[PATCH v2 40/51] IB/qib: Add qib_tx.c

Ralph Campbell
2009-12-03T19:06:34Z

creates the qib_tx.c file.

Signed-off-by: Ralph Campbell <ralph.campbell-h88ZbnxC6KDQT0dZR+AlfA@public.gmane.org>
---

drivers/infiniband/hw/qib/qib_tx.c | 585 ++++++++++++++++++++++++++++++++++++
1 files changed, 585 insertions(+), 0 deletions(-)
create mode 100644 drivers/infiniband/hw/qib/qib_tx.c

diff --git a/drivers/infiniband/hw/qib/qib_tx.c b/drivers/infiniband/hw/qib/qib_tx.c
new file mode 100644
index 0000000..7d77f29
--- /dev/null
+++ b/drivers/infiniband/hw/qib/qib_tx.c
@@ -0,0 +1,585 @@
+/*
+ * Copyright (c) 2008, 2009 QLogic Corporation. All rights reserved.
+ *
+ * This software is available to you under a choice of one of two
+ * licenses. You may choose to be licensed under the terms of the GNU
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the
+ * OpenIB.org BSD license below:
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ * - Redistributions of source code must retain the above
+ * copyright notice, this list of conditions and the following
+ * disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following
+ * disclaimer in the documentation and/or other materials
+ * provided with the distribution.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include <linux/spinlock.h>
+#include <linux/pci.h>
+#include <linux/io.h>
+#include <linux/delay.h>
+#include <linux/netdevice.h>
+#include <linux/vmalloc.h>
+
+#include "qib.h"
+
+static unsigned qib_hol_timeout_ms = 3000;
+module_param_named(hol_timeout_ms, qib_hol_timeout_ms, uint, S_IRUGO);
+MODULE_PARM_DESC(hol_timeout_ms,
+ "duration of user app suspension after link failure");
+
+unsigned qib_sdma_fetch_arb = 1;
+module_param_named(fetch_arb, qib_sdma_fetch_arb, uint, S_IRUGO);
+MODULE_PARM_DESC(fetch_arb, "IBA7220: change SDMA descriptor arbitration");
+
+/**
+ * qib_disarm_piobufs - cancel a range of PIO buffers
+ * @dd: the qlogic_ib device
+ * @first: the first PIO buffer to cancel
+ * @cnt: the number of PIO buffers to cancel
+ *
+ * Cancel a range of PIO buffers. Used at user process close,
+ * in case it died while writing to a PIO buffer.
+ */
+void qib_disarm_piobufs(struct qib_devdata *dd, unsigned first, unsigned cnt)
+{
+ unsigned long flags;
+ unsigned i;
+ unsigned last;
+
+ qib_cdbg(ERRPKT, "disarm %u PIObufs first=%u\n", cnt, first);
+ last = first + cnt;
+ spin_lock_irqsave(&dd->pioavail_lock, flags);
+ for (i = first; i < last; i++) {
+ __clear_bit(i, dd->pio_need_disarm);
+ dd->f_sendctrl(dd->pport, QIB_SENDCTRL_DISARM_BUF(i));
+ }
+ spin_unlock_irqrestore(&dd->pioavail_lock, flags);
+}
+
+/*
+ * This is called by a user process when it sees the DISARM_BUFS event
+ * bit is set.
+ */
+int qib_disarm_piobufs_ifneeded(struct qib_ctxtdata *rcd)
+{
+ struct qib_devdata *dd = rcd->dd;
+ unsigned i;
+ unsigned last;
+ unsigned n = 0;
+
+ last = rcd->pio_base + rcd->piocnt;
+ /*
+ * Don't need uctxt_lock here, since user has called in to us.
+ * Clear at start in case more interrupts set bits while we
+ * are disarming
+ */
+ if (rcd->user_event_mask) {
+ /*
+ * subctxt_cnt is 0 if not shared, so do base
+ * separately, first, then remaining subctxt, if any
+ */
+ clear_bit(_QIB_EVENT_DISARM_BUFS_BIT, &rcd->user_event_mask[0]);
+ for (i = 1; i < rcd->subctxt_cnt; i++)
+ clear_bit(_QIB_EVENT_DISARM_BUFS_BIT,
+ &rcd->user_event_mask[i]);
+ }
+ spin_lock_irq(&dd->pioavail_lock);
+ for (i = rcd->pio_base; i < last; i++) {
+ if (__test_and_clear_bit(i, dd->pio_need_disarm)) {
+ n++;
+ dd->f_sendctrl(rcd->ppd, QIB_SENDCTRL_DISARM_BUF(i));
+ }
+ }
+ spin_unlock_irq(&dd->pioavail_lock);
+ qib_cdbg(ERRPKT, "Ctxt%u, User disarm (%u bufs (%u-%u)) done\n",
+ rcd->ctxt, n, rcd->pio_base, last);
+ return 0;
+}
+
+static struct qib_pportdata *is_sdma_buf(struct qib_devdata *dd, unsigned i)
+{
+ struct qib_pportdata *ppd;
+ unsigned pidx;
+
+ for (pidx = 0; pidx < dd->num_pports; pidx++) {
+ ppd = dd->pport + pidx;
+ if (i >= ppd->sdma_state.first_sendbuf &&
+ i < ppd->sdma_state.last_sendbuf)
+ return ppd;
+ }
+ return NULL;
+}
+
+/*
+ * Return true if send buffer is being used by a user context.
+ * Sets _QIB_EVENT_DISARM_BUFS_BIT in user_event_mask as a side effect
+ */
+static int find_ctxt(struct qib_devdata *dd, unsigned bufn)
+{
+ struct qib_ctxtdata *rcd;
+ unsigned ctxt;
+ int ret = 0;
+
+ spin_lock(&dd->uctxt_lock);
+ for (ctxt = dd->first_user_ctxt; ctxt < dd->cfgctxts; ctxt++) {
+ rcd = dd->rcd[ctxt];
+ if (!rcd || bufn < rcd->pio_base ||
+ bufn >= rcd->pio_base + rcd->piocnt)
+ continue;
+ if (rcd->user_event_mask) {
+ int i;
+ /*
+ * subctxt_cnt is 0 if not shared, so do base
+ * separately, first, then remaining subctxt, if any
+ */
+ set_bit(_QIB_EVENT_DISARM_BUFS_BIT,
+ &rcd->user_event_mask[0]);
+ for (i = 1; i < rcd->subctxt_cnt; i++)
+ set_bit(_QIB_EVENT_DISARM_BUFS_BIT,
+ &rcd->user_event_mask[i]);
+ }
+ ret = 1;
+ break;
+ }
+ spin_unlock(&dd->uctxt_lock);
+
+ return ret;
+}
+
+/*
+ * Disarm a set of send buffers. If the buffer might be actively being
+ * written to, mark the buffer to be disarmed later when it is not being
+ * written to.
+ *
+ * This should only be called from the IRQ error handler.
+ */
+void qib_disarm_piobufs_set(struct qib_devdata *dd, unsigned long *mask,
+ unsigned cnt)
+{
+ struct qib_pportdata *ppd;
+ unsigned i;
+ unsigned long flags;
+
+ for (i = 0; i < cnt; i++) {
+ int which;
+ if (!test_bit(i, mask))
+ continue;
+ /*
+ * If the buffer is owned by the DMA hardware,
+ * reset the DMA engine.
+ */
+ ppd = is_sdma_buf(dd, i);
+ if (ppd) {
+ /* should do only once per port */
+ qib_cdbg(ERRPKT, "buf %u sdma; do cancel_sends\n", i);
+ qib_cancel_sends(ppd);
+ continue;
+ }
+ /*
+ * If the kernel is writing the buffer or the buffer is
+ * owned by a user process, we can't clear it yet.
+ */
+ spin_lock_irqsave(&dd->pioavail_lock, flags);
+ if (test_bit(i, dd->pio_writing) ||
+ (!test_bit(i << 1, dd->pioavailkernel) &&
+ find_ctxt(dd, i))) {
+ __set_bit(i, dd->pio_need_disarm);
+ which = 0;
+ } else {
+ which = 1;
+ dd->f_sendctrl(dd->pport, QIB_SENDCTRL_DISARM_BUF(i));
+ }
+ spin_unlock_irqrestore(&dd->pioavail_lock, flags);
+ qib_cdbg(ERRPKT, "disarm buf %u %s\n", i, which ?
+ "now" : "later");
+ }
+}
+
+/**
+ * update_send_bufs - update shadow copy of the PIO availability map
+ * @dd: the qlogic_ib device
+ *
+ * called whenever our local copy indicates we have run out of send buffers
+ */
+static void update_send_bufs(struct qib_devdata *dd)
+{
+ unsigned long flags;
+ unsigned i;
+ const unsigned piobregs = dd->pioavregs;
+
+ /*
+ * If the generation (check) bits have changed, then we update the
+ * busy bit for the corresponding PIO buffer. This algorithm will
+ * modify positions to the value they already have in some cases
+ * (i.e., no change), but it's faster than changing only the bits
+ * that have changed.
+ *
+ * We would like to do this atomicly, to avoid spinlocks in the
+ * critical send path, but that's not really possible, given the
+ * type of changes, and that this routine could be called on
+ * multiple cpu's simultaneously, so we lock in this routine only,
+ * to avoid conflicting updates; all we change is the shadow, and
+ * it's a single 64 bit memory location, so by definition the update
+ * is atomic in terms of what other cpu's can see in testing the
+ * bits. The spin_lock overhead isn't too bad, since it only
+ * happens when all buffers are in use, so only cpu overhead, not
+ * latency or bandwidth is affected.
+ */
+ if (!dd->pioavailregs_dma) {
+ qib_dbg("Update shadow pioavail, but regs_dma NULL!\n");
+ return;
+ }
+ if (qib_debug & __QIB_VERBDBG) {
+ /* only if packet debug and verbose */
+ volatile __le64 *dma = dd->pioavailregs_dma; /* DMA'ed */
+ unsigned long *shadow = dd->pioavailshadow;
+
+ qib_dbg("Refill avail, ts%lx; dmacopy: "
+ "%llx %llx %llx %llx %llx %llx"
+ "; shadow: %lx %lx %lx %lx %lx %lx\n",
+ (unsigned long)get_cycles(),
+ (unsigned long long) le64_to_cpu(dma[0]),
+ (unsigned long long) le64_to_cpu(dma[1]),
+ (unsigned long long) le64_to_cpu(dma[2]),
+ (unsigned long long) le64_to_cpu(dma[3]),
+ (unsigned long long) le64_to_cpu(dma[4]),
+ (unsigned long long) le64_to_cpu(dma[5]),
+ shadow[0], shadow[1], shadow[2], shadow[3],
+ shadow[4], shadow[5]);
+ }
+ spin_lock_irqsave(&dd->pioavail_lock, flags);
+ for (i = 0; i < piobregs; i++) {
+ u64 pchbusy, pchg, piov, pnew;
+
+ piov = le64_to_cpu(dd->pioavailregs_dma[i]);
+ pchg = dd->pioavailkernel[i] &
+ ~(dd->pioavailshadow[i] ^ piov);
+ pchbusy = pchg << QLOGIC_IB_SENDPIOAVAIL_BUSY_SHIFT;
+ if (pchg && (pchbusy & dd->pioavailshadow[i])) {
+ pnew = dd->pioavailshadow[i] & ~pchbusy;
+ pnew |= piov & pchbusy;
+ dd->pioavailshadow[i] = pnew;
+ }
+ }
+ spin_unlock_irqrestore(&dd->pioavail_lock, flags);
+}
+
+/*
+ * Debugging code and stats updates if no pio buffers available.
+ */
+static noinline void no_send_bufs(struct qib_devdata *dd)
+{
+ dd->upd_pio_shadow = 1;
+
+ /* not atomic, but if we lose a stat count in a while, that's OK */
+ qib_stats.sps_nopiobufs++;
+}
+
+/*
+ * Common code for normal driver send buffer allocation, and reserved
+ * allocation.
+ *
+ * Do appropriate marking as busy, etc.
+ * Returns buffer pointer if one is found, otherwise NULL.
+ */
+u32 __iomem *qib_getsendbuf_range(struct qib_devdata *dd, u32 *pbufnum,
+ u32 first, u32 last)
+{
+ unsigned i, j, updated = 0;
+ unsigned nbufs;
+ unsigned long flags;
+ unsigned long *shadow = dd->pioavailshadow;
+ u32 __iomem *buf;
+
+ if (!(dd->flags & QIB_PRESENT))
+ return NULL;
+
+ nbufs = last - first + 1; /* number in range to check */
+ if (dd->upd_pio_shadow) {
+ /*
+ * Minor optimization. If we had no buffers on last call,
+ * start out by doing the update; continue and do scan even
+ * if no buffers were updated, to be paranoid.
+ */
+ update_send_bufs(dd);
+ updated++;
+ }
+ i = first;
+rescan:
+ /*
+ * While test_and_set_bit() is atomic, we do that and then the
+ * change_bit(), and the pair is not. See if this is the cause
+ * of the remaining armlaunch errors.
+ */
+ spin_lock_irqsave(&dd->pioavail_lock, flags);
+ for (j = 0; j < nbufs; j++, i++) {
+ if (i > last)
+ i = first;
+ if (__test_and_set_bit((2 * i) + 1, shadow))
+ continue;
+ /* flip generation bit */
+ __change_bit(2 * i, shadow);
+ /* remember that the buffer can be written to now */
+ __set_bit(i, dd->pio_writing);
+ break;
+ }
+ spin_unlock_irqrestore(&dd->pioavail_lock, flags);
+
+ if (j == nbufs) {
+ if (!updated) {
+ /*
+ * First time through; shadow exhausted, but may be
+ * buffers available, try an update and then rescan.
+ */
+ update_send_bufs(dd);
+ updated++;
+ i = first;
+ goto rescan;
+ }
+ no_send_bufs(dd);
+ buf = NULL;
+ } else {
+ if (i < dd->piobcnt2k)
+ buf = (u32 __iomem *)(dd->pio2kbase +
+ i * dd->palign);
+ else
+ buf = (u32 __iomem *)(dd->pio4kbase +
+ (i - dd->piobcnt2k) * dd->align4k);
+ if (pbufnum)
+ *pbufnum = i;
+ dd->upd_pio_shadow = 0;
+ }
+
+ return buf;
+}
+
+/*
+ * Record that the caller is finished writing to the buffer so we don't
+ * disarm it while it is being written and disarm it now if needed.
+ */
+void qib_sendbuf_done(struct qib_devdata *dd, unsigned n)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&dd->pioavail_lock, flags);
+ __clear_bit(n, dd->pio_writing);
+ if (__test_and_clear_bit(n, dd->pio_need_disarm))
+ dd->f_sendctrl(dd->pport, QIB_SENDCTRL_DISARM_BUF(n));
+ spin_unlock_irqrestore(&dd->pioavail_lock, flags);
+}
+
+/**
+ * qib_chg_pioavailkernel - change which send buffers are available for kernel
+ * @dd: the qlogic_ib device
+ * @start: the starting send buffer number
+ * @len: the number of send buffers
+ * @avail: true if the buffers are available for kernel use, false otherwise
+ */
+void qib_chg_pioavailkernel(struct qib_devdata *dd, unsigned start,
+ unsigned len, u32 avail, struct qib_ctxtdata *rcd)
+{
+ unsigned long flags;
+ unsigned end;
+ unsigned ostart = start;
+
+ if (rcd)
+ qib_cdbg(SDMA, "start %u len %u avail %d ctxt%u\n", start,
+ len, avail, rcd->ctxt);
+ else
+ qib_cdbg(SDMA, "start %u len %u avail %d (nowait)\n",
+ start, len, avail);
+
+ /* There are two bits per send buffer (busy and generation) */
+ start *= 2;
+ end = start + len * 2;
+
+ spin_lock_irqsave(&dd->pioavail_lock, flags);
+ /* Set or clear the busy bit in the shadow. */
+ while (start < end) {
+ if (avail) {
+ unsigned long dma;
+ int i;
+
+ /*
+ * The BUSY bit will never be set, because we disarm
+ * the user buffers before we hand them back to the
+ * kernel. We do have to make sure the generation
+ * bit is set correctly in shadow, since it could
+ * have changed many times while allocated to user.
+ * We can't use the bitmap functions on the full
+ * dma array because it is always little-endian, so
+ * we have to flip to host-order first.
+ * BITS_PER_LONG is slightly wrong, since it's
+ * always 64 bits per register in chip...
+ * We only work on 64 bit kernels, so that's OK.
+ */
+ i = start / BITS_PER_LONG;
+ __clear_bit(QLOGIC_IB_SENDPIOAVAIL_BUSY_SHIFT + start,
+ dd->pioavailshadow);
+ dma = (unsigned long)
+ le64_to_cpu(dd->pioavailregs_dma[i]);
+ if (test_bit((QLOGIC_IB_SENDPIOAVAIL_CHECK_SHIFT +
+ start) % BITS_PER_LONG, &dma))
+ __set_bit(QLOGIC_IB_SENDPIOAVAIL_CHECK_SHIFT +
+ start, dd->pioavailshadow);
+ else
+ __clear_bit(QLOGIC_IB_SENDPIOAVAIL_CHECK_SHIFT
+ + start, dd->pioavailshadow);
+ __set_bit(start, dd->pioavailkernel);
+ } else {
+ __set_bit(start + QLOGIC_IB_SENDPIOAVAIL_BUSY_SHIFT,
+ dd->pioavailshadow);
+ __clear_bit(start, dd->pioavailkernel);
+ }
+ start += 2;
+ }
+
+ spin_unlock_irqrestore(&dd->pioavail_lock, flags);
+
+ dd->f_txchk_change(dd, ostart, len, avail, rcd);
+}
+
+/*
+ * Flush all sends that might be in the ready to send state, as well as any
+ * that are in the process of being sent. Used whenever we need to be
+ * sure the send side is idle. Cleans up all buffer state by canceling
+ * all pio buffers, and issuing an abort, which cleans up anything in the
+ * launch fifo. The cancel is superfluous on some chip versions, but
+ * it's safer to always do it.
+ * PIOAvail bits are updated by the chip as if a normal send had happened.
+ */
+void qib_cancel_sends(struct qib_pportdata *ppd)
+{
+ struct qib_devdata *dd = ppd->dd;
+ struct qib_ctxtdata *rcd;
+ unsigned long flags;
+ unsigned ctxt;
+ unsigned i;
+ unsigned last;
+
+ /*
+ * Tell PSM to disarm buffers again before trying to reuse them.
+ * We need to be sure the rcd doesn't change out from under us
+ * while we do so. We hold the two locks sequentially. We might
+ * needlessly set some need_disarm bits as a result, if the
+ * context is closed after we release the uctxt_lock, but that's
+ * fairly benign, and safer than nesting the locks.
+ */
+ for (ctxt = dd->first_user_ctxt; ctxt < dd->cfgctxts; ctxt++) {
+ spin_lock_irqsave(&dd->uctxt_lock, flags);
+ rcd = dd->rcd[ctxt];
+ if (rcd && rcd->ppd == ppd) {
+ last = rcd->pio_base + rcd->piocnt;
+ if (rcd->user_event_mask) {
+ /*
+ * subctxt_cnt is 0 if not shared, so do base
+ * separately, first, then remaining subctxt,
+ * if any
+ */
+ set_bit(_QIB_EVENT_DISARM_BUFS_BIT,
+ &rcd->user_event_mask[0]);
+ for (i = 1; i < rcd->subctxt_cnt; i++)
+ set_bit(_QIB_EVENT_DISARM_BUFS_BIT,
+ &rcd->user_event_mask[i]);
+ }
+ i = rcd->pio_base;
+ spin_unlock_irqrestore(&dd->uctxt_lock, flags);
+ spin_lock_irqsave(&dd->pioavail_lock, flags);
+ for (; i < last; i++)
+ __set_bit(i, dd->pio_need_disarm);
+ spin_unlock_irqrestore(&dd->pioavail_lock, flags);
+ } else
+ spin_unlock_irqrestore(&dd->uctxt_lock, flags);
+ }
+
+ if (dd->flags & QIB_HAS_SEND_DMA)
+ qib_sdma_process_event(ppd, qib_sdma_event_e70_go_idle);
+ else
+ dd->f_sendctrl(ppd, QIB_SENDCTRL_DISARM_ALL |
+ QIB_SENDCTRL_FLUSH);
+}
+
+/*
+ * Force an update of in-memory copy of the pioavail registers, when
+ * needed for any of a variety of reasons.
+ * If already off, this routine is a nop, on the assumption that the
+ * caller (or set of callers) will "do the right thing".
+ * This is a per-device operation, so just the first port.
+ */
+void qib_force_pio_avail_update(struct qib_devdata *dd)
+{
+ dd->f_sendctrl(dd->pport, QIB_SENDCTRL_AVAIL_BLIP);
+}
+
+void qib_hol_down(struct qib_pportdata *ppd)
+{
+ /*
+ * Cancel sends when the link goes DOWN so that we aren't doing it
+ * at INIT when we might be trying to send SMI packets.
+ */
+ if (!(ppd->lflags & QIBL_IB_AUTONEG_INPROG))
+ qib_cancel_sends(ppd);
+}
+
+/*
+ * Link is at INIT.
+ * We start the HoL timer so we can detect stuck packets blocking SMP replies.
+ * Timer may already be running, so use mod_timer, not add_timer.
+ */
+void qib_hol_init(struct qib_pportdata *ppd)
+{
+ if (ppd->hol_state != QIB_HOL_INIT) {
+ ppd->hol_state = QIB_HOL_INIT;
+ mod_timer(&ppd->hol_timer,
+ jiffies + msecs_to_jiffies(qib_hol_timeout_ms));
+ }
+}
+
+/*
+ * Link is up, continue any user processes, and ensure timer
+ * is a nop, if running. Let timer keep running, if set; it
+ * will nop when it sees the link is up.
+ */
+void qib_hol_up(struct qib_pportdata *ppd)
+{
+ ppd->hol_state = QIB_HOL_UP;
+}
+
+/*
+ * This is only called via the timer.
+ */
+void qib_hol_event(unsigned long opaque)
+{
+ struct qib_pportdata *ppd = (struct qib_pportdata *)opaque;
+
+ /* If hardware error, etc, skip. */
+ if (!(ppd->dd->flags & QIB_INITTED))
+ return;
+
+ if (ppd->hol_state != QIB_HOL_UP) {
+ /*
+ * Try to flush sends in case a stuck packet is blocking
+ * SMP replies.
+ */
+ qib_hol_down(ppd);
+ mod_timer(&ppd->hol_timer,
+ jiffies + msecs_to_jiffies(qib_hol_timeout_ms));
+ }
+}