Messages in this thread | | | Date | Wed, 5 Mar 2014 20:13:04 -0600 | From | Suravee Suthikulanit <> | Subject | Re: [PATCH 0/3] amd/pci: Add AMD hostbridge supports for newer AMD systems |
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On 3/5/2014 3:24 PM, Bjorn Helgaas wrote: > [+cc linux-acpi] > > On Wed, Mar 5, 2014 at 2:06 PM, <suravee.suthikulpanit@amd.com> wrote: >> From: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com> >> >> The current code only supports upto AMD hostbridge for family11h. >> This causes PCI numa_node information to be reported incorrectly >> for newer family with multi sockets. > > Where is the incorrect reporting? In ACPI tables? Is this patch a > way to cover up firmware defects in the ACPI description? Or is this > for machines without ACPI (it seems unlikely that machines with new > AMD processors would not have ACPI)?
This is incorrectly reported in the sysfs for each PCI device (e.g. /devices/pci0000:50/0000:50:00.2/numa_node). Without the patch, they return -1.
In file arch/x86/pci/acpi.c, in function pci_acpi_scan_root(), it is queries the node information as following:
#ifdef CONFIG_ACPI_NUMA pxm = acpi_get_pxm(device->handle); if (pxm >= 0) node = pxm_to_node(pxm); if (node != -1) set_mp_bus_to_node(busnum, node); else #endif node = get_mp_bus_to_node(busnum);
In this case, I see that the acpi_get_pxm() returns -1. Therefore, it falls back to using the node information in mp_bus_to_node[]. So, without this patch, it would also returning -1.
Also, the spec mentioned that the _PXM is optional, so I am not sure if this is a firmware bug.
Suravee
> > The whole point of ACPI is that we shouldn't need to update the kernel > for new hardware, so if there's a firmware bug, it should be fixed, or > if the ACPI spec isn't powerful enough, it should be extended. > >> This patch set introduces the logic to discover AMD hostbridges. >> >> Note: >> * Patch 1 and 2 are functional changes. >> * Patch 3 is code clean up/restructuring >> >> Suravee Suthikulpanit (3): >> amd/pci: Add supports for generic AMD hostbridges >> amd/pci: Support additional MMIO ranges capabilities >> amd/pci: Miscellaneous code clean up for early_fillup_mp_bus_info >> >> arch/x86/pci/amd_bus.c | 376 ++++++++++++++++++++++++++++++++---------------- >> 1 file changed, 251 insertions(+), 125 deletions(-) >> >> -- >> 1.7.10.4 >> >> >
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