IB/ipath: Fix calculation for number of kernel PIO buffers

If the module parameter "kpiobufs" is set too high, the calculation to
reset it to a sane value was incorrect.

Signed-off-by: Ralph Campbell <ralph.campbell@qlogic.com>
Signed-off-by: Bryan O'Sullivan <bryan.osullivan@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 d4f6b5239ef85f3035c05801adb5432c4b446067..1e77b55afe93d6fabf2a05bf8e036e89a75fbb88 100644 (file)
--- a/drivers/infiniband/hw/ipath/ipath_init_chip.c
+++ b/drivers/infiniband/hw/ipath/ipath_init_chip.c
@@ -668,6 +668,7 @@ int ipath_init_chip(struct ipath_devdata *dd, int reinit)
 {
        int ret = 0, i;
        u32 val32, kpiobufs;
+       u32 piobufs, uports;
        u64 val;
        struct ipath_portdata *pd = NULL; /* keep gcc4 happy */
        gfp_t gfp_flags = GFP_USER | __GFP_COMP;
@@ -702,16 +703,17 @@ int ipath_init_chip(struct ipath_devdata *dd, int reinit)
         * the in memory DMA'ed copies of the registers.  This has to
         * be done early, before we calculate lastport, etc.
         */
-       val = dd->ipath_piobcnt2k + dd->ipath_piobcnt4k;
+       piobufs = dd->ipath_piobcnt2k + dd->ipath_piobcnt4k;
        /*
         * calc number of pioavail registers, and save it; we have 2
         * bits per buffer.
         */
-       dd->ipath_pioavregs = ALIGN(val, sizeof(u64) * BITS_PER_BYTE / 2)
+       dd->ipath_pioavregs = ALIGN(piobufs, sizeof(u64) * BITS_PER_BYTE / 2)
                / (sizeof(u64) * BITS_PER_BYTE / 2);
+       uports = dd->ipath_cfgports ? dd->ipath_cfgports - 1 : 0;
        if (ipath_kpiobufs == 0) {
                /* not set by user (this is default) */
-               if ((dd->ipath_piobcnt2k + dd->ipath_piobcnt4k) > 128)
+               if (piobufs >= (uports * IPATH_MIN_USER_PORT_BUFCNT) + 32)
                        kpiobufs = 32;
                else
                        kpiobufs = 16;
@@ -719,31 +721,25 @@ int ipath_init_chip(struct ipath_devdata *dd, int reinit)
        else
                kpiobufs = ipath_kpiobufs;
 
-       if (kpiobufs >
-           (dd->ipath_piobcnt2k + dd->ipath_piobcnt4k -
-            (dd->ipath_cfgports * IPATH_MIN_USER_PORT_BUFCNT))) {
-               i = dd->ipath_piobcnt2k + dd->ipath_piobcnt4k -
-                       (dd->ipath_cfgports * IPATH_MIN_USER_PORT_BUFCNT);
+       if (kpiobufs + (uports * IPATH_MIN_USER_PORT_BUFCNT) > piobufs) {
+               i = (int) piobufs -
+                       (int) (uports * IPATH_MIN_USER_PORT_BUFCNT);
                if (i < 0)
                        i = 0;
-               dev_info(&dd->pcidev->dev, "Allocating %d PIO bufs for "
-                        "kernel leaves too few for %d user ports "
+               dev_info(&dd->pcidev->dev, "Allocating %d PIO bufs of "
+                        "%d for kernel leaves too few for %d user ports "
                         "(%d each); using %u\n", kpiobufs,
-                        dd->ipath_cfgports - 1,
-                        IPATH_MIN_USER_PORT_BUFCNT, i);
+                        piobufs, uports, IPATH_MIN_USER_PORT_BUFCNT, i);
                /*
                 * shouldn't change ipath_kpiobufs, because could be
                 * different for different devices...
                 */
                kpiobufs = i;
        }
-       dd->ipath_lastport_piobuf =
-               dd->ipath_piobcnt2k + dd->ipath_piobcnt4k - kpiobufs;
-       dd->ipath_pbufsport = dd->ipath_cfgports > 1
-               ? dd->ipath_lastport_piobuf / (dd->ipath_cfgports - 1)
-               : 0;
-       val32 = dd->ipath_lastport_piobuf -
-               (dd->ipath_pbufsport * (dd->ipath_cfgports - 1));
+       dd->ipath_lastport_piobuf = piobufs - kpiobufs;
+       dd->ipath_pbufsport =
+               uports ? dd->ipath_lastport_piobuf / uports : 0;
+       val32 = dd->ipath_lastport_piobuf - (dd->ipath_pbufsport * uports);
        if (val32 > 0) {
                ipath_dbg("allocating %u pbufs/port leaves %u unused, "
                          "add to kernel\n", dd->ipath_pbufsport, val32);
@@ -754,8 +750,7 @@ int ipath_init_chip(struct ipath_devdata *dd, int reinit)
        dd->ipath_lastpioindex = dd->ipath_lastport_piobuf;
        ipath_cdbg(VERBOSE, "%d PIO bufs for kernel out of %d total %u "
                   "each for %u user ports\n", kpiobufs,
-                  dd->ipath_piobcnt2k + dd->ipath_piobcnt4k,
-                  dd->ipath_pbufsport, dd->ipath_cfgports - 1);
+                  piobufs, dd->ipath_pbufsport, uports);
 
        dd->ipath_f_early_init(dd);