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/*
* 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 firmare 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_COMPONENT 0x08000000UL
#define ACPI_MEMORY_DEVICE_CLASS "memory"
#define ACPI_MEMORY_DEVICE_HID "PNP0C80"
#define ACPI_MEMORY_DEVICE_DRIVER_NAME "Hotplug Mem Driver"
#define ACPI_MEMORY_DEVICE_NAME "Hotplug Mem Device"
#define _COMPONENT ACPI_MEMORY_DEVICE_COMPONENT
ACPI_MODULE_NAME("acpi_memory")
MODULE_AUTHOR("Naveen B S <naveen.b.s@intel.com>");
MODULE_DESCRIPTION(ACPI_MEMORY_DEVICE_DRIVER_NAME);
MODULE_LICENSE("GPL");
/* ACPI _STA method values */
#define ACPI_MEMORY_STA_PRESENT (0x00000001UL)
#define ACPI_MEMORY_STA_ENABLED (0x00000002UL)
#define ACPI_MEMORY_STA_FUNCTIONAL (0x00000008UL)
/* 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 struct acpi_driver acpi_memory_device_driver = {
.name = ACPI_MEMORY_DEVICE_DRIVER_NAME,
.class = ACPI_MEMORY_DEVICE_CLASS,
.ids = ACPI_MEMORY_DEVICE_HID,
.ops = {
.add = acpi_memory_device_add,
.remove = acpi_memory_device_remove,
},
};
struct acpi_memory_device {
acpi_handle handle;
unsigned int state; /* State of the memory device */
unsigned short caching; /* memory cache attribute */
unsigned short write_protect; /* memory read/write attribute */
u64 start_addr; /* Memory Range start physical addr */
u64 length; /* Memory Range length */
};
static int
acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
{
acpi_status status;
struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
struct acpi_resource *resource = NULL;
struct acpi_resource_address64 address64;
ACPI_FUNCTION_TRACE("acpi_memory_get_device_resources");
/* Get the range from the _CRS */
status = acpi_get_current_resources(mem_device->handle, &buffer);
if (ACPI_FAILURE(status))
return_VALUE(-EINVAL);
resource = (struct acpi_resource *)buffer.pointer;
status = acpi_resource_to_address64(resource, &address64);
if (ACPI_SUCCESS(status)) {
if (address64.resource_type == ACPI_MEMORY_RANGE) {
/* Populate the structure */
mem_device->caching = address64.info.mem.caching;
mem_device->write_protect =
address64.info.mem.write_protect;
mem_device->start_addr = address64.minimum;
mem_device->length = address64.address_length;
}
}
acpi_os_free(buffer.pointer);
return_VALUE(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;
ACPI_FUNCTION_TRACE("acpi_memory_get_device");
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_VALUE(-EINVAL);
}
/* Get the parent device */
status = acpi_bus_get_device(phandle, &pdevice);
if (ACPI_FAILURE(status)) {
ACPI_EXCEPTION((AE_INFO, status, "Cannot get acpi bus device"));
return_VALUE(-EINVAL);
}
/*
* Now add the notified device. This creates the acpi_device
* and invokes .add function
*/
status = acpi_bus_add(&device, pdevice, handle, ACPI_BUS_TYPE_DEVICE);
if (ACPI_FAILURE(status)) {
ACPI_EXCEPTION((AE_INFO, status, "Cannot add acpi bus"));
return_VALUE(-EINVAL);
}
end:
*mem_device = acpi_driver_data(device);
if (!(*mem_device)) {
printk(KERN_ERR "\n driver data not found");
return_VALUE(-ENODEV);
}
return_VALUE(0);
}
static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
{
unsigned long current_status;
ACPI_FUNCTION_TRACE("acpi_memory_check_device");
/* Get device present/absent information from the _STA */
if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->handle, "_STA",
NULL, ¤t_status)))
return_VALUE(-ENODEV);
/*
* Check for device status. Device should be
* present/enabled/functioning.
*/
if (!((current_status & ACPI_MEMORY_STA_PRESENT)
&& (current_status & ACPI_MEMORY_STA_ENABLED)
&& (current_status & ACPI_MEMORY_STA_FUNCTIONAL)))
return_VALUE(-ENODEV);
return_VALUE(0);
}
static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
{
int result;
ACPI_FUNCTION_TRACE("acpi_memory_enable_device");
/* 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;
}
/*
* Tell the VM there is more memory here...
* Note: Assume that this function returns zero on success
*/
result = add_memory(mem_device->start_addr, mem_device->length);
if (result) {
printk(KERN_ERR PREFIX "add_memory failed\n");
mem_device->state = MEMORY_INVALID_STATE;
return result;
}
return result;
}
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 current_status;
ACPI_FUNCTION_TRACE("acpi_memory_powerdown_device");
/* 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->handle,
"_EJ0", &arg_list, NULL);
/* Return on _EJ0 failure */
if (ACPI_FAILURE(status)) {
ACPI_EXCEPTION((AE_INFO, status, "_EJ0 failed"));
return_VALUE(-ENODEV);
}
/* Evalute _STA to check if the device is disabled */
status = acpi_evaluate_integer(mem_device->handle, "_STA",
NULL, ¤t_status);
if (ACPI_FAILURE(status))
return_VALUE(-ENODEV);
/* Check for device status. Device should be disabled */
if (current_status & ACPI_MEMORY_STA_ENABLED)
return_VALUE(-EINVAL);
return_VALUE(0);
}
static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
{
int result;
u64 start = mem_device->start_addr;
u64 len = mem_device->length;
ACPI_FUNCTION_TRACE("acpi_memory_disable_device");
/*
* Ask the VM to offline this memory range.
* Note: Assume that this function returns zero on success
*/
result = remove_memory(start, len);
if (result)
return_VALUE(result);
/* 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;
ACPI_FUNCTION_TRACE("acpi_memory_device_notify");
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 ==
|