On Wed, Apr 16, 2014 at 1:31 PM, Bjorn Helgaas <bhelgaas@xxxxxxxxxx> wrote: > On Wed, Apr 16, 2014 at 09:04:04PM +0200, Borislav Petkov wrote: >> On Thu, Mar 20, 2014 at 02:48:30PM -0600, Bjorn Helgaas wrote: >> > Right. Even if we had this long-term solution, we'd still have >> > Stephane's current problem, because the PNP0C02 _CRS is still wrong. >> > >> > We do have a drivers/pnp/quirks.c where we could conceivably adjust >> > the PNP resource if we found the matching PCI device and MCHBAR. That >> > should solve Stephane's problem even with the current >> > drivers/pnp/system.c. >> >> Guys, this still triggers in -rc1. Do we have a fix or something >> testable at least? > > Hi Boris, > > Can you try the patch below? > > > > PNP: Work around Haswell BIOS defect in MCH area reporting > > From: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> > > Work around a Haswell BIOS defect that causes part of the MCH area to be > unreported. > > MCHBAR is not an architected PCI BAR, so MCH space is usually reported as a > PNP0C02 resource. The MCH space was 16KB prior to Haswell, but it is 32KB > in Haswell. Some Haswell BIOSes still report a PNP0C02 resource that is > only 16KB, which means the rest of the MCH space is consumed but > unreported. > Why are you saying this is Haswell vs. others. I see the problem on my IvyBridge laptop, like Boris. > This can cause resource map sanity check warnings or (theoretically) a > device conflict if we assigned the unreported space to another device. > > The Intel perf event uncore driver tripped over this when it claimed the > MCH region: > > resource map sanity check conflict: 0xfed10000 0xfed15fff 0xfed10000 0xfed13fff pnp 00:01 > Info: mapping multiple BARs. Your kernel is fine. > > To prevent this, if we find a PNP0C02 resource that covers part of the MCH > space, extend it to cover the entire space. > > Link: http://lkml.kernel.org/r/20140224162400.GE16457@xxxxxxx > Reported-by: Borislav Petkov <bp@xxxxxxxxx> > Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> > --- > drivers/pnp/quirks.c | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 52 insertions(+) > > diff --git a/drivers/pnp/quirks.c b/drivers/pnp/quirks.c > index 258fef272ea7..023edf592371 100644 > --- a/drivers/pnp/quirks.c > +++ b/drivers/pnp/quirks.c > @@ -334,6 +334,57 @@ static void quirk_amd_mmconfig_area(struct pnp_dev *dev) > } > #endif > > +static void quirk_intel_haswell_mch(struct pnp_dev *dev) > +{ > + struct pci_dev *host; > + u32 addr_lo, addr_hi; > + struct pci_bus_region region; > + struct resource mch; > + struct pnp_resource *pnp_res; > + struct resource *res; > + > + host = pci_get_device(PCI_VENDOR_ID_INTEL, 0x0c00, NULL); > + if (!host) > + return; > + > + /* > + * MCHBAR is not an architected PCI BAR, so MCH space is usually > + * reported as a PNP0C02 resource. The MCH space was 16KB prior to > + * Haswell, but it is 32KB in Haswell. Some Haswell BIOSes still > + * report a PNP0C02 resource that is only 16KB, which means the > + * rest of the MCH space is consumed but unreported. > + */ > + > + /* > + * Read MCHBAR for Host Member Mapped Register Range Base > + * https://www-ssl.intel.com/content/www/us/en/processors/core/4th-gen-core-family-desktop-vol-2-datasheet > + * Sec 3.1.12. > + */ > + pci_read_config_dword(host, 0x48, &addr_lo); > + region.start = addr_lo & ~0x7fff; > + pci_read_config_dword(host, 0x4c, &addr_hi); > + region.start |= (dma_addr_t) addr_hi << 32; > + region.end = region.start + 32*1024 - 1 ; > + pcibios_bus_to_resource(host->bus, &mch, ®ion); > + > + list_for_each_entry(pnp_res, &dev->resources, list) { > + res = &pnp_res->res; > + if (res->end < mch.start || res->start > mch.end) > + continue; /* no overlap */ > + if (res->start == mch.start && res->end == mch.end) > + continue; /* exact match */ > + > + dev_info(&dev->dev, FW_BUG > + "%pR covers only part of Intel Haswell MCH; extending to %pR\n", > + res, &mch); > + res->start = mch.start; > + res->end = mch.end; > + break; > + } > + > + pci_dev_put(host); > +} > + > /* > * PnP Quirks > * Cards or devices that need some tweaking due to incomplete resource info > @@ -364,6 +415,7 @@ static struct pnp_fixup pnp_fixups[] = { > #ifdef CONFIG_AMD_NB > {"PNP0c01", quirk_amd_mmconfig_area}, > #endif > + {"PNP0c02", quirk_intel_haswell_mch}, > {""} > }; > -- 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
