IB/ipath: Need to always request and handle PIO avail interrupts

Now that we always use PIO for vl15 on 7220, we could get stuck forever
if we happened to run out of PIO buffers from the verbs code, because
the setup code wouldn't run; the interrupt was also ignored if SDMA was
supported.  We also have to reduce the pio update threshold if we have
fewer kernel buffers than the existing threshold.

Clean up the initialization a bit to get ordering safer and more
sensible, and use the existing ipath_chg_kernavail call to do init,
rather than doing it separately.

Drop unnecessary clearing of pio buffer on pio parity error.

Drop incorrect updating of pioavailshadow when exitting freeze mode
(software state may not match chip state if buffer has been allocated
and not yet written).

If we couldn't get a kernel buffer for a while, make sure we are
in sync with hardware, mainly to handle the exitting freeze case.

Signed-off-by: Dave Olson <dave.olson@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 30 insertions, 42 deletions

diff --git a/drivers/infiniband/hw/ipath/ipath_file_ops.c b/drivers/infiniband/hw/ipath/ipath_file_ops.c
index 8b17522..3295177 100644
--- a/drivers/infiniband/hw/ipath/ipath_file_ops.c
+++ b/drivers/infiniband/hw/ipath/ipath_file_ops.c
@@ -173,47 +173,25 @@ static int ipath_get_base_info(struct file *fp,
 		(void *) dd->ipath_statusp -
 		(void *) dd->ipath_pioavailregs_dma;
 	if (!shared) {
-		kinfo->spi_piocnt = dd->ipath_pbufsport;
+		kinfo->spi_piocnt = pd->port_piocnt;
 		kinfo->spi_piobufbase = (u64) pd->port_piobufs;
 		kinfo->__spi_uregbase = (u64) dd->ipath_uregbase +
 			dd->ipath_ureg_align * pd->port_port;
 	} else if (master) {
-		kinfo->spi_piocnt = (dd->ipath_pbufsport / subport_cnt) +
-				    (dd->ipath_pbufsport % subport_cnt);
+		kinfo->spi_piocnt = (pd->port_piocnt / subport_cnt) +
+				    (pd->port_piocnt % subport_cnt);
 		/* Master's PIO buffers are after all the slave's */
 		kinfo->spi_piobufbase = (u64) pd->port_piobufs +
 			dd->ipath_palign *
-			(dd->ipath_pbufsport - kinfo->spi_piocnt);
+			(pd->port_piocnt - kinfo->spi_piocnt);
 	} else {
 		unsigned slave = subport_fp(fp) - 1;
 
-		kinfo->spi_piocnt = dd->ipath_pbufsport / subport_cnt;
+		kinfo->spi_piocnt = pd->port_piocnt / subport_cnt;
 		kinfo->spi_piobufbase = (u64) pd->port_piobufs +
 			dd->ipath_palign * kinfo->spi_piocnt * slave;
 	}
 
-	/*
-	 * Set the PIO avail update threshold to no larger
-	 * than the number of buffers per process. Note that
-	 * we decrease it here, but won't ever increase it.
-	 */
-	if (dd->ipath_pioupd_thresh &&
-	    kinfo->spi_piocnt < dd->ipath_pioupd_thresh) {
-		unsigned long flags;
-
-		dd->ipath_pioupd_thresh = kinfo->spi_piocnt;
-		ipath_dbg("Decreased pio update threshold to %u\n",
-			dd->ipath_pioupd_thresh);
-		spin_lock_irqsave(&dd->ipath_sendctrl_lock, flags);
-		dd->ipath_sendctrl &= ~(INFINIPATH_S_UPDTHRESH_MASK
-			<< INFINIPATH_S_UPDTHRESH_SHIFT);
-		dd->ipath_sendctrl |= dd->ipath_pioupd_thresh
-			<< INFINIPATH_S_UPDTHRESH_SHIFT;
-		ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl,
-			dd->ipath_sendctrl);
-		spin_unlock_irqrestore(&dd->ipath_sendctrl_lock, flags);
-	}
-
 	if (shared) {
 		kinfo->spi_port_uregbase = (u64) dd->ipath_uregbase +
 			dd->ipath_ureg_align * pd->port_port;
@@ -1309,19 +1287,19 @@ static int ipath_mmap(struct file *fp, struct vm_area_struct *vma)
 	ureg = dd->ipath_uregbase + dd->ipath_ureg_align * pd->port_port;
 	if (!pd->port_subport_cnt) {
 		/* port is not shared */
-		piocnt = dd->ipath_pbufsport;
+		piocnt = pd->port_piocnt;
 		piobufs = pd->port_piobufs;
 	} else if (!subport_fp(fp)) {
 		/* caller is the master */
-		piocnt = (dd->ipath_pbufsport / pd->port_subport_cnt) +
-			 (dd->ipath_pbufsport % pd->port_subport_cnt);
+		piocnt = (pd->port_piocnt / pd->port_subport_cnt) +
+			 (pd->port_piocnt % pd->port_subport_cnt);
 		piobufs = pd->port_piobufs +
-			dd->ipath_palign * (dd->ipath_pbufsport - piocnt);
+			dd->ipath_palign * (pd->port_piocnt - piocnt);
 	} else {
 		unsigned slave = subport_fp(fp) - 1;
 
 		/* caller is a slave */
-		piocnt = dd->ipath_pbufsport / pd->port_subport_cnt;
+		piocnt = pd->port_piocnt / pd->port_subport_cnt;
 		piobufs = pd->port_piobufs + dd->ipath_palign * piocnt * slave;
 	}
 
@@ -1633,9 +1611,6 @@ static int try_alloc_port(struct ipath_devdata *dd, int port,
 		port_fp(fp) = pd;
 		pd->port_pid = current->pid;
 		strncpy(pd->port_comm, current->comm, sizeof(pd->port_comm));
-		ipath_chg_pioavailkernel(dd,
-			dd->ipath_pbufsport * (pd->port_port - 1),
-			dd->ipath_pbufsport, 0);
 		ipath_stats.sps_ports++;
 		ret = 0;
 	} else
@@ -1938,11 +1913,25 @@ static int ipath_do_user_init(struct file *fp,
 
 	/* for now we do nothing with rcvhdrcnt: uinfo->spu_rcvhdrcnt */
 
+	/* some ports may get extra buffers, calculate that here */
+	if (pd->port_port <= dd->ipath_ports_extrabuf)
+		pd->port_piocnt = dd->ipath_pbufsport + 1;
+	else
+		pd->port_piocnt = dd->ipath_pbufsport;
+
 	/* for right now, kernel piobufs are at end, so port 1 is at 0 */
+	if (pd->port_port <= dd->ipath_ports_extrabuf)
+		pd->port_pio_base = (dd->ipath_pbufsport + 1)
+			* (pd->port_port - 1);
+	else
+		pd->port_pio_base = dd->ipath_ports_extrabuf +
+			dd->ipath_pbufsport * (pd->port_port - 1);
 	pd->port_piobufs = dd->ipath_piobufbase +
-		dd->ipath_pbufsport * (pd->port_port - 1) * dd->ipath_palign;
-	ipath_cdbg(VERBOSE, "Set base of piobufs for port %u to 0x%x\n",
-		   pd->port_port, pd->port_piobufs);
+		pd->port_pio_base * dd->ipath_palign;
+	ipath_cdbg(VERBOSE, "piobuf base for port %u is 0x%x, piocnt %u,"
+		" first pio %u\n", pd->port_port, pd->port_piobufs,
+		pd->port_piocnt, pd->port_pio_base);
+	ipath_chg_pioavailkernel(dd, pd->port_pio_base, pd->port_piocnt, 0);
 
 	/*
 	 * Now allocate the rcvhdr Q and eager TIDs; skip the TID
@@ -2107,7 +2096,6 @@ static int ipath_close(struct inode *in, struct file *fp)
 	}
 
 	if (dd->ipath_kregbase) {
-		int i;
 		/* atomically clear receive enable port and intr avail. */
 		clear_bit(dd->ipath_r_portenable_shift + port,
 			  &dd->ipath_rcvctrl);
@@ -2136,9 +2124,9 @@ static int ipath_close(struct inode *in, struct file *fp)
 		ipath_write_kreg_port(dd, dd->ipath_kregs->kr_rcvhdraddr,
 			pd->port_port, dd->ipath_dummy_hdrq_phys);
 
-		i = dd->ipath_pbufsport * (port - 1);
-		ipath_disarm_piobufs(dd, i, dd->ipath_pbufsport);
-		ipath_chg_pioavailkernel(dd, i, dd->ipath_pbufsport, 1);
+		ipath_disarm_piobufs(dd, pd->port_pio_base, pd->port_piocnt);
+		ipath_chg_pioavailkernel(dd, pd->port_pio_base,
+			pd->port_piocnt, 1);
 
 		dd->ipath_f_clear_tids(dd, pd->port_port);