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OpenCloudOS-Kernel/drivers/base/memory.c

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// SPDX-License-Identifier: GPL-2.0
/*
* Memory subsystem support
*
* Written by Matt Tolentino <matthew.e.tolentino@intel.com>
* Dave Hansen <haveblue@us.ibm.com>
*
* This file provides the necessary infrastructure to represent
* a SPARSEMEM-memory-model system's physical memory in /sysfs.
* All arch-independent code that assumes MEMORY_HOTPLUG requires
* SPARSEMEM should be contained here, or in mm/memory_hotplug.c.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/topology.h>
#include <linux/capability.h>
#include <linux/device.h>
#include <linux/memory.h>
#include <linux/memory_hotplug.h>
#include <linux/mm.h>
#include <linux/stat.h>
#include <linux/slab.h>
#include <linux/xarray.h>
#include <linux/atomic.h>
#include <linux/uaccess.h>
#define MEMORY_CLASS_NAME "memory"
static const char *const online_type_to_str[] = {
[MMOP_OFFLINE] = "offline",
[MMOP_ONLINE] = "online",
[MMOP_ONLINE_KERNEL] = "online_kernel",
[MMOP_ONLINE_MOVABLE] = "online_movable",
};
int memhp_online_type_from_str(const char *str)
{
int i;
for (i = 0; i < ARRAY_SIZE(online_type_to_str); i++) {
if (sysfs_streq(str, online_type_to_str[i]))
return i;
}
return -EINVAL;
}
#define to_memory_block(dev) container_of(dev, struct memory_block, dev)
static int sections_per_block;
static inline unsigned long memory_block_id(unsigned long section_nr)
{
return section_nr / sections_per_block;
}
static inline unsigned long pfn_to_block_id(unsigned long pfn)
{
return memory_block_id(pfn_to_section_nr(pfn));
}
static inline unsigned long phys_to_block_id(unsigned long phys)
{
return pfn_to_block_id(PFN_DOWN(phys));
}
static int memory_subsys_online(struct device *dev);
static int memory_subsys_offline(struct device *dev);
static struct bus_type memory_subsys = {
.name = MEMORY_CLASS_NAME,
.dev_name = MEMORY_CLASS_NAME,
.online = memory_subsys_online,
.offline = memory_subsys_offline,
};
/*
* Memory blocks are cached in a local radix tree to avoid
* a costly linear search for the corresponding device on
* the subsystem bus.
*/
static DEFINE_XARRAY(memory_blocks);
static BLOCKING_NOTIFIER_HEAD(memory_chain);
int register_memory_notifier(struct notifier_block *nb)
{
return blocking_notifier_chain_register(&memory_chain, nb);
}
EXPORT_SYMBOL(register_memory_notifier);
void unregister_memory_notifier(struct notifier_block *nb)
{
blocking_notifier_chain_unregister(&memory_chain, nb);
}
EXPORT_SYMBOL(unregister_memory_notifier);
static void memory_block_release(struct device *dev)
{
struct memory_block *mem = to_memory_block(dev);
kfree(mem);
}
unsigned long __weak memory_block_size_bytes(void)
{
return MIN_MEMORY_BLOCK_SIZE;
}
EXPORT_SYMBOL_GPL(memory_block_size_bytes);
/*
* Show the first physical section index (number) of this memory block.
*/
static ssize_t phys_index_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct memory_block *mem = to_memory_block(dev);
unsigned long phys_index;
phys_index = mem->start_section_nr / sections_per_block;
return sysfs_emit(buf, "%08lx\n", phys_index);
}
/*
* Legacy interface that we cannot remove. Always indicate "removable"
* with CONFIG_MEMORY_HOTREMOVE - bad heuristic.
*/
static ssize_t removable_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
return sysfs_emit(buf, "%d\n", (int)IS_ENABLED(CONFIG_MEMORY_HOTREMOVE));
}
/*
* online, offline, going offline, etc.
*/
static ssize_t state_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct memory_block *mem = to_memory_block(dev);
const char *output;
/*
* We can probably put these states in a nice little array
* so that they're not open-coded
*/
switch (mem->state) {
case MEM_ONLINE:
output = "online";
break;
case MEM_OFFLINE:
output = "offline";
break;
case MEM_GOING_OFFLINE:
output = "going-offline";
break;
default:
WARN_ON(1);
return sysfs_emit(buf, "ERROR-UNKNOWN-%ld\n", mem->state);
}
return sysfs_emit(buf, "%s\n", output);
}
int memory_notify(unsigned long val, void *v)
{
return blocking_notifier_call_chain(&memory_chain, val, v);
}
/*
* MEMORY_HOTPLUG depends on SPARSEMEM in mm/Kconfig, so it is
* OK to have direct references to sparsemem variables in here.
*/
static int
memory_block_action(unsigned long start_section_nr, unsigned long action,
int online_type, int nid)
{
unsigned long start_pfn;
unsigned long nr_pages = PAGES_PER_SECTION * sections_per_block;
int ret;
start_pfn = section_nr_to_pfn(start_section_nr);
switch (action) {
case MEM_ONLINE:
ret = online_pages(start_pfn, nr_pages, online_type, nid);
break;
case MEM_OFFLINE:
ret = offline_pages(start_pfn, nr_pages);
break;
default:
WARN(1, KERN_WARNING "%s(%ld, %ld) unknown action: "
"%ld\n", __func__, start_section_nr, action, action);
ret = -EINVAL;
}
return ret;
}
static int memory_block_change_state(struct memory_block *mem,
unsigned long to_state, unsigned long from_state_req)
{
int ret = 0;
if (mem->state != from_state_req)
return -EINVAL;
if (to_state == MEM_OFFLINE)
mem->state = MEM_GOING_OFFLINE;
ret = memory_block_action(mem->start_section_nr, to_state,
mem->online_type, mem->nid);
mem->state = ret ? from_state_req : to_state;
return ret;
}
/* The device lock serializes operations on memory_subsys_[online|offline] */
static int memory_subsys_online(struct device *dev)
{
struct memory_block *mem = to_memory_block(dev);
int ret;
if (mem->state == MEM_ONLINE)
return 0;
/*
* When called via device_online() without configuring the online_type,
* we want to default to MMOP_ONLINE.
*/
if (mem->online_type == MMOP_OFFLINE)
mem->online_type = MMOP_ONLINE;
ret = memory_block_change_state(mem, MEM_ONLINE, MEM_OFFLINE);
mem->online_type = MMOP_OFFLINE;
return ret;
}
static int memory_subsys_offline(struct device *dev)
{
struct memory_block *mem = to_memory_block(dev);
if (mem->state == MEM_OFFLINE)
return 0;
return memory_block_change_state(mem, MEM_OFFLINE, MEM_ONLINE);
}
static ssize_t state_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
const int online_type = memhp_online_type_from_str(buf);
struct memory_block *mem = to_memory_block(dev);
int ret;
if (online_type < 0)
return -EINVAL;
ret = lock_device_hotplug_sysfs();
if (ret)
return ret;
switch (online_type) {
case MMOP_ONLINE_KERNEL:
case MMOP_ONLINE_MOVABLE:
case MMOP_ONLINE:
/* mem->online_type is protected by device_hotplug_lock */
mem->online_type = online_type;
ret = device_online(&mem->dev);
break;
case MMOP_OFFLINE:
ret = device_offline(&mem->dev);
break;
default:
ret = -EINVAL; /* should never happen */
}
unlock_device_hotplug();
if (ret < 0)
return ret;
if (ret)
return -EINVAL;
return count;
}
/*
* phys_device is a bad name for this. What I really want
* is a way to differentiate between memory ranges that
* are part of physical devices that constitute
* a complete removable unit or fru.
* i.e. do these ranges belong to the same physical device,
* s.t. if I offline all of these sections I can then
* remove the physical device?
*/
static ssize_t phys_device_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct memory_block *mem = to_memory_block(dev);
return sysfs_emit(buf, "%d\n", mem->phys_device);
}
#ifdef CONFIG_MEMORY_HOTREMOVE
static int print_allowed_zone(char *buf, int len, int nid,
unsigned long start_pfn, unsigned long nr_pages,
int online_type, struct zone *default_zone)
{
struct zone *zone;
zone = zone_for_pfn_range(online_type, nid, start_pfn, nr_pages);
if (zone == default_zone)
return 0;
return sysfs_emit_at(buf, len, " %s", zone->name);
}
static ssize_t valid_zones_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct memory_block *mem = to_memory_block(dev);
unsigned long start_pfn = section_nr_to_pfn(mem->start_section_nr);
unsigned long nr_pages = PAGES_PER_SECTION * sections_per_block;
struct zone *default_zone;
int len = 0;
int nid;
/*
* Check the existing zone. Make sure that we do that only on the
* online nodes otherwise the page_zone is not reliable
*/
if (mem->state == MEM_ONLINE) {
/*
* The block contains more than one zone can not be offlined.
* This can happen e.g. for ZONE_DMA and ZONE_DMA32
*/
default_zone = test_pages_in_a_zone(start_pfn,
start_pfn + nr_pages);
if (!default_zone)
return sysfs_emit(buf, "%s\n", "none");
len += sysfs_emit_at(buf, len, "%s", default_zone->name);
goto out;
}
nid = mem->nid;
default_zone = zone_for_pfn_range(MMOP_ONLINE, nid, start_pfn,
nr_pages);
len += sysfs_emit_at(buf, len, "%s", default_zone->name);
len += print_allowed_zone(buf, len, nid, start_pfn, nr_pages,
MMOP_ONLINE_KERNEL, default_zone);
len += print_allowed_zone(buf, len, nid, start_pfn, nr_pages,
MMOP_ONLINE_MOVABLE, default_zone);
out:
len += sysfs_emit_at(buf, len, "\n");
return len;
}
static DEVICE_ATTR_RO(valid_zones);
#endif
static DEVICE_ATTR_RO(phys_index);
static DEVICE_ATTR_RW(state);
static DEVICE_ATTR_RO(phys_device);
static DEVICE_ATTR_RO(removable);
/*
* Show the memory block size (shared by all memory blocks).
*/
static ssize_t block_size_bytes_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
return sysfs_emit(buf, "%lx\n", memory_block_size_bytes());
}
static DEVICE_ATTR_RO(block_size_bytes);
/*
* Memory auto online policy.
*/
static ssize_t auto_online_blocks_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
return sysfs_emit(buf, "%s\n",
online_type_to_str[memhp_default_online_type]);
}
static ssize_t auto_online_blocks_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
const int online_type = memhp_online_type_from_str(buf);
if (online_type < 0)
return -EINVAL;
memhp_default_online_type = online_type;
return count;
}
static DEVICE_ATTR_RW(auto_online_blocks);
/*
* Some architectures will have custom drivers to do this, and
* will not need to do it from userspace. The fake hot-add code
* as well as ppc64 will do all of their discovery in userspace
* and will require this interface.
*/
#ifdef CONFIG_ARCH_MEMORY_PROBE
static ssize_t probe_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
u64 phys_addr;
int nid, ret;
unsigned long pages_per_block = PAGES_PER_SECTION * sections_per_block;
ret = kstrtoull(buf, 0, &phys_addr);
if (ret)
return ret;
if (phys_addr & ((pages_per_block << PAGE_SHIFT) - 1))
return -EINVAL;
ret = lock_device_hotplug_sysfs();
if (ret)
return ret;
nid = memory_add_physaddr_to_nid(phys_addr);
ret = __add_memory(nid, phys_addr,
MIN_MEMORY_BLOCK_SIZE * sections_per_block,
MHP_NONE);
if (ret)
goto out;
ret = count;
out:
unlock_device_hotplug();
return ret;
}
static DEVICE_ATTR_WO(probe);
#endif
#ifdef CONFIG_MEMORY_FAILURE
/*
* Support for offlining pages of memory
*/
/* Soft offline a page */
static ssize_t soft_offline_page_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
int ret;
u64 pfn;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
if (kstrtoull(buf, 0, &pfn) < 0)
return -EINVAL;
pfn >>= PAGE_SHIFT;
ret = soft_offline_page(pfn, 0);
return ret == 0 ? count : ret;
}
/* Forcibly offline a page, including killing processes. */
static ssize_t hard_offline_page_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
int ret;
u64 pfn;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
if (kstrtoull(buf, 0, &pfn) < 0)
return -EINVAL;
pfn >>= PAGE_SHIFT;
ret = memory_failure(pfn, 0);
return ret ? ret : count;
}
static DEVICE_ATTR_WO(soft_offline_page);
static DEVICE_ATTR_WO(hard_offline_page);
#endif
/*
* Note that phys_device is optional. It is here to allow for
* differentiation between which *physical* devices each
* section belongs to...
*/
int __weak arch_get_memory_phys_device(unsigned long start_pfn)
{
return 0;
}
/*
* A reference for the returned memory block device is acquired.
*
* Called under device_hotplug_lock.
*/
static struct memory_block *find_memory_block_by_id(unsigned long block_id)
{
struct memory_block *mem;
mem = xa_load(&memory_blocks, block_id);
if (mem)
get_device(&mem->dev);
return mem;
}
/*
* Called under device_hotplug_lock.
*/
struct memory_block *find_memory_block(struct mem_section *section)
{
unsigned long block_id = memory_block_id(__section_nr(section));
return find_memory_block_by_id(block_id);
}
static struct attribute *memory_memblk_attrs[] = {
&dev_attr_phys_index.attr,
&dev_attr_state.attr,
&dev_attr_phys_device.attr,
&dev_attr_removable.attr,
#ifdef CONFIG_MEMORY_HOTREMOVE
&dev_attr_valid_zones.attr,
#endif
NULL
};
static struct attribute_group memory_memblk_attr_group = {
.attrs = memory_memblk_attrs,
};
static const struct attribute_group *memory_memblk_attr_groups[] = {
&memory_memblk_attr_group,
NULL,
};
/*
* register_memory - Setup a sysfs device for a memory block
*/
static
int register_memory(struct memory_block *memory)
{
int ret;
memory->dev.bus = &memory_subsys;
memory->dev.id = memory->start_section_nr / sections_per_block;
memory->dev.release = memory_block_release;
memory->dev.groups = memory_memblk_attr_groups;
memory->dev.offline = memory->state == MEM_OFFLINE;
ret = device_register(&memory->dev);
if (ret) {
put_device(&memory->dev);
return ret;
}
ret = xa_err(xa_store(&memory_blocks, memory->dev.id, memory,
GFP_KERNEL));
if (ret) {
put_device(&memory->dev);
device_unregister(&memory->dev);
}
return ret;
}
static int init_memory_block(unsigned long block_id, unsigned long state)
{
struct memory_block *mem;
unsigned long start_pfn;
int ret = 0;
mem = find_memory_block_by_id(block_id);
if (mem) {
put_device(&mem->dev);
return -EEXIST;
}
mem = kzalloc(sizeof(*mem), GFP_KERNEL);
if (!mem)
return -ENOMEM;
mem->start_section_nr = block_id * sections_per_block;
mem->state = state;
start_pfn = section_nr_to_pfn(mem->start_section_nr);
mem->phys_device = arch_get_memory_phys_device(start_pfn);
mem->nid = NUMA_NO_NODE;
ret = register_memory(mem);
return ret;
}
static int add_memory_block(unsigned long base_section_nr)
{
int section_count = 0;
unsigned long nr;
for (nr = base_section_nr; nr < base_section_nr + sections_per_block;
nr++)
if (present_section_nr(nr))
section_count++;
if (section_count == 0)
return 0;
return init_memory_block(memory_block_id(base_section_nr),
MEM_ONLINE);
}
static void unregister_memory(struct memory_block *memory)
{
if (WARN_ON_ONCE(memory->dev.bus != &memory_subsys))
return;
WARN_ON(xa_erase(&memory_blocks, memory->dev.id) == NULL);
/* drop the ref. we got via find_memory_block() */
put_device(&memory->dev);
device_unregister(&memory->dev);
}
/*
* Create memory block devices for the given memory area. Start and size
* have to be aligned to memory block granularity. Memory block devices
* will be initialized as offline.
*
* Called under device_hotplug_lock.
*/
int create_memory_block_devices(unsigned long start, unsigned long size)
{
const unsigned long start_block_id = pfn_to_block_id(PFN_DOWN(start));
unsigned long end_block_id = pfn_to_block_id(PFN_DOWN(start + size));
struct memory_block *mem;
unsigned long block_id;
int ret = 0;
if (WARN_ON_ONCE(!IS_ALIGNED(start, memory_block_size_bytes()) ||
!IS_ALIGNED(size, memory_block_size_bytes())))
return -EINVAL;
for (block_id = start_block_id; block_id != end_block_id; block_id++) {
ret = init_memory_block(block_id, MEM_OFFLINE);
if (ret)
break;
}
if (ret) {
end_block_id = block_id;
for (block_id = start_block_id; block_id != end_block_id;
block_id++) {
mem = find_memory_block_by_id(block_id);
if (WARN_ON_ONCE(!mem))
continue;
unregister_memory(mem);
}
}
return ret;
}
/*
* Remove memory block devices for the given memory area. Start and size
* have to be aligned to memory block granularity. Memory block devices
* have to be offline.
*
* Called under device_hotplug_lock.
*/
void remove_memory_block_devices(unsigned long start, unsigned long size)
{
const unsigned long start_block_id = pfn_to_block_id(PFN_DOWN(start));
const unsigned long end_block_id = pfn_to_block_id(PFN_DOWN(start + size));
struct memory_block *mem;
unsigned long block_id;
if (WARN_ON_ONCE(!IS_ALIGNED(start, memory_block_size_bytes()) ||
!IS_ALIGNED(size, memory_block_size_bytes())))
return;
for (block_id = start_block_id; block_id != end_block_id; block_id++) {
mem = find_memory_block_by_id(block_id);
if (WARN_ON_ONCE(!mem))
continue;
unregister_memory_block_under_nodes(mem);
unregister_memory(mem);
}
}
/* return true if the memory block is offlined, otherwise, return false */
bool is_memblock_offlined(struct memory_block *mem)
{
return mem->state == MEM_OFFLINE;
}
static struct attribute *memory_root_attrs[] = {
#ifdef CONFIG_ARCH_MEMORY_PROBE
&dev_attr_probe.attr,
#endif
#ifdef CONFIG_MEMORY_FAILURE
&dev_attr_soft_offline_page.attr,
&dev_attr_hard_offline_page.attr,
#endif
&dev_attr_block_size_bytes.attr,
&dev_attr_auto_online_blocks.attr,
NULL
};
static struct attribute_group memory_root_attr_group = {
.attrs = memory_root_attrs,
};
static const struct attribute_group *memory_root_attr_groups[] = {
&memory_root_attr_group,
NULL,
};
/*
* Initialize the sysfs support for memory devices. At the time this function
* is called, we cannot have concurrent creation/deletion of memory block
* devices, the device_hotplug_lock is not needed.
*/
void __init memory_dev_init(void)
{
int ret;
unsigned long block_sz, nr;
/* Validate the configured memory block size */
block_sz = memory_block_size_bytes();
if (!is_power_of_2(block_sz) || block_sz < MIN_MEMORY_BLOCK_SIZE)
panic("Memory block size not suitable: 0x%lx\n", block_sz);
sections_per_block = block_sz / MIN_MEMORY_BLOCK_SIZE;
ret = subsys_system_register(&memory_subsys, memory_root_attr_groups);
if (ret)
panic("%s() failed to register subsystem: %d\n", __func__, ret);
/*
* Create entries for memory sections that were found
* during boot and have been initialized
*/
for (nr = 0; nr <= __highest_present_section_nr;
nr += sections_per_block) {
ret = add_memory_block(nr);
if (ret)
panic("%s() failed to add memory block: %d\n", __func__,
ret);
}
}
/**
* walk_memory_blocks - walk through all present memory blocks overlapped
* by the range [start, start + size)
*
* @start: start address of the memory range
* @size: size of the memory range
* @arg: argument passed to func
* @func: callback for each memory section walked
*
* This function walks through all present memory blocks overlapped by the
* range [start, start + size), calling func on each memory block.
*
* In case func() returns an error, walking is aborted and the error is
* returned.
*
* Called under device_hotplug_lock.
*/
int walk_memory_blocks(unsigned long start, unsigned long size,
void *arg, walk_memory_blocks_func_t func)
{
const unsigned long start_block_id = phys_to_block_id(start);
const unsigned long end_block_id = phys_to_block_id(start + size - 1);
struct memory_block *mem;
unsigned long block_id;
int ret = 0;
if (!size)
return 0;
for (block_id = start_block_id; block_id <= end_block_id; block_id++) {
mem = find_memory_block_by_id(block_id);
if (!mem)
continue;
ret = func(mem, arg);
put_device(&mem->dev);
if (ret)
break;
}
return ret;
}
struct for_each_memory_block_cb_data {
walk_memory_blocks_func_t func;
void *arg;
};
static int for_each_memory_block_cb(struct device *dev, void *data)
{
struct memory_block *mem = to_memory_block(dev);
struct for_each_memory_block_cb_data *cb_data = data;
return cb_data->func(mem, cb_data->arg);
}
/**
* for_each_memory_block - walk through all present memory blocks
*
* @arg: argument passed to func
* @func: callback for each memory block walked
*
* This function walks through all present memory blocks, calling func on
* each memory block.
*
* In case func() returns an error, walking is aborted and the error is
* returned.
*/
int for_each_memory_block(void *arg, walk_memory_blocks_func_t func)
{
struct for_each_memory_block_cb_data cb_data = {
.func = func,
.arg = arg,
};
return bus_for_each_dev(&memory_subsys, NULL, &cb_data,
for_each_memory_block_cb);
}
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