/*
* ACPI 3.0 based NUMA setup
* Copyright 2004 Andi Kleen, SuSE Labs.
*
* Reads the ACPI SRAT table to figure out what memory belongs to which CPUs.
*
* Called from acpi_numa_init while reading the SRAT and SLIT tables.
* Assumes all memory regions belonging to a single proximity domain
* are in one chunk. Holes between them will be included in the node.
*/
#include <linux/kernel.h>
#include <linux/acpi.h>
#include <linux/mmzone.h>
#include <linux/bitmap.h>
#include <linux/module.h>
#include <linux/topology.h>
#include <asm/proto.h>
#include <asm/numa.h>
#include <asm/e820.h>
static struct acpi_table_slit *acpi_slit;
static nodemask_t nodes_parsed __initdata;
static nodemask_t nodes_found __initdata;
static struct bootnode nodes[MAX_NUMNODES] __initdata;
static u8 pxm2node[256] = { [0 ... 255] = 0xff };
/* Too small nodes confuse the VM badly. Usually they result
from BIOS bugs. */
#define NODE_MIN_SIZE (4*1024*1024)
static int node_to_pxm(int n);
int pxm_to_node(int pxm)
{
if ((unsigned)pxm >= 256)
return -1;
/* Extend 0xff to (int)-1 */
return (signed char)pxm2node[pxm];
}
static __init int setup_node(int pxm)
{
unsigned node = pxm2node[pxm];
if (node == 0xff) {
if (nodes_weight(nodes_found) >= MAX_NUMNODES)
return -1;
node = first_unset_node(nodes_found);
node_set(node, nodes_found);
pxm2node[pxm] = node;
}
return pxm2node[pxm];
}
static __init int conflicting_nodes(unsigned long start, unsigned long end)
{
int i;
for_each_node_mask(i, nodes_parsed) {
struct bootnode *nd = &nodes[i];
if (nd->start == nd->end)
continue;
if (nd->end > start && nd->start < end)
return i;
if (nd->end == end && nd->start == start)
return i;
}
return -1;
}
static __init void cutoff_node(int i, unsigned long start, unsigned long end)
{
struct bootnode *nd = &nodes[i];
if (nd->start < start) {
nd->start = start;
if (nd->end < nd->start)
nd->start = nd->end;
}
if (nd->end > end) {
nd->end = end;
if (nd->start > nd->end)
nd->start = nd->end;
}
}
static __init void bad_srat(void)
{
int i;
printk(KERN_ERR "SRAT: SRAT not used.\n");
acpi_numa = -1;
for (i = 0; i < MAX_LOCAL_APIC; i++)
apicid_to_node[i] = NUMA_NO_NODE;
}
static __init inline int srat_disabled(void)
{
return numa_off || acpi_numa < 0;
}
/*
* A lot of BIOS fill in 10 (= no distance) everywhere. This messes
* up the NUMA heuristics which wants the local node to have a smaller
* distance than the others.
* Do some quick checks here and only use the SLIT if it passes.
*/
static __init int slit_valid(struct acpi_table_slit *slit)
{
int i, j;
int d = slit->localities;
for (i = 0; i < d; i++) {
for (j = 0; j < d; j++) {
u8 val = slit->entry[d*i + j];
if (i == j) {
if (val != 10)
return 0;
} else if (val <= 10)
return 0;
}
}
return 1;
}
/* Callback for SLIT parsing */
void __init acpi_numa_slit_init(struct acpi_table_slit *slit)
{
if (!slit_valid(slit)) {
printk(KERN_INFO "ACPI: SLIT table looks invalid. Not used.\n");
return;
}
acpi_slit = slit;
}
/* Callback for Proximity Domain -> LAPIC mapping */
void __init
acpi_numa_processor_affinity_init(struct acpi_table_processor_affinity *pa)
{
int pxm, node;
if (srat_disabled())
return;
if (pa->header.length != sizeof(struct acpi_table_processor_affinity)) { bad_srat();
return;
}
if (pa->flags.enabled == 0)
return;
pxm = pa->proximity_domain;
node = setup_node(pxm);
if (node < 0) {
printk(KERN_ERR "SRAT: Too many proximity domains %x\n", pxm);
bad_srat();
return;
}
apicid_to_node[pa->apic_id] = node;
acpi_numa = 1;
printk(KERN_INFO "SRAT: PXM %u -> APIC %u -> Node %u\n",
pxm, pa->apic_id, node);
}
/* Callback for parsing of the Proximity Domain <-> Memory Area mappings */
void __init
acpi_numa_memory_affinity_init(struct acpi_table_memory_affinity *ma)
{
struct bootnode *nd;
unsigned long start, end;
int node, pxm;
int i;
if (srat_disabled())
return;
if (ma->header.length != sizeof(struct acpi_table_memory_affinity)) {
bad_srat();
return;
}
if (ma->flags.enabled == 0)
return;
start = ma->base_addr_lo | ((u64)ma->base_addr_hi << 32);
end = start + (ma->length_lo | ((u64)ma->length_hi << 32));
pxm = ma->proximity_domain;
node = setup_node(pxm);
if (node < 0) {
printk(KERN_ERR "SRAT: Too many proximity domains.\n");
bad_srat();
return;
}
/* It is fine to add this area to the nodes data it will be used later*/
if (ma->flags.hot_pluggable == 1)
printk(KERN_INFO "SRAT: hot plug zone found %lx - %lx \n",
start, end);
i = conflicting_nodes(start, end);
if (i == node) {
printk(KERN_WARNING
"SRAT: Warning: PXM %d (%lx-%lx) overlaps with itself (%Lx-%Lx)\n",
pxm, start, end, nodes[i].start, nodes[i].end);
} else if (i >= 0) {
printk(KERN_ERR
"SRAT: PXM %d (%lx-%lx) overlaps with PXM %d (%Lx-%Lx)\n",
pxm, start, end, node_to_pxm(i),
nodes[i].start, nodes[i].end);
bad_srat();
return;
}
nd = &nodes[node];
if (!node_test_and_set(node, nodes_parsed)) {
nd->start = start;
nd->end = end;
} else {
if (start < nd->start)
nd->start = start;
if (nd->end < end)
nd->end = end;
}
printk(KERN_INFO "SRAT: Node %u PXM %u %Lx-%Lx\n", node, pxm,
nd->start, nd->end);
}
/* Sanity check to catch more bad SRATs (they are amazingly common).
Make sure the PXMs cover all memory. */
static int nodes_cover_memory(void)
{
int i;
unsigned long pxmram, e820ram;
pxmram = 0;
for_each_node_mask(i, nodes_parsed) {
unsigned long s = nodes[i].start >> PAGE_SHIFT;
unsigned long e = nodes[i].end >> PAGE_SHIFT;
pxmram += e - s;
pxmram -= e820_hole_size(s, e);
}
e820ram = end_pfn - e820_hole_size(0, end_pfn);
/* We seem to lose 3 pages somewhere. Allow a bit of slack. */
if ((long)(e820ram - pxmram) >= 1*1024*1024) {
printk(KERN_ERR
"SRAT: PXMs only cover %luMB of your %luMB e820 RAM. Not used.\n",
(pxmram << PAGE_SHIFT) >> 20,
(e820ram << PAGE_SHIFT) >> 20);
return 0;
}
return 1;
}
static void unparse_node(int node)
{
int i;
node_clear(node, nodes_parsed);
for (i = 0; i < MAX_LOCAL_APIC; i++) {
if (apicid_to_node[i] == node)
apicid_to_node[i] = NUMA_NO_NODE;
}
}
void __init acpi_numa_arch_fixup(void) {}
/* Use the information discovered above to actually set up the nodes. */
int __init acpi_scan_nodes(unsigned long start, unsigned long end)
{
int i;
/* First clean up the node list */
for (i = 0; i < MAX_NUMNODES; i++) {
cutoff_node(i, start, end);
if ((nodes[i].end - nodes[i].start) < NODE_MIN_SIZE)
unparse_node(i);
}
if (acpi_numa <= 0)
return -1;
if (!nodes_cover_memory()) {
bad_srat();
return -1;
}
memnode_shift = compute_hash_shift(nodes, MAX_NUMNODES);
if (memnode_shift < 0) {
printk(KERN_ERR
"SRAT: No NUMA node hash function found. Contact maintainer\n");
bad_srat();
return -1;
}
/* Finally register nodes */
for_each_node_mask(i, nodes_parsed)
setup_node_bootmem(i, nodes[i].start, nodes[i].end);
for (i = 0; i < NR_CPUS; i++) {
if (cpu_to_node[i] == NUMA_NO_NODE)
continue;
if (!node_isset(cpu_to_node[i], nodes_parsed))
numa_set_node(i, NUMA_NO_NODE);
}
numa_init_array();
return 0;
}
static int node_to_pxm(int n)
{
int i;
if (pxm2node[n] == n)
return n;
for (i = 0; i < 256; i++)
if (pxm2node[i] == n)
return i;
return 0;
}
int __node_distance(int a, int b)
{
int index;
if (!acpi_slit)
return a == b ? 10 : 20;
index = acpi_slit->localities * node_to_pxm(a);
return acpi_slit->entry[index + node_to_pxm(b)];
}
EXPORT_SYMBOL(__node_distance);
