@@ -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
{""}
};