ehci, TIMER_ASYNC_SHRINK); stopped = !HC_IS_RUNNING(ehci_to_hcd(ehci)->state); ehci->qh_scan_next = ehci->async->qh_next.qh; while (ehci->qh_scan_next) { qh = ehci->qh_scan_next; ehci->qh_scan_next = qh->qh_next.qh; rescan: /* 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 start_unlink_async(). */ qh = qh_get(qh); temp = qh_completions(ehci, qh); if (qh->needs_rescan) unlink_async(ehci, qh); qh->unlink_time = jiffies + EHCI_SHRINK_JIFFIES; qh_put(qh); if (temp != 0) goto rescan; } /* unlink idle entries, reducing DMA 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) && qh->qh_state == QH_STATE_LINKED) { if (!ehci->reclaim && (stopped || time_after_eq(jiffies, qh->unlink_time))) start_unlink_async(ehci, qh); else action = TIMER_ASYNC_SHRINK; } } if (action == TIMER_ASYNC_SHRINK) timer_action (ehci, TIMER_ASYNC_SHRINK); }