IB/ipath: Make send buffers available for kernel if not allocated to …

…user

A fixed partitioning of send buffers is determined at driver load time
for user processes and kernel use.  Since send buffers are a scarce
resource, it makes sense to allow the kernel to use the buffers if they
are not in use by a user process.

Also, eliminate code duplication for ipath_force_pio_avail_update().

Signed-off-by: Ralph Campbell <ralph.campbell@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

drivers/infiniband/hw/ipath/ipath_diag.c

@@ -439,7 +439,9 @@ static ssize_t ipath_diagpkt_write(struct file *fp,
 		goto bail;
 	}
 
-	piobuf = ipath_getpiobuf(dd, &pbufn);
+	plen >>= 2;		/* in dwords */
+
+	piobuf = ipath_getpiobuf(dd, plen, &pbufn);
 	if (!piobuf) {
 		ipath_cdbg(VERBOSE, "No PIO buffers avail unit for %u\n",
 			   dd->ipath_unit);
@@ -449,8 +451,6 @@ static ssize_t ipath_diagpkt_write(struct file *fp,
 	/* disarm it just to be extra sure */
 	ipath_disarm_piobufs(dd, pbufn, 1);
 
-	plen >>= 2;		/* in dwords */
-
 	if (ipath_debug & __IPATH_PKTDBG)
 		ipath_cdbg(VERBOSE, "unit %u 0x%x+1w pio%d\n",
 			   dd->ipath_unit, plen - 1, pbufn);