+/**
+ * rm_pkey - decrecment the reference count for the given PKEY
+ * @dd: the infinipath device
+ * @key: the PKEY index
+ *
+ * Return true if this was the last reference and the hardware table entry
+ * needs to be changed.
+ */
+static int rm_pkey(struct ipath_devdata *dd, u16 key)
+{
+ int i;
+ int ret;
+
+ for (i = 0; i < ARRAY_SIZE(dd->ipath_pkeys); i++) {
+ if (dd->ipath_pkeys[i] != key)
+ continue;
+ if (atomic_dec_and_test(&dd->ipath_pkeyrefs[i])) {
+ dd->ipath_pkeys[i] = 0;
+ ret = 1;
+ goto bail;
+ }
+ break;
+ }
+
+ ret = 0;
+
+bail:
+ return ret;
+}
+
+/**
+ * add_pkey - add the given PKEY to the hardware table
+ * @dd: the infinipath device
+ * @key: the PKEY
+ *
+ * Return an error code if unable to add the entry, zero if no change,
+ * or 1 if the hardware PKEY register needs to be updated.
+ */
+static int add_pkey(struct ipath_devdata *dd, u16 key)
+{
+ int i;
+ u16 lkey = key & 0x7FFF;
+ int any = 0;
+ int ret;
+
+ if (lkey == 0x7FFF) {
+ ret = 0;
+ goto bail;
+ }
+
+ /* Look for an empty slot or a matching PKEY. */
+ for (i = 0; i < ARRAY_SIZE(dd->ipath_pkeys); i++) {
+ if (!dd->ipath_pkeys[i]) {
+ any++;
+ continue;
+ }
+ /* If it matches exactly, try to increment the ref count */
+ if (dd->ipath_pkeys[i] == key) {
+ if (atomic_inc_return(&dd->ipath_pkeyrefs[i]) > 1) {
+ ret = 0;
+ goto bail;
+ }
+ /* Lost the race. Look for an empty slot below. */
+ atomic_dec(&dd->ipath_pkeyrefs[i]);
+ any++;
+ }
+ /*
+ * It makes no sense to have both the limited and unlimited
+ * PKEY set at the same time since the unlimited one will
+ * disable the limited one.
+ */
+ if ((dd->ipath_pkeys[i] & 0x7FFF) == lkey) {
+ ret = -EEXIST;
+ goto bail;
+ }
+ }
+ if (!any) {
+ ret = -EBUSY;
+ goto bail;
+ }
+ for (i = 0; i < ARRAY_SIZE(dd->ipath_pkeys); i++) {
+ if (!dd->ipath_pkeys[i] &&
+ atomic_inc_return(&dd->ipath_pkeyrefs[i]) == 1) {
+ /* for ipathstats, etc. */
+ ipath_stats.sps_pkeys[i] = lkey;
+ dd->ipath_pkeys[i] = key;
+ ret = 1;
+ goto bail;
+ }
+ }
+ ret = -EBUSY;
+
+bail:
+ return ret;
+}
+
+/**
+ * set_pkeys - set the PKEY table for port 0
+ * @dd: the infinipath device
+ * @pkeys: the PKEY table
+ */
+static int set_pkeys(struct ipath_devdata *dd, u16 *pkeys)
+{
+ struct ipath_portdata *pd;
+ int i;
+ int changed = 0;
+
+ pd = dd->ipath_pd[0];
+
+ for (i = 0; i < ARRAY_SIZE(pd->port_pkeys); i++) {
+ u16 key = pkeys[i];
+ u16 okey = pd->port_pkeys[i];
+
+ if (key == okey)
+ continue;
+ /*
+ * The value of this PKEY table entry is changing.
+ * Remove the old entry in the hardware's array of PKEYs.
+ */
+ if (okey & 0x7FFF)
+ changed |= rm_pkey(dd, okey);
+ if (key & 0x7FFF) {
+ int ret = add_pkey(dd, key);
+
+ if (ret < 0)
+ key = 0;
+ else
+ changed |= ret;
+ }
+ pd->port_pkeys[i] = key;
+ }
+ if (changed) {
+ u64 pkey;
+
+ pkey = (u64) dd->ipath_pkeys[0] |
+ ((u64) dd->ipath_pkeys[1] << 16) |
+ ((u64) dd->ipath_pkeys[2] << 32) |
+ ((u64) dd->ipath_pkeys[3] << 48);
+ ipath_cdbg(VERBOSE, "p0 new pkey reg %llx\n",
+ (unsigned long long) pkey);
+ ipath_write_kreg(dd, dd->ipath_kregs->kr_partitionkey,
+ pkey);
+ }
+ return 0;
+}
+