linux/linux-5.4.31/arch/powerpc/mm/numa.c

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2024-01-30 10:43:28 +00:00
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* pSeries NUMA support
*
* Copyright (C) 2002 Anton Blanchard <anton@au.ibm.com>, IBM
*/
#define pr_fmt(fmt) "numa: " fmt
#include <linux/threads.h>
#include <linux/memblock.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/mmzone.h>
#include <linux/export.h>
#include <linux/nodemask.h>
#include <linux/cpu.h>
#include <linux/notifier.h>
#include <linux/of.h>
#include <linux/pfn.h>
#include <linux/cpuset.h>
#include <linux/node.h>
#include <linux/stop_machine.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/uaccess.h>
#include <linux/slab.h>
#include <asm/cputhreads.h>
#include <asm/sparsemem.h>
#include <asm/prom.h>
#include <asm/smp.h>
#include <asm/topology.h>
#include <asm/firmware.h>
#include <asm/paca.h>
#include <asm/hvcall.h>
#include <asm/setup.h>
#include <asm/vdso.h>
#include <asm/drmem.h>
static int numa_enabled = 1;
static char *cmdline __initdata;
static int numa_debug;
#define dbg(args...) if (numa_debug) { printk(KERN_INFO args); }
int numa_cpu_lookup_table[NR_CPUS];
cpumask_var_t node_to_cpumask_map[MAX_NUMNODES];
struct pglist_data *node_data[MAX_NUMNODES];
EXPORT_SYMBOL(numa_cpu_lookup_table);
EXPORT_SYMBOL(node_to_cpumask_map);
EXPORT_SYMBOL(node_data);
static int min_common_depth;
static int n_mem_addr_cells, n_mem_size_cells;
static int form1_affinity;
#define MAX_DISTANCE_REF_POINTS 4
static int distance_ref_points_depth;
static const __be32 *distance_ref_points;
static int distance_lookup_table[MAX_NUMNODES][MAX_DISTANCE_REF_POINTS];
/*
* Allocate node_to_cpumask_map based on number of available nodes
* Requires node_possible_map to be valid.
*
* Note: cpumask_of_node() is not valid until after this is done.
*/
static void __init setup_node_to_cpumask_map(void)
{
unsigned int node;
/* setup nr_node_ids if not done yet */
if (nr_node_ids == MAX_NUMNODES)
setup_nr_node_ids();
/* allocate the map */
for_each_node(node)
alloc_bootmem_cpumask_var(&node_to_cpumask_map[node]);
/* cpumask_of_node() will now work */
dbg("Node to cpumask map for %u nodes\n", nr_node_ids);
}
static int __init fake_numa_create_new_node(unsigned long end_pfn,
unsigned int *nid)
{
unsigned long long mem;
char *p = cmdline;
static unsigned int fake_nid;
static unsigned long long curr_boundary;
/*
* Modify node id, iff we started creating NUMA nodes
* We want to continue from where we left of the last time
*/
if (fake_nid)
*nid = fake_nid;
/*
* In case there are no more arguments to parse, the
* node_id should be the same as the last fake node id
* (we've handled this above).
*/
if (!p)
return 0;
mem = memparse(p, &p);
if (!mem)
return 0;
if (mem < curr_boundary)
return 0;
curr_boundary = mem;
if ((end_pfn << PAGE_SHIFT) > mem) {
/*
* Skip commas and spaces
*/
while (*p == ',' || *p == ' ' || *p == '\t')
p++;
cmdline = p;
fake_nid++;
*nid = fake_nid;
dbg("created new fake_node with id %d\n", fake_nid);
return 1;
}
return 0;
}
static void reset_numa_cpu_lookup_table(void)
{
unsigned int cpu;
for_each_possible_cpu(cpu)
numa_cpu_lookup_table[cpu] = -1;
}
static void map_cpu_to_node(int cpu, int node)
{
update_numa_cpu_lookup_table(cpu, node);
dbg("adding cpu %d to node %d\n", cpu, node);
if (!(cpumask_test_cpu(cpu, node_to_cpumask_map[node])))
cpumask_set_cpu(cpu, node_to_cpumask_map[node]);
}
#if defined(CONFIG_HOTPLUG_CPU) || defined(CONFIG_PPC_SPLPAR)
static void unmap_cpu_from_node(unsigned long cpu)
{
int node = numa_cpu_lookup_table[cpu];
dbg("removing cpu %lu from node %d\n", cpu, node);
if (cpumask_test_cpu(cpu, node_to_cpumask_map[node])) {
cpumask_clear_cpu(cpu, node_to_cpumask_map[node]);
} else {
printk(KERN_ERR "WARNING: cpu %lu not found in node %d\n",
cpu, node);
}
}
#endif /* CONFIG_HOTPLUG_CPU || CONFIG_PPC_SPLPAR */
int cpu_distance(__be32 *cpu1_assoc, __be32 *cpu2_assoc)
{
int dist = 0;
int i, index;
for (i = 0; i < distance_ref_points_depth; i++) {
index = be32_to_cpu(distance_ref_points[i]);
if (cpu1_assoc[index] == cpu2_assoc[index])
break;
dist++;
}
return dist;
}
/* must hold reference to node during call */
static const __be32 *of_get_associativity(struct device_node *dev)
{
return of_get_property(dev, "ibm,associativity", NULL);
}
int __node_distance(int a, int b)
{
int i;
int distance = LOCAL_DISTANCE;
if (!form1_affinity)
return ((a == b) ? LOCAL_DISTANCE : REMOTE_DISTANCE);
for (i = 0; i < distance_ref_points_depth; i++) {
if (distance_lookup_table[a][i] == distance_lookup_table[b][i])
break;
/* Double the distance for each NUMA level */
distance *= 2;
}
return distance;
}
EXPORT_SYMBOL(__node_distance);
static void initialize_distance_lookup_table(int nid,
const __be32 *associativity)
{
int i;
if (!form1_affinity)
return;
for (i = 0; i < distance_ref_points_depth; i++) {
const __be32 *entry;
entry = &associativity[be32_to_cpu(distance_ref_points[i]) - 1];
distance_lookup_table[nid][i] = of_read_number(entry, 1);
}
}
/* Returns nid in the range [0..MAX_NUMNODES-1], or -1 if no useful numa
* info is found.
*/
static int associativity_to_nid(const __be32 *associativity)
{
int nid = NUMA_NO_NODE;
if (!numa_enabled)
goto out;
if (of_read_number(associativity, 1) >= min_common_depth)
nid = of_read_number(&associativity[min_common_depth], 1);
/* POWER4 LPAR uses 0xffff as invalid node */
if (nid == 0xffff || nid >= MAX_NUMNODES)
nid = NUMA_NO_NODE;
if (nid > 0 &&
of_read_number(associativity, 1) >= distance_ref_points_depth) {
/*
* Skip the length field and send start of associativity array
*/
initialize_distance_lookup_table(nid, associativity + 1);
}
out:
return nid;
}
/* Returns the nid associated with the given device tree node,
* or -1 if not found.
*/
static int of_node_to_nid_single(struct device_node *device)
{
int nid = NUMA_NO_NODE;
const __be32 *tmp;
tmp = of_get_associativity(device);
if (tmp)
nid = associativity_to_nid(tmp);
return nid;
}
/* Walk the device tree upwards, looking for an associativity id */
int of_node_to_nid(struct device_node *device)
{
int nid = NUMA_NO_NODE;
of_node_get(device);
while (device) {
nid = of_node_to_nid_single(device);
if (nid != -1)
break;
device = of_get_next_parent(device);
}
of_node_put(device);
return nid;
}
EXPORT_SYMBOL(of_node_to_nid);
static int __init find_min_common_depth(void)
{
int depth;
struct device_node *root;
if (firmware_has_feature(FW_FEATURE_OPAL))
root = of_find_node_by_path("/ibm,opal");
else
root = of_find_node_by_path("/rtas");
if (!root)
root = of_find_node_by_path("/");
/*
* This property is a set of 32-bit integers, each representing
* an index into the ibm,associativity nodes.
*
* With form 0 affinity the first integer is for an SMP configuration
* (should be all 0's) and the second is for a normal NUMA
* configuration. We have only one level of NUMA.
*
* With form 1 affinity the first integer is the most significant
* NUMA boundary and the following are progressively less significant
* boundaries. There can be more than one level of NUMA.
*/
distance_ref_points = of_get_property(root,
"ibm,associativity-reference-points",
&distance_ref_points_depth);
if (!distance_ref_points) {
dbg("NUMA: ibm,associativity-reference-points not found.\n");
goto err;
}
distance_ref_points_depth /= sizeof(int);
if (firmware_has_feature(FW_FEATURE_OPAL) ||
firmware_has_feature(FW_FEATURE_TYPE1_AFFINITY)) {
dbg("Using form 1 affinity\n");
form1_affinity = 1;
}
if (form1_affinity) {
depth = of_read_number(distance_ref_points, 1);
} else {
if (distance_ref_points_depth < 2) {
printk(KERN_WARNING "NUMA: "
"short ibm,associativity-reference-points\n");
goto err;
}
depth = of_read_number(&distance_ref_points[1], 1);
}
/*
* Warn and cap if the hardware supports more than
* MAX_DISTANCE_REF_POINTS domains.
*/
if (distance_ref_points_depth > MAX_DISTANCE_REF_POINTS) {
printk(KERN_WARNING "NUMA: distance array capped at "
"%d entries\n", MAX_DISTANCE_REF_POINTS);
distance_ref_points_depth = MAX_DISTANCE_REF_POINTS;
}
of_node_put(root);
return depth;
err:
of_node_put(root);
return -1;
}
static void __init get_n_mem_cells(int *n_addr_cells, int *n_size_cells)
{
struct device_node *memory = NULL;
memory = of_find_node_by_type(memory, "memory");
if (!memory)
panic("numa.c: No memory nodes found!");
*n_addr_cells = of_n_addr_cells(memory);
*n_size_cells = of_n_size_cells(memory);
of_node_put(memory);
}
static unsigned long read_n_cells(int n, const __be32 **buf)
{
unsigned long result = 0;
while (n--) {
result = (result << 32) | of_read_number(*buf, 1);
(*buf)++;
}
return result;
}
struct assoc_arrays {
u32 n_arrays;
u32 array_sz;
const __be32 *arrays;
};
/*
* Retrieve and validate the list of associativity arrays for drconf
* memory from the ibm,associativity-lookup-arrays property of the
* device tree..
*
* The layout of the ibm,associativity-lookup-arrays property is a number N
* indicating the number of associativity arrays, followed by a number M
* indicating the size of each associativity array, followed by a list
* of N associativity arrays.
*/
static int of_get_assoc_arrays(struct assoc_arrays *aa)
{
struct device_node *memory;
const __be32 *prop;
u32 len;
memory = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
if (!memory)
return -1;
prop = of_get_property(memory, "ibm,associativity-lookup-arrays", &len);
if (!prop || len < 2 * sizeof(unsigned int)) {
of_node_put(memory);
return -1;
}
aa->n_arrays = of_read_number(prop++, 1);
aa->array_sz = of_read_number(prop++, 1);
of_node_put(memory);
/* Now that we know the number of arrays and size of each array,
* revalidate the size of the property read in.
*/
if (len < (aa->n_arrays * aa->array_sz + 2) * sizeof(unsigned int))
return -1;
aa->arrays = prop;
return 0;
}
/*
* This is like of_node_to_nid_single() for memory represented in the
* ibm,dynamic-reconfiguration-memory node.
*/
static int of_drconf_to_nid_single(struct drmem_lmb *lmb)
{
struct assoc_arrays aa = { .arrays = NULL };
int default_nid = NUMA_NO_NODE;
int nid = default_nid;
int rc, index;
if ((min_common_depth < 0) || !numa_enabled)
return default_nid;
rc = of_get_assoc_arrays(&aa);
if (rc)
return default_nid;
if (min_common_depth <= aa.array_sz &&
!(lmb->flags & DRCONF_MEM_AI_INVALID) && lmb->aa_index < aa.n_arrays) {
index = lmb->aa_index * aa.array_sz + min_common_depth - 1;
nid = of_read_number(&aa.arrays[index], 1);
if (nid == 0xffff || nid >= MAX_NUMNODES)
nid = default_nid;
if (nid > 0) {
index = lmb->aa_index * aa.array_sz;
initialize_distance_lookup_table(nid,
&aa.arrays[index]);
}
}
return nid;
}
/*
* Figure out to which domain a cpu belongs and stick it there.
* Return the id of the domain used.
*/
static int numa_setup_cpu(unsigned long lcpu)
{
int nid = NUMA_NO_NODE;
struct device_node *cpu;
/*
* If a valid cpu-to-node mapping is already available, use it
* directly instead of querying the firmware, since it represents
* the most recent mapping notified to us by the platform (eg: VPHN).
*/
if ((nid = numa_cpu_lookup_table[lcpu]) >= 0) {
map_cpu_to_node(lcpu, nid);
return nid;
}
cpu = of_get_cpu_node(lcpu, NULL);
if (!cpu) {
WARN_ON(1);
if (cpu_present(lcpu))
goto out_present;
else
goto out;
}
nid = of_node_to_nid_single(cpu);
out_present:
if (nid < 0 || !node_possible(nid))
nid = first_online_node;
map_cpu_to_node(lcpu, nid);
of_node_put(cpu);
out:
return nid;
}
static void verify_cpu_node_mapping(int cpu, int node)
{
int base, sibling, i;
/* Verify that all the threads in the core belong to the same node */
base = cpu_first_thread_sibling(cpu);
for (i = 0; i < threads_per_core; i++) {
sibling = base + i;
if (sibling == cpu || cpu_is_offline(sibling))
continue;
if (cpu_to_node(sibling) != node) {
WARN(1, "CPU thread siblings %d and %d don't belong"
" to the same node!\n", cpu, sibling);
break;
}
}
}
/* Must run before sched domains notifier. */
static int ppc_numa_cpu_prepare(unsigned int cpu)
{
int nid;
nid = numa_setup_cpu(cpu);
verify_cpu_node_mapping(cpu, nid);
return 0;
}
static int ppc_numa_cpu_dead(unsigned int cpu)
{
#ifdef CONFIG_HOTPLUG_CPU
unmap_cpu_from_node(cpu);
#endif
return 0;
}
/*
* Check and possibly modify a memory region to enforce the memory limit.
*
* Returns the size the region should have to enforce the memory limit.
* This will either be the original value of size, a truncated value,
* or zero. If the returned value of size is 0 the region should be
* discarded as it lies wholly above the memory limit.
*/
static unsigned long __init numa_enforce_memory_limit(unsigned long start,
unsigned long size)
{
/*
* We use memblock_end_of_DRAM() in here instead of memory_limit because
* we've already adjusted it for the limit and it takes care of
* having memory holes below the limit. Also, in the case of
* iommu_is_off, memory_limit is not set but is implicitly enforced.
*/
if (start + size <= memblock_end_of_DRAM())
return size;
if (start >= memblock_end_of_DRAM())
return 0;
return memblock_end_of_DRAM() - start;
}
/*
* Reads the counter for a given entry in
* linux,drconf-usable-memory property
*/
static inline int __init read_usm_ranges(const __be32 **usm)
{
/*
* For each lmb in ibm,dynamic-memory a corresponding
* entry in linux,drconf-usable-memory property contains
* a counter followed by that many (base, size) duple.
* read the counter from linux,drconf-usable-memory
*/
return read_n_cells(n_mem_size_cells, usm);
}
/*
* Extract NUMA information from the ibm,dynamic-reconfiguration-memory
* node. This assumes n_mem_{addr,size}_cells have been set.
*/
static void __init numa_setup_drmem_lmb(struct drmem_lmb *lmb,
const __be32 **usm)
{
unsigned int ranges, is_kexec_kdump = 0;
unsigned long base, size, sz;
int nid;
/*
* Skip this block if the reserved bit is set in flags (0x80)
* or if the block is not assigned to this partition (0x8)
*/
if ((lmb->flags & DRCONF_MEM_RESERVED)
|| !(lmb->flags & DRCONF_MEM_ASSIGNED))
return;
if (*usm)
is_kexec_kdump = 1;
base = lmb->base_addr;
size = drmem_lmb_size();
ranges = 1;
if (is_kexec_kdump) {
ranges = read_usm_ranges(usm);
if (!ranges) /* there are no (base, size) duple */
return;
}
do {
if (is_kexec_kdump) {
base = read_n_cells(n_mem_addr_cells, usm);
size = read_n_cells(n_mem_size_cells, usm);
}
nid = of_drconf_to_nid_single(lmb);
fake_numa_create_new_node(((base + size) >> PAGE_SHIFT),
&nid);
node_set_online(nid);
sz = numa_enforce_memory_limit(base, size);
if (sz)
memblock_set_node(base, sz, &memblock.memory, nid);
} while (--ranges);
}
static int __init parse_numa_properties(void)
{
struct device_node *memory;
int default_nid = 0;
unsigned long i;
if (numa_enabled == 0) {
printk(KERN_WARNING "NUMA disabled by user\n");
return -1;
}
min_common_depth = find_min_common_depth();
if (min_common_depth < 0) {
/*
* if we fail to parse min_common_depth from device tree
* mark the numa disabled, boot with numa disabled.
*/
numa_enabled = false;
return min_common_depth;
}
dbg("NUMA associativity depth for CPU/Memory: %d\n", min_common_depth);
/*
* Even though we connect cpus to numa domains later in SMP
* init, we need to know the node ids now. This is because
* each node to be onlined must have NODE_DATA etc backing it.
*/
for_each_present_cpu(i) {
struct device_node *cpu;
int nid;
cpu = of_get_cpu_node(i, NULL);
BUG_ON(!cpu);
nid = of_node_to_nid_single(cpu);
of_node_put(cpu);
/*
* Don't fall back to default_nid yet -- we will plug
* cpus into nodes once the memory scan has discovered
* the topology.
*/
if (nid < 0)
continue;
node_set_online(nid);
}
get_n_mem_cells(&n_mem_addr_cells, &n_mem_size_cells);
for_each_node_by_type(memory, "memory") {
unsigned long start;
unsigned long size;
int nid;
int ranges;
const __be32 *memcell_buf;
unsigned int len;
memcell_buf = of_get_property(memory,
"linux,usable-memory", &len);
if (!memcell_buf || len <= 0)
memcell_buf = of_get_property(memory, "reg", &len);
if (!memcell_buf || len <= 0)
continue;
/* ranges in cell */
ranges = (len >> 2) / (n_mem_addr_cells + n_mem_size_cells);
new_range:
/* these are order-sensitive, and modify the buffer pointer */
start = read_n_cells(n_mem_addr_cells, &memcell_buf);
size = read_n_cells(n_mem_size_cells, &memcell_buf);
/*
* Assumption: either all memory nodes or none will
* have associativity properties. If none, then
* everything goes to default_nid.
*/
nid = of_node_to_nid_single(memory);
if (nid < 0)
nid = default_nid;
fake_numa_create_new_node(((start + size) >> PAGE_SHIFT), &nid);
node_set_online(nid);
size = numa_enforce_memory_limit(start, size);
if (size)
memblock_set_node(start, size, &memblock.memory, nid);
if (--ranges)
goto new_range;
}
/*
* Now do the same thing for each MEMBLOCK listed in the
* ibm,dynamic-memory property in the
* ibm,dynamic-reconfiguration-memory node.
*/
memory = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
if (memory) {
walk_drmem_lmbs(memory, numa_setup_drmem_lmb);
of_node_put(memory);
}
return 0;
}
static void __init setup_nonnuma(void)
{
unsigned long top_of_ram = memblock_end_of_DRAM();
unsigned long total_ram = memblock_phys_mem_size();
unsigned long start_pfn, end_pfn;
unsigned int nid = 0;
struct memblock_region *reg;
printk(KERN_DEBUG "Top of RAM: 0x%lx, Total RAM: 0x%lx\n",
top_of_ram, total_ram);
printk(KERN_DEBUG "Memory hole size: %ldMB\n",
(top_of_ram - total_ram) >> 20);
for_each_memblock(memory, reg) {
start_pfn = memblock_region_memory_base_pfn(reg);
end_pfn = memblock_region_memory_end_pfn(reg);
fake_numa_create_new_node(end_pfn, &nid);
memblock_set_node(PFN_PHYS(start_pfn),
PFN_PHYS(end_pfn - start_pfn),
&memblock.memory, nid);
node_set_online(nid);
}
}
void __init dump_numa_cpu_topology(void)
{
unsigned int node;
unsigned int cpu, count;
if (!numa_enabled)
return;
for_each_online_node(node) {
pr_info("Node %d CPUs:", node);
count = 0;
/*
* If we used a CPU iterator here we would miss printing
* the holes in the cpumap.
*/
for (cpu = 0; cpu < nr_cpu_ids; cpu++) {
if (cpumask_test_cpu(cpu,
node_to_cpumask_map[node])) {
if (count == 0)
pr_cont(" %u", cpu);
++count;
} else {
if (count > 1)
pr_cont("-%u", cpu - 1);
count = 0;
}
}
if (count > 1)
pr_cont("-%u", nr_cpu_ids - 1);
pr_cont("\n");
}
}
/* Initialize NODE_DATA for a node on the local memory */
static void __init setup_node_data(int nid, u64 start_pfn, u64 end_pfn)
{
u64 spanned_pages = end_pfn - start_pfn;
const size_t nd_size = roundup(sizeof(pg_data_t), SMP_CACHE_BYTES);
u64 nd_pa;
void *nd;
int tnid;
nd_pa = memblock_phys_alloc_try_nid(nd_size, SMP_CACHE_BYTES, nid);
if (!nd_pa)
panic("Cannot allocate %zu bytes for node %d data\n",
nd_size, nid);
nd = __va(nd_pa);
/* report and initialize */
pr_info(" NODE_DATA [mem %#010Lx-%#010Lx]\n",
nd_pa, nd_pa + nd_size - 1);
tnid = early_pfn_to_nid(nd_pa >> PAGE_SHIFT);
if (tnid != nid)
pr_info(" NODE_DATA(%d) on node %d\n", nid, tnid);
node_data[nid] = nd;
memset(NODE_DATA(nid), 0, sizeof(pg_data_t));
NODE_DATA(nid)->node_id = nid;
NODE_DATA(nid)->node_start_pfn = start_pfn;
NODE_DATA(nid)->node_spanned_pages = spanned_pages;
}
static void __init find_possible_nodes(void)
{
struct device_node *rtas;
u32 numnodes, i;
if (!numa_enabled)
return;
rtas = of_find_node_by_path("/rtas");
if (!rtas)
return;
if (of_property_read_u32_index(rtas,
"ibm,max-associativity-domains",
min_common_depth, &numnodes))
goto out;
for (i = 0; i < numnodes; i++) {
if (!node_possible(i))
node_set(i, node_possible_map);
}
out:
of_node_put(rtas);
}
void __init mem_topology_setup(void)
{
int cpu;
if (parse_numa_properties())
setup_nonnuma();
/*
* Modify the set of possible NUMA nodes to reflect information
* available about the set of online nodes, and the set of nodes
* that we expect to make use of for this platform's affinity
* calculations.
*/
nodes_and(node_possible_map, node_possible_map, node_online_map);
find_possible_nodes();
setup_node_to_cpumask_map();
reset_numa_cpu_lookup_table();
for_each_present_cpu(cpu)
numa_setup_cpu(cpu);
}
void __init initmem_init(void)
{
int nid;
max_low_pfn = memblock_end_of_DRAM() >> PAGE_SHIFT;
max_pfn = max_low_pfn;
memblock_dump_all();
for_each_online_node(nid) {
unsigned long start_pfn, end_pfn;
get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
setup_node_data(nid, start_pfn, end_pfn);
sparse_memory_present_with_active_regions(nid);
}
sparse_init();
/*
* We need the numa_cpu_lookup_table to be accurate for all CPUs,
* even before we online them, so that we can use cpu_to_{node,mem}
* early in boot, cf. smp_prepare_cpus().
* _nocalls() + manual invocation is used because cpuhp is not yet
* initialized for the boot CPU.
*/
cpuhp_setup_state_nocalls(CPUHP_POWER_NUMA_PREPARE, "powerpc/numa:prepare",
ppc_numa_cpu_prepare, ppc_numa_cpu_dead);
}
static int __init early_numa(char *p)
{
if (!p)
return 0;
if (strstr(p, "off"))
numa_enabled = 0;
if (strstr(p, "debug"))
numa_debug = 1;
p = strstr(p, "fake=");
if (p)
cmdline = p + strlen("fake=");
return 0;
}
early_param("numa", early_numa);
/*
* The platform can inform us through one of several mechanisms
* (post-migration device tree updates, PRRN or VPHN) that the NUMA
* assignment of a resource has changed. This controls whether we act
* on that. Disabled by default.
*/
static bool topology_updates_enabled;
static int __init early_topology_updates(char *p)
{
if (!p)
return 0;
if (!strcmp(p, "on")) {
pr_warn("Caution: enabling topology updates\n");
topology_updates_enabled = true;
}
return 0;
}
early_param("topology_updates", early_topology_updates);
#ifdef CONFIG_MEMORY_HOTPLUG
/*
* Find the node associated with a hot added memory section for
* memory represented in the device tree by the property
* ibm,dynamic-reconfiguration-memory/ibm,dynamic-memory.
*/
static int hot_add_drconf_scn_to_nid(unsigned long scn_addr)
{
struct drmem_lmb *lmb;
unsigned long lmb_size;
int nid = NUMA_NO_NODE;
lmb_size = drmem_lmb_size();
for_each_drmem_lmb(lmb) {
/* skip this block if it is reserved or not assigned to
* this partition */
if ((lmb->flags & DRCONF_MEM_RESERVED)
|| !(lmb->flags & DRCONF_MEM_ASSIGNED))
continue;
if ((scn_addr < lmb->base_addr)
|| (scn_addr >= (lmb->base_addr + lmb_size)))
continue;
nid = of_drconf_to_nid_single(lmb);
break;
}
return nid;
}
/*
* Find the node associated with a hot added memory section for memory
* represented in the device tree as a node (i.e. memory@XXXX) for
* each memblock.
*/
static int hot_add_node_scn_to_nid(unsigned long scn_addr)
{
struct device_node *memory;
int nid = NUMA_NO_NODE;
for_each_node_by_type(memory, "memory") {
unsigned long start, size;
int ranges;
const __be32 *memcell_buf;
unsigned int len;
memcell_buf = of_get_property(memory, "reg", &len);
if (!memcell_buf || len <= 0)
continue;
/* ranges in cell */
ranges = (len >> 2) / (n_mem_addr_cells + n_mem_size_cells);
while (ranges--) {
start = read_n_cells(n_mem_addr_cells, &memcell_buf);
size = read_n_cells(n_mem_size_cells, &memcell_buf);
if ((scn_addr < start) || (scn_addr >= (start + size)))
continue;
nid = of_node_to_nid_single(memory);
break;
}
if (nid >= 0)
break;
}
of_node_put(memory);
return nid;
}
/*
* Find the node associated with a hot added memory section. Section
* corresponds to a SPARSEMEM section, not an MEMBLOCK. It is assumed that
* sections are fully contained within a single MEMBLOCK.
*/
int hot_add_scn_to_nid(unsigned long scn_addr)
{
struct device_node *memory = NULL;
int nid;
if (!numa_enabled)
return first_online_node;
memory = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
if (memory) {
nid = hot_add_drconf_scn_to_nid(scn_addr);
of_node_put(memory);
} else {
nid = hot_add_node_scn_to_nid(scn_addr);
}
if (nid < 0 || !node_possible(nid))
nid = first_online_node;
return nid;
}
static u64 hot_add_drconf_memory_max(void)
{
struct device_node *memory = NULL;
struct device_node *dn = NULL;
const __be64 *lrdr = NULL;
dn = of_find_node_by_path("/rtas");
if (dn) {
lrdr = of_get_property(dn, "ibm,lrdr-capacity", NULL);
of_node_put(dn);
if (lrdr)
return be64_to_cpup(lrdr);
}
memory = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
if (memory) {
of_node_put(memory);
return drmem_lmb_memory_max();
}
return 0;
}
/*
* memory_hotplug_max - return max address of memory that may be added
*
* This is currently only used on systems that support drconfig memory
* hotplug.
*/
u64 memory_hotplug_max(void)
{
return max(hot_add_drconf_memory_max(), memblock_end_of_DRAM());
}
#endif /* CONFIG_MEMORY_HOTPLUG */
/* Virtual Processor Home Node (VPHN) support */
#ifdef CONFIG_PPC_SPLPAR
struct topology_update_data {
struct topology_update_data *next;
unsigned int cpu;
int old_nid;
int new_nid;
};
#define TOPOLOGY_DEF_TIMER_SECS 60
static u8 vphn_cpu_change_counts[NR_CPUS][MAX_DISTANCE_REF_POINTS];
static cpumask_t cpu_associativity_changes_mask;
static int vphn_enabled;
static int prrn_enabled;
static void reset_topology_timer(void);
static int topology_timer_secs = 1;
static int topology_inited;
/*
* Change polling interval for associativity changes.
*/
int timed_topology_update(int nsecs)
{
if (vphn_enabled) {
if (nsecs > 0)
topology_timer_secs = nsecs;
else
topology_timer_secs = TOPOLOGY_DEF_TIMER_SECS;
reset_topology_timer();
}
return 0;
}
/*
* Store the current values of the associativity change counters in the
* hypervisor.
*/
static void setup_cpu_associativity_change_counters(void)
{
int cpu;
/* The VPHN feature supports a maximum of 8 reference points */
BUILD_BUG_ON(MAX_DISTANCE_REF_POINTS > 8);
for_each_possible_cpu(cpu) {
int i;
u8 *counts = vphn_cpu_change_counts[cpu];
volatile u8 *hypervisor_counts = lppaca_of(cpu).vphn_assoc_counts;
for (i = 0; i < distance_ref_points_depth; i++)
counts[i] = hypervisor_counts[i];
}
}
/*
* The hypervisor maintains a set of 8 associativity change counters in
* the VPA of each cpu that correspond to the associativity levels in the
* ibm,associativity-reference-points property. When an associativity
* level changes, the corresponding counter is incremented.
*
* Set a bit in cpu_associativity_changes_mask for each cpu whose home
* node associativity levels have changed.
*
* Returns the number of cpus with unhandled associativity changes.
*/
static int update_cpu_associativity_changes_mask(void)
{
int cpu;
cpumask_t *changes = &cpu_associativity_changes_mask;
for_each_possible_cpu(cpu) {
int i, changed = 0;
u8 *counts = vphn_cpu_change_counts[cpu];
volatile u8 *hypervisor_counts = lppaca_of(cpu).vphn_assoc_counts;
for (i = 0; i < distance_ref_points_depth; i++) {
if (hypervisor_counts[i] != counts[i]) {
counts[i] = hypervisor_counts[i];
changed = 1;
}
}
if (changed) {
cpumask_or(changes, changes, cpu_sibling_mask(cpu));
cpu = cpu_last_thread_sibling(cpu);
}
}
return cpumask_weight(changes);
}
/*
* Retrieve the new associativity information for a virtual processor's
* home node.
*/
static long vphn_get_associativity(unsigned long cpu,
__be32 *associativity)
{
long rc;
rc = hcall_vphn(get_hard_smp_processor_id(cpu),
VPHN_FLAG_VCPU, associativity);
switch (rc) {
case H_FUNCTION:
printk_once(KERN_INFO
"VPHN is not supported. Disabling polling...\n");
stop_topology_update();
break;
case H_HARDWARE:
printk(KERN_ERR
"hcall_vphn() experienced a hardware fault "
"preventing VPHN. Disabling polling...\n");
stop_topology_update();
break;
case H_SUCCESS:
dbg("VPHN hcall succeeded. Reset polling...\n");
timed_topology_update(0);
break;
}
return rc;
}
int find_and_online_cpu_nid(int cpu)
{
__be32 associativity[VPHN_ASSOC_BUFSIZE] = {0};
int new_nid;
/* Use associativity from first thread for all siblings */
if (vphn_get_associativity(cpu, associativity))
return cpu_to_node(cpu);
new_nid = associativity_to_nid(associativity);
if (new_nid < 0 || !node_possible(new_nid))
new_nid = first_online_node;
if (NODE_DATA(new_nid) == NULL) {
#ifdef CONFIG_MEMORY_HOTPLUG
/*
* Need to ensure that NODE_DATA is initialized for a node from
* available memory (see memblock_alloc_try_nid). If unable to
* init the node, then default to nearest node that has memory
* installed. Skip onlining a node if the subsystems are not
* yet initialized.
*/
if (!topology_inited || try_online_node(new_nid))
new_nid = first_online_node;
#else
/*
* Default to using the nearest node that has memory installed.
* Otherwise, it would be necessary to patch the kernel MM code
* to deal with more memoryless-node error conditions.
*/
new_nid = first_online_node;
#endif
}
pr_debug("%s:%d cpu %d nid %d\n", __FUNCTION__, __LINE__,
cpu, new_nid);
return new_nid;
}
/*
* Update the CPU maps and sysfs entries for a single CPU when its NUMA
* characteristics change. This function doesn't perform any locking and is
* only safe to call from stop_machine().
*/
static int update_cpu_topology(void *data)
{
struct topology_update_data *update;
unsigned long cpu;
if (!data)
return -EINVAL;
cpu = smp_processor_id();
for (update = data; update; update = update->next) {
int new_nid = update->new_nid;
if (cpu != update->cpu)
continue;
unmap_cpu_from_node(cpu);
map_cpu_to_node(cpu, new_nid);
set_cpu_numa_node(cpu, new_nid);
set_cpu_numa_mem(cpu, local_memory_node(new_nid));
vdso_getcpu_init();
}
return 0;
}
static int update_lookup_table(void *data)
{
struct topology_update_data *update;
if (!data)
return -EINVAL;
/*
* Upon topology update, the numa-cpu lookup table needs to be updated
* for all threads in the core, including offline CPUs, to ensure that
* future hotplug operations respect the cpu-to-node associativity
* properly.
*/
for (update = data; update; update = update->next) {
int nid, base, j;
nid = update->new_nid;
base = cpu_first_thread_sibling(update->cpu);
for (j = 0; j < threads_per_core; j++) {
update_numa_cpu_lookup_table(base + j, nid);
}
}
return 0;
}
/*
* Update the node maps and sysfs entries for each cpu whose home node
* has changed. Returns 1 when the topology has changed, and 0 otherwise.
*
* cpus_locked says whether we already hold cpu_hotplug_lock.
*/
int numa_update_cpu_topology(bool cpus_locked)
{
unsigned int cpu, sibling, changed = 0;
struct topology_update_data *updates, *ud;
cpumask_t updated_cpus;
struct device *dev;
int weight, new_nid, i = 0;
if (!prrn_enabled && !vphn_enabled && topology_inited)
return 0;
weight = cpumask_weight(&cpu_associativity_changes_mask);
if (!weight)
return 0;
updates = kcalloc(weight, sizeof(*updates), GFP_KERNEL);
if (!updates)
return 0;
cpumask_clear(&updated_cpus);
for_each_cpu(cpu, &cpu_associativity_changes_mask) {
/*
* If siblings aren't flagged for changes, updates list
* will be too short. Skip on this update and set for next
* update.
*/
if (!cpumask_subset(cpu_sibling_mask(cpu),
&cpu_associativity_changes_mask)) {
pr_info("Sibling bits not set for associativity "
"change, cpu%d\n", cpu);
cpumask_or(&cpu_associativity_changes_mask,
&cpu_associativity_changes_mask,
cpu_sibling_mask(cpu));
cpu = cpu_last_thread_sibling(cpu);
continue;
}
new_nid = find_and_online_cpu_nid(cpu);
if (new_nid == numa_cpu_lookup_table[cpu]) {
cpumask_andnot(&cpu_associativity_changes_mask,
&cpu_associativity_changes_mask,
cpu_sibling_mask(cpu));
dbg("Assoc chg gives same node %d for cpu%d\n",
new_nid, cpu);
cpu = cpu_last_thread_sibling(cpu);
continue;
}
for_each_cpu(sibling, cpu_sibling_mask(cpu)) {
ud = &updates[i++];
ud->next = &updates[i];
ud->cpu = sibling;
ud->new_nid = new_nid;
ud->old_nid = numa_cpu_lookup_table[sibling];
cpumask_set_cpu(sibling, &updated_cpus);
}
cpu = cpu_last_thread_sibling(cpu);
}
/*
* Prevent processing of 'updates' from overflowing array
* where last entry filled in a 'next' pointer.
*/
if (i)
updates[i-1].next = NULL;
pr_debug("Topology update for the following CPUs:\n");
if (cpumask_weight(&updated_cpus)) {
for (ud = &updates[0]; ud; ud = ud->next) {
pr_debug("cpu %d moving from node %d "
"to %d\n", ud->cpu,
ud->old_nid, ud->new_nid);
}
}
/*
* In cases where we have nothing to update (because the updates list
* is too short or because the new topology is same as the old one),
* skip invoking update_cpu_topology() via stop-machine(). This is
* necessary (and not just a fast-path optimization) since stop-machine
* can end up electing a random CPU to run update_cpu_topology(), and
* thus trick us into setting up incorrect cpu-node mappings (since
* 'updates' is kzalloc()'ed).
*
* And for the similar reason, we will skip all the following updating.
*/
if (!cpumask_weight(&updated_cpus))
goto out;
if (cpus_locked)
stop_machine_cpuslocked(update_cpu_topology, &updates[0],
&updated_cpus);
else
stop_machine(update_cpu_topology, &updates[0], &updated_cpus);
/*
* Update the numa-cpu lookup table with the new mappings, even for
* offline CPUs. It is best to perform this update from the stop-
* machine context.
*/
if (cpus_locked)
stop_machine_cpuslocked(update_lookup_table, &updates[0],
cpumask_of(raw_smp_processor_id()));
else
stop_machine(update_lookup_table, &updates[0],
cpumask_of(raw_smp_processor_id()));
for (ud = &updates[0]; ud; ud = ud->next) {
unregister_cpu_under_node(ud->cpu, ud->old_nid);
register_cpu_under_node(ud->cpu, ud->new_nid);
dev = get_cpu_device(ud->cpu);
if (dev)
kobject_uevent(&dev->kobj, KOBJ_CHANGE);
cpumask_clear_cpu(ud->cpu, &cpu_associativity_changes_mask);
changed = 1;
}
out:
kfree(updates);
return changed;
}
int arch_update_cpu_topology(void)
{
return numa_update_cpu_topology(true);
}
static void topology_work_fn(struct work_struct *work)
{
rebuild_sched_domains();
}
static DECLARE_WORK(topology_work, topology_work_fn);
static void topology_schedule_update(void)
{
schedule_work(&topology_work);
}
static void topology_timer_fn(struct timer_list *unused)
{
if (prrn_enabled && cpumask_weight(&cpu_associativity_changes_mask))
topology_schedule_update();
else if (vphn_enabled) {
if (update_cpu_associativity_changes_mask() > 0)
topology_schedule_update();
reset_topology_timer();
}
}
static struct timer_list topology_timer;
static void reset_topology_timer(void)
{
if (vphn_enabled)
mod_timer(&topology_timer, jiffies + topology_timer_secs * HZ);
}
#ifdef CONFIG_SMP
static int dt_update_callback(struct notifier_block *nb,
unsigned long action, void *data)
{
struct of_reconfig_data *update = data;
int rc = NOTIFY_DONE;
switch (action) {
case OF_RECONFIG_UPDATE_PROPERTY:
if (of_node_is_type(update->dn, "cpu") &&
!of_prop_cmp(update->prop->name, "ibm,associativity")) {
u32 core_id;
of_property_read_u32(update->dn, "reg", &core_id);
rc = dlpar_cpu_readd(core_id);
rc = NOTIFY_OK;
}
break;
}
return rc;
}
static struct notifier_block dt_update_nb = {
.notifier_call = dt_update_callback,
};
#endif
/*
* Start polling for associativity changes.
*/
int start_topology_update(void)
{
int rc = 0;
if (!topology_updates_enabled)
return 0;
if (firmware_has_feature(FW_FEATURE_PRRN)) {
if (!prrn_enabled) {
prrn_enabled = 1;
#ifdef CONFIG_SMP
rc = of_reconfig_notifier_register(&dt_update_nb);
#endif
}
}
if (firmware_has_feature(FW_FEATURE_VPHN) &&
lppaca_shared_proc(get_lppaca())) {
if (!vphn_enabled) {
vphn_enabled = 1;
setup_cpu_associativity_change_counters();
timer_setup(&topology_timer, topology_timer_fn,
TIMER_DEFERRABLE);
reset_topology_timer();
}
}
pr_info("Starting topology update%s%s\n",
(prrn_enabled ? " prrn_enabled" : ""),
(vphn_enabled ? " vphn_enabled" : ""));
return rc;
}
/*
* Disable polling for VPHN associativity changes.
*/
int stop_topology_update(void)
{
int rc = 0;
if (!topology_updates_enabled)
return 0;
if (prrn_enabled) {
prrn_enabled = 0;
#ifdef CONFIG_SMP
rc = of_reconfig_notifier_unregister(&dt_update_nb);
#endif
}
if (vphn_enabled) {
vphn_enabled = 0;
rc = del_timer_sync(&topology_timer);
}
pr_info("Stopping topology update\n");
return rc;
}
int prrn_is_enabled(void)
{
return prrn_enabled;
}
void __init shared_proc_topology_init(void)
{
if (lppaca_shared_proc(get_lppaca())) {
bitmap_fill(cpumask_bits(&cpu_associativity_changes_mask),
nr_cpumask_bits);
numa_update_cpu_topology(false);
}
}
static int topology_read(struct seq_file *file, void *v)
{
if (vphn_enabled || prrn_enabled)
seq_puts(file, "on\n");
else
seq_puts(file, "off\n");
return 0;
}
static int topology_open(struct inode *inode, struct file *file)
{
return single_open(file, topology_read, NULL);
}
static ssize_t topology_write(struct file *file, const char __user *buf,
size_t count, loff_t *off)
{
char kbuf[4]; /* "on" or "off" plus null. */
int read_len;
read_len = count < 3 ? count : 3;
if (copy_from_user(kbuf, buf, read_len))
return -EINVAL;
kbuf[read_len] = '\0';
if (!strncmp(kbuf, "on", 2)) {
topology_updates_enabled = true;
start_topology_update();
} else if (!strncmp(kbuf, "off", 3)) {
stop_topology_update();
topology_updates_enabled = false;
} else
return -EINVAL;
return count;
}
static const struct file_operations topology_ops = {
.read = seq_read,
.write = topology_write,
.open = topology_open,
.release = single_release
};
static int topology_update_init(void)
{
start_topology_update();
if (vphn_enabled)
topology_schedule_update();
if (!proc_create("powerpc/topology_updates", 0644, NULL, &topology_ops))
return -ENOMEM;
topology_inited = 1;
return 0;
}
device_initcall(topology_update_init);
#endif /* CONFIG_PPC_SPLPAR */