[XEN] Add basic NUMA/SRAT support to Xen from Linux 2.6.16.29.

Signed-off-by: Ryan Harper <ryanh@us.ibm.com>

1 files changed, 325 insertions, 0 deletions

diff --git a/xen/arch/x86/srat.c b/xen/arch/x86/srat.c
new file mode 100644
index 0000000000..dfa85b2539
--- /dev/null
+++ b/xen/arch/x86/srat.c
@@ -0,0 +1,325 @@
+/*
+ * 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.
+ * 
+ * Adapted for Xen: Ryan Harper <ryanh@us.ibm.com>
+ */
+
+#if 0
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <asm/proto.h>
+#include <xen/bitmap.h>
+#include <xen/numa.h>
+#include <xen/topology.h>
+#include <asm/e820.h>
+#endif
+#include <xen/init.h>
+#include <xen/mm.h>
+#include <xen/inttypes.h>
+#include <xen/nodemask.h>
+#include <xen/acpi.h>
+
+#include <asm/numa.h>
+#include <asm/page.h>
+
+static struct acpi_table_slit *acpi_slit;
+
+static nodemask_t nodes_parsed __initdata;
+static nodemask_t nodes_found __initdata;
+static struct node 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(u64 start, u64 end)
+{
+	int i;
+	for_each_node_mask(i, nodes_parsed) {
+		struct node *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, u64 start, u64 end)
+{
+	struct node *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 node *nd;
+	u64 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 %"PRIx64" - %"PRIx64" \n",
+				start, end);
+	i = conflicting_nodes(start, end);
+	if (i == node) {
+		printk(KERN_WARNING
+		"SRAT: Warning: PXM %d (%"PRIx64"-%"PRIx64") overlaps with itself (%"
+		PRIx64"-%"PRIx64")\n", pxm, start, end, nodes[i].start, nodes[i].end);
+	} else if (i >= 0) {
+		printk(KERN_ERR
+		       "SRAT: PXM %d (%"PRIx64"-%"PRIx64") overlaps with PXM %d (%"
+		       PRIx64"-%"PRIx64")\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 %"PRIx64"-%"PRIx64"\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;
+	u64 pxmram, e820ram;
+
+	pxmram = 0;
+	for_each_node_mask(i, nodes_parsed) {
+		u64 s = nodes[i].start >> PAGE_SHIFT;
+		u64 e = nodes[i].end >> PAGE_SHIFT;
+		pxmram += e - s;
+	}
+
+	e820ram = max_page;
+	/* 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 %"PRIu64"MB of your %"
+			PRIu64"MB 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(u64 start, u64 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);