alistair23-linux/drivers/acpi/acpi_memhotplug.c
Zhao Yakui 5d2619fca7 ACPI: Ingore the memory block with zero block size in course of memory hotplug
If the memory block size is zero, ignore it and don't do the memory hotplug
flowchart. Otherwise it will complain the following warning message:
  >System RAM resource 0 - ffffffffffffffff cannot be added

Signed-off-by: Zhao Yakui <yakui.zhao@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
2009-08-02 12:25:12 -04:00

592 lines
15 KiB
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 <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 int acpi_memory_device_start(struct acpi_device *device);
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,
.start = acpi_memory_device_start,
},
};
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, &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_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, &current_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) {
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));
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;
}
static int acpi_memory_device_start (struct acpi_device *device)
{
struct acpi_memory_device *mem_device;
int result = 0;
/*
* 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;
mem_device = acpi_driver_data(device);
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;
}
/*
* Helper function to check for memory device
*/
static acpi_status is_memory_device(acpi_handle handle)
{
char *hardware_id;
acpi_status status;
struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
struct acpi_device_info *info;
status = acpi_get_object_info(handle, &buffer);
if (ACPI_FAILURE(status))
return status;
info = buffer.pointer;
if (!(info->valid & ACPI_VALID_HID)) {
kfree(buffer.pointer);
return AE_ERROR;
}
hardware_id = info->hardware_id.value;
if ((hardware_id == NULL) ||
(strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
status = AE_ERROR;
kfree(buffer.pointer);
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);
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);
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);