On 01/12/2011 14:27, m...@freebsd.org wrote:
On Wed, Jan 12, 2011 at 1:21 PM, John Baldwin<j...@freebsd.org> wrote:
On Wednesday, January 12, 2011 4:08:50 pm Matthew D Fleming wrote:
Author: mdf
Date: Wed Jan 12 21:08:49 2011
New Revision: 217330
URL: http://svn.freebsd.org/changeset/base/217330
Log:
Fix a brain fart. Since this file is shared between i386 and amd64, a
bus_size_t may be 32 or 64 bits. Change the bounce_zone alignment field
to explicitly be 32 bits, as I can't really imagine a DMA device that
needs anything close to 2GB alignment of data.
Hmm, we do have devices with 4GB boundaries though. I think I'd prefer it if
you instead if you did this:
#if defined(amd64) || defined(PAE)
#define SYSCTL_ADD_BUS_SIZE_T SYSCTL_ADD_UQUAD
#else
#define SYSCTL_ADD_BUS_SIZE_T SYSCTL_ADD_UINT
#endif
and then just used SYSCTL_ADD_BUS_SIZE_T() in the code so we could let the
members in the bounce zone retain the same types passed to
bus_dma_tag_create().
But would there be a device that can't start DMA except on a 4GB
boundary? I thought that's what this member was for.
You never know about weird, custom devices...
This is safer and would be more future proof. its the whole reason we
have the different types... And sysctl is too type-poor these days,
imho, since it goes to the base type and has little facility to go for
the logical type. Go on, tell me how to specify a physical address that
will always work...
Warner
_______________________________________________
svn-src-head@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/svn-src-head
To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
