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
 23pg_data_t *node_data[MAX_NUMNODES];
 24EXPORT_SYMBOL(node_data);
 25
 26cpumask_t node_to_cpumask_map[MAX_NUMNODES];
 27EXPORT_SYMBOL(node_to_cpumask_map);
 28
 29static void plain_setup(void)
 30{
 31	node_set(0, node_possible_map);
 32}
 33
 34const struct numa_mode numa_mode_plain = {
 35	.name = "plain",
 36	.setup = plain_setup,
 37};
 38
 39static const struct numa_mode *mode = &numa_mode_plain;
 40
 41int numa_pfn_to_nid(unsigned long pfn)
 42{
 43	return mode->__pfn_to_nid ? mode->__pfn_to_nid(pfn) : 0;
 44}
 45
 46void numa_update_cpu_topology(void)
 47{
 48	if (mode->update_cpu_topology)
 49		mode->update_cpu_topology();
 50}
 51
 52int __node_distance(int a, int b)
 53{
 54	return mode->distance ? mode->distance(a, b) : 0;
 55}
 56
 57int numa_debug_enabled;
 58
 59/*
 60 * alloc_node_data() - Allocate node data
 61 */
 62static __init pg_data_t *alloc_node_data(void)
 63{
 64	pg_data_t *res;
 65
 66	res = (pg_data_t *) memblock_alloc(sizeof(pg_data_t), 8);
 67	memset(res, 0, sizeof(pg_data_t));
 68	return res;
 69}
 70
 71/*
 72 * numa_setup_memory() - Assign bootmem to nodes
 73 *
 74 * The memory is first added to memblock without any respect to nodes.
 75 * This is fixed before remaining memblock memory is handed over to the
 76 * buddy allocator.
 77 * An important side effect is that large bootmem allocations might easily
 78 * cross node boundaries, which can be needed for large allocations with
 79 * smaller memory stripes in each node (i.e. when using NUMA emulation).
 80 *
 81 * Memory defines nodes:
 82 * Therefore this routine also sets the nodes online with memory.
 83 */
 84static void __init numa_setup_memory(void)
 85{
 86	unsigned long cur_base, align, end_of_dram;
 87	int nid = 0;
 88
 89	end_of_dram = memblock_end_of_DRAM();
 90	align = mode->align ? mode->align() : ULONG_MAX;
 91
 92	/*
 93	 * Step through all available memory and assign it to the nodes
 94	 * indicated by the mode implementation.
 95	 * All nodes which are seen here will be set online.
 96	 */
 97	cur_base = 0;
 98	do {
 99		nid = numa_pfn_to_nid(PFN_DOWN(cur_base));
100		node_set_online(nid);
101		memblock_set_node(cur_base, align, &memblock.memory, nid);
102		cur_base += align;
103	} while (cur_base < end_of_dram);
104
105	/* Allocate and fill out node_data */
106	for (nid = 0; nid < MAX_NUMNODES; nid++)
107		NODE_DATA(nid) = alloc_node_data();
108
109	for_each_online_node(nid) {
110		unsigned long start_pfn, end_pfn;
111		unsigned long t_start, t_end;
112		int i;
113
114		start_pfn = ULONG_MAX;
115		end_pfn = 0;
116		for_each_mem_pfn_range(i, nid, &t_start, &t_end, NULL) {
117			if (t_start < start_pfn)
118				start_pfn = t_start;
119			if (t_end > end_pfn)
120				end_pfn = t_end;
121		}
122		NODE_DATA(nid)->node_spanned_pages = end_pfn - start_pfn;
123		NODE_DATA(nid)->node_id = nid;
124	}
125}
126
127/*
128 * numa_setup() - Earliest initialization
129 *
130 * Assign the mode and call the mode's setup routine.
131 */
132void __init numa_setup(void)
133{
134	pr_info("NUMA mode: %s\n", mode->name);
135	nodes_clear(node_possible_map);
136	if (mode->setup)
137		mode->setup();
138	numa_setup_memory();
139	memblock_dump_all();
140}
141
142/*
143 * numa_init_early() - Initialization initcall
144 *
145 * This runs when only one CPU is online and before the first
146 * topology update is called for by the scheduler.
147 */
148static int __init numa_init_early(void)
149{
150	/* Attach all possible CPUs to node 0 for now. */
151	cpumask_copy(&node_to_cpumask_map[0], cpu_possible_mask);
152	return 0;
153}
154early_initcall(numa_init_early);
155
156/*
157 * numa_init_late() - Initialization initcall
158 *
159 * Register NUMA nodes.
160 */
161static int __init numa_init_late(void)
162{
163	int nid;
164
165	for_each_online_node(nid)
166		register_one_node(nid);
167	return 0;
168}
169arch_initcall(numa_init_late);
170
171static int __init parse_debug(char *parm)
172{
173	numa_debug_enabled = 1;
174	return 0;
175}
176early_param("numa_debug", parse_debug);
177
178static int __init parse_numa(char *parm)
179{
180	if (strcmp(parm, numa_mode_plain.name) == 0)
181		mode = &numa_mode_plain;
182#ifdef CONFIG_NUMA_EMU
183	if (strcmp(parm, numa_mode_emu.name) == 0)
184		mode = &numa_mode_emu;
185#endif
186	return 0;
187}
188early_param("numa", parse_numa);