summaryrefslogtreecommitdiff
path: root/arch/s390/numa/mode_emu.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/s390/numa/mode_emu.c')
-rw-r--r--arch/s390/numa/mode_emu.c577
1 files changed, 0 insertions, 577 deletions
diff --git a/arch/s390/numa/mode_emu.c b/arch/s390/numa/mode_emu.c
deleted file mode 100644
index 72d742bb2d17..000000000000
--- a/arch/s390/numa/mode_emu.c
+++ /dev/null
@@ -1,577 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * NUMA support for s390
- *
- * NUMA emulation (aka fake NUMA) distributes the available memory to nodes
- * without using real topology information about the physical memory of the
- * machine.
- *
- * It distributes the available CPUs to nodes while respecting the original
- * machine topology information. This is done by trying to avoid to separate
- * CPUs which reside on the same book or even on the same MC.
- *
- * Because the current Linux scheduler code requires a stable cpu to node
- * mapping, cores are pinned to nodes when the first CPU thread is set online.
- *
- * Copyright IBM Corp. 2015
- */
-
-#define KMSG_COMPONENT "numa_emu"
-#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
-
-#include <linux/kernel.h>
-#include <linux/cpumask.h>
-#include <linux/memblock.h>
-#include <linux/node.h>
-#include <linux/memory.h>
-#include <linux/slab.h>
-#include <asm/smp.h>
-#include <asm/topology.h>
-#include "numa_mode.h"
-#include "toptree.h"
-
-/* Distances between the different system components */
-#define DIST_EMPTY 0
-#define DIST_CORE 1
-#define DIST_MC 2
-#define DIST_BOOK 3
-#define DIST_DRAWER 4
-#define DIST_MAX 5
-
-/* Node distance reported to common code */
-#define EMU_NODE_DIST 10
-
-/* Node ID for free (not yet pinned) cores */
-#define NODE_ID_FREE -1
-
-/* Different levels of toptree */
-enum toptree_level {CORE, MC, BOOK, DRAWER, NODE, TOPOLOGY};
-
-/* The two toptree IDs */
-enum {TOPTREE_ID_PHYS, TOPTREE_ID_NUMA};
-
-/* Number of NUMA nodes */
-static int emu_nodes = 1;
-/* NUMA stripe size */
-static unsigned long emu_size;
-
-/*
- * Node to core pinning information updates are protected by
- * "sched_domains_mutex".
- */
-static struct {
- s32 to_node_id[CONFIG_NR_CPUS]; /* Pinned core to node mapping */
- int total; /* Total number of pinned cores */
- int per_node_target; /* Cores per node without extra cores */
- int per_node[MAX_NUMNODES]; /* Number of cores pinned to node */
-} *emu_cores;
-
-/*
- * Pin a core to a node
- */
-static void pin_core_to_node(int core_id, int node_id)
-{
- if (emu_cores->to_node_id[core_id] == NODE_ID_FREE) {
- emu_cores->per_node[node_id]++;
- emu_cores->to_node_id[core_id] = node_id;
- emu_cores->total++;
- } else {
- WARN_ON(emu_cores->to_node_id[core_id] != node_id);
- }
-}
-
-/*
- * Number of pinned cores of a node
- */
-static int cores_pinned(struct toptree *node)
-{
- return emu_cores->per_node[node->id];
-}
-
-/*
- * ID of the node where the core is pinned (or NODE_ID_FREE)
- */
-static int core_pinned_to_node_id(struct toptree *core)
-{
- return emu_cores->to_node_id[core->id];
-}
-
-/*
- * Number of cores in the tree that are not yet pinned
- */
-static int cores_free(struct toptree *tree)
-{
- struct toptree *core;
- int count = 0;
-
- toptree_for_each(core, tree, CORE) {
- if (core_pinned_to_node_id(core) == NODE_ID_FREE)
- count++;
- }
- return count;
-}
-
-/*
- * Return node of core
- */
-static struct toptree *core_node(struct toptree *core)
-{
- return core->parent->parent->parent->parent;
-}
-
-/*
- * Return drawer of core
- */
-static struct toptree *core_drawer(struct toptree *core)
-{
- return core->parent->parent->parent;
-}
-
-/*
- * Return book of core
- */
-static struct toptree *core_book(struct toptree *core)
-{
- return core->parent->parent;
-}
-
-/*
- * Return mc of core
- */
-static struct toptree *core_mc(struct toptree *core)
-{
- return core->parent;
-}
-
-/*
- * Distance between two cores
- */
-static int dist_core_to_core(struct toptree *core1, struct toptree *core2)
-{
- if (core_drawer(core1)->id != core_drawer(core2)->id)
- return DIST_DRAWER;
- if (core_book(core1)->id != core_book(core2)->id)
- return DIST_BOOK;
- if (core_mc(core1)->id != core_mc(core2)->id)
- return DIST_MC;
- /* Same core or sibling on same MC */
- return DIST_CORE;
-}
-
-/*
- * Distance of a node to a core
- */
-static int dist_node_to_core(struct toptree *node, struct toptree *core)
-{
- struct toptree *core_node;
- int dist_min = DIST_MAX;
-
- toptree_for_each(core_node, node, CORE)
- dist_min = min(dist_min, dist_core_to_core(core_node, core));
- return dist_min == DIST_MAX ? DIST_EMPTY : dist_min;
-}
-
-/*
- * Unify will delete empty nodes, therefore recreate nodes.
- */
-static void toptree_unify_tree(struct toptree *tree)
-{
- int nid;
-
- toptree_unify(tree);
- for (nid = 0; nid < emu_nodes; nid++)
- toptree_get_child(tree, nid);
-}
-
-/*
- * Find the best/nearest node for a given core and ensure that no node
- * gets more than "emu_cores->per_node_target + extra" cores.
- */
-static struct toptree *node_for_core(struct toptree *numa, struct toptree *core,
- int extra)
-{
- struct toptree *node, *node_best = NULL;
- int dist_cur, dist_best, cores_target;
-
- cores_target = emu_cores->per_node_target + extra;
- dist_best = DIST_MAX;
- node_best = NULL;
- toptree_for_each(node, numa, NODE) {
- /* Already pinned cores must use their nodes */
- if (core_pinned_to_node_id(core) == node->id) {
- node_best = node;
- break;
- }
- /* Skip nodes that already have enough cores */
- if (cores_pinned(node) >= cores_target)
- continue;
- dist_cur = dist_node_to_core(node, core);
- if (dist_cur < dist_best) {
- dist_best = dist_cur;
- node_best = node;
- }
- }
- return node_best;
-}
-
-/*
- * Find the best node for each core with respect to "extra" core count
- */
-static void toptree_to_numa_single(struct toptree *numa, struct toptree *phys,
- int extra)
-{
- struct toptree *node, *core, *tmp;
-
- toptree_for_each_safe(core, tmp, phys, CORE) {
- node = node_for_core(numa, core, extra);
- if (!node)
- return;
- toptree_move(core, node);
- pin_core_to_node(core->id, node->id);
- }
-}
-
-/*
- * Move structures of given level to specified NUMA node
- */
-static void move_level_to_numa_node(struct toptree *node, struct toptree *phys,
- enum toptree_level level, bool perfect)
-{
- int cores_free, cores_target = emu_cores->per_node_target;
- struct toptree *cur, *tmp;
-
- toptree_for_each_safe(cur, tmp, phys, level) {
- cores_free = cores_target - toptree_count(node, CORE);
- if (perfect) {
- if (cores_free == toptree_count(cur, CORE))
- toptree_move(cur, node);
- } else {
- if (cores_free >= toptree_count(cur, CORE))
- toptree_move(cur, node);
- }
- }
-}
-
-/*
- * Move structures of a given level to NUMA nodes. If "perfect" is specified
- * move only perfectly fitting structures. Otherwise move also smaller
- * than needed structures.
- */
-static void move_level_to_numa(struct toptree *numa, struct toptree *phys,
- enum toptree_level level, bool perfect)
-{
- struct toptree *node;
-
- toptree_for_each(node, numa, NODE)
- move_level_to_numa_node(node, phys, level, perfect);
-}
-
-/*
- * For the first run try to move the big structures
- */
-static void toptree_to_numa_first(struct toptree *numa, struct toptree *phys)
-{
- struct toptree *core;
-
- /* Always try to move perfectly fitting structures first */
- move_level_to_numa(numa, phys, DRAWER, true);
- move_level_to_numa(numa, phys, DRAWER, false);
- move_level_to_numa(numa, phys, BOOK, true);
- move_level_to_numa(numa, phys, BOOK, false);
- move_level_to_numa(numa, phys, MC, true);
- move_level_to_numa(numa, phys, MC, false);
- /* Now pin all the moved cores */
- toptree_for_each(core, numa, CORE)
- pin_core_to_node(core->id, core_node(core)->id);
-}
-
-/*
- * Allocate new topology and create required nodes
- */
-static struct toptree *toptree_new(int id, int nodes)
-{
- struct toptree *tree;
- int nid;
-
- tree = toptree_alloc(TOPOLOGY, id);
- if (!tree)
- goto fail;
- for (nid = 0; nid < nodes; nid++) {
- if (!toptree_get_child(tree, nid))
- goto fail;
- }
- return tree;
-fail:
- panic("NUMA emulation could not allocate topology");
-}
-
-/*
- * Allocate and initialize core to node mapping
- */
-static void __ref create_core_to_node_map(void)
-{
- int i;
-
- emu_cores = memblock_alloc(sizeof(*emu_cores), 8);
- if (!emu_cores)
- panic("%s: Failed to allocate %zu bytes align=0x%x\n",
- __func__, sizeof(*emu_cores), 8);
- for (i = 0; i < ARRAY_SIZE(emu_cores->to_node_id); i++)
- emu_cores->to_node_id[i] = NODE_ID_FREE;
-}
-
-/*
- * Move cores from physical topology into NUMA target topology
- * and try to keep as much of the physical topology as possible.
- */
-static struct toptree *toptree_to_numa(struct toptree *phys)
-{
- static int first = 1;
- struct toptree *numa;
- int cores_total;
-
- cores_total = emu_cores->total + cores_free(phys);
- emu_cores->per_node_target = cores_total / emu_nodes;
- numa = toptree_new(TOPTREE_ID_NUMA, emu_nodes);
- if (first) {
- toptree_to_numa_first(numa, phys);
- first = 0;
- }
- toptree_to_numa_single(numa, phys, 0);
- toptree_to_numa_single(numa, phys, 1);
- toptree_unify_tree(numa);
-
- WARN_ON(cpumask_weight(&phys->mask));
- return numa;
-}
-
-/*
- * Create a toptree out of the physical topology that we got from the hypervisor
- */
-static struct toptree *toptree_from_topology(void)
-{
- struct toptree *phys, *node, *drawer, *book, *mc, *core;
- struct cpu_topology_s390 *top;
- int cpu;
-
- phys = toptree_new(TOPTREE_ID_PHYS, 1);
-
- for_each_cpu(cpu, &cpus_with_topology) {
- top = &cpu_topology[cpu];
- node = toptree_get_child(phys, 0);
- drawer = toptree_get_child(node, top->drawer_id);
- book = toptree_get_child(drawer, top->book_id);
- mc = toptree_get_child(book, top->socket_id);
- core = toptree_get_child(mc, smp_get_base_cpu(cpu));
- if (!drawer || !book || !mc || !core)
- panic("NUMA emulation could not allocate memory");
- cpumask_set_cpu(cpu, &core->mask);
- toptree_update_mask(mc);
- }
- return phys;
-}
-
-/*
- * Add toptree core to topology and create correct CPU masks
- */
-static void topology_add_core(struct toptree *core)
-{
- struct cpu_topology_s390 *top;
- int cpu;
-
- for_each_cpu(cpu, &core->mask) {
- top = &cpu_topology[cpu];
- cpumask_copy(&top->thread_mask, &core->mask);
- cpumask_copy(&top->core_mask, &core_mc(core)->mask);
- cpumask_copy(&top->book_mask, &core_book(core)->mask);
- cpumask_copy(&top->drawer_mask, &core_drawer(core)->mask);
- cpumask_set_cpu(cpu, &node_to_cpumask_map[core_node(core)->id]);
- top->node_id = core_node(core)->id;
- }
-}
-
-/*
- * Apply toptree to topology and create CPU masks
- */
-static void toptree_to_topology(struct toptree *numa)
-{
- struct toptree *core;
- int i;
-
- /* Clear all node masks */
- for (i = 0; i < MAX_NUMNODES; i++)
- cpumask_clear(&node_to_cpumask_map[i]);
-
- /* Rebuild all masks */
- toptree_for_each(core, numa, CORE)
- topology_add_core(core);
-}
-
-/*
- * Show the node to core mapping
- */
-static void print_node_to_core_map(void)
-{
- int nid, cid;
-
- if (!numa_debug_enabled)
- return;
- printk(KERN_DEBUG "NUMA node to core mapping\n");
- for (nid = 0; nid < emu_nodes; nid++) {
- printk(KERN_DEBUG " node %3d: ", nid);
- for (cid = 0; cid < ARRAY_SIZE(emu_cores->to_node_id); cid++) {
- if (emu_cores->to_node_id[cid] == nid)
- printk(KERN_CONT "%d ", cid);
- }
- printk(KERN_CONT "\n");
- }
-}
-
-static void pin_all_possible_cpus(void)
-{
- int core_id, node_id, cpu;
- static int initialized;
-
- if (initialized)
- return;
- print_node_to_core_map();
- node_id = 0;
- for_each_possible_cpu(cpu) {
- core_id = smp_get_base_cpu(cpu);
- if (emu_cores->to_node_id[core_id] != NODE_ID_FREE)
- continue;
- pin_core_to_node(core_id, node_id);
- cpu_topology[cpu].node_id = node_id;
- node_id = (node_id + 1) % emu_nodes;
- }
- print_node_to_core_map();
- initialized = 1;
-}
-
-/*
- * Transfer physical topology into a NUMA topology and modify CPU masks
- * according to the NUMA topology.
- *
- * Must be called with "sched_domains_mutex" lock held.
- */
-static void emu_update_cpu_topology(void)
-{
- struct toptree *phys, *numa;
-
- if (emu_cores == NULL)
- create_core_to_node_map();
- phys = toptree_from_topology();
- numa = toptree_to_numa(phys);
- toptree_free(phys);
- toptree_to_topology(numa);
- toptree_free(numa);
- pin_all_possible_cpus();
-}
-
-/*
- * If emu_size is not set, use CONFIG_EMU_SIZE. Then round to minimum
- * alignment (needed for memory hotplug).
- */
-static unsigned long emu_setup_size_adjust(unsigned long size)
-{
- unsigned long size_new;
-
- size = size ? : CONFIG_EMU_SIZE;
- size_new = roundup(size, memory_block_size_bytes());
- if (size_new == size)
- return size;
- pr_warn("Increasing memory stripe size from %ld MB to %ld MB\n",
- size >> 20, size_new >> 20);
- return size_new;
-}
-
-/*
- * If we have not enough memory for the specified nodes, reduce the node count.
- */
-static int emu_setup_nodes_adjust(int nodes)
-{
- int nodes_max;
-
- nodes_max = memblock.memory.total_size / emu_size;
- nodes_max = max(nodes_max, 1);
- if (nodes_max >= nodes)
- return nodes;
- pr_warn("Not enough memory for %d nodes, reducing node count\n", nodes);
- return nodes_max;
-}
-
-/*
- * Early emu setup
- */
-static void emu_setup(void)
-{
- int nid;
-
- emu_size = emu_setup_size_adjust(emu_size);
- emu_nodes = emu_setup_nodes_adjust(emu_nodes);
- for (nid = 0; nid < emu_nodes; nid++)
- node_set(nid, node_possible_map);
- pr_info("Creating %d nodes with memory stripe size %ld MB\n",
- emu_nodes, emu_size >> 20);
-}
-
-/*
- * Return node id for given page number
- */
-static int emu_pfn_to_nid(unsigned long pfn)
-{
- return (pfn / (emu_size >> PAGE_SHIFT)) % emu_nodes;
-}
-
-/*
- * Return stripe size
- */
-static unsigned long emu_align(void)
-{
- return emu_size;
-}
-
-/*
- * Return distance between two nodes
- */
-static int emu_distance(int node1, int node2)
-{
- return (node1 != node2) * EMU_NODE_DIST;
-}
-
-/*
- * Define callbacks for generic s390 NUMA infrastructure
- */
-const struct numa_mode numa_mode_emu = {
- .name = "emu",
- .setup = emu_setup,
- .update_cpu_topology = emu_update_cpu_topology,
- .__pfn_to_nid = emu_pfn_to_nid,
- .align = emu_align,
- .distance = emu_distance,
-};
-
-/*
- * Kernel parameter: emu_nodes=<n>
- */
-static int __init early_parse_emu_nodes(char *p)
-{
- int count;
-
- if (!p || kstrtoint(p, 0, &count) != 0 || count <= 0)
- return 0;
- emu_nodes = min(count, MAX_NUMNODES);
- return 0;
-}
-early_param("emu_nodes", early_parse_emu_nodes);
-
-/*
- * Kernel parameter: emu_size=[<n>[k|M|G|T]]
- */
-static int __init early_parse_emu_size(char *p)
-{
- if (p)
- emu_size = memparse(p, NULL);
- return 0;
-}
-early_param("emu_size", early_parse_emu_size);