On Mon, May 7, 2012 at 12:35 AM, Andreas Herrmann <andreas.herrmann3@xxxxxxx> wrote: > On Fri, May 04, 2012 at 10:35:05AM -0600, Bjorn Helgaas wrote: >> On Fri, May 4, 2012 at 7:03 AM, Andreas Herrmann >> <andreas.herrmann3@xxxxxxx> wrote: >> > On Wed, May 02, 2012 at 11:33:17AM -0600, Bjorn Helgaas wrote: >> >> On Fri, Apr 27, 2012 at 8:36 AM, Andreas Herrmann >> >> <andreas.herrmann3@xxxxxxx> wrote: >> >> > >> >> > Once upon a time this function was overloaded with quirky stuff to fix >> >> > resource detection on systems w/ _CRS defects (seems that some Sun and >> >> > HP systems were affected). >> >> > >> >> > See commit 30a18d6c3f1e774de656ebd8ff219d53e2ba4029 >> >> > (x86: multi pci root bus with different io resource range, on 64-bit) >> >> > >> >> > Restore the old function and thus decouple it from the quirk that is >> >> > CPU family specific (e.g. it won't work on AMD family 15h CPUs). BTW, >> >> > I assume that the _CRS stuff is working on current systems. >> >> > >> >> > This is required to properly initilize the numa_node information of >> >> > existing PCI busses and associated devices. >> >> >> >> I applied some of Yinghai's patches that also touch this area. Can >> >> you refresh these so they apply on top of my "next" branch >> >> (git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci.git next)? >> > >> > Arrgh, will adapt my patch and resend it (asap). >> > >> >> Can you also be more specific about what these patches fix? >> > >> >> My understanding is that amd_bus.c (1) sets NUMA info with >> >> set_mp_bus_to_node() and (2) figures out MMIO and I/O port apertures, >> >> which are only used when blind probing and when ignoring _CRS. >> >> >> >> It seems like the main change in this patch is that we skip (2) >> >> completely when family >= 0x11, and I don't understand what that could >> >> fix. >> > >> > The patch restores a very old function that was used to detect the >> > nearest node for a PCI bus, so yes it's used to do (1). IMHO this >> > function was totally screwed up with Yinghai's code to do (2). It >> > seems that Sun has (had?) some systems where (2) was req'd. I don't >> > care about this part. But I'd like to do (1) on all AMD CPU NUMA >> > systems. >> >> Thanks for the explanation. But I'm afraid I'm still confused. >> >> First, it sounds like you're trying to change the way we do part (1), >> i.e., the set_mp_bus_to_node() calls, but I think the effect of your >> patch is to stop doing part (2) in some cases. >> >> Second, I am pretty sure that the current early_fill_mp_bus_info() >> (before your patch) does the exact same set_mp_bus_to_node() calls as >> your early_fill_mp_bus_to_node() does. > > > I want to do (1) on all AMD CPUs that might be used in NUMA systems. > > What's done for (2) is very specific to certain AMD CPU families -- > some of the register accesses are wrong/incomplete for newer AMD > CPUs. Furhtermore _CRS should provide the required info. I really > don't want to extend all the quirky stuff in (2) for future AMD CPUs. I'm all in favor of limiting part (2) to older AMD CPUs. I certainly don't want to maintain it for future CPUs. >> Finally, on all systems with ACPI, the set_mp_bus_to_node() call in >> pci_acpi_scan_root() should be doing what you need. In fact, that >> call happens later, so it should be overwriting the information filled >> in by amd_bus.c. If there's something wrong in this ACPI path, the >> most likely cause is a BIOS defect, such as a missing _PXM method on >> the PNP0A03/0A08 host bridge device. > > Good point. I'll check what's wrong in this ACPI path. I hope you find something, especially if it's a bug in the Linux code that interprets the NUMA info. Then we could fix that and limit both parts to older CPUs. Bjorn -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
