IB/ipath: misc driver support code

EEPROM support, interrupt handling, statistics gathering, and write
combining management for x86_64.

A note regarding i2c: The Atmel EEPROM hardware we use looks like an
i2c device electrically, but is not i2c compliant at all from a
functional perspective.  We tried using the kernel's i2c support to
talk to it, but failed.

Normal i2c devices have a single 7-bit or 10-bit i2c address that they
respond to.  Valid 7-bit addresses range from 0x03 to 0x77.  Addresses
0x00 to 0x02 and 0x78 to 0x7F are special reserved addresses
(e.g. 0x00 is the "general call" address.)  The Atmel device, on the
other hand, responds to ALL addresses.  It's designed to be the only
device on a given i2c bus.  A given i2c device address corresponds to
the memory address within the i2c device itself.

At least one reason why the linux core i2c stuff won't work for this
is that it prohibits access to reserved addresses like 0x00, which are
really valid addresses on the Atmel devices.

Signed-off-by: Bryan O'Sullivan <bos@pathscale.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 303 insertions, 0 deletions

diff --git a/drivers/infiniband/hw/ipath/ipath_stats.c b/drivers/infiniband/hw/ipath/ipath_stats.c
new file mode 100644
index 0000000..fe20913
--- /dev/null
+++ b/drivers/infiniband/hw/ipath/ipath_stats.c
@@ -0,0 +1,303 @@
+/*
+ * Copyright (c) 2003, 2004, 2005, 2006 PathScale, Inc. 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/pci.h>
+
+#include "ipath_kernel.h"
+
+struct infinipath_stats ipath_stats;
+
+/**
+ * ipath_snap_cntr - snapshot a chip counter
+ * @dd: the infinipath device
+ * @creg: the counter to snapshot
+ *
+ * called from add_timer and user counter read calls, to deal with
+ * counters that wrap in "human time".  The words sent and received, and
+ * the packets sent and received are all that we worry about.  For now,
+ * at least, we don't worry about error counters, because if they wrap
+ * that quickly, we probably don't care.  We may eventually just make this
+ * handle all the counters.  word counters can wrap in about 20 seconds
+ * of full bandwidth traffic, packet counters in a few hours.
+ */
+
+u64 ipath_snap_cntr(struct ipath_devdata *dd, ipath_creg creg)
+{
+	u32 val, reg64 = 0;
+	u64 val64;
+	unsigned long t0, t1;
+	u64 ret;
+
+	t0 = jiffies;
+	/* If fast increment counters are only 32 bits, snapshot them,
+	 * and maintain them as 64bit values in the driver */
+	if (!(dd->ipath_flags & IPATH_32BITCOUNTERS) &&
+	    (creg == dd->ipath_cregs->cr_wordsendcnt ||
+	     creg == dd->ipath_cregs->cr_wordrcvcnt ||
+	     creg == dd->ipath_cregs->cr_pktsendcnt ||
+	     creg == dd->ipath_cregs->cr_pktrcvcnt)) {
+		val64 = ipath_read_creg(dd, creg);
+		val = val64 == ~0ULL ? ~0U : 0;
+		reg64 = 1;
+	} else			/* val64 just to keep gcc quiet... */
+		val64 = val = ipath_read_creg32(dd, creg);
+	/*
+	 * See if a second has passed.  This is just a way to detect things
+	 * that are quite broken.  Normally this should take just a few
+	 * cycles (the check is for long enough that we don't care if we get
+	 * pre-empted.)  An Opteron HT O read timeout is 4 seconds with
+	 * normal NB values
+	 */
+	t1 = jiffies;
+	if (time_before(t0 + HZ, t1) && val == -1) {
+		ipath_dev_err(dd, "Error!  Read counter 0x%x timed out\n",
+			      creg);
+		ret = 0ULL;
+		goto bail;
+	}
+	if (reg64) {
+		ret = val64;
+		goto bail;
+	}
+
+	if (creg == dd->ipath_cregs->cr_wordsendcnt) {
+		if (val != dd->ipath_lastsword) {
+			dd->ipath_sword += val - dd->ipath_lastsword;
+			dd->ipath_lastsword = val;
+		}
+		val64 = dd->ipath_sword;
+	} else if (creg == dd->ipath_cregs->cr_wordrcvcnt) {
+		if (val != dd->ipath_lastrword) {
+			dd->ipath_rword += val - dd->ipath_lastrword;
+			dd->ipath_lastrword = val;
+		}
+		val64 = dd->ipath_rword;
+	} else if (creg == dd->ipath_cregs->cr_pktsendcnt) {
+		if (val != dd->ipath_lastspkts) {
+			dd->ipath_spkts += val - dd->ipath_lastspkts;
+			dd->ipath_lastspkts = val;
+		}
+		val64 = dd->ipath_spkts;
+	} else if (creg == dd->ipath_cregs->cr_pktrcvcnt) {
+		if (val != dd->ipath_lastrpkts) {
+			dd->ipath_rpkts += val - dd->ipath_lastrpkts;
+			dd->ipath_lastrpkts = val;
+		}
+		val64 = dd->ipath_rpkts;
+	} else
+		val64 = (u64) val;
+
+	ret = val64;
+
+bail:
+	return ret;
+}
+
+/**
+ * ipath_qcheck - print delta of egrfull/hdrqfull errors for kernel ports
+ * @dd: the infinipath device
+ *
+ * print the delta of egrfull/hdrqfull errors for kernel ports no more than
+ * every 5 seconds.  User processes are printed at close, but kernel doesn't
+ * close, so...  Separate routine so may call from other places someday, and
+ * so function name when printed by _IPATH_INFO is meaningfull
+ */
+static void ipath_qcheck(struct ipath_devdata *dd)
+{
+	static u64 last_tot_hdrqfull;
+	size_t blen = 0;
+	char buf[128];
+
+	*buf = 0;
+	if (dd->ipath_pd[0]->port_hdrqfull != dd->ipath_p0_hdrqfull) {
+		blen = snprintf(buf, sizeof buf, "port 0 hdrqfull %u",
+				dd->ipath_pd[0]->port_hdrqfull -
+				dd->ipath_p0_hdrqfull);
+		dd->ipath_p0_hdrqfull = dd->ipath_pd[0]->port_hdrqfull;
+	}
+	if (ipath_stats.sps_etidfull != dd->ipath_last_tidfull) {
+		blen += snprintf(buf + blen, sizeof buf - blen,
+				 "%srcvegrfull %llu",
+				 blen ? ", " : "",
+				 (unsigned long long)
+				 (ipath_stats.sps_etidfull -
+				  dd->ipath_last_tidfull));
+		dd->ipath_last_tidfull = ipath_stats.sps_etidfull;
+	}
+
+	/*
+	 * this is actually the number of hdrq full interrupts, not actual
+	 * events, but at the moment that's mostly what I'm interested in.
+	 * Actual count, etc. is in the counters, if needed.  For production
+	 * users this won't ordinarily be printed.
+	 */
+
+	if ((ipath_debug & (__IPATH_PKTDBG | __IPATH_DBG)) &&
+	    ipath_stats.sps_hdrqfull != last_tot_hdrqfull) {
+		blen += snprintf(buf + blen, sizeof buf - blen,
+				 "%shdrqfull %llu (all ports)",
+				 blen ? ", " : "",
+				 (unsigned long long)
+				 (ipath_stats.sps_hdrqfull -
+				  last_tot_hdrqfull));
+		last_tot_hdrqfull = ipath_stats.sps_hdrqfull;
+	}
+	if (blen)
+		ipath_dbg("%s\n", buf);
+
+	if (dd->ipath_port0head != (u32)
+	    le64_to_cpu(*dd->ipath_hdrqtailptr)) {
+		if (dd->ipath_lastport0rcv_cnt ==
+		    ipath_stats.sps_port0pkts) {
+			ipath_cdbg(PKT, "missing rcv interrupts? "
+				   "port0 hd=%llx tl=%x; port0pkts %llx\n",
+				   (unsigned long long)
+				   le64_to_cpu(*dd->ipath_hdrqtailptr),
+				   dd->ipath_port0head,
+				   (unsigned long long)
+				   ipath_stats.sps_port0pkts);
+			ipath_kreceive(dd);
+		}
+		dd->ipath_lastport0rcv_cnt = ipath_stats.sps_port0pkts;
+	}
+}
+
+/**
+ * ipath_get_faststats - get word counters from chip before they overflow
+ * @opaque - contains a pointer to the infinipath device ipath_devdata
+ *
+ * called from add_timer
+ */
+void ipath_get_faststats(unsigned long opaque)
+{
+	struct ipath_devdata *dd = (struct ipath_devdata *) opaque;
+	u32 val;
+	static unsigned cnt;
+
+	/*
+	 * don't access the chip while running diags, or memory diags can
+	 * fail
+	 */
+	if (!dd->ipath_kregbase || !(dd->ipath_flags & IPATH_PRESENT) ||
+	    ipath_diag_inuse)
+		/* but re-arm the timer, for diags case; won't hurt other */
+		goto done;
+
+	if (dd->ipath_flags & IPATH_32BITCOUNTERS) {
+		ipath_snap_cntr(dd, dd->ipath_cregs->cr_wordsendcnt);
+		ipath_snap_cntr(dd, dd->ipath_cregs->cr_wordrcvcnt);
+		ipath_snap_cntr(dd, dd->ipath_cregs->cr_pktsendcnt);
+		ipath_snap_cntr(dd, dd->ipath_cregs->cr_pktrcvcnt);
+	}
+
+	ipath_qcheck(dd);
+
+	/*
+	 * deal with repeat error suppression.  Doesn't really matter if
+	 * last error was almost a full interval ago, or just a few usecs
+	 * ago; still won't get more than 2 per interval.  We may want
+	 * longer intervals for this eventually, could do with mod, counter
+	 * or separate timer.  Also see code in ipath_handle_errors() and
+	 * ipath_handle_hwerrors().
+	 */
+
+	if (dd->ipath_lasterror)
+		dd->ipath_lasterror = 0;
+	if (dd->ipath_lasthwerror)
+		dd->ipath_lasthwerror = 0;
+	if ((dd->ipath_maskederrs & ~dd->ipath_ignorederrs)
+	    && time_after(jiffies, dd->ipath_unmasktime)) {
+		char ebuf[256];
+		ipath_decode_err(ebuf, sizeof ebuf,
+				 (dd->ipath_maskederrs & ~dd->
+				  ipath_ignorederrs));
+		if ((dd->ipath_maskederrs & ~dd->ipath_ignorederrs) &
+		    ~(INFINIPATH_E_RRCVEGRFULL | INFINIPATH_E_RRCVHDRFULL))
+			ipath_dev_err(dd, "Re-enabling masked errors "
+				      "(%s)\n", ebuf);
+		else {
+			/*
+			 * rcvegrfull and rcvhdrqfull are "normal", for some
+			 * types of processes (mostly benchmarks) that send
+			 * huge numbers of messages, while not processing
+			 * them.  So only complain about these at debug
+			 * level.
+			 */
+			ipath_dbg("Disabling frequent queue full errors "
+				  "(%s)\n", ebuf);
+		}
+		dd->ipath_maskederrs = dd->ipath_ignorederrs;
+		ipath_write_kreg(dd, dd->ipath_kregs->kr_errormask,
+				 ~dd->ipath_maskederrs);
+	}
+
+	/* limit qfull messages to ~one per minute per port */
+	if ((++cnt & 0x10)) {
+		for (val = dd->ipath_cfgports - 1; ((int)val) >= 0;
+		     val--) {
+			if (dd->ipath_lastegrheads[val] != -1)
+				dd->ipath_lastegrheads[val] = -1;
+			if (dd->ipath_lastrcvhdrqtails[val] != -1)
+				dd->ipath_lastrcvhdrqtails[val] = -1;
+		}
+	}
+
+	if (dd->ipath_nosma_bufs) {
+		dd->ipath_nosma_secs += 5;
+		if (dd->ipath_nosma_secs >= 30) {
+			ipath_cdbg(SMA, "No SMA bufs avail %u seconds; "
+				   "cancelling pending sends\n",
+				   dd->ipath_nosma_secs);
+			/*
+			 * issue an abort as well, in case we have a packet
+			 * stuck in launch fifo.  This could corrupt an
+			 * outgoing user packet in the worst case,
+			 * but this is a pretty catastrophic, anyway.
+			 */
+			ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl,
+					 INFINIPATH_S_ABORT);
+			ipath_disarm_piobufs(dd, dd->ipath_lastport_piobuf,
+					     dd->ipath_piobcnt2k +
+					     dd->ipath_piobcnt4k -
+					     dd->ipath_lastport_piobuf);
+			/* start again, if necessary */
+			dd->ipath_nosma_secs = 0;
+		} else
+			ipath_cdbg(SMA, "No SMA bufs avail %u tries, "
+				   "after %u seconds\n",
+				   dd->ipath_nosma_bufs,
+				   dd->ipath_nosma_secs);
+	}
+
+done:
+	mod_timer(&dd->ipath_stats_timer, jiffies + HZ * 5);
+}