the data the inline functions access together at the start of the bus_space
struct. The start-of part isn't so important, it's the grouping-together
that's the point: now all the most-accessed data should be in one cache line.
Suggested by: cognet
every operation to retrieve the bs_cookie value almost nothing actually uses.
The bus_space struct contains a private data pointer (poorly named bs_cookie,
now renamed to bs_privdata) which is used only by a few old armv4 xscale
implementations. The bus_space functions were all defined to take this
value as the first parameter instead of the bus_space_tag_t, requiring all
the inline macro and function expansions to dereference the tag to pass it
to another function, which never uses it. Now all the functions take the tag
as the first parameter and retrieve the privdata if they need it.
Also fix a couple bus_space_unmap() implementations that were calling
kva_free() instead of pmap_unmapdev().
Discussed with: cognet
register from a bus space resource.
Note that this macro is just for ARM, and is intended to have a short
lifespan. The DMA engines in some SoCs need the physical address of a
memory-mapped device register as one of the arguments for the transfer.
Several scattered ad-hoc solutions have been converted to use this macro,
which now also serves to mark the places where a more complete fix needs
to be applied (after that fix has been designed).
Passing a count of zero on i386 and amd64 for [I386|AMD64]_BUS_SPACE_MEM
causes a crash/hang since the 'loop' instruction decrements the counter
before checking if it's zero.
PR: kern/80980
Discussed with: jhb
into _bus.h to help with name space polution from including all of bus.h.
In a few days, I'll commit changes to the MI code to take advantage of thse
sepration (after I've made sure that these changes don't break anything in
the main tree, I've tested in my trees, but you never know...).
Suggested by: bde (in 2002 or 2003 I think)
Reviewed in principle by: jhb
sys/bus_dma.h instead of being copied in every single arch. This slightly
reorders a flag that was specific to AXP and thus changes the ABI there.
The interface still relies on bus_space definitions found in <machine/bus.h>
so it cannot be included on its own yet, but that will be fixed at a later
date. Add an MD <machine/bus_dma.h> for ever arch for consistency and to
allow for future MD augmentation of the API. sparc64 makes heavy use of
this right now due to its different bus_dma implemenation.
It only supports sa1110 (on simics) right now, but xscale support should come
soon.
Some of the initial work has been provided by :
Stephane Potvin <sepotvin at videotron.ca>
Most of this comes from NetBSD.
