From: Scott Long <[EMAIL PROTECTED]> Subject: Re: mapping small parts of a pci card to conserve KVA Date: Tue, 15 Feb 2005 14:03:12 -0700
> Andrew Gallatin wrote: > > > I maintain drivers for a PCI card which presents itself as having > > 16MB of address space. Eg: > > > > mx0: <Myrinet PCIXE> mem 0xf9000000-0xf9ffffff irq 20 at device 3.0 on pci1 > > > > However, most of that address space does not need to be mapped into > > the host. Really, only a little over 2MB needs to be mapped (3 regions > > with length 1024 bytes, 256 bytes, and 2MB). > > > > I've tried to re-write things so that I make multiple calls > > to bus_alloc_resource() with the (hopefully) appropriate offset and > > lengths. Eg: > > > > rid = PCIR_MAPS; > > *res = bus_alloc_resource(is->arch.dev, SYS_RES_MEMORY, &rid, > > (u_long)offset, > > (u_long)(offset + len - 1), len, > > RF_ACTIVE|PCI_RF_DENSE); > > > > At least on 5.3R, I seem to get back the same struct resource * from > > each call. rman_get_virtual() returns a different kva for each > > mapping, yet they all seem to map to the same physical address. > > Eg, I call vtophys() on the results of rman_get_virtual(), > > for each segment, and they all map to 0xf9000000. > > > > Is there a way to just map what I need? > > > > Thanks, > > > > Drew > > > > You can use pmap_mapdev() to create a KVA mapping of an arbitrary > physaddr+len. In fact, this is exactly what newbus uses to create the > PCI MEMIO resources when bus_alloc_resource() is called. I'm not sure > if the range is mapped and activated before the driver makes that call, > Warner or John might know for sure. If you go that route, you need to allocate the resource (all of it). RF_ACTIVE in the flags, or bus_activate_resource is what maps it in, so if you don't do that, you can call pmap_mamdev. Warner _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"
