drivers/acpi/acpi_memhotplug.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Copyright (C) 2004, 2013 Intel Corporation
  * Author: Naveen B S <naveen.b.s@intel.com>
  * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
  *
  * 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,
 					       &current_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 */
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* Copyright (C) 2004, 2013 Intel Corporation
	* Author: Naveen B S <naveen.b.s@intel.com>
	* Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
	*
	* 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,
	&current_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 */