From 12382d11670e893f976ae19087fde2f83ed4813d Mon Sep 17 00:00:00 2001 From: Alex Elder Date: Wed, 31 Aug 2022 17:40:12 -0500 Subject: net: ipa: use an array for transactions Transactions are always allocated one at a time. The maximum number of them we could ever need occurs if each TRE is assigned to a transaction. So a channel requires no more transactions than the number of TREs in its transfer ring. That number is known to be a power-of-2 less than 65536. The transaction pool abstraction is used for other things, but for transactions we can use a simple array of transaction structures, and use a free index to indicate which entry in the array is the next one free for allocation. By having the number of elements in the array be a power-of-2, we can use an ever-incrementing 16-bit free index, and use it modulo the array size. Distinguish a "trans_id" (whose value can exceed the number of entries in the transaction array) from a "trans_index" (which is less than the number of entries). Signed-off-by: Alex Elder Signed-off-by: David S. Miller --- drivers/net/ipa/gsi.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'drivers/net/ipa/gsi.h') diff --git a/drivers/net/ipa/gsi.h b/drivers/net/ipa/gsi.h index 23de5f67374c..4a88aec7e7d9 100644 --- a/drivers/net/ipa/gsi.h +++ b/drivers/net/ipa/gsi.h @@ -82,7 +82,9 @@ struct gsi_trans_pool { struct gsi_trans_info { atomic_t tre_avail; /* TREs available for allocation */ - struct gsi_trans_pool pool; /* transaction pool */ + + u16 free_id; /* first free trans in array */ + struct gsi_trans *trans; /* transaction array */ struct gsi_trans **map; /* TRE -> transaction map */ struct gsi_trans_pool sg_pool; /* scatterlist pool */ -- cgit v1.2.3