Commit eaf88450 authored by Ben Collins's avatar Ben Collins
Browse files

ieee1394: save RAM by using a single tlabel for broadcast transactions 



Since broadcast transactions are already complete when the request has
been sent, the same transaction label can be reused all over again, see
IEEE 1394 7.3.2.5 and 6.2.4.3.  Therefore we can reduce the footprint
of struct hpsb_host by the size of one struct hpsb_tlabel_pool.

Signed-off-by: default avatarStefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: default avatarBen Collins <bcollins@ubuntu.com>
parent 647dcb5f

drivers/ieee1394/hosts.h

+8 −8
Original line number Diff line number Diff line
@@ -33,7 +33,7 @@ struct hpsb_host { 
	int node_count;      /* number of identified nodes on this bus */

	int selfid_count;    /* total number of SelfIDs received */

	int nodes_active;    /* number of nodes with active link layer */

	u8 speed[63];       /* speed between each node and local node */

	u8 speed[ALL_NODES]; /* speed between each node and local node */



	nodeid_t node_id;    /* node ID of this host */

	nodeid_t irm_id;     /* ID of this bus' isochronous resource manager */
@@ -56,7 +56,7 @@ struct hpsb_host { 
	struct csr_control csr;



	/* Per node tlabel pool allocation */

	struct hpsb_tlabel_pool tpool[64];

	struct hpsb_tlabel_pool tpool[ALL_NODES];



	struct hpsb_host_driver *driver;

drivers/ieee1394/ieee1394_transactions.c

+8 −2
Original line number Diff line number Diff line
@@ -136,8 +136,11 @@ int hpsb_get_tlabel(struct hpsb_packet *packet) 
{

	unsigned long flags;

	struct hpsb_tlabel_pool *tp;

	int n = NODEID_TO_NODE(packet->node_id);



	tp = &packet->host->tpool[packet->node_id & NODE_MASK];

	if (unlikely(n == ALL_NODES))

		return 0;

	tp = &packet->host->tpool[n];



	if (irqs_disabled() || in_atomic()) {

		if (down_trylock(&tp->count))
@@ -175,8 +178,11 @@ void hpsb_free_tlabel(struct hpsb_packet *packet) 
{

	unsigned long flags;

	struct hpsb_tlabel_pool *tp;

	int n = NODEID_TO_NODE(packet->node_id);



	tp = &packet->host->tpool[packet->node_id & NODE_MASK];

	if (unlikely(n == ALL_NODES))

		return;

	tp = &packet->host->tpool[n];



	BUG_ON(packet->tlabel > 63 || packet->tlabel < 0);

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