/*

   * AMD NUMA support.

   * Discover the memory map and associated nodes.

   *

   * This version reads it directly from the AMD northbridge.

   *

   * Copyright 2002,2003 Andi Kleen, SuSE Labs.
   */
  #include <linux/kernel.h>
  #include <linux/init.h>
  #include <linux/string.h>
  #include <linux/module.h>
  #include <linux/nodemask.h>

  #include <linux/memblock.h>

  #include <linux/bootmem.h>

  #include <asm/io.h>
  #include <linux/pci_ids.h>

  #include <linux/acpi.h>

  #include <asm/types.h>
  #include <asm/mmzone.h>
  #include <asm/proto.h>
  #include <asm/e820.h>
  #include <asm/pci-direct.h>
  #include <asm/numa.h>

  #include <asm/mpspec.h>
  #include <asm/apic.h>

  #include <asm/amd_nb.h>

  static unsigned char __initdata nodeids[8];

  static __init int find_northbridge(void)
  {

  	int num;

  	for (num = 0; num < 32; num++) {

  		u32 header;

  
  		header = read_pci_config(0, num, 0, 0x00);

  		if (header != (PCI_VENDOR_ID_AMD | (0x1100<<16)) &&
  			header != (PCI_VENDOR_ID_AMD | (0x1200<<16)) &&
  			header != (PCI_VENDOR_ID_AMD | (0x1300<<16)))

  			continue;

  		header = read_pci_config(0, num, 1, 0x00);

  		if (header != (PCI_VENDOR_ID_AMD | (0x1101<<16)) &&
  			header != (PCI_VENDOR_ID_AMD | (0x1201<<16)) &&
  			header != (PCI_VENDOR_ID_AMD | (0x1301<<16)))

  			continue;
  		return num;
  	}

  	return -ENOENT;

  }

  static __init void early_get_boot_cpu_id(void)
  {
  	/*

  	 * need to get the APIC ID of the BSP so can use that to

  	 * create apicid_to_node in amd_scan_nodes()

  	 */

  #ifdef CONFIG_X86_MPPARSE

  	/*
  	 * get boot-time SMP configuration:
  	 */
  	if (smp_found_config)
  		early_get_smp_config();

  #endif

  }

  int __init amd_numa_init(void)

  {

  	u64 start = PFN_PHYS(0);
  	u64 end = PFN_PHYS(max_pfn);

  	unsigned numnodes;

  	u64 prevbase;

  	int i, j, nb;

  	u32 nodeid, reg;

  	unsigned int bits, cores, apicid_base;

  	if (!early_pci_allowed())

  		return -EINVAL;

  	nb = find_northbridge();
  	if (nb < 0)

  		return nb;

  	pr_info("Scanning NUMA topology in Northbridge %d
  ", nb);

  	reg = read_pci_config(0, nb, 0, 0x60);

  	numnodes = ((reg >> 4) & 0xF) + 1;

  	if (numnodes <= 1)

  		return -ENOENT;

  	pr_info("Number of physical nodes %d
  ", numnodes);

  	prevbase = 0;

  	for (i = 0; i < 8; i++) {

  		u64 base, limit;

  		base = read_pci_config(0, nb, 1, 0x40 + i*8);
  		limit = read_pci_config(0, nb, 1, 0x44 + i*8);

  		nodeids[i] = nodeid = limit & 7;

  		if ((base & 3) == 0) {

  			if (i < numnodes)

  				pr_info("Skipping disabled node %d
  ", i);

  			continue;

  		}

  		if (nodeid >= numnodes) {

  			pr_info("Ignoring excess node %d (%Lx:%Lx)
  ", nodeid,

  				base, limit);

  			continue;

  		}

  		if (!limit) {

  			pr_info("Skipping node entry %d (base %Lx)
  ",

  				i, base);

  			continue;
  		}
  		if ((base >> 8) & 3 || (limit >> 8) & 3) {

  			pr_err("Node %d using interleaving mode %Lx/%Lx
  ",

  			       nodeid, (base >> 8) & 3, (limit >> 8) & 3);

  			return -EINVAL;

  		}

  		if (node_isset(nodeid, numa_nodes_parsed)) {

  			pr_info("Node %d already present, skipping
  ",
  				nodeid);

  			continue;
  		}

  		limit >>= 16;
  		limit <<= 24;

  		limit |= (1<<24)-1;

  		limit++;

  		if (limit > end)
  			limit = end;

  		if (limit <= base)

  			continue;

  		base >>= 16;

  		base <<= 24;
  
  		if (base < start)
  			base = start;
  		if (limit > end)
  			limit = end;
  		if (limit == base) {

  			pr_err("Empty node %d
  ", nodeid);

  			continue;

  		}

  		if (limit < base) {

  			pr_err("Node %d bogus settings %Lx-%Lx.
  ",

  			       nodeid, base, limit);

  			continue;

  		}

  		/* Could sort here, but pun for now. Should not happen anyroads. */

  		if (prevbase > base) {

  			pr_err("Node map not sorted %Lx,%Lx
  ",

  			       prevbase, base);

  			return -EINVAL;

  		}

  		pr_info("Node %d MemBase %016Lx Limit %016Lx
  ",

  			nodeid, base, limit);

  		prevbase = base;

  		numa_add_memblk(nodeid, base, limit);

  		node_set(nodeid, numa_nodes_parsed);

  	}

  	if (!nodes_weight(numa_nodes_parsed))

  		return -ENOENT;

  
  	/*
  	 * We seem to have valid NUMA configuration.  Map apicids to nodes
  	 * using the coreid bits from early_identify_cpu.
  	 */
  	bits = boot_cpu_data.x86_coreid_bits;
  	cores = 1 << bits;
  	apicid_base = 0;
  
  	/* get the APIC ID of the BSP early for systems with apicid lifting */
  	early_get_boot_cpu_id();
  	if (boot_cpu_physical_apicid > 0) {
  		pr_info("BSP APIC ID: %02x
  ", boot_cpu_physical_apicid);
  		apicid_base = boot_cpu_physical_apicid;
  	}

  	for_each_node_mask(i, numa_nodes_parsed)

  		for (j = apicid_base; j < cores + apicid_base; j++)
  			set_apicid_to_node((i << bits) + j, i);

  	return 0;
  }