arch/x86_64/mm/srat.c

   1 /*
   2  * ACPI 3.0 based NUMA setup
   3  * Copyright 2004 Andi Kleen, SuSE Labs.
   4  *
   5  * Reads the ACPI SRAT table to figure out what memory belongs to which CPUs.
   6  *
   7  * Called from acpi_numa_init while reading the SRAT and SLIT tables.
   8  * Assumes all memory regions belonging to a single proximity domain
   9  * are in one chunk. Holes between them will be included in the node.
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/acpi.h>
  14 #include <linux/mmzone.h>
  15 #include <linux/bitmap.h>
  16 #include <linux/module.h>
  17 #include <linux/topology.h>
  18 #include <asm/proto.h>
  19 #include <asm/numa.h>
  20
  21 static struct acpi_table_slit *acpi_slit;
  22
  23 /* Internal processor count */
  24 static unsigned int __initdata num_processors = 0;
  25
  26 static nodemask_t nodes_parsed __initdata;
  27 static nodemask_t nodes_found __initdata;
  28 static struct node nodes[MAX_NUMNODES] __initdata;
  29 static __u8  pxm2node[256] = { [0 ... 255] = 0xff };
  30
  31 static __init int setup_node(int pxm)
  32 {
  33         unsigned node = pxm2node[pxm];
  34         if (node == 0xff) {
  35                 if (nodes_weight(nodes_found) >= MAX_NUMNODES)
  36                         return -1;
  37                 node = first_unset_node(nodes_found);
  38                 node_set(node, nodes_found);
  39                 pxm2node[pxm] = node;
  40         }
  41         return pxm2node[pxm];
  42 }
  43
  44 static __init int conflicting_nodes(unsigned long start, unsigned long end)
  45 {
  46         int i;
  47         for_each_online_node(i) {
  48                 struct node *nd = &nodes[i];
  49                 if (nd->start == nd->end)
  50                         continue;
  51                 if (nd->end > start && nd->start < end)
  52                         return 1;
  53                 if (nd->end == end && nd->start == start)
  54                         return 1;
  55         }
  56         return -1;
  57 }
  58
  59 static __init void cutoff_node(int i, unsigned long start, unsigned long end)
  60 {
  61         struct node *nd = &nodes[i];
  62         if (nd->start < start) {
  63                 nd->start = start;
  64                 if (nd->end < nd->start)
  65                         nd->start = nd->end;
  66         }
  67         if (nd->end > end) {
  68                 if (!(end & 0xfff))
  69                         end--;
  70                 nd->end = end;
  71                 if (nd->start > nd->end)
  72                         nd->start = nd->end;
  73         }
  74 }
  75
  76 static __init void bad_srat(void)
  77 {
  78         printk(KERN_ERR "SRAT: SRAT not used.\n");
  79         acpi_numa = -1;
  80 }
  81
  82 static __init inline int srat_disabled(void)
  83 {
  84         return numa_off || acpi_numa < 0;
  85 }
  86
  87 /* Callback for SLIT parsing */
  88 void __init acpi_numa_slit_init(struct acpi_table_slit *slit)
  89 {
  90         acpi_slit = slit;
  91 }
  92
  93 /* Callback for Proximity Domain -> LAPIC mapping */
  94 void __init
  95 acpi_numa_processor_affinity_init(struct acpi_table_processor_affinity *pa)
  96 {
  97         int pxm, node;
  98         if (srat_disabled() || pa->flags.enabled == 0)
  99                 return;
 100         pxm = pa->proximity_domain;
 101         node = setup_node(pxm);
 102         if (node < 0) {
 103                 printk(KERN_ERR "SRAT: Too many proximity domains %x\n", pxm);
 104                 bad_srat();
 105                 return;
 106         }
 107         if (num_processors >= NR_CPUS) {
 108                 printk(KERN_ERR "SRAT: Processor #%d (lapic %u) INVALID. (Max ID: %d).\n",
 109                         num_processors, pa->apic_id, NR_CPUS);
 110                 bad_srat();
 111                 return;
 112         }
 113         cpu_to_node[num_processors] = node;
 114         acpi_numa = 1;
 115         printk(KERN_INFO "SRAT: PXM %u -> APIC %u -> CPU %u -> Node %u\n",
 116                pxm, pa->apic_id, num_processors, node);
 117
 118         num_processors++;
 119 }
 120
 121 /* Callback for parsing of the Proximity Domain <-> Memory Area mappings */
 122 void __init
 123 acpi_numa_memory_affinity_init(struct acpi_table_memory_affinity *ma)
 124 {
 125         struct node *nd;
 126         unsigned long start, end;
 127         int node, pxm;
 128         int i;
 129
 130         if (srat_disabled() || ma->flags.enabled == 0)
 131                 return;
 132         pxm = ma->proximity_domain;
 133         node = setup_node(pxm);
 134         if (node < 0) {
 135                 printk(KERN_ERR "SRAT: Too many proximity domains.\n");
 136                 bad_srat();
 137                 return;
 138         }
 139         start = ma->base_addr_lo | ((u64)ma->base_addr_hi << 32);
 140         end = start + (ma->length_lo | ((u64)ma->length_hi << 32));
 141         /* It is fine to add this area to the nodes data it will be used later*/
 142         if (ma->flags.hot_pluggable == 1)
 143                 printk(KERN_INFO "SRAT: hot plug zone found %lx - %lx \n",
 144                                 start, end);
 145         i = conflicting_nodes(start, end);
 146         if (i >= 0) {
 147                 printk(KERN_ERR
 148                        "SRAT: pxm %d overlap %lx-%lx with node %d(%Lx-%Lx)\n",
 149                        pxm, start, end, i, nodes[i].start, nodes[i].end);
 150                 bad_srat();
 151                 return;
 152         }
 153         nd = &nodes[node];
 154         if (!node_test_and_set(node, nodes_parsed)) {
 155                 nd->start = start;
 156                 nd->end = end;
 157         } else {
 158                 if (start < nd->start)
 159                         nd->start = start;
 160                 if (nd->end < end)
 161                         nd->end = end;
 162         }
 163         if (!(nd->end & 0xfff))
 164                 nd->end--;
 165         printk(KERN_INFO "SRAT: Node %u PXM %u %Lx-%Lx\n", node, pxm,
 166                nd->start, nd->end);
 167 }
 168
 169 void __init acpi_numa_arch_fixup(void) {}
 170
 171 /* Use the information discovered above to actually set up the nodes. */
 172 int __init acpi_scan_nodes(unsigned long start, unsigned long end)
 173 {
 174         int i;
 175         if (acpi_numa <= 0)
 176                 return -1;
 177         memnode_shift = compute_hash_shift(nodes, nodes_weight(nodes_parsed));
 178         if (memnode_shift < 0) {
 179                 printk(KERN_ERR
 180                      "SRAT: No NUMA node hash function found. Contact maintainer\n");
 181                 bad_srat();
 182                 return -1;
 183         }
 184         for (i = 0; i < MAX_NUMNODES; i++) {
 185                 if (!node_isset(i, nodes_parsed))
 186                         continue;
 187                 cutoff_node(i, start, end);
 188                 if (nodes[i].start == nodes[i].end) {
 189                         node_clear(i, nodes_parsed);
 190                         continue;
 191                 }
 192                 setup_node_bootmem(i, nodes[i].start, nodes[i].end);
 193         }
 194         for (i = 0; i < NR_CPUS; i++) {
 195                 if (cpu_to_node[i] == NUMA_NO_NODE)
 196                         continue;
 197                 if (!node_isset(cpu_to_node[i], nodes_parsed))
 198                         cpu_to_node[i] = NUMA_NO_NODE;
 199         }
 200         numa_init_array();
 201         return 0;
 202 }
 203
 204 int node_to_pxm(int n)
 205 {
 206        int i;
 207        if (pxm2node[n] == n)
 208                return n;
 209        for (i = 0; i < 256; i++)
 210                if (pxm2node[i] == n)
 211                        return i;
 212        return 0;
 213 }
 214
 215 int __node_distance(int a, int b)
 216 {
 217         int index;
 218
 219         if (!acpi_slit)
 220                 return a == b ? 10 : 20;
 221         index = acpi_slit->localities * node_to_pxm(a);
 222         return acpi_slit->entry[index + node_to_pxm(b)];
 223 }
 224
 225 EXPORT_SYMBOL(__node_distance);