diff options
Diffstat (limited to 'sys/dev')
| -rw-r--r-- | sys/dev/cardbus/rbus.h | 32 |
1 files changed, 17 insertions, 15 deletions
diff --git a/sys/dev/cardbus/rbus.h b/sys/dev/cardbus/rbus.h index 907f94ab4df..7811c77740a 100644 --- a/sys/dev/cardbus/rbus.h +++ b/sys/dev/cardbus/rbus.h @@ -1,4 +1,4 @@ -/* $OpenBSD: rbus.h,v 1.4 2005/09/13 18:44:38 fgsch Exp $ */ +/* $OpenBSD: rbus.h,v 1.5 2006/06/08 22:38:40 fkr Exp $ */ /* $NetBSD: rbus.h,v 1.3 1999/12/15 12:28:55 kleink Exp $ */ /* * Copyright (c) 1999 @@ -36,32 +36,34 @@ #define _DEV_CARDBUS_RBUS_H_ /* - * This file defines rbus (pseudo) class + * This file defines the rbus (pseudo) class * * What is rbus? * * Ths rbus is a recursive bus-space administrator. This means a * parent bus-space administrator, which usually belongs to a bus * bridge, makes some child bus-space administrators and gives - * (restricted) bus-space for children. There are a root bus-space - * administrator which maintains whole bus-space. + * (restricted) bus-space to children. There is a root bus-space + * administrator which maintains the whole bus-space. * * Why recursive? * - * The recursive bus-space administration has two virtues. The - * former is this modelling matches the actual memory and io space - * management of bridge devices well. The latter is the rbus is - * distributed management system, so it matches well with + * The recursive bus-space administration has two reasons. For one + * this modelling matches the actual memory and io space management + * of bridge devices quite well. Furthermore is the rbus a + * distributed management system, as such it plays well with * multi-thread kernel. * * Abstraction * - * The rbus models bus-to-bus bridge into three way: dedicate, share - * and slave. Dedicate means that the bridge has dedicate bus space. - * Share means that the bridge has bus space, but this bus space is - * shared with other bus bridges. Slave means the bus bridge which - * does not have it own bus space and ask a parent bus bridge for bus - * space when a client requests bus space to the bridge. + * rbus can model a bus-to-bus bridge in three ways: dedicated, shared + * and slave. + * Dedicated: the bridge has its own bus space. + * Shared: the bridge has bus space, but this bus space is + * shared with other bus bridges. + * Slave: the bus bridge does not have its own bus space and has to ask + * a parent bus bridge for bus space once a client is requesting bus space + * to the bridge. */ @@ -76,7 +78,7 @@ struct extent; /* * General rule * - * 1) When a rbustag has no space for child (it means rb_extent is + * 1) When a rbustag has no space for child (meaning: rb_extent is * NULL), ask bus-space for parent through rb_parent. * * 2) When a rbustag has its own space (whether shared or dedicated), |