Changing how PCI-PCI bridges do resource allocation

[John Baldwin]

On Tuesday, April 26, 2011 10:45:33 am Alexander Motin wrote:
> John Baldwin wrote:
> > On Tuesday, April 26, 2011 2:53:24 am Alexander Motin wrote:
> >> On 26.04.2011 00:21, John Baldwin wrote:
> >>> On Monday, April 25, 2011 3:09:47 pm John Baldwin wrote:
> >>>> On Wednesday, April 20, 2011 4:38:30 am Alexander Motin wrote:
> >>>>> On 19.04.2011 21:50, John Baldwin wrote:
> >>>>>> I've already had at least one testing report that this fixes the issues with
> >>>>>> some machines' BIOS clearing the I/O windows on some PCI-PCI bridges when ACPI
> >>>>>> is enabled as this code re-discovers the original windows and programs them
> >>>>>> correctly.  More testing would be good however.
> >>>>> I would like this helped my Acer TM6292 which also has alike problems
> >>>>> with missing PCIe bridge resources, but unluckily it doesn't.
> >>>>>
> >>>>> Here is verbose dmesg when my system uses this dirty hack:
> >>>>> http://people.freebsd.org/~mav/tm6292_pcie.patch
> >>>>>    to restore bridges resources to the pre-ACPI state:
> >>>>> http://people.freebsd.org/~mav/dmesg.boot.hacks
> >>>>>
> >>>>> Here is respective `pciconf -lvcb` output:
> >>>>> http://people.freebsd.org/~mav/pciconf.hacks
> >>>>>
> >>>>> Here is dmesg with patches, but without NEW_PCIB:
> >>>>> http://people.freebsd.org/~mav/dmesg.boot.olbpcib
> >>>>>
> >>>>> Here is dmesg with patches with NEW_PCIB:
> >>>>> http://people.freebsd.org/~mav/dmesg.boot.newpcib
> >>>> Ah, your problem is we pick bad ranges when we alloc fresh resources for your
> >>>> bridges.  I am working on making that better for ACPI, but for now you can try
> >>>> setting hw.acpi.host_mem_start to a value like '0xf0000000' in loader.conf.
> >>>>
> >>>> Although, it looks like it is not being honored currently.  Try adding a printf
> >>>> in acpi_pcib_alloc_resource() in sys/dev/acpica/acpi_pcib_acpi.c to log the
> >>>> type, start, and end of each resource range.
> >>> Actually, try this patch.  Then I think you can use the host_mem_start tunable:
> >> I've tried it. With this patch host_mem_start tunable seems like makes 
> >> effect. Numbers look closer, but bge0 and iwn0 beyond the bridges are 
> >> still not working.
> > 
> > Hmmm, I think I need to clear the completely bogus windows when we fail to
> > allocate the initial window.  Try this (relative to the previous patches):
> 
> Dmesg changed a bit, but still no luck:
> http://people.freebsd.org/~mav/newpcib/dmesg.next

Oh, I'm dumb.  'w->base' should be set to 'max_address' and 'w->limit' should
be set to 0 to turn off the bogus windows like this:

--- //depot/projects/pci/sys/dev/pci/pci_pci.c	2011-04-19 17:42:14.000000000 0000
+++ /home/jhb/work/p4/pci/sys/dev/pci/pci_pci.c	2011-04-19 17:42:14.000000000 0000
@@ -60,6 +60,7 @@
 static int		pcib_resume(device_t dev);
 static int		pcib_power_for_sleep(device_t pcib, device_t dev,
 			    int *pstate);
+static void		pcib_write_windows(struct pcib_softc *sc, int mask);
 
 static device_method_t pcib_methods[] = {
     /* Device interface */
@@ -181,6 +182,9 @@
 		device_printf(sc->dev,
 		    "failed to allocate initial %s window: %#jx-%#jx\n",
 		    w->name, (uintmax_t)w->base, (uintmax_t)w->limit);
+		w->base = max_address;
+		w->limit = 0;
+		pcib_write_windows(sc, w->mask);
 		return;
 	}
 

-- 
John Baldwin