Work around BIOSes that don't report the entire Intel MCH area. MCHBAR is not an architected PCI BAR, so MCH space is usually reported as a PNP0C02 resource. The MCH space was once 16KB, but is 32KB in newer parts. Some BIOSes still report a PNP0C02 resource that is only 16KB, which means the rest of the MCH space is consumed but unreported. 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> Tested-by: Borislav Petkov <bp@xxxxxxx> Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> Acked-by: Borislav Petkov <bp@xxxxxxx> Acked-by: Stephane Eranian <eranian@xxxxxxxxxx> --- drivers/pnp/quirks.c | 79 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 79 insertions(+) diff --git a/drivers/pnp/quirks.c b/drivers/pnp/quirks.c index 258fef272ea7..3736bc408adb 100644 --- a/drivers/pnp/quirks.c +++ b/drivers/pnp/quirks.c @@ -15,6 +15,7 @@ #include <linux/types.h> #include <linux/kernel.h> +#include <linux/pci.h> #include <linux/string.h> #include <linux/slab.h> #include <linux/pnp.h> @@ -334,6 +335,81 @@ static void quirk_amd_mmconfig_area(struct pnp_dev *dev) } #endif +#ifdef CONFIG_X86 +/* Device IDs of parts that have 32KB MCH space */ +static const unsigned int mch_quirk_devices[] = { + 0x0154, /* Ivy Bridge */ + 0x0c00, /* Haswell */ +}; + +static struct pci_dev *get_intel_host(void) +{ + int i; + struct pci_dev *host; + + for (i = 0; i < ARRAY_SIZE(mch_quirk_devices); i++) { + host = pci_get_device(PCI_VENDOR_ID_INTEL, mch_quirk_devices[i], + NULL); + if (host) + return host; + } + return NULL; +} + +static void quirk_intel_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 = get_intel_host(); + if (!host) + return; + + /* + * MCHBAR is not an architected PCI BAR, so MCH space is usually + * reported as a PNP0C02 resource. The MCH space was originally + * 16KB, but is 32KB in newer parts. Some 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 |= (u64) addr_hi << 32; + region.end = region.start + 32*1024 - 1; + + memset(&mch, 0, sizeof(mch)); + mch.flags = IORESOURCE_MEM; + 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 "PNP resource %pR covers only part of %s Intel MCH; extending to %pR\n", + res, pci_name(host), &mch); + res->start = mch.start; + res->end = mch.end; + break; + } + + pci_dev_put(host); +} +#endif + /* * PnP Quirks * Cards or devices that need some tweaking due to incomplete resource info @@ -364,6 +440,9 @@ static struct pnp_fixup pnp_fixups[] = { #ifdef CONFIG_AMD_NB {"PNP0c01", quirk_amd_mmconfig_area}, #endif +#ifdef CONFIG_X86 + {"PNP0c02", quirk_intel_mch}, +#endif {""} }; -- 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
