1 files changed, 78 insertions, 0 deletions
diff --git a/arch/x86_64/pci/k8-bus.c b/arch/x86_64/pci/k8-bus.c
new file mode 100644
index 00000000000..62349c78db5
--- /dev/null
+++ b/arch/x86_64/pci/k8-bus.c
@@ -0,0 +1,78 @@
+#include <linux/init.h>
+#include <linux/pci.h>
+#include <asm/mpspec.h>
+#include <linux/cpumask.h>
+
+/*
+ * This discovers the pcibus <-> node mapping on AMD K8.
+ *
+ * RED-PEN need to call this again on PCI hotplug
+ * RED-PEN empty cpus get reported wrong
+ */
+
+#define NODE_ID_REGISTER 0x60
+#define NODE_ID(dword) (dword & 0x07)
+#define LDT_BUS_NUMBER_REGISTER_0 0x94
+#define LDT_BUS_NUMBER_REGISTER_1 0xB4
+#define LDT_BUS_NUMBER_REGISTER_2 0xD4
+#define NR_LDT_BUS_NUMBER_REGISTERS 3
+#define SECONDARY_LDT_BUS_NUMBER(dword) ((dword >> 8) & 0xFF)
+#define SUBORDINATE_LDT_BUS_NUMBER(dword) ((dword >> 16) & 0xFF)
+#define PCI_DEVICE_ID_K8HTCONFIG 0x1100
+
+/**
+ * fill_mp_bus_to_cpumask()
+ * fills the mp_bus_to_cpumask array based according to the LDT Bus Number
+ * Registers found in the K8 northbridge
+ */
+__init static int
+fill_mp_bus_to_cpumask(void)
+{
+	struct pci_dev *nb_dev = NULL;
+	int i, j, printed;
+	u32 ldtbus, nid;
+	static int lbnr[3] = {
+		LDT_BUS_NUMBER_REGISTER_0,
+		LDT_BUS_NUMBER_REGISTER_1,
+		LDT_BUS_NUMBER_REGISTER_2
+	};
+
+	while ((nb_dev = pci_get_device(PCI_VENDOR_ID_AMD,
+			PCI_DEVICE_ID_K8HTCONFIG, nb_dev))) {
+		pci_read_config_dword(nb_dev, NODE_ID_REGISTER, &nid);
+
+		for (i = 0; i < NR_LDT_BUS_NUMBER_REGISTERS; i++) {
+			pci_read_config_dword(nb_dev, lbnr[i], &ldtbus);
+			/*
+			 * if there are no busses hanging off of the current
+			 * ldt link then both the secondary and subordinate
+			 * bus number fields are set to 0.
+			 */
+			if (!(SECONDARY_LDT_BUS_NUMBER(ldtbus) == 0
+				&& SUBORDINATE_LDT_BUS_NUMBER(ldtbus) == 0)) {
+				for (j = SECONDARY_LDT_BUS_NUMBER(ldtbus);
+				     j <= SUBORDINATE_LDT_BUS_NUMBER(ldtbus);
+				     j++)
+					pci_bus_to_cpumask[j] =
+						node_to_cpumask(NODE_ID(nid));
+			}
+		}
+	}
+
+	/* quick sanity check */
+	printed = 0;
+	for (i = 0; i < 256; i++) {
+		if (cpus_empty(pci_bus_to_cpumask[i])) {
+			pci_bus_to_cpumask[i] = CPU_MASK_ALL;
+			if (printed)
+				continue;
+			printk(KERN_ERR
+			       "k8-bus.c: some busses have empty cpu mask\n");
+			printed = 1;
+		}
+	}
+
+	return 0;
+}
+
+fs_initcall(fill_mp_bus_to_cpumask);