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 #include <asm/e820.h>
  21
  22 static struct acpi_table_slit *acpi_slit;
  23
  24 static nodemask_t nodes_parsed __initdata;
  25 static nodemask_t nodes_found __initdata;
  26 static struct node nodes[MAX_NUMNODES] __initdata;
  27 static u8 pxm2node[256] = { [0 ... 255] = 0xff };
  28
  29 /* Too small nodes confuse the VM badly. Usually they result
  30    from BIOS bugs. */
  31 #define NODE_MIN_SIZE (4*1024*1024)
  32
  33 static int node_to_pxm(int n);
  34
  35 int pxm_to_node(int pxm)
  36 {
  37         if ((unsigned)pxm >= 256)
  38                 return -1;
  39         /* Extend 0xff to (int)-1 */
  40         return (signed char)pxm2node[pxm];
  41 }
  42
  43 static __init int setup_node(int pxm)
  44 {
  45         unsigned node = pxm2node[pxm];
  46         if (node == 0xff) {
  47                 if (nodes_weight(nodes_found) >= MAX_NUMNODES)
  48                         return -1;
  49                 node = first_unset_node(nodes_found);
  50                 node_set(node, nodes_found);
  51                 pxm2node[pxm] = node;
  52         }
  53         return pxm2node[pxm];
  54 }
  55
  56 static __init int conflicting_nodes(unsigned long start, unsigned long end)
  57 {
  58         int i;
  59         for_each_node_mask(i, nodes_parsed) {
  60                 struct node *nd = &nodes[i];
  61                 if (nd->start == nd->end)
  62                         continue;
  63                 if (nd->end > start && nd->start < end)
  64                         return i;
  65                 if (nd->end == end && nd->start == start)
  66                         return i;
  67         }
  68         return -1;
  69 }
  70
  71 static __init void cutoff_node(int i, unsigned long start, unsigned long end)
  72 {
  73         struct node *nd = &nodes[i];
  74         if (nd->start < start) {
  75                 nd->start = start;
  76                 if (nd->end < nd->start)
  77                         nd->start = nd->end;
  78         }
  79         if (nd->end > end) {
  80                 nd->end = end;
  81                 if (nd->start > nd->end)
  82                         nd->start = nd->end;
  83         }
  84 }
  85
  86 static __init void bad_srat(void)
  87 {
  88         int i;
  89         printk(KERN_ERR "SRAT: SRAT not used.\n");
  90         acpi_numa = -1;
  91         for (i = 0; i < MAX_LOCAL_APIC; i++)
  92                 apicid_to_node[i] = NUMA_NO_NODE;
  93 }
  94
  95 static __init inline int srat_disabled(void)
  96 {
  97         return numa_off || acpi_numa < 0;
  98 }
  99
 100 /*
 101  * A lot of BIOS fill in 10 (= no distance) everywhere. This messes
 102  * up the NUMA heuristics which wants the local node to have a smaller
 103  * distance than the others.
 104  * Do some quick checks here and only use the SLIT if it passes.
 105  */
 106 static __init int slit_valid(struct acpi_table_slit *slit)
 107 {
 108         int i, j;
 109         int d = slit->localities;
 110         for (i = 0; i < d; i++) {
 111                 for (j = 0; j < d; j++)  {
 112                         u8 val = slit->entry[d*i + j];
 113                         if (i == j) {
 114                                 if (val != 10)
 115                                         return 0;
 116                         } else if (val <= 10)
 117                                 return 0;
 118                 }
 119         }
 120         return 1;
 121 }
 122
 123 /* Callback for SLIT parsing */
 124 void __init acpi_numa_slit_init(struct acpi_table_slit *slit)
 125 {
 126         if (!slit_valid(slit)) {
 127                 printk(KERN_INFO "ACPI: SLIT table looks invalid. Not used.\n");
 128                 return;
 129         }
 130         acpi_slit = slit;
 131 }
 132
 133 /* Callback for Proximity Domain -> LAPIC mapping */
 134 void __init
 135 acpi_numa_processor_affinity_init(struct acpi_table_processor_affinity *pa)
 136 {
 137         int pxm, node;
 138         if (srat_disabled())
 139                 return;
 140         if (pa->header.length != sizeof(struct acpi_table_processor_affinity)) {                bad_srat();
 141                 return;
 142         }
 143         if (pa->flags.enabled == 0)
 144                 return;
 145         pxm = pa->proximity_domain;
 146         node = setup_node(pxm);
 147         if (node < 0) {
 148                 printk(KERN_ERR "SRAT: Too many proximity domains %x\n", pxm);
 149                 bad_srat();
 150                 return;
 151         }
 152         apicid_to_node[pa->apic_id] = node;
 153         acpi_numa = 1;
 154         printk(KERN_INFO "SRAT: PXM %u -> APIC %u -> Node %u\n",
 155                pxm, pa->apic_id, node);
 156 }
 157
 158 /* Callback for parsing of the Proximity Domain <-> Memory Area mappings */
 159 void __init
 160 acpi_numa_memory_affinity_init(struct acpi_table_memory_affinity *ma)
 161 {
 162         struct node *nd;
 163         unsigned long start, end;
 164         int node, pxm;
 165         int i;
 166
 167         if (srat_disabled())
 168                 return;
 169         if (ma->header.length != sizeof(struct acpi_table_memory_affinity)) {
 170                 bad_srat();
 171                 return;
 172         }
 173         if (ma->flags.enabled == 0)
 174                 return;
 175         start = ma->base_addr_lo | ((u64)ma->base_addr_hi << 32);
 176         end = start + (ma->length_lo | ((u64)ma->length_hi << 32));
 177         pxm = ma->proximity_domain;
 178         node = setup_node(pxm);
 179         if (node < 0) {
 180                 printk(KERN_ERR "SRAT: Too many proximity domains.\n");
 181                 bad_srat();
 182                 return;
 183         }
 184         /* It is fine to add this area to the nodes data it will be used later*/
 185         if (ma->flags.hot_pluggable == 1)
 186                 printk(KERN_INFO "SRAT: hot plug zone found %lx - %lx \n",
 187                                 start, end);
 188         i = conflicting_nodes(start, end);
 189         if (i == node) {
 190                 printk(KERN_WARNING
 191                 "SRAT: Warning: PXM %d (%lx-%lx) overlaps with itself (%Lx-%Lx)\n",
 192                         pxm, start, end, nodes[i].start, nodes[i].end);
 193         } else if (i >= 0) {
 194                 printk(KERN_ERR
 195                        "SRAT: PXM %d (%lx-%lx) overlaps with PXM %d (%Lx-%Lx)\n",
 196                        pxm, start, end, node_to_pxm(i),
 197                         nodes[i].start, nodes[i].end);
 198                 bad_srat();
 199                 return;
 200         }
 201         nd = &nodes[node];
 202         if (!node_test_and_set(node, nodes_parsed)) {
 203                 nd->start = start;
 204                 nd->end = end;
 205         } else {
 206                 if (start < nd->start)
 207                         nd->start = start;
 208                 if (nd->end < end)
 209                         nd->end = end;
 210         }
 211         printk(KERN_INFO "SRAT: Node %u PXM %u %Lx-%Lx\n", node, pxm,
 212                nd->start, nd->end);
 213 }
 214
 215 /* Sanity check to catch more bad SRATs (they are amazingly common).
 216    Make sure the PXMs cover all memory. */
 217 static int nodes_cover_memory(void)
 218 {
 219         int i;
 220         unsigned long pxmram, e820ram;
 221
 222         pxmram = 0;
 223         for_each_node_mask(i, nodes_parsed) {
 224                 unsigned long s = nodes[i].start >> PAGE_SHIFT;
 225                 unsigned long e = nodes[i].end >> PAGE_SHIFT;
 226                 pxmram += e - s;
 227                 pxmram -= e820_hole_size(s, e);
 228         }
 229
 230         e820ram = end_pfn - e820_hole_size(0, end_pfn);
 231         /* We seem to lose 3 pages somewhere. Allow a bit of slack. */
 232         if ((long)(e820ram - pxmram) >= 1*1024*1024) {
 233                 printk(KERN_ERR
 234         "SRAT: PXMs only cover %luMB of your %luMB e820 RAM. Not used.\n",
 235                         (pxmram << PAGE_SHIFT) >> 20,
 236                         (e820ram << PAGE_SHIFT) >> 20);
 237                 return 0;
 238         }
 239         return 1;
 240 }
 241
 242 static void unparse_node(int node)
 243 {
 244         int i;
 245         node_clear(node, nodes_parsed);
 246         for (i = 0; i < MAX_LOCAL_APIC; i++) {
 247                 if (apicid_to_node[i] == node)
 248                         apicid_to_node[i] = NUMA_NO_NODE;
 249         }
 250 }
 251
 252 void __init acpi_numa_arch_fixup(void) {}
 253
 254 /* Use the information discovered above to actually set up the nodes. */
 255 int __init acpi_scan_nodes(unsigned long start, unsigned long end)
 256 {
 257         int i;
 258
 259         /* First clean up the node list */
 260         for (i = 0; i < MAX_NUMNODES; i++) {
 261                 cutoff_node(i, start, end);
 262                 if ((nodes[i].end - nodes[i].start) < NODE_MIN_SIZE)
 263                         unparse_node(i);
 264         }
 265
 266         if (acpi_numa <= 0)
 267                 return -1;
 268
 269         if (!nodes_cover_memory()) {
 270                 bad_srat();
 271                 return -1;
 272         }
 273
 274         memnode_shift = compute_hash_shift(nodes, nodes_weight(nodes_parsed));
 275         if (memnode_shift < 0) {
 276                 printk(KERN_ERR
 277                      "SRAT: No NUMA node hash function found. Contact maintainer\n");
 278                 bad_srat();
 279                 return -1;
 280         }
 281
 282         /* Finally register nodes */
 283         for_each_node_mask(i, nodes_parsed)
 284                 setup_node_bootmem(i, nodes[i].start, nodes[i].end);
 285         for (i = 0; i < NR_CPUS; i++) {
 286                 if (cpu_to_node[i] == NUMA_NO_NODE)
 287                         continue;
 288                 if (!node_isset(cpu_to_node[i], nodes_parsed))
 289                         numa_set_node(i, NUMA_NO_NODE);
 290         }
 291         numa_init_array();
 292         return 0;
 293 }
 294
 295 static int node_to_pxm(int n)
 296 {
 297        int i;
 298        if (pxm2node[n] == n)
 299                return n;
 300        for (i = 0; i < 256; i++)
 301                if (pxm2node[i] == n)
 302                        return i;
 303        return 0;
 304 }
 305
 306 int __node_distance(int a, int b)
 307 {
 308         int index;
 309
 310         if (!acpi_slit)
 311                 return a == b ? 10 : 20;
 312         index = acpi_slit->localities * node_to_pxm(a);
 313         return acpi_slit->entry[index + node_to_pxm(b)];
 314 }
 315
 316 EXPORT_SYMBOL(__node_distance);