Commit ff7166c4 authored Aug 03, 2012 by Jack Morgenstein Committed by Roland Dreier Sep 30, 2012

IB/core: Handle table with full and partial membership for the same P_Key



Extend the cached and non-cached P_Key table lookups to handle limited
and full membership of the same P_Key to co-exist in the P_Key table.

This is necessary for SR-IOV, to allow for some guests would to have
the full membership P_Key in their virtual P_Key table, while other
guests on the same physical HCA would have the limited one.
To support this, we need both the limited and full membership P_Keys
to be present in the master's (hypervisor physical port) P_Key table.

The algorithm for handling P_Key tables which contain both the limited
and the full membership versions of the same P_Key works as follows:

When scanning the P_Key table for a 15-bit P_Key:

A. If there is a full member version of that P_Key anywhere in the
    table, return its index (even if a limited-member version of the
    P_Key exists earlier in the table).

B. If the full member version is not in the table, but the
   limited-member version is in the table, return the index of the
   limited P_Key.

Signed-off-by: Liran Liss <liranl@mellanox.com>
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

parent d2b57063

drivers/infiniband/core/cache.c

+12 −3

Original line number	Diff line number	Diff line
		@@ -167,6 +167,7 @@ int ib_find_cached_pkey(struct ib_device *device,
		unsigned long flags;
		int i;
		int ret = -ENOENT;
		int partial_ix = -1;

		if (port_num < start_port(device) \|\| port_num > end_port(device))
		return -EINVAL;
		@@ -179,9 +180,17 @@ int ib_find_cached_pkey(struct ib_device *device,

		for (i = 0; i < cache->table_len; ++i)
		if ((cache->table[i] & 0x7fff) == (pkey & 0x7fff)) {
		if (cache->table[i] & 0x8000) {
		*index = i;
		ret = 0;
		break;
		} else
		partial_ix = i;
		}

		if (ret && partial_ix >= 0) {
		*index = partial_ix;
		ret = 0;
		}

		read_unlock_irqrestore(&device->cache.lock, flags);

drivers/infiniband/core/device.c

+13 −3

Original line number	Diff line number	Diff line
		@@ -707,18 +707,28 @@ int ib_find_pkey(struct ib_device *device,
		{
		int ret, i;
		u16 tmp_pkey;
		int partial_ix = -1;

		for (i = 0; i < device->pkey_tbl_len[port_num - start_port(device)]; ++i) {
		ret = ib_query_pkey(device, port_num, i, &tmp_pkey);
		if (ret)
		return ret;

		if ((pkey & 0x7fff) == (tmp_pkey & 0x7fff)) {
		/* if there is full-member pkey take it.*/
		if (tmp_pkey & 0x8000) {
		*index = i;
		return 0;
		}
		if (partial_ix < 0)
		partial_ix = i;
		}
		}

		/no full-member, if exists take the limited/
		if (partial_ix >= 0) {
		*index = partial_ix;
		return 0;
		}
		return -ENOENT;
		}
		EXPORT_SYMBOL(ib_find_pkey);