4 * Copyright (C) 2002 Anton Blanchard <anton@au.ibm.com>, IBM
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
11 #define pr_fmt(fmt) "numa: " fmt
13 #include <linux/threads.h>
14 #include <linux/memblock.h>
15 #include <linux/init.h>
17 #include <linux/mmzone.h>
18 #include <linux/export.h>
19 #include <linux/nodemask.h>
20 #include <linux/cpu.h>
21 #include <linux/notifier.h>
23 #include <linux/pfn.h>
24 #include <linux/cpuset.h>
25 #include <linux/node.h>
26 #include <linux/stop_machine.h>
27 #include <linux/proc_fs.h>
28 #include <linux/seq_file.h>
29 #include <linux/uaccess.h>
30 #include <linux/slab.h>
31 #include <asm/cputhreads.h>
32 #include <asm/sparsemem.h>
35 #include <asm/topology.h>
36 #include <asm/firmware.h>
38 #include <asm/hvcall.h>
39 #include <asm/setup.h>
41 #include <asm/drmem.h>
43 static int numa_enabled
= 1;
45 static char *cmdline __initdata
;
47 static int numa_debug
;
48 #define dbg(args...) if (numa_debug) { printk(KERN_INFO args); }
50 int numa_cpu_lookup_table
[NR_CPUS
];
51 cpumask_var_t node_to_cpumask_map
[MAX_NUMNODES
];
52 struct pglist_data
*node_data
[MAX_NUMNODES
];
54 EXPORT_SYMBOL(numa_cpu_lookup_table
);
55 EXPORT_SYMBOL(node_to_cpumask_map
);
56 EXPORT_SYMBOL(node_data
);
58 static int min_common_depth
;
59 static int n_mem_addr_cells
, n_mem_size_cells
;
60 static int form1_affinity
;
62 #define MAX_DISTANCE_REF_POINTS 4
63 static int distance_ref_points_depth
;
64 static const __be32
*distance_ref_points
;
65 static int distance_lookup_table
[MAX_NUMNODES
][MAX_DISTANCE_REF_POINTS
];
68 * Allocate node_to_cpumask_map based on number of available nodes
69 * Requires node_possible_map to be valid.
71 * Note: cpumask_of_node() is not valid until after this is done.
73 static void __init
setup_node_to_cpumask_map(void)
77 /* setup nr_node_ids if not done yet */
78 if (nr_node_ids
== MAX_NUMNODES
)
81 /* allocate the map */
83 alloc_bootmem_cpumask_var(&node_to_cpumask_map
[node
]);
85 /* cpumask_of_node() will now work */
86 dbg("Node to cpumask map for %u nodes\n", nr_node_ids
);
89 static int __init
fake_numa_create_new_node(unsigned long end_pfn
,
92 unsigned long long mem
;
94 static unsigned int fake_nid
;
95 static unsigned long long curr_boundary
;
98 * Modify node id, iff we started creating NUMA nodes
99 * We want to continue from where we left of the last time
104 * In case there are no more arguments to parse, the
105 * node_id should be the same as the last fake node id
106 * (we've handled this above).
111 mem
= memparse(p
, &p
);
115 if (mem
< curr_boundary
)
120 if ((end_pfn
<< PAGE_SHIFT
) > mem
) {
122 * Skip commas and spaces
124 while (*p
== ',' || *p
== ' ' || *p
== '\t')
130 dbg("created new fake_node with id %d\n", fake_nid
);
136 static void reset_numa_cpu_lookup_table(void)
140 for_each_possible_cpu(cpu
)
141 numa_cpu_lookup_table
[cpu
] = -1;
144 static void map_cpu_to_node(int cpu
, int node
)
146 update_numa_cpu_lookup_table(cpu
, node
);
148 dbg("adding cpu %d to node %d\n", cpu
, node
);
150 if (!(cpumask_test_cpu(cpu
, node_to_cpumask_map
[node
])))
151 cpumask_set_cpu(cpu
, node_to_cpumask_map
[node
]);
154 #if defined(CONFIG_HOTPLUG_CPU) || defined(CONFIG_PPC_SPLPAR)
155 static void unmap_cpu_from_node(unsigned long cpu
)
157 int node
= numa_cpu_lookup_table
[cpu
];
159 dbg("removing cpu %lu from node %d\n", cpu
, node
);
161 if (cpumask_test_cpu(cpu
, node_to_cpumask_map
[node
])) {
162 cpumask_clear_cpu(cpu
, node_to_cpumask_map
[node
]);
164 printk(KERN_ERR
"WARNING: cpu %lu not found in node %d\n",
168 #endif /* CONFIG_HOTPLUG_CPU || CONFIG_PPC_SPLPAR */
170 /* must hold reference to node during call */
171 static const __be32
*of_get_associativity(struct device_node
*dev
)
173 return of_get_property(dev
, "ibm,associativity", NULL
);
176 int __node_distance(int a
, int b
)
179 int distance
= LOCAL_DISTANCE
;
182 return ((a
== b
) ? LOCAL_DISTANCE
: REMOTE_DISTANCE
);
184 for (i
= 0; i
< distance_ref_points_depth
; i
++) {
185 if (distance_lookup_table
[a
][i
] == distance_lookup_table
[b
][i
])
188 /* Double the distance for each NUMA level */
194 EXPORT_SYMBOL(__node_distance
);
196 static void initialize_distance_lookup_table(int nid
,
197 const __be32
*associativity
)
204 for (i
= 0; i
< distance_ref_points_depth
; i
++) {
207 entry
= &associativity
[be32_to_cpu(distance_ref_points
[i
]) - 1];
208 distance_lookup_table
[nid
][i
] = of_read_number(entry
, 1);
212 /* Returns nid in the range [0..MAX_NUMNODES-1], or -1 if no useful numa
215 static int associativity_to_nid(const __be32
*associativity
)
217 int nid
= NUMA_NO_NODE
;
219 if (min_common_depth
== -1)
222 if (of_read_number(associativity
, 1) >= min_common_depth
)
223 nid
= of_read_number(&associativity
[min_common_depth
], 1);
225 /* POWER4 LPAR uses 0xffff as invalid node */
226 if (nid
== 0xffff || nid
>= MAX_NUMNODES
)
230 of_read_number(associativity
, 1) >= distance_ref_points_depth
) {
232 * Skip the length field and send start of associativity array
234 initialize_distance_lookup_table(nid
, associativity
+ 1);
241 /* Returns the nid associated with the given device tree node,
242 * or -1 if not found.
244 static int of_node_to_nid_single(struct device_node
*device
)
246 int nid
= NUMA_NO_NODE
;
249 tmp
= of_get_associativity(device
);
251 nid
= associativity_to_nid(tmp
);
255 /* Walk the device tree upwards, looking for an associativity id */
256 int of_node_to_nid(struct device_node
*device
)
258 int nid
= NUMA_NO_NODE
;
262 nid
= of_node_to_nid_single(device
);
266 device
= of_get_next_parent(device
);
272 EXPORT_SYMBOL(of_node_to_nid
);
274 static int __init
find_min_common_depth(void)
277 struct device_node
*root
;
279 if (firmware_has_feature(FW_FEATURE_OPAL
))
280 root
= of_find_node_by_path("/ibm,opal");
282 root
= of_find_node_by_path("/rtas");
284 root
= of_find_node_by_path("/");
287 * This property is a set of 32-bit integers, each representing
288 * an index into the ibm,associativity nodes.
290 * With form 0 affinity the first integer is for an SMP configuration
291 * (should be all 0's) and the second is for a normal NUMA
292 * configuration. We have only one level of NUMA.
294 * With form 1 affinity the first integer is the most significant
295 * NUMA boundary and the following are progressively less significant
296 * boundaries. There can be more than one level of NUMA.
298 distance_ref_points
= of_get_property(root
,
299 "ibm,associativity-reference-points",
300 &distance_ref_points_depth
);
302 if (!distance_ref_points
) {
303 dbg("NUMA: ibm,associativity-reference-points not found.\n");
307 distance_ref_points_depth
/= sizeof(int);
309 if (firmware_has_feature(FW_FEATURE_OPAL
) ||
310 firmware_has_feature(FW_FEATURE_TYPE1_AFFINITY
)) {
311 dbg("Using form 1 affinity\n");
315 if (form1_affinity
) {
316 depth
= of_read_number(distance_ref_points
, 1);
318 if (distance_ref_points_depth
< 2) {
319 printk(KERN_WARNING
"NUMA: "
320 "short ibm,associativity-reference-points\n");
324 depth
= of_read_number(&distance_ref_points
[1], 1);
328 * Warn and cap if the hardware supports more than
329 * MAX_DISTANCE_REF_POINTS domains.
331 if (distance_ref_points_depth
> MAX_DISTANCE_REF_POINTS
) {
332 printk(KERN_WARNING
"NUMA: distance array capped at "
333 "%d entries\n", MAX_DISTANCE_REF_POINTS
);
334 distance_ref_points_depth
= MAX_DISTANCE_REF_POINTS
;
345 static void __init
get_n_mem_cells(int *n_addr_cells
, int *n_size_cells
)
347 struct device_node
*memory
= NULL
;
349 memory
= of_find_node_by_type(memory
, "memory");
351 panic("numa.c: No memory nodes found!");
353 *n_addr_cells
= of_n_addr_cells(memory
);
354 *n_size_cells
= of_n_size_cells(memory
);
358 static unsigned long read_n_cells(int n
, const __be32
**buf
)
360 unsigned long result
= 0;
363 result
= (result
<< 32) | of_read_number(*buf
, 1);
369 struct assoc_arrays
{
372 const __be32
*arrays
;
376 * Retrieve and validate the list of associativity arrays for drconf
377 * memory from the ibm,associativity-lookup-arrays property of the
380 * The layout of the ibm,associativity-lookup-arrays property is a number N
381 * indicating the number of associativity arrays, followed by a number M
382 * indicating the size of each associativity array, followed by a list
383 * of N associativity arrays.
385 static int of_get_assoc_arrays(struct assoc_arrays
*aa
)
387 struct device_node
*memory
;
391 memory
= of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
395 prop
= of_get_property(memory
, "ibm,associativity-lookup-arrays", &len
);
396 if (!prop
|| len
< 2 * sizeof(unsigned int)) {
401 aa
->n_arrays
= of_read_number(prop
++, 1);
402 aa
->array_sz
= of_read_number(prop
++, 1);
406 /* Now that we know the number of arrays and size of each array,
407 * revalidate the size of the property read in.
409 if (len
< (aa
->n_arrays
* aa
->array_sz
+ 2) * sizeof(unsigned int))
417 * This is like of_node_to_nid_single() for memory represented in the
418 * ibm,dynamic-reconfiguration-memory node.
420 static int of_drconf_to_nid_single(struct drmem_lmb
*lmb
)
422 struct assoc_arrays aa
= { .arrays
= NULL
};
424 int nid
= default_nid
;
427 rc
= of_get_assoc_arrays(&aa
);
431 if (min_common_depth
> 0 && min_common_depth
<= aa
.array_sz
&&
432 !(lmb
->flags
& DRCONF_MEM_AI_INVALID
) &&
433 lmb
->aa_index
< aa
.n_arrays
) {
434 index
= lmb
->aa_index
* aa
.array_sz
+ min_common_depth
- 1;
435 nid
= of_read_number(&aa
.arrays
[index
], 1);
437 if (nid
== 0xffff || nid
>= MAX_NUMNODES
)
441 index
= lmb
->aa_index
* aa
.array_sz
;
442 initialize_distance_lookup_table(nid
,
451 * Figure out to which domain a cpu belongs and stick it there.
452 * Return the id of the domain used.
454 static int numa_setup_cpu(unsigned long lcpu
)
456 int nid
= NUMA_NO_NODE
;
457 struct device_node
*cpu
;
460 * If a valid cpu-to-node mapping is already available, use it
461 * directly instead of querying the firmware, since it represents
462 * the most recent mapping notified to us by the platform (eg: VPHN).
464 if ((nid
= numa_cpu_lookup_table
[lcpu
]) >= 0) {
465 map_cpu_to_node(lcpu
, nid
);
469 cpu
= of_get_cpu_node(lcpu
, NULL
);
473 if (cpu_present(lcpu
))
479 nid
= of_node_to_nid_single(cpu
);
482 if (nid
< 0 || !node_possible(nid
))
483 nid
= first_online_node
;
485 map_cpu_to_node(lcpu
, nid
);
491 static void verify_cpu_node_mapping(int cpu
, int node
)
493 int base
, sibling
, i
;
495 /* Verify that all the threads in the core belong to the same node */
496 base
= cpu_first_thread_sibling(cpu
);
498 for (i
= 0; i
< threads_per_core
; i
++) {
501 if (sibling
== cpu
|| cpu_is_offline(sibling
))
504 if (cpu_to_node(sibling
) != node
) {
505 WARN(1, "CPU thread siblings %d and %d don't belong"
506 " to the same node!\n", cpu
, sibling
);
512 /* Must run before sched domains notifier. */
513 static int ppc_numa_cpu_prepare(unsigned int cpu
)
517 nid
= numa_setup_cpu(cpu
);
518 verify_cpu_node_mapping(cpu
, nid
);
522 static int ppc_numa_cpu_dead(unsigned int cpu
)
524 #ifdef CONFIG_HOTPLUG_CPU
525 unmap_cpu_from_node(cpu
);
531 * Check and possibly modify a memory region to enforce the memory limit.
533 * Returns the size the region should have to enforce the memory limit.
534 * This will either be the original value of size, a truncated value,
535 * or zero. If the returned value of size is 0 the region should be
536 * discarded as it lies wholly above the memory limit.
538 static unsigned long __init
numa_enforce_memory_limit(unsigned long start
,
542 * We use memblock_end_of_DRAM() in here instead of memory_limit because
543 * we've already adjusted it for the limit and it takes care of
544 * having memory holes below the limit. Also, in the case of
545 * iommu_is_off, memory_limit is not set but is implicitly enforced.
548 if (start
+ size
<= memblock_end_of_DRAM())
551 if (start
>= memblock_end_of_DRAM())
554 return memblock_end_of_DRAM() - start
;
558 * Reads the counter for a given entry in
559 * linux,drconf-usable-memory property
561 static inline int __init
read_usm_ranges(const __be32
**usm
)
564 * For each lmb in ibm,dynamic-memory a corresponding
565 * entry in linux,drconf-usable-memory property contains
566 * a counter followed by that many (base, size) duple.
567 * read the counter from linux,drconf-usable-memory
569 return read_n_cells(n_mem_size_cells
, usm
);
573 * Extract NUMA information from the ibm,dynamic-reconfiguration-memory
574 * node. This assumes n_mem_{addr,size}_cells have been set.
576 static void __init
numa_setup_drmem_lmb(struct drmem_lmb
*lmb
,
579 unsigned int ranges
, is_kexec_kdump
= 0;
580 unsigned long base
, size
, sz
;
584 * Skip this block if the reserved bit is set in flags (0x80)
585 * or if the block is not assigned to this partition (0x8)
587 if ((lmb
->flags
& DRCONF_MEM_RESERVED
)
588 || !(lmb
->flags
& DRCONF_MEM_ASSIGNED
))
594 base
= lmb
->base_addr
;
595 size
= drmem_lmb_size();
598 if (is_kexec_kdump
) {
599 ranges
= read_usm_ranges(usm
);
600 if (!ranges
) /* there are no (base, size) duple */
605 if (is_kexec_kdump
) {
606 base
= read_n_cells(n_mem_addr_cells
, usm
);
607 size
= read_n_cells(n_mem_size_cells
, usm
);
610 nid
= of_drconf_to_nid_single(lmb
);
611 fake_numa_create_new_node(((base
+ size
) >> PAGE_SHIFT
),
613 node_set_online(nid
);
614 sz
= numa_enforce_memory_limit(base
, size
);
616 memblock_set_node(base
, sz
, &memblock
.memory
, nid
);
620 static int __init
parse_numa_properties(void)
622 struct device_node
*memory
;
626 if (numa_enabled
== 0) {
627 printk(KERN_WARNING
"NUMA disabled by user\n");
631 min_common_depth
= find_min_common_depth();
633 if (min_common_depth
< 0)
634 return min_common_depth
;
636 dbg("NUMA associativity depth for CPU/Memory: %d\n", min_common_depth
);
639 * Even though we connect cpus to numa domains later in SMP
640 * init, we need to know the node ids now. This is because
641 * each node to be onlined must have NODE_DATA etc backing it.
643 for_each_present_cpu(i
) {
644 struct device_node
*cpu
;
647 cpu
= of_get_cpu_node(i
, NULL
);
649 nid
= of_node_to_nid_single(cpu
);
653 * Don't fall back to default_nid yet -- we will plug
654 * cpus into nodes once the memory scan has discovered
659 node_set_online(nid
);
662 get_n_mem_cells(&n_mem_addr_cells
, &n_mem_size_cells
);
664 for_each_node_by_type(memory
, "memory") {
669 const __be32
*memcell_buf
;
672 memcell_buf
= of_get_property(memory
,
673 "linux,usable-memory", &len
);
674 if (!memcell_buf
|| len
<= 0)
675 memcell_buf
= of_get_property(memory
, "reg", &len
);
676 if (!memcell_buf
|| len
<= 0)
680 ranges
= (len
>> 2) / (n_mem_addr_cells
+ n_mem_size_cells
);
682 /* these are order-sensitive, and modify the buffer pointer */
683 start
= read_n_cells(n_mem_addr_cells
, &memcell_buf
);
684 size
= read_n_cells(n_mem_size_cells
, &memcell_buf
);
687 * Assumption: either all memory nodes or none will
688 * have associativity properties. If none, then
689 * everything goes to default_nid.
691 nid
= of_node_to_nid_single(memory
);
695 fake_numa_create_new_node(((start
+ size
) >> PAGE_SHIFT
), &nid
);
696 node_set_online(nid
);
698 size
= numa_enforce_memory_limit(start
, size
);
700 memblock_set_node(start
, size
, &memblock
.memory
, nid
);
707 * Now do the same thing for each MEMBLOCK listed in the
708 * ibm,dynamic-memory property in the
709 * ibm,dynamic-reconfiguration-memory node.
711 memory
= of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
713 walk_drmem_lmbs(memory
, numa_setup_drmem_lmb
);
720 static void __init
setup_nonnuma(void)
722 unsigned long top_of_ram
= memblock_end_of_DRAM();
723 unsigned long total_ram
= memblock_phys_mem_size();
724 unsigned long start_pfn
, end_pfn
;
725 unsigned int nid
= 0;
726 struct memblock_region
*reg
;
728 printk(KERN_DEBUG
"Top of RAM: 0x%lx, Total RAM: 0x%lx\n",
729 top_of_ram
, total_ram
);
730 printk(KERN_DEBUG
"Memory hole size: %ldMB\n",
731 (top_of_ram
- total_ram
) >> 20);
733 for_each_memblock(memory
, reg
) {
734 start_pfn
= memblock_region_memory_base_pfn(reg
);
735 end_pfn
= memblock_region_memory_end_pfn(reg
);
737 fake_numa_create_new_node(end_pfn
, &nid
);
738 memblock_set_node(PFN_PHYS(start_pfn
),
739 PFN_PHYS(end_pfn
- start_pfn
),
740 &memblock
.memory
, nid
);
741 node_set_online(nid
);
745 void __init
dump_numa_cpu_topology(void)
748 unsigned int cpu
, count
;
750 if (min_common_depth
== -1 || !numa_enabled
)
753 for_each_online_node(node
) {
754 pr_info("Node %d CPUs:", node
);
758 * If we used a CPU iterator here we would miss printing
759 * the holes in the cpumap.
761 for (cpu
= 0; cpu
< nr_cpu_ids
; cpu
++) {
762 if (cpumask_test_cpu(cpu
,
763 node_to_cpumask_map
[node
])) {
769 pr_cont("-%u", cpu
- 1);
775 pr_cont("-%u", nr_cpu_ids
- 1);
780 /* Initialize NODE_DATA for a node on the local memory */
781 static void __init
setup_node_data(int nid
, u64 start_pfn
, u64 end_pfn
)
783 u64 spanned_pages
= end_pfn
- start_pfn
;
784 const size_t nd_size
= roundup(sizeof(pg_data_t
), SMP_CACHE_BYTES
);
789 nd_pa
= memblock_phys_alloc_try_nid(nd_size
, SMP_CACHE_BYTES
, nid
);
791 panic("Cannot allocate %zu bytes for node %d data\n",
796 /* report and initialize */
797 pr_info(" NODE_DATA [mem %#010Lx-%#010Lx]\n",
798 nd_pa
, nd_pa
+ nd_size
- 1);
799 tnid
= early_pfn_to_nid(nd_pa
>> PAGE_SHIFT
);
801 pr_info(" NODE_DATA(%d) on node %d\n", nid
, tnid
);
804 memset(NODE_DATA(nid
), 0, sizeof(pg_data_t
));
805 NODE_DATA(nid
)->node_id
= nid
;
806 NODE_DATA(nid
)->node_start_pfn
= start_pfn
;
807 NODE_DATA(nid
)->node_spanned_pages
= spanned_pages
;
810 static void __init
find_possible_nodes(void)
812 struct device_node
*rtas
;
815 if (min_common_depth
<= 0)
818 rtas
= of_find_node_by_path("/rtas");
822 if (of_property_read_u32_index(rtas
,
823 "ibm,max-associativity-domains",
824 min_common_depth
, &numnodes
))
827 for (i
= 0; i
< numnodes
; i
++) {
828 if (!node_possible(i
))
829 node_set(i
, node_possible_map
);
836 void __init
mem_topology_setup(void)
840 if (parse_numa_properties())
844 * Modify the set of possible NUMA nodes to reflect information
845 * available about the set of online nodes, and the set of nodes
846 * that we expect to make use of for this platform's affinity
849 nodes_and(node_possible_map
, node_possible_map
, node_online_map
);
851 find_possible_nodes();
853 setup_node_to_cpumask_map();
855 reset_numa_cpu_lookup_table();
857 for_each_present_cpu(cpu
)
861 void __init
initmem_init(void)
865 max_low_pfn
= memblock_end_of_DRAM() >> PAGE_SHIFT
;
866 max_pfn
= max_low_pfn
;
870 for_each_online_node(nid
) {
871 unsigned long start_pfn
, end_pfn
;
873 get_pfn_range_for_nid(nid
, &start_pfn
, &end_pfn
);
874 setup_node_data(nid
, start_pfn
, end_pfn
);
875 sparse_memory_present_with_active_regions(nid
);
881 * We need the numa_cpu_lookup_table to be accurate for all CPUs,
882 * even before we online them, so that we can use cpu_to_{node,mem}
883 * early in boot, cf. smp_prepare_cpus().
884 * _nocalls() + manual invocation is used because cpuhp is not yet
885 * initialized for the boot CPU.
887 cpuhp_setup_state_nocalls(CPUHP_POWER_NUMA_PREPARE
, "powerpc/numa:prepare",
888 ppc_numa_cpu_prepare
, ppc_numa_cpu_dead
);
891 static int __init
early_numa(char *p
)
896 if (strstr(p
, "off"))
899 if (strstr(p
, "debug"))
902 p
= strstr(p
, "fake=");
904 cmdline
= p
+ strlen("fake=");
908 early_param("numa", early_numa
);
911 * The platform can inform us through one of several mechanisms
912 * (post-migration device tree updates, PRRN or VPHN) that the NUMA
913 * assignment of a resource has changed. This controls whether we act
914 * on that. Disabled by default.
916 static bool topology_updates_enabled
;
918 static int __init
early_topology_updates(char *p
)
923 if (!strcmp(p
, "on")) {
924 pr_warn("Caution: enabling topology updates\n");
925 topology_updates_enabled
= true;
930 early_param("topology_updates", early_topology_updates
);
932 #ifdef CONFIG_MEMORY_HOTPLUG
934 * Find the node associated with a hot added memory section for
935 * memory represented in the device tree by the property
936 * ibm,dynamic-reconfiguration-memory/ibm,dynamic-memory.
938 static int hot_add_drconf_scn_to_nid(unsigned long scn_addr
)
940 struct drmem_lmb
*lmb
;
941 unsigned long lmb_size
;
942 int nid
= NUMA_NO_NODE
;
944 lmb_size
= drmem_lmb_size();
946 for_each_drmem_lmb(lmb
) {
947 /* skip this block if it is reserved or not assigned to
949 if ((lmb
->flags
& DRCONF_MEM_RESERVED
)
950 || !(lmb
->flags
& DRCONF_MEM_ASSIGNED
))
953 if ((scn_addr
< lmb
->base_addr
)
954 || (scn_addr
>= (lmb
->base_addr
+ lmb_size
)))
957 nid
= of_drconf_to_nid_single(lmb
);
965 * Find the node associated with a hot added memory section for memory
966 * represented in the device tree as a node (i.e. memory@XXXX) for
969 static int hot_add_node_scn_to_nid(unsigned long scn_addr
)
971 struct device_node
*memory
;
972 int nid
= NUMA_NO_NODE
;
974 for_each_node_by_type(memory
, "memory") {
975 unsigned long start
, size
;
977 const __be32
*memcell_buf
;
980 memcell_buf
= of_get_property(memory
, "reg", &len
);
981 if (!memcell_buf
|| len
<= 0)
985 ranges
= (len
>> 2) / (n_mem_addr_cells
+ n_mem_size_cells
);
988 start
= read_n_cells(n_mem_addr_cells
, &memcell_buf
);
989 size
= read_n_cells(n_mem_size_cells
, &memcell_buf
);
991 if ((scn_addr
< start
) || (scn_addr
>= (start
+ size
)))
994 nid
= of_node_to_nid_single(memory
);
1002 of_node_put(memory
);
1008 * Find the node associated with a hot added memory section. Section
1009 * corresponds to a SPARSEMEM section, not an MEMBLOCK. It is assumed that
1010 * sections are fully contained within a single MEMBLOCK.
1012 int hot_add_scn_to_nid(unsigned long scn_addr
)
1014 struct device_node
*memory
= NULL
;
1017 if (!numa_enabled
|| (min_common_depth
< 0))
1018 return first_online_node
;
1020 memory
= of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
1022 nid
= hot_add_drconf_scn_to_nid(scn_addr
);
1023 of_node_put(memory
);
1025 nid
= hot_add_node_scn_to_nid(scn_addr
);
1028 if (nid
< 0 || !node_possible(nid
))
1029 nid
= first_online_node
;
1034 static u64
hot_add_drconf_memory_max(void)
1036 struct device_node
*memory
= NULL
;
1037 struct device_node
*dn
= NULL
;
1038 const __be64
*lrdr
= NULL
;
1040 dn
= of_find_node_by_path("/rtas");
1042 lrdr
= of_get_property(dn
, "ibm,lrdr-capacity", NULL
);
1045 return be64_to_cpup(lrdr
);
1048 memory
= of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
1050 of_node_put(memory
);
1051 return drmem_lmb_memory_max();
1057 * memory_hotplug_max - return max address of memory that may be added
1059 * This is currently only used on systems that support drconfig memory
1062 u64
memory_hotplug_max(void)
1064 return max(hot_add_drconf_memory_max(), memblock_end_of_DRAM());
1066 #endif /* CONFIG_MEMORY_HOTPLUG */
1068 /* Virtual Processor Home Node (VPHN) support */
1069 #ifdef CONFIG_PPC_SPLPAR
1071 #include "book3s64/vphn.h"
1073 struct topology_update_data
{
1074 struct topology_update_data
*next
;
1080 #define TOPOLOGY_DEF_TIMER_SECS 60
1082 static u8 vphn_cpu_change_counts
[NR_CPUS
][MAX_DISTANCE_REF_POINTS
];
1083 static cpumask_t cpu_associativity_changes_mask
;
1084 static int vphn_enabled
;
1085 static int prrn_enabled
;
1086 static void reset_topology_timer(void);
1087 static int topology_timer_secs
= 1;
1088 static int topology_inited
;
1091 * Change polling interval for associativity changes.
1093 int timed_topology_update(int nsecs
)
1097 topology_timer_secs
= nsecs
;
1099 topology_timer_secs
= TOPOLOGY_DEF_TIMER_SECS
;
1101 reset_topology_timer();
1108 * Store the current values of the associativity change counters in the
1111 static void setup_cpu_associativity_change_counters(void)
1115 /* The VPHN feature supports a maximum of 8 reference points */
1116 BUILD_BUG_ON(MAX_DISTANCE_REF_POINTS
> 8);
1118 for_each_possible_cpu(cpu
) {
1120 u8
*counts
= vphn_cpu_change_counts
[cpu
];
1121 volatile u8
*hypervisor_counts
= lppaca_of(cpu
).vphn_assoc_counts
;
1123 for (i
= 0; i
< distance_ref_points_depth
; i
++)
1124 counts
[i
] = hypervisor_counts
[i
];
1129 * The hypervisor maintains a set of 8 associativity change counters in
1130 * the VPA of each cpu that correspond to the associativity levels in the
1131 * ibm,associativity-reference-points property. When an associativity
1132 * level changes, the corresponding counter is incremented.
1134 * Set a bit in cpu_associativity_changes_mask for each cpu whose home
1135 * node associativity levels have changed.
1137 * Returns the number of cpus with unhandled associativity changes.
1139 static int update_cpu_associativity_changes_mask(void)
1142 cpumask_t
*changes
= &cpu_associativity_changes_mask
;
1144 for_each_possible_cpu(cpu
) {
1146 u8
*counts
= vphn_cpu_change_counts
[cpu
];
1147 volatile u8
*hypervisor_counts
= lppaca_of(cpu
).vphn_assoc_counts
;
1149 for (i
= 0; i
< distance_ref_points_depth
; i
++) {
1150 if (hypervisor_counts
[i
] != counts
[i
]) {
1151 counts
[i
] = hypervisor_counts
[i
];
1156 cpumask_or(changes
, changes
, cpu_sibling_mask(cpu
));
1157 cpu
= cpu_last_thread_sibling(cpu
);
1161 return cpumask_weight(changes
);
1165 * Retrieve the new associativity information for a virtual processor's
1168 static long hcall_vphn(unsigned long cpu
, __be32
*associativity
)
1171 long retbuf
[PLPAR_HCALL9_BUFSIZE
] = {0};
1173 int hwcpu
= get_hard_smp_processor_id(cpu
);
1175 rc
= plpar_hcall9(H_HOME_NODE_ASSOCIATIVITY
, retbuf
, flags
, hwcpu
);
1176 vphn_unpack_associativity(retbuf
, associativity
);
1181 static long vphn_get_associativity(unsigned long cpu
,
1182 __be32
*associativity
)
1186 rc
= hcall_vphn(cpu
, associativity
);
1190 printk_once(KERN_INFO
1191 "VPHN is not supported. Disabling polling...\n");
1192 stop_topology_update();
1196 "hcall_vphn() experienced a hardware fault "
1197 "preventing VPHN. Disabling polling...\n");
1198 stop_topology_update();
1201 dbg("VPHN hcall succeeded. Reset polling...\n");
1202 timed_topology_update(0);
1209 int find_and_online_cpu_nid(int cpu
)
1211 __be32 associativity
[VPHN_ASSOC_BUFSIZE
] = {0};
1214 /* Use associativity from first thread for all siblings */
1215 if (vphn_get_associativity(cpu
, associativity
))
1216 return cpu_to_node(cpu
);
1218 new_nid
= associativity_to_nid(associativity
);
1219 if (new_nid
< 0 || !node_possible(new_nid
))
1220 new_nid
= first_online_node
;
1222 if (NODE_DATA(new_nid
) == NULL
) {
1223 #ifdef CONFIG_MEMORY_HOTPLUG
1225 * Need to ensure that NODE_DATA is initialized for a node from
1226 * available memory (see memblock_alloc_try_nid). If unable to
1227 * init the node, then default to nearest node that has memory
1228 * installed. Skip onlining a node if the subsystems are not
1231 if (!topology_inited
|| try_online_node(new_nid
))
1232 new_nid
= first_online_node
;
1235 * Default to using the nearest node that has memory installed.
1236 * Otherwise, it would be necessary to patch the kernel MM code
1237 * to deal with more memoryless-node error conditions.
1239 new_nid
= first_online_node
;
1243 pr_debug("%s:%d cpu %d nid %d\n", __FUNCTION__
, __LINE__
,
1249 * Update the CPU maps and sysfs entries for a single CPU when its NUMA
1250 * characteristics change. This function doesn't perform any locking and is
1251 * only safe to call from stop_machine().
1253 static int update_cpu_topology(void *data
)
1255 struct topology_update_data
*update
;
1261 cpu
= smp_processor_id();
1263 for (update
= data
; update
; update
= update
->next
) {
1264 int new_nid
= update
->new_nid
;
1265 if (cpu
!= update
->cpu
)
1268 unmap_cpu_from_node(cpu
);
1269 map_cpu_to_node(cpu
, new_nid
);
1270 set_cpu_numa_node(cpu
, new_nid
);
1271 set_cpu_numa_mem(cpu
, local_memory_node(new_nid
));
1278 static int update_lookup_table(void *data
)
1280 struct topology_update_data
*update
;
1286 * Upon topology update, the numa-cpu lookup table needs to be updated
1287 * for all threads in the core, including offline CPUs, to ensure that
1288 * future hotplug operations respect the cpu-to-node associativity
1291 for (update
= data
; update
; update
= update
->next
) {
1294 nid
= update
->new_nid
;
1295 base
= cpu_first_thread_sibling(update
->cpu
);
1297 for (j
= 0; j
< threads_per_core
; j
++) {
1298 update_numa_cpu_lookup_table(base
+ j
, nid
);
1306 * Update the node maps and sysfs entries for each cpu whose home node
1307 * has changed. Returns 1 when the topology has changed, and 0 otherwise.
1309 * cpus_locked says whether we already hold cpu_hotplug_lock.
1311 int numa_update_cpu_topology(bool cpus_locked
)
1313 unsigned int cpu
, sibling
, changed
= 0;
1314 struct topology_update_data
*updates
, *ud
;
1315 cpumask_t updated_cpus
;
1317 int weight
, new_nid
, i
= 0;
1319 if (!prrn_enabled
&& !vphn_enabled
&& topology_inited
)
1322 weight
= cpumask_weight(&cpu_associativity_changes_mask
);
1326 updates
= kcalloc(weight
, sizeof(*updates
), GFP_KERNEL
);
1330 cpumask_clear(&updated_cpus
);
1332 for_each_cpu(cpu
, &cpu_associativity_changes_mask
) {
1334 * If siblings aren't flagged for changes, updates list
1335 * will be too short. Skip on this update and set for next
1338 if (!cpumask_subset(cpu_sibling_mask(cpu
),
1339 &cpu_associativity_changes_mask
)) {
1340 pr_info("Sibling bits not set for associativity "
1341 "change, cpu%d\n", cpu
);
1342 cpumask_or(&cpu_associativity_changes_mask
,
1343 &cpu_associativity_changes_mask
,
1344 cpu_sibling_mask(cpu
));
1345 cpu
= cpu_last_thread_sibling(cpu
);
1349 new_nid
= find_and_online_cpu_nid(cpu
);
1351 if (new_nid
== numa_cpu_lookup_table
[cpu
]) {
1352 cpumask_andnot(&cpu_associativity_changes_mask
,
1353 &cpu_associativity_changes_mask
,
1354 cpu_sibling_mask(cpu
));
1355 dbg("Assoc chg gives same node %d for cpu%d\n",
1357 cpu
= cpu_last_thread_sibling(cpu
);
1361 for_each_cpu(sibling
, cpu_sibling_mask(cpu
)) {
1363 ud
->next
= &updates
[i
];
1365 ud
->new_nid
= new_nid
;
1366 ud
->old_nid
= numa_cpu_lookup_table
[sibling
];
1367 cpumask_set_cpu(sibling
, &updated_cpus
);
1369 cpu
= cpu_last_thread_sibling(cpu
);
1373 * Prevent processing of 'updates' from overflowing array
1374 * where last entry filled in a 'next' pointer.
1377 updates
[i
-1].next
= NULL
;
1379 pr_debug("Topology update for the following CPUs:\n");
1380 if (cpumask_weight(&updated_cpus
)) {
1381 for (ud
= &updates
[0]; ud
; ud
= ud
->next
) {
1382 pr_debug("cpu %d moving from node %d "
1384 ud
->old_nid
, ud
->new_nid
);
1389 * In cases where we have nothing to update (because the updates list
1390 * is too short or because the new topology is same as the old one),
1391 * skip invoking update_cpu_topology() via stop-machine(). This is
1392 * necessary (and not just a fast-path optimization) since stop-machine
1393 * can end up electing a random CPU to run update_cpu_topology(), and
1394 * thus trick us into setting up incorrect cpu-node mappings (since
1395 * 'updates' is kzalloc()'ed).
1397 * And for the similar reason, we will skip all the following updating.
1399 if (!cpumask_weight(&updated_cpus
))
1403 stop_machine_cpuslocked(update_cpu_topology
, &updates
[0],
1406 stop_machine(update_cpu_topology
, &updates
[0], &updated_cpus
);
1409 * Update the numa-cpu lookup table with the new mappings, even for
1410 * offline CPUs. It is best to perform this update from the stop-
1414 stop_machine_cpuslocked(update_lookup_table
, &updates
[0],
1415 cpumask_of(raw_smp_processor_id()));
1417 stop_machine(update_lookup_table
, &updates
[0],
1418 cpumask_of(raw_smp_processor_id()));
1420 for (ud
= &updates
[0]; ud
; ud
= ud
->next
) {
1421 unregister_cpu_under_node(ud
->cpu
, ud
->old_nid
);
1422 register_cpu_under_node(ud
->cpu
, ud
->new_nid
);
1424 dev
= get_cpu_device(ud
->cpu
);
1426 kobject_uevent(&dev
->kobj
, KOBJ_CHANGE
);
1427 cpumask_clear_cpu(ud
->cpu
, &cpu_associativity_changes_mask
);
1436 int arch_update_cpu_topology(void)
1438 return numa_update_cpu_topology(true);
1441 static void topology_work_fn(struct work_struct
*work
)
1443 rebuild_sched_domains();
1445 static DECLARE_WORK(topology_work
, topology_work_fn
);
1447 static void topology_schedule_update(void)
1449 schedule_work(&topology_work
);
1452 static void topology_timer_fn(struct timer_list
*unused
)
1454 if (prrn_enabled
&& cpumask_weight(&cpu_associativity_changes_mask
))
1455 topology_schedule_update();
1456 else if (vphn_enabled
) {
1457 if (update_cpu_associativity_changes_mask() > 0)
1458 topology_schedule_update();
1459 reset_topology_timer();
1462 static struct timer_list topology_timer
;
1464 static void reset_topology_timer(void)
1467 mod_timer(&topology_timer
, jiffies
+ topology_timer_secs
* HZ
);
1472 static int dt_update_callback(struct notifier_block
*nb
,
1473 unsigned long action
, void *data
)
1475 struct of_reconfig_data
*update
= data
;
1476 int rc
= NOTIFY_DONE
;
1479 case OF_RECONFIG_UPDATE_PROPERTY
:
1480 if (of_node_is_type(update
->dn
, "cpu") &&
1481 !of_prop_cmp(update
->prop
->name
, "ibm,associativity")) {
1483 of_property_read_u32(update
->dn
, "reg", &core_id
);
1484 rc
= dlpar_cpu_readd(core_id
);
1493 static struct notifier_block dt_update_nb
= {
1494 .notifier_call
= dt_update_callback
,
1500 * Start polling for associativity changes.
1502 int start_topology_update(void)
1506 if (!topology_updates_enabled
)
1509 if (firmware_has_feature(FW_FEATURE_PRRN
)) {
1510 if (!prrn_enabled
) {
1513 rc
= of_reconfig_notifier_register(&dt_update_nb
);
1517 if (firmware_has_feature(FW_FEATURE_VPHN
) &&
1518 lppaca_shared_proc(get_lppaca())) {
1519 if (!vphn_enabled
) {
1521 setup_cpu_associativity_change_counters();
1522 timer_setup(&topology_timer
, topology_timer_fn
,
1524 reset_topology_timer();
1528 pr_info("Starting topology update%s%s\n",
1529 (prrn_enabled
? " prrn_enabled" : ""),
1530 (vphn_enabled
? " vphn_enabled" : ""));
1536 * Disable polling for VPHN associativity changes.
1538 int stop_topology_update(void)
1542 if (!topology_updates_enabled
)
1548 rc
= of_reconfig_notifier_unregister(&dt_update_nb
);
1553 rc
= del_timer_sync(&topology_timer
);
1556 pr_info("Stopping topology update\n");
1561 int prrn_is_enabled(void)
1563 return prrn_enabled
;
1566 void __init
shared_proc_topology_init(void)
1568 if (lppaca_shared_proc(get_lppaca())) {
1569 bitmap_fill(cpumask_bits(&cpu_associativity_changes_mask
),
1571 numa_update_cpu_topology(false);
1575 static int topology_read(struct seq_file
*file
, void *v
)
1577 if (vphn_enabled
|| prrn_enabled
)
1578 seq_puts(file
, "on\n");
1580 seq_puts(file
, "off\n");
1585 static int topology_open(struct inode
*inode
, struct file
*file
)
1587 return single_open(file
, topology_read
, NULL
);
1590 static ssize_t
topology_write(struct file
*file
, const char __user
*buf
,
1591 size_t count
, loff_t
*off
)
1593 char kbuf
[4]; /* "on" or "off" plus null. */
1596 read_len
= count
< 3 ? count
: 3;
1597 if (copy_from_user(kbuf
, buf
, read_len
))
1600 kbuf
[read_len
] = '\0';
1602 if (!strncmp(kbuf
, "on", 2)) {
1603 topology_updates_enabled
= true;
1604 start_topology_update();
1605 } else if (!strncmp(kbuf
, "off", 3)) {
1606 stop_topology_update();
1607 topology_updates_enabled
= false;
1614 static const struct file_operations topology_ops
= {
1616 .write
= topology_write
,
1617 .open
= topology_open
,
1618 .release
= single_release
1621 static int topology_update_init(void)
1623 start_topology_update();
1626 topology_schedule_update();
1628 if (!proc_create("powerpc/topology_updates", 0644, NULL
, &topology_ops
))
1631 topology_inited
= 1;
1634 device_initcall(topology_update_init
);
1635 #endif /* CONFIG_PPC_SPLPAR */