arch/s390/numa/numa.c

   1 /*
   2  * NUMA support for s390
   3  *
   4  * Implement NUMA core code.
   5  *
   6  * Copyright IBM Corp. 2015
   7  */
   8
   9 #define KMSG_COMPONENT "numa"
  10 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  11
  12 #include <linux/kernel.h>
  13 #include <linux/mmzone.h>
  14 #include <linux/cpumask.h>
  15 #include <linux/bootmem.h>
  16 #include <linux/memblock.h>
  17 #include <linux/slab.h>
  18 #include <linux/node.h>
  19
  20 #include <asm/numa.h>
  21 #include "numa_mode.h"
  22
  23 pg_data_t *node_data[MAX_NUMNODES];
  24 EXPORT_SYMBOL(node_data);
  25
  26 cpumask_t node_to_cpumask_map[MAX_NUMNODES];
  27 EXPORT_SYMBOL(node_to_cpumask_map);
  28
  29 const struct numa_mode numa_mode_plain = {
  30         .name = "plain",
  31 };
  32
  33 static const struct numa_mode *mode = &numa_mode_plain;
  34
  35 int numa_pfn_to_nid(unsigned long pfn)
  36 {
  37         return mode->__pfn_to_nid ? mode->__pfn_to_nid(pfn) : 0;
  38 }
  39
  40 void numa_update_cpu_topology(void)
  41 {
  42         if (mode->update_cpu_topology)
  43                 mode->update_cpu_topology();
  44 }
  45
  46 int __node_distance(int a, int b)
  47 {
  48         return mode->distance ? mode->distance(a, b) : 0;
  49 }
  50
  51 int numa_debug_enabled;
  52
  53 /*
  54  * alloc_node_data() - Allocate node data
  55  */
  56 static __init pg_data_t *alloc_node_data(void)
  57 {
  58         pg_data_t *res;
  59
  60         res = (pg_data_t *) memblock_alloc(sizeof(pg_data_t), 8);
  61         memset(res, 0, sizeof(pg_data_t));
  62         return res;
  63 }
  64
  65 /*
  66  * numa_setup_memory() - Assign bootmem to nodes
  67  *
  68  * The memory is first added to memblock without any respect to nodes.
  69  * This is fixed before remaining memblock memory is handed over to the
  70  * buddy allocator.
  71  * An important side effect is that large bootmem allocations might easily
  72  * cross node boundaries, which can be needed for large allocations with
  73  * smaller memory stripes in each node (i.e. when using NUMA emulation).
  74  *
  75  * Memory defines nodes:
  76  * Therefore this routine also sets the nodes online with memory.
  77  */
  78 static void __init numa_setup_memory(void)
  79 {
  80         unsigned long cur_base, align, end_of_dram;
  81         int nid = 0;
  82
  83         end_of_dram = memblock_end_of_DRAM();
  84         align = mode->align ? mode->align() : ULONG_MAX;
  85
  86         /*
  87          * Step through all available memory and assign it to the nodes
  88          * indicated by the mode implementation.
  89          * All nodes which are seen here will be set online.
  90          */
  91         cur_base = 0;
  92         do {
  93                 nid = numa_pfn_to_nid(PFN_DOWN(cur_base));
  94                 node_set_online(nid);
  95                 memblock_set_node(cur_base, align, &memblock.memory, nid);
  96                 cur_base += align;
  97         } while (cur_base < end_of_dram);
  98
  99         /* Allocate and fill out node_data */
 100         for (nid = 0; nid < MAX_NUMNODES; nid++)
 101                 NODE_DATA(nid) = alloc_node_data();
 102
 103         for_each_online_node(nid) {
 104                 unsigned long start_pfn, end_pfn;
 105                 unsigned long t_start, t_end;
 106                 int i;
 107
 108                 start_pfn = ULONG_MAX;
 109                 end_pfn = 0;
 110                 for_each_mem_pfn_range(i, nid, &t_start, &t_end, NULL) {
 111                         if (t_start < start_pfn)
 112                                 start_pfn = t_start;
 113                         if (t_end > end_pfn)
 114                                 end_pfn = t_end;
 115                 }
 116                 NODE_DATA(nid)->node_spanned_pages = end_pfn - start_pfn;
 117                 NODE_DATA(nid)->node_id = nid;
 118         }
 119 }
 120
 121 /*
 122  * numa_setup() - Earliest initialization
 123  *
 124  * Assign the mode and call the mode's setup routine.
 125  */
 126 void __init numa_setup(void)
 127 {
 128         pr_info("NUMA mode: %s\n", mode->name);
 129         if (mode->setup)
 130                 mode->setup();
 131         numa_setup_memory();
 132         memblock_dump_all();
 133 }
 134
 135
 136 /*
 137  * numa_init_early() - Initialization initcall
 138  *
 139  * This runs when only one CPU is online and before the first
 140  * topology update is called for by the scheduler.
 141  */
 142 static int __init numa_init_early(void)
 143 {
 144         /* Attach all possible CPUs to node 0 for now. */
 145         cpumask_copy(&node_to_cpumask_map[0], cpu_possible_mask);
 146         return 0;
 147 }
 148 early_initcall(numa_init_early);
 149
 150 /*
 151  * numa_init_late() - Initialization initcall
 152  *
 153  * Register NUMA nodes.
 154  */
 155 static int __init numa_init_late(void)
 156 {
 157         int nid;
 158
 159         for_each_online_node(nid)
 160                 register_one_node(nid);
 161         return 0;
 162 }
 163 arch_initcall(numa_init_late);
 164
 165 static int __init parse_debug(char *parm)
 166 {
 167         numa_debug_enabled = 1;
 168         return 0;
 169 }
 170 early_param("numa_debug", parse_debug);
 171
 172 static int __init parse_numa(char *parm)
 173 {
 174         if (strcmp(parm, numa_mode_plain.name) == 0)
 175                 mode = &numa_mode_plain;
 176 #ifdef CONFIG_NUMA_EMU
 177         if (strcmp(parm, numa_mode_emu.name) == 0)
 178                 mode = &numa_mode_emu;
 179 #endif
 180         return 0;
 181 }
 182 early_param("numa", parse_numa);