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linux/drivers/base/node.c
David Hildenbrand 395f6081ba drivers/base/memory: determine and store zone for single-zone memory blocks 
test_pages_in_a_zone() is just another nasty PFN walker that can easily
stumble over ZONE_DEVICE memory ranges falling into the same memory block
as ordinary system RAM: the memmap of parts of these ranges might possibly
be uninitialized.  In fact, we observed (on an older kernel) with UBSAN:

  UBSAN: Undefined behaviour in ./include/linux/mm.h:1133:50
  index 7 is out of range for type 'zone [5]'
  CPU: 121 PID: 35603 Comm: read_all Kdump: loaded Tainted: [...]
  Hardware name: Dell Inc. PowerEdge R7425/08V001, BIOS 1.12.2 11/15/2019
  Call Trace:
   dump_stack+0x9a/0xf0
   ubsan_epilogue+0x9/0x7a
   __ubsan_handle_out_of_bounds+0x13a/0x181
   test_pages_in_a_zone+0x3c4/0x500
   show_valid_zones+0x1fa/0x380
   dev_attr_show+0x43/0xb0
   sysfs_kf_seq_show+0x1c5/0x440
   seq_read+0x49d/0x1190
   vfs_read+0xff/0x300
   ksys_read+0xb8/0x170
   do_syscall_64+0xa5/0x4b0
   entry_SYSCALL_64_after_hwframe+0x6a/0xdf
  RIP: 0033:0x7f01f4439b52

We seem to stumble over a memmap that contains a garbage zone id.  While
we could try inserting pfn_to_online_page() calls, it will just make
memory offlining slower, because we use test_pages_in_a_zone() to make
sure we're offlining pages that all belong to the same zone.

Let's just get rid of this PFN walker and determine the single zone of a
memory block -- if any -- for early memory blocks during boot.  For memory
onlining, we know the single zone already.  Let's avoid any additional
memmap scanning and just rely on the zone information available during
boot.

For memory hot(un)plug, we only really care about memory blocks that:
* span a single zone (and, thereby, a single node)
* are completely System RAM (IOW, no holes, no ZONE_DEVICE)
If one of these conditions is not met, we reject memory offlining.
Hotplugged memory blocks (starting out offline), always meet both
conditions.

There are three scenarios to handle:

(1) Memory hot(un)plug

A memory block with zone == NULL cannot be offlined, corresponding to
our previous test_pages_in_a_zone() check.

After successful memory onlining/offlining, we simply set the zone
accordingly.
* Memory onlining: set the zone we just used for onlining
* Memory offlining: set zone = NULL

So a hotplugged memory block starts with zone = NULL. Once memory
onlining is done, we set the proper zone.

(2) Boot memory with !CONFIG_NUMA

We know that there is just a single pgdat, so we simply scan all zones
of that pgdat for an intersection with our memory block PFN range when
adding the memory block. If more than one zone intersects (e.g., DMA and
DMA32 on x86 for the first memory block) we set zone = NULL and
consequently mimic what test_pages_in_a_zone() used to do.

(3) Boot memory with CONFIG_NUMA

At the point in time we create the memory block devices during boot, we
don't know yet which nodes *actually* span a memory block. While we could
scan all zones of all nodes for intersections, overlapping nodes complicate
the situation and scanning all nodes is possibly expensive. But that
problem has already been solved by the code that sets the node of a memory
block and creates the link in the sysfs --
do_register_memory_block_under_node().

So, we hook into the code that sets the node id for a memory block. If
we already have a different node id set for the memory block, we know
that multiple nodes *actually* have PFNs falling into our memory block:
we set zone = NULL and consequently mimic what test_pages_in_a_zone() used
to do. If there is no node id set, we do the same as (2) for the given
node.

Note that the call order in driver_init() is:
-> memory_dev_init(): create memory block devices
-> node_dev_init(): link memory block devices to the node and set the
		    node id

So in summary, we detect if there is a single zone responsible for this
memory block and we consequently store the zone in that case in the
memory block, updating it during memory onlining/offlining.

Link: https://lkml.kernel.org/r/20220210184359.235565-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reported-by: Rafael Parra <rparrazo@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Rafael Parra <rparrazo@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22 15:57:10 -07:00

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// SPDX-License-Identifier: GPL-2.0
/*
* Basic Node interface support
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/memory.h>
#include <linux/vmstat.h>
#include <linux/notifier.h>
#include <linux/node.h>
#include <linux/hugetlb.h>
#include <linux/compaction.h>
#include <linux/cpumask.h>
#include <linux/topology.h>
#include <linux/nodemask.h>
#include <linux/cpu.h>
#include <linux/device.h>
#include <linux/pm_runtime.h>
#include <linux/swap.h>
#include <linux/slab.h>
static struct bus_type node_subsys = {
.name = "node",
.dev_name = "node",
};
static inline ssize_t cpumap_read(struct file *file, struct kobject *kobj,
struct bin_attribute *attr, char *buf,
loff_t off, size_t count)
{
struct device *dev = kobj_to_dev(kobj);
struct node *node_dev = to_node(dev);
cpumask_var_t mask;
ssize_t n;
if (!alloc_cpumask_var(&mask, GFP_KERNEL))
return 0;
cpumask_and(mask, cpumask_of_node(node_dev->dev.id), cpu_online_mask);
n = cpumap_print_bitmask_to_buf(buf, mask, off, count);
free_cpumask_var(mask);
return n;
}
static BIN_ATTR_RO(cpumap, 0);
static inline ssize_t cpulist_read(struct file *file, struct kobject *kobj,
struct bin_attribute *attr, char *buf,
loff_t off, size_t count)
{
struct device *dev = kobj_to_dev(kobj);
struct node *node_dev = to_node(dev);
cpumask_var_t mask;
ssize_t n;
if (!alloc_cpumask_var(&mask, GFP_KERNEL))
return 0;
cpumask_and(mask, cpumask_of_node(node_dev->dev.id), cpu_online_mask);
n = cpumap_print_list_to_buf(buf, mask, off, count);
free_cpumask_var(mask);
return n;
}
static BIN_ATTR_RO(cpulist, 0);
/**
* struct node_access_nodes - Access class device to hold user visible
* relationships to other nodes.
* @dev: Device for this memory access class
* @list_node: List element in the node's access list
* @access: The access class rank
* @hmem_attrs: Heterogeneous memory performance attributes
*/
struct node_access_nodes {
struct device dev;
struct list_head list_node;
unsigned int access;
#ifdef CONFIG_HMEM_REPORTING
struct node_hmem_attrs hmem_attrs;
#endif
};
#define to_access_nodes(dev) container_of(dev, struct node_access_nodes, dev)
static struct attribute *node_init_access_node_attrs[] = {
NULL,
};
static struct attribute *node_targ_access_node_attrs[] = {
NULL,
};
static const struct attribute_group initiators = {
.name = "initiators",
.attrs = node_init_access_node_attrs,
};
static const struct attribute_group targets = {
.name = "targets",
.attrs = node_targ_access_node_attrs,
};
static const struct attribute_group *node_access_node_groups[] = {
&initiators,
&targets,
NULL,
};
static void node_remove_accesses(struct node *node)
{
struct node_access_nodes *c, *cnext;
list_for_each_entry_safe(c, cnext, &node->access_list, list_node) {
list_del(&c->list_node);
device_unregister(&c->dev);
}
}
static void node_access_release(struct device *dev)
{
kfree(to_access_nodes(dev));
}
static struct node_access_nodes *node_init_node_access(struct node *node,
unsigned int access)
{
struct node_access_nodes *access_node;
struct device *dev;
list_for_each_entry(access_node, &node->access_list, list_node)
if (access_node->access == access)
return access_node;
access_node = kzalloc(sizeof(*access_node), GFP_KERNEL);
if (!access_node)
return NULL;
access_node->access = access;
dev = &access_node->dev;
dev->parent = &node->dev;
dev->release = node_access_release;
dev->groups = node_access_node_groups;
if (dev_set_name(dev, "access%u", access))
goto free;
if (device_register(dev))
goto free_name;
pm_runtime_no_callbacks(dev);
list_add_tail(&access_node->list_node, &node->access_list);
return access_node;
free_name:
kfree_const(dev->kobj.name);
free:
kfree(access_node);
return NULL;
}
#ifdef CONFIG_HMEM_REPORTING
#define ACCESS_ATTR(name) \
static ssize_t name##_show(struct device *dev, \
struct device_attribute *attr, \
char *buf) \
{ \
return sysfs_emit(buf, "%u\n", \
to_access_nodes(dev)->hmem_attrs.name); \
} \
static DEVICE_ATTR_RO(name)
ACCESS_ATTR(read_bandwidth);
ACCESS_ATTR(read_latency);
ACCESS_ATTR(write_bandwidth);
ACCESS_ATTR(write_latency);
static struct attribute *access_attrs[] = {
&dev_attr_read_bandwidth.attr,
&dev_attr_read_latency.attr,
&dev_attr_write_bandwidth.attr,
&dev_attr_write_latency.attr,
NULL,
};
/**
* node_set_perf_attrs - Set the performance values for given access class
* @nid: Node identifier to be set
* @hmem_attrs: Heterogeneous memory performance attributes
* @access: The access class the for the given attributes
*/
void node_set_perf_attrs(unsigned int nid, struct node_hmem_attrs *hmem_attrs,
unsigned int access)
{
struct node_access_nodes *c;
struct node *node;
int i;
if (WARN_ON_ONCE(!node_online(nid)))
return;
node = node_devices[nid];
c = node_init_node_access(node, access);
if (!c)
return;
c->hmem_attrs = *hmem_attrs;
for (i = 0; access_attrs[i] != NULL; i++) {
if (sysfs_add_file_to_group(&c->dev.kobj, access_attrs[i],
"initiators")) {
pr_info("failed to add performance attribute to node %d\n",
nid);
break;
}
}
}
/**
* struct node_cache_info - Internal tracking for memory node caches
* @dev: Device represeting the cache level
* @node: List element for tracking in the node
* @cache_attrs:Attributes for this cache level
*/
struct node_cache_info {
struct device dev;
struct list_head node;
struct node_cache_attrs cache_attrs;
};
#define to_cache_info(device) container_of(device, struct node_cache_info, dev)
#define CACHE_ATTR(name, fmt) \
static ssize_t name##_show(struct device *dev, \
struct device_attribute *attr, \
char *buf) \
{ \
return sysfs_emit(buf, fmt "\n", \
to_cache_info(dev)->cache_attrs.name); \
} \
static DEVICE_ATTR_RO(name);
CACHE_ATTR(size, "%llu")
CACHE_ATTR(line_size, "%u")
CACHE_ATTR(indexing, "%u")
CACHE_ATTR(write_policy, "%u")
static struct attribute *cache_attrs[] = {
&dev_attr_indexing.attr,
&dev_attr_size.attr,
&dev_attr_line_size.attr,
&dev_attr_write_policy.attr,
NULL,
};
ATTRIBUTE_GROUPS(cache);
static void node_cache_release(struct device *dev)
{
kfree(dev);
}
static void node_cacheinfo_release(struct device *dev)
{
struct node_cache_info *info = to_cache_info(dev);
kfree(info);
}
static void node_init_cache_dev(struct node *node)
{
struct device *dev;
dev = kzalloc(sizeof(*dev), GFP_KERNEL);
if (!dev)
return;
device_initialize(dev);
dev->parent = &node->dev;
dev->release = node_cache_release;
if (dev_set_name(dev, "memory_side_cache"))
goto put_device;
if (device_add(dev))
goto put_device;
pm_runtime_no_callbacks(dev);
node->cache_dev = dev;
return;
put_device:
put_device(dev);
}
/**
* node_add_cache() - add cache attribute to a memory node
* @nid: Node identifier that has new cache attributes
* @cache_attrs: Attributes for the cache being added
*/
void node_add_cache(unsigned int nid, struct node_cache_attrs *cache_attrs)
{
struct node_cache_info *info;
struct device *dev;
struct node *node;
if (!node_online(nid) || !node_devices[nid])
return;
node = node_devices[nid];
list_for_each_entry(info, &node->cache_attrs, node) {
if (info->cache_attrs.level == cache_attrs->level) {
dev_warn(&node->dev,
"attempt to add duplicate cache level:%d\n",
cache_attrs->level);
return;
}
}
if (!node->cache_dev)
node_init_cache_dev(node);
if (!node->cache_dev)
return;
info = kzalloc(sizeof(*info), GFP_KERNEL);
if (!info)
return;
dev = &info->dev;
device_initialize(dev);
dev->parent = node->cache_dev;
dev->release = node_cacheinfo_release;
dev->groups = cache_groups;
if (dev_set_name(dev, "index%d", cache_attrs->level))
goto put_device;
info->cache_attrs = *cache_attrs;
if (device_add(dev)) {
dev_warn(&node->dev, "failed to add cache level:%d\n",
cache_attrs->level);
goto put_device;
}
pm_runtime_no_callbacks(dev);
list_add_tail(&info->node, &node->cache_attrs);
return;
put_device:
put_device(dev);
}
static void node_remove_caches(struct node *node)
{
struct node_cache_info *info, *next;
if (!node->cache_dev)
return;
list_for_each_entry_safe(info, next, &node->cache_attrs, node) {
list_del(&info->node);
device_unregister(&info->dev);
}
device_unregister(node->cache_dev);
}
static void node_init_caches(unsigned int nid)
{
INIT_LIST_HEAD(&node_devices[nid]->cache_attrs);
}
#else
static void node_init_caches(unsigned int nid) { }
static void node_remove_caches(struct node *node) { }
#endif
#define K(x) ((x) << (PAGE_SHIFT - 10))
static ssize_t node_read_meminfo(struct device *dev,
struct device_attribute *attr, char *buf)
{
int len = 0;
int nid = dev->id;
struct pglist_data *pgdat = NODE_DATA(nid);
struct sysinfo i;
unsigned long sreclaimable, sunreclaimable;
unsigned long swapcached = 0;
si_meminfo_node(&i, nid);
sreclaimable = node_page_state_pages(pgdat, NR_SLAB_RECLAIMABLE_B);
sunreclaimable = node_page_state_pages(pgdat, NR_SLAB_UNRECLAIMABLE_B);
#ifdef CONFIG_SWAP
swapcached = node_page_state_pages(pgdat, NR_SWAPCACHE);
#endif
len = sysfs_emit_at(buf, len,
"Node %d MemTotal: %8lu kB\n"
"Node %d MemFree: %8lu kB\n"
"Node %d MemUsed: %8lu kB\n"
"Node %d SwapCached: %8lu kB\n"
"Node %d Active: %8lu kB\n"
"Node %d Inactive: %8lu kB\n"
"Node %d Active(anon): %8lu kB\n"
"Node %d Inactive(anon): %8lu kB\n"
"Node %d Active(file): %8lu kB\n"
"Node %d Inactive(file): %8lu kB\n"
"Node %d Unevictable: %8lu kB\n"
"Node %d Mlocked: %8lu kB\n",
nid, K(i.totalram),
nid, K(i.freeram),
nid, K(i.totalram - i.freeram),
nid, K(swapcached),
nid, K(node_page_state(pgdat, NR_ACTIVE_ANON) +
node_page_state(pgdat, NR_ACTIVE_FILE)),
nid, K(node_page_state(pgdat, NR_INACTIVE_ANON) +
node_page_state(pgdat, NR_INACTIVE_FILE)),
nid, K(node_page_state(pgdat, NR_ACTIVE_ANON)),
nid, K(node_page_state(pgdat, NR_INACTIVE_ANON)),
nid, K(node_page_state(pgdat, NR_ACTIVE_FILE)),
nid, K(node_page_state(pgdat, NR_INACTIVE_FILE)),
nid, K(node_page_state(pgdat, NR_UNEVICTABLE)),
nid, K(sum_zone_node_page_state(nid, NR_MLOCK)));
#ifdef CONFIG_HIGHMEM
len += sysfs_emit_at(buf, len,
"Node %d HighTotal: %8lu kB\n"
"Node %d HighFree: %8lu kB\n"
"Node %d LowTotal: %8lu kB\n"
"Node %d LowFree: %8lu kB\n",
nid, K(i.totalhigh),
nid, K(i.freehigh),
nid, K(i.totalram - i.totalhigh),
nid, K(i.freeram - i.freehigh));
#endif
len += sysfs_emit_at(buf, len,
"Node %d Dirty: %8lu kB\n"
"Node %d Writeback: %8lu kB\n"
"Node %d FilePages: %8lu kB\n"
"Node %d Mapped: %8lu kB\n"
"Node %d AnonPages: %8lu kB\n"
"Node %d Shmem: %8lu kB\n"
"Node %d KernelStack: %8lu kB\n"
#ifdef CONFIG_SHADOW_CALL_STACK
"Node %d ShadowCallStack:%8lu kB\n"
#endif
"Node %d PageTables: %8lu kB\n"
"Node %d NFS_Unstable: %8lu kB\n"
"Node %d Bounce: %8lu kB\n"
"Node %d WritebackTmp: %8lu kB\n"
"Node %d KReclaimable: %8lu kB\n"
"Node %d Slab: %8lu kB\n"
"Node %d SReclaimable: %8lu kB\n"
"Node %d SUnreclaim: %8lu kB\n"
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
"Node %d AnonHugePages: %8lu kB\n"
"Node %d ShmemHugePages: %8lu kB\n"
"Node %d ShmemPmdMapped: %8lu kB\n"
"Node %d FileHugePages: %8lu kB\n"
"Node %d FilePmdMapped: %8lu kB\n"
#endif
,
nid, K(node_page_state(pgdat, NR_FILE_DIRTY)),
nid, K(node_page_state(pgdat, NR_WRITEBACK)),
nid, K(node_page_state(pgdat, NR_FILE_PAGES)),
nid, K(node_page_state(pgdat, NR_FILE_MAPPED)),
nid, K(node_page_state(pgdat, NR_ANON_MAPPED)),
nid, K(i.sharedram),
nid, node_page_state(pgdat, NR_KERNEL_STACK_KB),
#ifdef CONFIG_SHADOW_CALL_STACK
nid, node_page_state(pgdat, NR_KERNEL_SCS_KB),
#endif
nid, K(node_page_state(pgdat, NR_PAGETABLE)),
nid, 0UL,
nid, K(sum_zone_node_page_state(nid, NR_BOUNCE)),
nid, K(node_page_state(pgdat, NR_WRITEBACK_TEMP)),
nid, K(sreclaimable +
node_page_state(pgdat, NR_KERNEL_MISC_RECLAIMABLE)),
nid, K(sreclaimable + sunreclaimable),
nid, K(sreclaimable),
nid, K(sunreclaimable)
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
,
nid, K(node_page_state(pgdat, NR_ANON_THPS)),
nid, K(node_page_state(pgdat, NR_SHMEM_THPS)),
nid, K(node_page_state(pgdat, NR_SHMEM_PMDMAPPED)),
nid, K(node_page_state(pgdat, NR_FILE_THPS)),
nid, K(node_page_state(pgdat, NR_FILE_PMDMAPPED))
#endif
);
len += hugetlb_report_node_meminfo(buf, len, nid);
return len;
}
#undef K
static DEVICE_ATTR(meminfo, 0444, node_read_meminfo, NULL);
static ssize_t node_read_numastat(struct device *dev,
struct device_attribute *attr, char *buf)
{
fold_vm_numa_events();
return sysfs_emit(buf,
"numa_hit %lu\n"
"numa_miss %lu\n"
"numa_foreign %lu\n"
"interleave_hit %lu\n"
"local_node %lu\n"
"other_node %lu\n",
sum_zone_numa_event_state(dev->id, NUMA_HIT),
sum_zone_numa_event_state(dev->id, NUMA_MISS),
sum_zone_numa_event_state(dev->id, NUMA_FOREIGN),
sum_zone_numa_event_state(dev->id, NUMA_INTERLEAVE_HIT),
sum_zone_numa_event_state(dev->id, NUMA_LOCAL),
sum_zone_numa_event_state(dev->id, NUMA_OTHER));
}
static DEVICE_ATTR(numastat, 0444, node_read_numastat, NULL);
static ssize_t node_read_vmstat(struct device *dev,
struct device_attribute *attr, char *buf)
{
int nid = dev->id;
struct pglist_data *pgdat = NODE_DATA(nid);
int i;
int len = 0;
for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
len += sysfs_emit_at(buf, len, "%s %lu\n",
zone_stat_name(i),
sum_zone_node_page_state(nid, i));
#ifdef CONFIG_NUMA
fold_vm_numa_events();
for (i = 0; i < NR_VM_NUMA_EVENT_ITEMS; i++)
len += sysfs_emit_at(buf, len, "%s %lu\n",
numa_stat_name(i),
sum_zone_numa_event_state(nid, i));
#endif
for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) {
unsigned long pages = node_page_state_pages(pgdat, i);
if (vmstat_item_print_in_thp(i))
pages /= HPAGE_PMD_NR;
len += sysfs_emit_at(buf, len, "%s %lu\n", node_stat_name(i),
pages);
}
return len;
}
static DEVICE_ATTR(vmstat, 0444, node_read_vmstat, NULL);
static ssize_t node_read_distance(struct device *dev,
struct device_attribute *attr, char *buf)
{
int nid = dev->id;
int len = 0;
int i;
/*
* buf is currently PAGE_SIZE in length and each node needs 4 chars
* at the most (distance + space or newline).
*/
BUILD_BUG_ON(MAX_NUMNODES * 4 > PAGE_SIZE);
for_each_online_node(i) {
len += sysfs_emit_at(buf, len, "%s%d",
i ? " " : "", node_distance(nid, i));
}
len += sysfs_emit_at(buf, len, "\n");
return len;
}
static DEVICE_ATTR(distance, 0444, node_read_distance, NULL);
static struct attribute *node_dev_attrs[] = {
&dev_attr_meminfo.attr,
&dev_attr_numastat.attr,
&dev_attr_distance.attr,
&dev_attr_vmstat.attr,
NULL
};
static struct bin_attribute *node_dev_bin_attrs[] = {
&bin_attr_cpumap,
&bin_attr_cpulist,
NULL
};
static const struct attribute_group node_dev_group = {
.attrs = node_dev_attrs,
.bin_attrs = node_dev_bin_attrs
};
static const struct attribute_group *node_dev_groups[] = {
&node_dev_group,
#ifdef CONFIG_HAVE_ARCH_NODE_DEV_GROUP
&arch_node_dev_group,
#endif
NULL
};
#ifdef CONFIG_HUGETLBFS
/*
* hugetlbfs per node attributes registration interface:
* When/if hugetlb[fs] subsystem initializes [sometime after this module],
* it will register its per node attributes for all online nodes with
* memory. It will also call register_hugetlbfs_with_node(), below, to
* register its attribute registration functions with this node driver.
* Once these hooks have been initialized, the node driver will call into
* the hugetlb module to [un]register attributes for hot-plugged nodes.
*/
static node_registration_func_t __hugetlb_register_node;
static node_registration_func_t __hugetlb_unregister_node;
static inline bool hugetlb_register_node(struct node *node)
{
if (__hugetlb_register_node &&
node_state(node->dev.id, N_MEMORY)) {
__hugetlb_register_node(node);
return true;
}
return false;
}
static inline void hugetlb_unregister_node(struct node *node)
{
if (__hugetlb_unregister_node)
__hugetlb_unregister_node(node);
}
void register_hugetlbfs_with_node(node_registration_func_t doregister,
node_registration_func_t unregister)
{
__hugetlb_register_node = doregister;
__hugetlb_unregister_node = unregister;
}
#else
static inline void hugetlb_register_node(struct node *node) {}
static inline void hugetlb_unregister_node(struct node *node) {}
#endif
static void node_device_release(struct device *dev)
{
struct node *node = to_node(dev);
#if defined(CONFIG_MEMORY_HOTPLUG) && defined(CONFIG_HUGETLBFS)
/*
* We schedule the work only when a memory section is
* onlined/offlined on this node. When we come here,
* all the memory on this node has been offlined,
* so we won't enqueue new work to this work.
*
* The work is using node->node_work, so we should
* flush work before freeing the memory.
*/
flush_work(&node->node_work);
#endif
kfree(node);
}
/*
* register_node - Setup a sysfs device for a node.
* @num - Node number to use when creating the device.
*
* Initialize and register the node device.
*/
static int register_node(struct node *node, int num)
{
int error;
node->dev.id = num;
node->dev.bus = &node_subsys;
node->dev.release = node_device_release;
node->dev.groups = node_dev_groups;
error = device_register(&node->dev);
if (error)
put_device(&node->dev);
else {
hugetlb_register_node(node);
compaction_register_node(node);
}
return error;
}
/**
* unregister_node - unregister a node device
* @node: node going away
*
* Unregisters a node device @node. All the devices on the node must be
* unregistered before calling this function.
*/
void unregister_node(struct node *node)
{
hugetlb_unregister_node(node); /* no-op, if memoryless node */
node_remove_accesses(node);
node_remove_caches(node);
device_unregister(&node->dev);
}
struct node *node_devices[MAX_NUMNODES];
/*
* register cpu under node
*/
int register_cpu_under_node(unsigned int cpu, unsigned int nid)
{
int ret;
struct device *obj;
if (!node_online(nid))
return 0;
obj = get_cpu_device(cpu);
if (!obj)
return 0;
ret = sysfs_create_link(&node_devices[nid]->dev.kobj,
&obj->kobj,
kobject_name(&obj->kobj));
if (ret)
return ret;
return sysfs_create_link(&obj->kobj,
&node_devices[nid]->dev.kobj,
kobject_name(&node_devices[nid]->dev.kobj));
}
/**
* register_memory_node_under_compute_node - link memory node to its compute
* node for a given access class.
* @mem_nid: Memory node number
* @cpu_nid: Cpu node number
* @access: Access class to register
*
* Description:
* For use with platforms that may have separate memory and compute nodes.
* This function will export node relationships linking which memory
* initiator nodes can access memory targets at a given ranked access
* class.
*/
int register_memory_node_under_compute_node(unsigned int mem_nid,
unsigned int cpu_nid,
unsigned int access)
{
struct node *init_node, *targ_node;
struct node_access_nodes *initiator, *target;
int ret;
if (!node_online(cpu_nid) || !node_online(mem_nid))
return -ENODEV;
init_node = node_devices[cpu_nid];
targ_node = node_devices[mem_nid];
initiator = node_init_node_access(init_node, access);
target = node_init_node_access(targ_node, access);
if (!initiator || !target)
return -ENOMEM;
ret = sysfs_add_link_to_group(&initiator->dev.kobj, "targets",
&targ_node->dev.kobj,
dev_name(&targ_node->dev));
if (ret)
return ret;
ret = sysfs_add_link_to_group(&target->dev.kobj, "initiators",
&init_node->dev.kobj,
dev_name(&init_node->dev));
if (ret)
goto err;
return 0;
err:
sysfs_remove_link_from_group(&initiator->dev.kobj, "targets",
dev_name(&targ_node->dev));
return ret;
}
int unregister_cpu_under_node(unsigned int cpu, unsigned int nid)
{
struct device *obj;
if (!node_online(nid))
return 0;
obj = get_cpu_device(cpu);
if (!obj)
return 0;
sysfs_remove_link(&node_devices[nid]->dev.kobj,
kobject_name(&obj->kobj));
sysfs_remove_link(&obj->kobj,
kobject_name(&node_devices[nid]->dev.kobj));
return 0;
}
#ifdef CONFIG_MEMORY_HOTPLUG
static int __ref get_nid_for_pfn(unsigned long pfn)
{
#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
if (system_state < SYSTEM_RUNNING)
return early_pfn_to_nid(pfn);
#endif
return pfn_to_nid(pfn);
}
static void do_register_memory_block_under_node(int nid,
struct memory_block *mem_blk,
enum meminit_context context)
{
int ret;
memory_block_add_nid(mem_blk, nid, context);
ret = sysfs_create_link_nowarn(&node_devices[nid]->dev.kobj,
&mem_blk->dev.kobj,
kobject_name(&mem_blk->dev.kobj));
if (ret && ret != -EEXIST)
dev_err_ratelimited(&node_devices[nid]->dev,
"can't create link to %s in sysfs (%d)\n",
kobject_name(&mem_blk->dev.kobj), ret);
ret = sysfs_create_link_nowarn(&mem_blk->dev.kobj,
&node_devices[nid]->dev.kobj,
kobject_name(&node_devices[nid]->dev.kobj));
if (ret && ret != -EEXIST)
dev_err_ratelimited(&mem_blk->dev,
"can't create link to %s in sysfs (%d)\n",
kobject_name(&node_devices[nid]->dev.kobj),
ret);
}
/* register memory section under specified node if it spans that node */
static int register_mem_block_under_node_early(struct memory_block *mem_blk,
void *arg)
{
unsigned long memory_block_pfns = memory_block_size_bytes() / PAGE_SIZE;
unsigned long start_pfn = section_nr_to_pfn(mem_blk->start_section_nr);
unsigned long end_pfn = start_pfn + memory_block_pfns - 1;
int nid = *(int *)arg;
unsigned long pfn;
for (pfn = start_pfn; pfn <= end_pfn; pfn++) {
int page_nid;
/*
* memory block could have several absent sections from start.
* skip pfn range from absent section
*/
if (!pfn_in_present_section(pfn)) {
pfn = round_down(pfn + PAGES_PER_SECTION,
PAGES_PER_SECTION) - 1;
continue;
}
/*
* We need to check if page belongs to nid only at the boot
* case because node's ranges can be interleaved.
*/
page_nid = get_nid_for_pfn(pfn);
if (page_nid < 0)
continue;
if (page_nid != nid)
continue;
do_register_memory_block_under_node(nid, mem_blk, MEMINIT_EARLY);
return 0;
}
/* mem section does not span the specified node */
return 0;
}
/*
* During hotplug we know that all pages in the memory block belong to the same
* node.
*/
static int register_mem_block_under_node_hotplug(struct memory_block *mem_blk,
void *arg)
{
int nid = *(int *)arg;
do_register_memory_block_under_node(nid, mem_blk, MEMINIT_HOTPLUG);
return 0;
}
/*
* Unregister a memory block device under the node it spans. Memory blocks
* with multiple nodes cannot be offlined and therefore also never be removed.
*/
void unregister_memory_block_under_nodes(struct memory_block *mem_blk)
{
if (mem_blk->nid == NUMA_NO_NODE)
return;
sysfs_remove_link(&node_devices[mem_blk->nid]->dev.kobj,
kobject_name(&mem_blk->dev.kobj));
sysfs_remove_link(&mem_blk->dev.kobj,
kobject_name(&node_devices[mem_blk->nid]->dev.kobj));
}
void register_memory_blocks_under_node(int nid, unsigned long start_pfn,
unsigned long end_pfn,
enum meminit_context context)
{
walk_memory_blocks_func_t func;
if (context == MEMINIT_HOTPLUG)
func = register_mem_block_under_node_hotplug;
else
func = register_mem_block_under_node_early;
walk_memory_blocks(PFN_PHYS(start_pfn), PFN_PHYS(end_pfn - start_pfn),
(void *)&nid, func);
return;
}
#ifdef CONFIG_HUGETLBFS
/*
* Handle per node hstate attribute [un]registration on transistions
* to/from memoryless state.
*/
static void node_hugetlb_work(struct work_struct *work)
{
struct node *node = container_of(work, struct node, node_work);
/*
* We only get here when a node transitions to/from memoryless state.
* We can detect which transition occurred by examining whether the
* node has memory now. hugetlb_register_node() already check this
* so we try to register the attributes. If that fails, then the
* node has transitioned to memoryless, try to unregister the
* attributes.
*/
if (!hugetlb_register_node(node))
hugetlb_unregister_node(node);
}
static void init_node_hugetlb_work(int nid)
{
INIT_WORK(&node_devices[nid]->node_work, node_hugetlb_work);
}
static int node_memory_callback(struct notifier_block *self,
unsigned long action, void *arg)
{
struct memory_notify *mnb = arg;
int nid = mnb->status_change_nid;
switch (action) {
case MEM_ONLINE:
case MEM_OFFLINE:
/*
* offload per node hstate [un]registration to a work thread
* when transitioning to/from memoryless state.
*/
if (nid != NUMA_NO_NODE)
schedule_work(&node_devices[nid]->node_work);
break;
case MEM_GOING_ONLINE:
case MEM_GOING_OFFLINE:
case MEM_CANCEL_ONLINE:
case MEM_CANCEL_OFFLINE:
default:
break;
}
return NOTIFY_OK;
}
#endif /* CONFIG_HUGETLBFS */
#endif /* CONFIG_MEMORY_HOTPLUG */
#if !defined(CONFIG_MEMORY_HOTPLUG) || !defined(CONFIG_HUGETLBFS)
static inline int node_memory_callback(struct notifier_block *self,
unsigned long action, void *arg)
{
return NOTIFY_OK;
}
static void init_node_hugetlb_work(int nid) { }
#endif
int __register_one_node(int nid)
{
int error;
int cpu;
node_devices[nid] = kzalloc(sizeof(struct node), GFP_KERNEL);
if (!node_devices[nid])
return -ENOMEM;
error = register_node(node_devices[nid], nid);
/* link cpu under this node */
for_each_present_cpu(cpu) {
if (cpu_to_node(cpu) == nid)
register_cpu_under_node(cpu, nid);
}
INIT_LIST_HEAD(&node_devices[nid]->access_list);
/* initialize work queue for memory hot plug */
init_node_hugetlb_work(nid);
node_init_caches(nid);
return error;
}
void unregister_one_node(int nid)
{
if (!node_devices[nid])
return;
unregister_node(node_devices[nid]);
node_devices[nid] = NULL;
}
/*
* node states attributes
*/
struct node_attr {
struct device_attribute attr;
enum node_states state;
};
static ssize_t show_node_state(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct node_attr *na = container_of(attr, struct node_attr, attr);
return sysfs_emit(buf, "%*pbl\n",
nodemask_pr_args(&node_states[na->state]));
}
#define _NODE_ATTR(name, state) \
{ __ATTR(name, 0444, show_node_state, NULL), state }
static struct node_attr node_state_attr[] = {
[N_POSSIBLE] = _NODE_ATTR(possible, N_POSSIBLE),
[N_ONLINE] = _NODE_ATTR(online, N_ONLINE),
[N_NORMAL_MEMORY] = _NODE_ATTR(has_normal_memory, N_NORMAL_MEMORY),
#ifdef CONFIG_HIGHMEM
[N_HIGH_MEMORY] = _NODE_ATTR(has_high_memory, N_HIGH_MEMORY),
#endif
[N_MEMORY] = _NODE_ATTR(has_memory, N_MEMORY),
[N_CPU] = _NODE_ATTR(has_cpu, N_CPU),
[N_GENERIC_INITIATOR] = _NODE_ATTR(has_generic_initiator,
N_GENERIC_INITIATOR),
};
static struct attribute *node_state_attrs[] = {
&node_state_attr[N_POSSIBLE].attr.attr,
&node_state_attr[N_ONLINE].attr.attr,
&node_state_attr[N_NORMAL_MEMORY].attr.attr,
#ifdef CONFIG_HIGHMEM
&node_state_attr[N_HIGH_MEMORY].attr.attr,
#endif
&node_state_attr[N_MEMORY].attr.attr,
&node_state_attr[N_CPU].attr.attr,
&node_state_attr[N_GENERIC_INITIATOR].attr.attr,
NULL
};
static const struct attribute_group memory_root_attr_group = {
.attrs = node_state_attrs,
};
static const struct attribute_group *cpu_root_attr_groups[] = {
&memory_root_attr_group,
NULL,
};
#define NODE_CALLBACK_PRI 2 /* lower than SLAB */
void __init node_dev_init(void)
{
static struct notifier_block node_memory_callback_nb = {
.notifier_call = node_memory_callback,
.priority = NODE_CALLBACK_PRI,
};
int ret, i;
BUILD_BUG_ON(ARRAY_SIZE(node_state_attr) != NR_NODE_STATES);
BUILD_BUG_ON(ARRAY_SIZE(node_state_attrs)-1 != NR_NODE_STATES);
ret = subsys_system_register(&node_subsys, cpu_root_attr_groups);
if (ret)
panic("%s() failed to register subsystem: %d\n", __func__, ret);
register_hotmemory_notifier(&node_memory_callback_nb);
/*
* Create all node devices, which will properly link the node
* to applicable memory block devices and already created cpu devices.
*/
for_each_online_node(i) {
ret = register_one_node(i);
if (ret)
panic("%s() failed to add node: %d\n", __func__, ret);
}
}
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