- 根目录:
- drivers
- acpi
- acpi_memhotplug.c
/*
* Copyright (C) 2004 Intel Corporation <naveen.b.s@intel.com>
*
* All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or (at
* your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
* NON INFRINGEMENT. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
*
* 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/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/memory_hotplug.h>
#include <linux/slab.h>
#include <acpi/acpi_drivers.h>
#define ACPI_MEMORY_DEVICE_CLASS "memory"
#define ACPI_MEMORY_DEVICE_HID "PNP0C80"
#define ACPI_MEMORY_DEVICE_NAME "Hotplug Mem Device"
#define _COMPONENT ACPI_MEMORY_DEVICE_COMPONENT
#undef PREFIX
#define PREFIX "ACPI:memory_hp:"
ACPI_MODULE_NAME("acpi_memhotplug");
MODULE_AUTHOR("Naveen B S <naveen.b.s@intel.com>");
MODULE_DESCRIPTION("Hotplug Mem Driver");
MODULE_LICENSE("GPL");
/* Memory Device States */
#define MEMORY_INVALID_STATE 0
#define MEMORY_POWER_ON_STATE 1
#define MEMORY_POWER_OFF_STATE 2
static int acpi_memory_device_add(struct acpi_device *device);
static int acpi_memory_device_remove(struct acpi_device *device, int type);
static const struct acpi_device_id memory_device_ids[] = {
{ACPI_MEMORY_DEVICE_HID, 0},
{"", 0},
};
MODULE_DEVICE_TABLE(acpi, memory_device_ids);
static struct acpi_driver acpi_memory_device_driver = {
.name = "acpi_memhotplug",
.class = ACPI_MEMORY_DEVICE_CLASS,
.ids = memory_device_ids,
.ops = {
.add = acpi_memory_device_add,
.remove = acpi_memory_device_remove,
},
};
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;
unsigned int state; /* State of the memory device */
struct list_head res_list;
};
static int acpi_hotmem_initialized;
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.minimum)) {
info->length += address64.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.minimum;
new->length = address64.address_length;
list_add_tail(&new->list, &mem_device->res_list);
return AE_OK;
}
static int
acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
{
acpi_status status;
struct acpi_memory_info *info, *n;
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)) {
list_for_each_entry_safe(info, n, &mem_device->res_list, list)
kfree(info);
INIT_LIST_HEAD(&mem_device->res_list);
return -EINVAL;
}
return 0;
}
static int
acpi_memory_get_device(acpi_handle handle,
struct acpi_memory_device **mem_device)
{
acpi_status status;
acpi_handle phandle;
struct acpi_device *device = NULL;
struct acpi_device *pdevice = NULL;
int result;
if (!acpi_bus_get_device(handle, &device) && device)
goto end;
status = acpi_get_parent(handle, &phandle);
if (ACPI_FAILURE(status)) {
ACPI_EXCEPTION((AE_INFO, status, "Cannot find acpi parent"));
return -EINVAL;
}
/* Get the parent device */
result = acpi_bus_get_device(phandle, &pdevice);
if (result) {
printk(KERN_WARNING PREFIX "Cannot get acpi bus device");
return -EINVAL;
}
/*
* Now add the notified device. This creates the acpi_device
* and invokes .add function
*/
result = acpi_bus_add(&device, pdevice, handle, ACPI_BUS_TYPE_DEVICE);
if (result) {
printk(KERN_WARNING PREFIX "Cannot add acpi bus");
return -EINVAL;
}
end:
*mem_device = acpi_driver_data(device);
if (!(*mem_device)) {
printk(KERN_ERR "\n driver data not found");
return -ENODEV;
}
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, "_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_memory_enable_device(struct acpi_memory_device *mem_device)
{
int result, num_enabled = 0;
struct acpi_memory_info *info;
int node;
/* Get the range from the _CRS */
result = acpi_memory_get_device_resources(mem_device);
if (result) {
printk(KERN_ERR PREFIX "get_device_resources failed\n");
mem_device->state = MEMORY_INVALID_STATE;
return result;
}
node = acpi_get_node(mem_device->device->handle);
/*
* 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 (info->enabled) { /* just sanity check...*/
num_enabled++;
continue;
}
/*
* If the memory block size is zero, please ignore it.
* Don't try to do the following memory hotplug flowchart.
*/
if (!info->length)
continue;
if (node < 0)
node = memory_add_physaddr_to_nid(info->start_addr);
result = add_memory(node, info->start_addr, info->length);
if (result)
continue;
info->enabled = 1;
num_enabled++;
}
if (!num_enabled) {
printk(KERN_ERR PREFIX "add_memory failed\n");
mem_device->state = MEMORY_INVALID_STATE;
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 int acpi_memory_powerdown_device(struct acpi_memory_device *mem_device)
{
acpi_status status;
struct acpi_object_list arg_list;
union acpi_object arg;
unsigned long long current_status;
/* Issue the _EJ0 command */
arg_list.count = 1;
arg_list.pointer = &arg;
arg.type = ACPI_TYPE_INTEGER;
arg.integer.value = 1;
status = acpi_evaluate_object(mem_device->device->handle,
"_EJ0", &arg_list, NULL);
/* Return on _EJ0 failure */
if (ACPI_FAILURE(status)) {
ACPI_EXCEPTION((AE_INFO, status, "_EJ0 failed"));
return -ENODEV;
}
/* Evalute _STA to check if the device is disabled */
status = acpi_evaluate_integer(mem_device->device->handle, "_STA",
NULL, ¤t_status);
if (ACPI_FAILURE(status))
return -ENODEV;
/* Check for device status. Device should be disabled */
if (current_status & ACPI_STA_DEVICE_ENABLED)
return -EINVAL;
return 0;
}
static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
{
int result;
struct acpi_memory_info *info, *n;
/*
* Ask the VM to offline this memory range.
* Note: Assume that this function returns zero on success
*/
list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
if (info->enabled) {
result = remove_memory(info->start_addr, info->length);
if (result)
return result;
}
kfree(info);
}
/* Power-off and eject the device */
result = acpi_memory_powerdown_device(mem_device);
if (result) {
/* Set the status of the device to invalid */
mem_device->state = MEMORY_INVALID_STATE;
return result;
}
mem_device->state = MEMORY_POWER_OFF_STATE;
return result;
}
static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
{
struct acpi_memory_device *mem_device;
struct acpi_device *device;
switch (event) {
case ACPI_NOTIFY_BUS_CHECK:
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"\nReceived BUS CHECK notification for device\n"));
/* Fall Through */
case ACPI_NOTIFY_DEVICE_CHECK:
if (event == ACPI_NOTIFY_DEVICE_CHECK)
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"\nReceived DEVICE CHECK notification for device\n"));
if (acpi_memory_get_device(handle, &mem_device)) {
printk(KERN_ERR PREFIX "Cannot find driver data\n");
return;
}
if (!acpi_memory_check_device(mem_device)) {
if (acpi_memory_enable_device(mem_device))
printk(KERN_ERR PREFIX
"Cannot enable memory device\n");
}
break;
case ACPI_NOTIFY_EJECT_REQUEST:
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"\nReceived EJECT REQUEST notification for device\n"));
if (acpi_bus_get_device(handle, &device)) {
printk(KERN_ERR PREFIX "Device doesn't exist\n");
break;
}
mem_device = acpi_driver_data(device);
if (!mem_device) {
printk(KERN_ERR PREFIX "Driver Data is NULL\n");
break;
}
/*
* Currently disabling memory device from kernel mode
* TBD: Can also be disabled from user mode scripts
* TBD: Can also be disabled by Callback registration
* with generic sysfs driver
*/
if (acpi_memory_disable_device(mem_device))
printk(KERN_ERR PREFIX
"Disable memory device\n");
/*
* TBD: Invoke acpi_bus_remove to cleanup data structures
*/
break;
default:
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Unsupported event [0x%x]\n", event));
break;
}
return;
}
static int acpi_memory_device_add(struct acpi_device *device)
{
int result;
struct acpi_memory_device *mem_device = NULL;
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;
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;
}
/* Set the device state */
mem_device->state = MEMORY_POWER_ON_STATE;
printk(KERN_DEBUG "%s \n", acpi_device_name(device));
/*
* Early boot code has recognized memory area by EFI/E820.
* If DSDT shows these memory devices on boot, hotplug is not necessary
* for them. So, it just returns until completion of this driver's
* start up.
*/
if (!acpi_hotmem_initialized)
return 0;
if (!acpi_memory_check_device(mem_device)) {
/* call add_memory func */
result = acpi_memory_enable_device(mem_device);
if (result)
printk(KERN_ERR PREFIX
"Error in acpi_memory_enable_device\n");
}
return result;
}
static int acpi_memory_device_remove(struct acpi_device *device, int type)
{
struct acpi_memory_device *mem_device = NULL;
if (!device || !acpi_driver_data(device))
return -EINVAL;
mem_device = acpi_driver_data(device);
kfree(mem_device);
return 0;
}
/*
* Helper function to check for memory device
*/
static acpi_status is_memory_device(acpi_handle handle)
{
char *hardware_id;
acpi_status status;
struct acpi_device_info *info;
status = acpi_get_object_info(handle, &info);
if (ACPI_FAILURE(status))
return status;
if (!(info->valid & ACPI_VALID_HID)) {
kfree(info);
return AE_ERROR;
}
hardware_id = info->hardware_id.string;
if ((hardware_id == NULL) ||
(strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
status = AE_ERROR;
kfree(info);
return status;
}
static acpi_status
acpi_memory_register_notify_handler(acpi_handle handle,
u32 level, void *ctxt, void **retv)
{
acpi_status status;
status = is_memory_device(handle);
if (ACPI_FAILURE(status))
return AE_OK; /* continue */
status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
acpi_memory_device_notify, NULL);
/* continue */
return AE_OK;
}
static acpi_status
acpi_memory_deregister_notify_handler(acpi_handle handle,
u32 level, void *ctxt, void **retv)
{
acpi_status status;
status = is_memory_device(handle);
if (ACPI_FAILURE(status))
return AE_OK; /* continue */
status = acpi_remove_notify_handler(handle,
ACPI_SYSTEM_NOTIFY,
acpi_memory_device_notify);
return AE_OK; /* continue */
}
static int __init acpi_memory_device_init(void)
{
int result;
acpi_status status;
result = acpi_bus_register_driver(&acpi_memory_device_driver);
if (result < 0)
return -ENODEV;
status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
ACPI_UINT32_MAX,
acpi_memory_register_notify_handler, NULL,
NULL, NULL);
if (ACPI_FAILURE(status)) {
ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
acpi_bus_unregister_driver(&acpi_memory_device_driver);
return -ENODEV;
}
acpi_hotmem_initialized = 1;
return 0;
}
static void __exit acpi_memory_device_exit(void)
{
acpi_status status;
/*
* Adding this to un-install notification handlers for all the device
* handles.
*/
status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
ACPI_UINT32_MAX,
acpi_memory_deregister_notify_handler, NULL,
NULL, NULL);
if (ACPI_FAILURE(status))
ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
acpi_bus_unregister_driver(&acpi_memory_device_driver);
return;
}
module_init(acpi_memory_device_init);
module_exit(acpi_memory_device_exit);