Date: Wed, 29 Dec 1999 02:39:36 -0700 From: Warner Losh <imp@village.org> To: new-bus@freebsd.org Subject: Another question Message-ID: <199912290939.CAA01692@harmony.village.org>
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I have a question about a parent giving a child a portion of the address range that the parent has allocated for that child's use. I've allocated a 16k chunk of system isa memory at the bridge level. From time to time children need a hunk of this memory to map in their attribute memory. The attribute memory has various config registers in it as well as the CIS. My thinking on the matter was that I'd allocate the 16k chunk at bridge attach time, and then just give it out to the children who are requesting a memory area be mapped in as the default. However, when I go to do this, the allocation fails because the bridge is holding the allocation. What's the right new bus way to deal with this. Is it to free the resource at the bridge level and give it to the child? Is there some subspace mapping available that I've missed? Finally, the attribute memory on a pccard can be much bigger than the 4k window which the pcic bridge allows to be mapped at one time. How does one specify a card relative offset using the new bus allocation routines (eg, I want to say "allocate this hunk of memory at the default place and start at offset 16k in the card's address space"). I suppose I could come up with a kludge that moves the offset after it has been allocated/activated, but I thought I'd bounce things off the folks here. Warner To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-new-bus" in the body of the message
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