IB/ipath: Enable reduced PIO update for HCAs that support it.
Newer HCAs have a threshold counter to reduce the number of DMAs the
chip makes to update the PIO buffer availability status bits. This
patch enables the feature.
Signed-off-by: Dave Olson <dave.olson@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
diff --git a/drivers/infiniband/hw/ipath/ipath_init_chip.c b/drivers/infiniband/hw/ipath/ipath_init_chip.c
index 720ff4d..1adafa9 100644
--- a/drivers/infiniband/hw/ipath/ipath_init_chip.c
+++ b/drivers/infiniband/hw/ipath/ipath_init_chip.c
@@ -341,6 +341,7 @@
{
u32 rtmp;
int i;
+ unsigned long flags;
/*
* ensure chip does no sends or receives, tail updates, or
@@ -356,8 +357,13 @@
ipath_write_kreg(dd, dd->ipath_kregs->kr_rcvctrl,
dd->ipath_rcvctrl);
+ spin_lock_irqsave(&dd->ipath_sendctrl_lock, flags);
+ dd->ipath_sendctrl = 0U; /* no sdma, etc */
ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl, dd->ipath_sendctrl);
- ipath_write_kreg(dd, dd->ipath_kregs->kr_control, dd->ipath_control);
+ ipath_read_kreg64(dd, dd->ipath_kregs->kr_scratch);
+ spin_unlock_irqrestore(&dd->ipath_sendctrl_lock, flags);
+
+ ipath_write_kreg(dd, dd->ipath_kregs->kr_control, 0ULL);
rtmp = ipath_read_kreg32(dd, dd->ipath_kregs->kr_rcvtidcnt);
if (rtmp != dd->ipath_rcvtidcnt)
@@ -478,6 +484,14 @@
/* Enable PIO send, and update of PIOavail regs to memory. */
dd->ipath_sendctrl = INFINIPATH_S_PIOENABLE |
INFINIPATH_S_PIOBUFAVAILUPD;
+
+ /*
+ * Set the PIO avail update threshold to host memory
+ * on chips that support it.
+ */
+ if (dd->ipath_pioupd_thresh)
+ dd->ipath_sendctrl |= dd->ipath_pioupd_thresh
+ << INFINIPATH_S_UPDTHRESH_SHIFT;
ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl, dd->ipath_sendctrl);
ipath_read_kreg64(dd, dd->ipath_kregs->kr_scratch);
spin_unlock_irqrestore(&dd->ipath_sendctrl_lock, flags);
@@ -757,6 +771,12 @@
ipath_cdbg(VERBOSE, "%d PIO bufs for kernel out of %d total %u "
"each for %u user ports\n", kpiobufs,
piobufs, dd->ipath_pbufsport, uports);
+ if (dd->ipath_pioupd_thresh) {
+ if (dd->ipath_pbufsport < dd->ipath_pioupd_thresh)
+ dd->ipath_pioupd_thresh = dd->ipath_pbufsport;
+ if (kpiobufs < dd->ipath_pioupd_thresh)
+ dd->ipath_pioupd_thresh = kpiobufs;
+ }
dd->ipath_f_early_init(dd);
/*