// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2004, 2013 Intel Corporation
* Author: Naveen B S <[email protected]>
* Author: Rafael J. Wysocki <[email protected]>
*
* All rights reserved.
*
* ACPI based HotPlug driver that supports Memory Hotplug
* This driver fields notifications from firmware for memory add
* and remove operations and alerts the VM of the affected memory
* ranges.
*/
#include <linux/acpi.h>
#include <linux/memory.h>
#include <linux/memory_hotplug.h>
#include "internal.h"
#define ACPI_MEMORY_DEVICE_CLASS "memory"
#define ACPI_MEMORY_DEVICE_HID "PNP0C80"
#define ACPI_MEMORY_DEVICE_NAME "Hotplug Mem Device"
static const struct acpi_device_id memory_device_ids[] = {
{ACPI_MEMORY_DEVICE_HID, 0},
{"", 0},
};
#ifdef CONFIG_ACPI_HOTPLUG_MEMORY
static int acpi_memory_device_add(struct acpi_device *device,
const struct acpi_device_id *not_used);
static void acpi_memory_device_remove(struct acpi_device *device);
static struct acpi_scan_handler memory_device_handler = {
.ids = memory_device_ids,
.attach = acpi_memory_device_add,
.detach = acpi_memory_device_remove,
.hotplug = {
.enabled = true,
},
};
struct acpi_memory_info {
struct list_head list;
u64 start_addr; /* Memory Range start physical addr */
u64 length; /* Memory Range length */
unsigned short caching; /* memory cache attribute */
unsigned short write_protect; /* memory read/write attribute */
unsigned int enabled:1;
};
struct acpi_memory_device {
struct acpi_device *device;
struct list_head res_list;
int mgid;
};
static acpi_status
acpi_memory_get_resource(struct acpi_resource *resource, void *context)
{
struct acpi_memory_device *mem_device = context;
struct acpi_resource_address64 address64;
struct acpi_memory_info *info, *new;
acpi_status status;
status = acpi_resource_to_address64(resource, &address64);
if (ACPI_FAILURE(status) ||
(address64.resource_type != ACPI_MEMORY_RANGE))
return AE_OK;
list_for_each_entry(info, &mem_device->res_list, list) {
/* Can we combine the resource range information? */
if ((info->caching == address64.info.mem.caching) &&
(info->write_protect == address64.info.mem.write_protect) &&
(info->start_addr + info->length == address64.address.minimum)) {
info->length += address64.address.address_length;
return AE_OK;
}
}
new = kzalloc(sizeof(struct acpi_memory_info), GFP_KERNEL);
if (!new)
return AE_ERROR;
INIT_LIST_HEAD(&new->list);
new->caching = address64.info.mem.caching;
new->write_protect = address64.info.mem.write_protect;
new->start_addr = address64.address.minimum;
new->length = address64.address.address_length;
list_add_tail(&new->list, &mem_device->res_list);
return AE_OK;
}
static void
acpi_memory_free_device_resources(struct acpi_memory_device *mem_device)
{
struct acpi_memory_info *info, *n;
list_for_each_entry_safe(info, n, &mem_device->res_list, list)
kfree(info);
INIT_LIST_HEAD(&mem_device->res_list);
}
static int
acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
{
acpi_status status;
if (!list_empty(&mem_device->res_list))
return 0;
status = acpi_walk_resources(mem_device->device->handle, METHOD_NAME__CRS,
acpi_memory_get_resource, mem_device);
if (ACPI_FAILURE(status)) {
acpi_memory_free_device_resources(mem_device);
return -EINVAL;
}
return 0;
}
static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
{
unsigned long long current_status;
/* Get device present/absent information from the _STA */
if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->device->handle,
METHOD_NAME__STA, NULL,
¤t_status)))
return -ENODEV;
/*
* Check for device status. Device should be
* present/enabled/functioning.
*/
if (!((current_status & ACPI_STA_DEVICE_PRESENT)
&& (current_status & ACPI_STA_DEVICE_ENABLED)
&& (current_status & ACPI_STA_DEVICE_FUNCTIONING)))
return -ENODEV;
return 0;
}
static int acpi_bind_memblk(struct memory_block *mem, void *arg)
{
return acpi_bind_one(&mem->dev, arg);
}
static int acpi_bind_memory_blocks(struct acpi_memory_info *info,
struct acpi_device *adev)
{
return walk_memory_blocks(info->start_addr, info->length, adev,
acpi_bind_memblk);
}
static int acpi_unbind_memblk(struct memory_block *mem, void *arg)
{
acpi_unbind_one(&mem->dev);
return 0;
}
static void acpi_unbind_memory_blocks(struct acpi_memory_info *info)
{
walk_memory_blocks(info->start_addr, info->length, NULL,
acpi_unbind_memblk);
}
static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
{
acpi_handle handle = mem_device->device->handle;
mhp_t mhp_flags = MHP_NID_IS_MGID;
int result, num_enabled = 0;
struct acpi_memory_info *info;
u64 total_length = 0;
int node, mgid;
node = acpi_get_node(handle);
list_for_each_entry(info, &mem_device->res_list, list) {
if (!info->length)
continue;
/* We want a single node for the whole memory group */
if (node < 0)
node = memory_add_physaddr_to_nid(info->start_addr);
total_length += info->length;
}
if (!total_length) {
dev_err(&mem_device->device->dev, "device is empty\n");
return -EINVAL;
}
mgid = memory_group_register_static(node, PFN_UP(total_length));
if (mgid < 0)
return mgid;
mem_device->mgid = mgid;
/*
* Tell the VM there is more memory here...
* Note: Assume that this function returns zero on success
* We don't have memory-hot-add rollback function,now.
* (i.e. memory-hot-remove function)
*/
list_for_each_entry(info, &mem_device->res_list, list) {
/*
* If the memory block size is zero, please ignore it.
* Don't try to do the following memory hotplug flowchart.
*/
if (!info->length)
continue;
mhp_flags |= MHP_MEMMAP_ON_MEMORY;
result = __add_memory(mgid, info->start_addr, info->length,
mhp_flags);
/*
* If the memory block has been used by the kernel, add_memory()
* returns -EEXIST. If add_memory() returns the other error, it
* means that this memory block is not used by the kernel.
*/
if (result && result != -EEXIST)
continue;
result = acpi_bind_memory_blocks(info, mem_device->device);
if (result) {
acpi_unbind_memory_blocks(info);
return -ENODEV;
}
info->enabled = 1;
/*
* Add num_enable even if add_memory() returns -EEXIST, so the
* device is bound to this driver.
*/
num_enabled++;
}
if (!num_enabled) {
dev_err(&mem_device->device->dev, "add_memory failed\n");
return -EINVAL;
}
/*
* Sometimes the memory device will contain several memory blocks.
* When one memory block is hot-added to the system memory, it will
* be regarded as a success.
* Otherwise if the last memory block can't be hot-added to the system
* memory, it will be failure and the memory device can't be bound with
* driver.
*/
return 0;
}
static void acpi_memory_remove_memory(struct acpi_memory_device *mem_device)
{
struct acpi_memory_info *info, *n;
list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
if (!info->enabled)
continue;
acpi_unbind_memory_blocks(info);
__remove_memory(info->start_addr, info->length);
list_del(&info->list);
kfree(info);
}
}
static void acpi_memory_device_free(struct acpi_memory_device *mem_device)
{
if (!mem_device)
return;
/* In case we succeeded adding *some* memory, unregistering fails. */
if (mem_device->mgid >= 0)
memory_group_unregister(mem_device->mgid);
acpi_memory_free_device_resources(mem_device);
mem_device->device->driver_data = NULL;
kfree(mem_device);
}
static int acpi_memory_device_add(struct acpi_device *device,
const struct acpi_device_id *not_used)
{
struct acpi_memory_device *mem_device;
int result;
if (!device)
return -EINVAL;
mem_device = kzalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
if (!mem_device)
return -ENOMEM;
INIT_LIST_HEAD(&mem_device->res_list);
mem_device->device = device;
mem_device->mgid = -1;
sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
device->driver_data = mem_device;
/* Get the range from the _CRS */
result = acpi_memory_get_device_resources(mem_device);
if (result) {
device->driver_data = NULL;
kfree(mem_device);
return result;
}
result = acpi_memory_check_device(mem_device);
if (result) {
acpi_memory_device_free(mem_device);
return 0;
}
result = acpi_memory_enable_device(mem_device);
if (result) {
dev_err(&device->dev, "acpi_memory_enable_device() error\n");
acpi_memory_device_free(mem_device);
return result;
}
dev_dbg(&device->dev, "Memory device configured by ACPI\n");
return 1;
}
static void acpi_memory_device_remove(struct acpi_device *device)
{
struct acpi_memory_device *mem_device;
if (!device || !acpi_driver_data(device))
return;
mem_device = acpi_driver_data(device);
acpi_memory_remove_memory(mem_device);
acpi_memory_device_free(mem_device);
}
static bool __initdata acpi_no_memhotplug;
void __init acpi_memory_hotplug_init(void)
{
if (acpi_no_memhotplug) {
memory_device_handler.attach = NULL;
acpi_scan_add_handler(&memory_device_handler);
return;
}
acpi_scan_add_handler_with_hotplug(&memory_device_handler, "memory");
}
static int __init disable_acpi_memory_hotplug(char *str)
{
acpi_no_memhotplug = true;
return 1;
}
__setup("acpi_no_memhotplug", disable_acpi_memory_hotplug);
#else
static struct acpi_scan_handler memory_device_handler = {
.ids = memory_device_ids,
};
void __init acpi_memory_hotplug_init(void)
{
acpi_scan_add_handler(&memory_device_handler);
}
#endif /* CONFIG_ACPI_HOTPLUG_MEMORY */
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