/*
* dcdbas.c: Dell Systems Management Base Driver
*
* The Dell Systems Management Base Driver provides a sysfs interface for
* systems management software to perform System Management Interrupts (SMIs)
* and Host Control Actions (power cycle or power off after OS shutdown) on
* Dell systems.
*
* See Documentation/dcdbas.txt for more information.
*
* Copyright (C) 1995-2005 Dell Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License v2.0 as published by
* the Free Software Foundation.
*
* 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. See the
* GNU General Public License for more details.
*/
#include <linux/platform_device.h>
#include <linux/dma-mapping.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/mc146818rtc.h>
#include <linux/module.h>
#include <linux/reboot.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/spinlock.h>
#include <linux/string.h>
#include <linux/types.h>
#include <asm/io.h>
#include <asm/semaphore.h>
#include "dcdbas.h"
#define DRIVER_NAME "dcdbas"
#define DRIVER_VERSION "5.6.0-2"
#define DRIVER_DESCRIPTION "Dell Systems Management Base Driver"
static struct platform_device *dcdbas_pdev;
static u8 *smi_data_buf;
static dma_addr_t smi_data_buf_handle;
static unsigned long smi_data_buf_size;
static u32 smi_data_buf_phys_addr;
static DECLARE_MUTEX(smi_data_lock);
static unsigned int host_control_action;
static unsigned int host_control_smi_type;
static unsigned int host_control_on_shutdown;
/**
* smi_data_buf_free: free SMI data buffer
*/
static void smi_data_buf_free(void)
{
if (!smi_data_buf)
return;
dev_dbg(&dcdbas_pdev->dev, "%s: phys: %x size: %lu\n",
__FUNCTION__, smi_data_buf_phys_addr, smi_data_buf_size);
dma_free_coherent(&dcdbas_pdev->dev, smi_data_buf_size, smi_data_buf,
smi_data_buf_handle);
smi_data_buf = NULL;
smi_data_buf_handle = 0;
smi_data_buf_phys_addr = 0;
smi_data_buf_size = 0;
}
/**
* smi_data_buf_realloc: grow SMI data buffer if needed
*/
static int smi_data_buf_realloc(unsigned long size)
{
void *buf;
dma_addr_t handle;
if (smi_data_buf_size >= size)
return 0;
if (size > MAX_SMI_DATA_BUF_SIZE)
return -EINVAL;
/* new buffer is needed */
buf = dma_alloc_coherent(&dcdbas_pdev->dev, size, &handle, GFP_KERNEL);
if (!buf) {
dev_dbg(&dcdbas_pdev->dev,
"%s: failed to allocate memory size %lu\n",
__FUNCTION__, size);
return -ENOMEM;
}
/* memory zeroed by dma_alloc_coherent */
if (smi_data_buf)
memcpy(buf, smi_data_buf, smi_data_buf_size);
/* free any existing buffer */
smi_data_buf_free();
/* set up new buffer for use */
smi_data_buf = buf;
smi_data_buf_handle = handle;
smi_data_buf_phys_addr = (u32) virt_to_phys(buf);
smi_data_buf_size = size;
dev_dbg(&dcdbas_pdev->dev, "%s: phys: %x size: %lu\n",
__FUNCTION__, smi_data_buf_phys_addr, smi_data_buf_size);
return 0;
}
static ssize_t smi_data_buf_phys_addr_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
return sprintf(buf, "%x\n", smi_data_buf_phys_addr);
}
static ssize_t smi_data_buf_size_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
return sprintf(buf, "%lu\n", smi_data_buf_size);
}
static ssize_t smi_data_buf_size_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
unsigned long buf_size;
ssize_t ret;
buf_size = simple_strtoul(buf, NULL, 10);
/* make sure SMI data buffer is at least buf_size */
down(&smi_data_lock);
ret = smi_data_buf_realloc(buf_size);
up(&smi_data_lock);
if (ret)
return ret;
return count;
}
static ssize_t smi_data_read(struct kobject *kobj, char *buf, loff_t pos,
size_t count)
{
size_t max_read;
ssize_t ret;
down(&smi_data_lock);
if (pos >= smi_data_buf_size) {
ret = 0;
goto out;
}
max_read = smi_data_buf_size - pos;
ret = min(max_read, count);
memcpy(buf, smi_data_buf + pos, ret);
out:
up(&smi_data_lock);
return ret;
}
static ssize_t smi_data_write(struct kobject *kobj, char *buf, loff_t pos,
size_t count)
{
ssize_t ret;
down(&smi_data_lock);
ret = smi_data_buf_realloc(pos + count);
if (ret)
goto out;
memcpy(smi_data_buf + pos, buf, count);
ret = count;
out:
up(&smi_data_lock);
return ret;
}
static ssize_t host_control_action_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
return sprintf(buf, "%u\n", host_control_action);
}
static ssize_t host_control_action_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
ssize_t ret;
/* make sure buffer is available for host control command */
down(&smi_data_lock);
ret = smi_data_buf_realloc(sizeof(struct apm_cmd));
up(&smi_data_lock);
if (ret)
return ret;
host_control_action = simple_strtoul(buf, NULL, 10);
return count;
}
static ssize_t host_control_smi_type_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
return sprintf(buf, "%u\n", host_control_smi_type);
}
static ssize_t host_control_smi_type_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
host_control_smi_type = simple_strtoul(buf, NULL, 10);
return count;
}
static ssize_t host_control_on_shutdown_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
return sprintf(buf, "%u\n", host_control_on_shutdown);
}
static ssize_t host_control_on_shutdown_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
host_control_on_shutdown = simple_strtoul(buf, NULL, 10);
return count;
}
/**
* smi_request: generate SMI request
*
* Called with smi_data_lock.
*/
static int smi_request(struct smi_cmd *smi_cmd)
{
cpumask_t old_mask;
int ret = 0;
if (smi_cmd->magic != SMI_CMD_MAGIC) {
dev_info(&dcdbas_pdev->dev, "%s: invalid magic value\n",
__FUNCTION__);
return -EBADR;
}
/* SMI requires CPU 0 */
old_mask = current->cpus_allowed;
set_cpus_allowed(current, cpumask_of_cpu(0));
if (smp_processor_id() != 0) {
dev_dbg(&dcdbas_pdev->dev, "%s: failed to get CPU 0\n",
__FUNCTION__);
ret = -EBUSY;
goto out;
}
/* generate SMI */
asm volatile (
"outb %b0,%w1"
: /* no output args */
: "a" (smi_cmd->command_code),
"d" (smi_cmd->command_address),
"b" (smi_cmd->ebx),
"c" (smi_cmd->ecx)
: "memory"
);
out:
set_cpus_allowed(current, old_mask);
return ret;
}
/**
* smi_request_store:
*
* The valid values are:
* 0: zero SMI data buffer
* 1: generate calling interface SMI
* 2: generate raw SMI
*
* User application writes smi_cmd to smi_data before telling driver
* to generate SMI.
*/
static ssize_t smi_request_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct smi_cmd *smi_cmd;
unsigned long val = simple_strtoul(buf, NULL, 10);
ssize_t ret;
down(&smi_data_lock);
if (smi_data_buf_size < sizeof(struct smi_cmd)) {
ret = -ENODEV;
goto out;
}
smi_cmd = (struct smi_cmd *)smi_data_buf;
switch (val) {
case 2:
/* Raw SMI */
ret = smi_request(smi_cmd);
if (!ret)
ret = count;
break;
case 1:
/* Calling Interface SMI */
smi_cmd->ebx = (u32) virt_to_phys(smi_cmd->command_buffer);
ret = smi_request(smi_cmd);
if (!ret)
ret = count;
break;
case 0:
memset(smi_data_buf, 0, smi_data_buf_size);
ret = count;
break;
default:
ret = -EINVAL;
break;
}
out:
up(&smi_data_lock);
return ret;
}
/**
* host_control_smi: generate host control SMI
*
* Caller must set up the host control command in smi_data_buf.
*/
static int host_control_smi(void)
{
struct apm_cmd *apm_cmd;
u8 *data;
unsigned long flags;
u32 num_ticks;
s8 cmd_status;
u8 index;
apm_cmd = (struct apm_cmd *)smi_data_buf;
apm_cmd->status = ESM_STATUS_CMD_UNSUCCESSFUL;
switch (host_control_smi_type) {
case HC_SMITYPE_TYPE1:
spin_lock_irqsave(&rtc_lock, flags);
/* write SMI data buffer physical address */
data = (u8 *)&smi_data_buf_phys_addr;
for (index = PE1300_CMOS_CMD_STRUCT_PTR;
index < (PE1300_CMOS_CMD_STRUCT_PTR + 4);
index++, data++) {
outb(index,
(CMOS_BASE_PORT + CMOS_PAGE2_INDEX_PORT_PIIX4));
outb(*data,
(CMOS_BASE_PORT + CMOS_PAGE2_DATA_PORT_PIIX4));
}
/* first set status to -1 as called by spec */
cmd_status = ESM_STATUS_CMD_UNSUCCESSFUL;
outb((u8) cmd_status, PCAT_APM_STATUS_PORT);
/* generate SMM call */
outb(ESM_APM_CMD, PCAT_APM_CONTROL_PORT);
spin_unlock_irqrestore(&rtc_lock, flags);
/* wait a few to see if it executed */
num_ticks = TIMEOUT_USEC_SHORT_SEMA_BLOCKING;
while ((cmd_status = inb(PCAT_APM_STATUS_PORT))
== ESM_STATUS_CMD_UNSUCCESSFUL) {
num_ticks--;
if (num_ticks == EXPIRED_TIMER)
return -ETIME;
}
break;
case HC_SMITYPE_TYPE2:
case HC_SMITYPE_TYPE3:
spin_lock_irqsave(&rtc_lock, flags);
/* write SMI data buffer physical address */
data = (u8 *)&smi_data_buf_phys_addr;
for (index = PE1400_CMOS_CMD_STRUCT_PTR;
index < (PE1400_CMOS_CMD_STRUCT_PTR + 4);
index++, data++) {
outb(index, (CMOS_BASE_PORT + CMOS_PAGE1_INDEX_PORT));
outb(*data, (CMOS_BASE_PORT + CMOS_PAGE1_DATA_PORT));
}
/* generate SMM call */
if (host_control_smi_type == HC_SMITYPE_TYPE3)
outb(ESM_APM_CMD, PCAT_APM_CONTROL_PORT);
else
outb(ESM_APM_CMD, PE1400_APM_CONTROL_PORT);
/* restore RTC index pointer since it was written to above */
CMOS_READ(RTC_REG_C);
spin_unlock_irqrestore(&rtc_lock, flags);
/* read control port back to serialize write */
cmd_status = inb(PE1400_APM_CONTROL_PORT);
/* wait a few to see if it executed */
num_ticks = TIMEOUT_USEC_SHORT_SEMA_BLOCKING;
while (apm_cmd->status == ESM_STATUS_CMD_UNSUCCESSFUL) {
num_ticks--;
if (num_ticks == EXPIRED_TIMER)
return -ETIME;
}
break;
default:
dev_dbg(&dcdbas_pdev->dev, "%s: invalid SMI type %u\n",
__FUNCTION__, host_control_smi_type);
return -ENOSYS;
}
return 0;
}
/**
* dcdbas_host_control: initiate host control
*
* This function is called by the driver after the system has
* finished shutting down if the user application specified a
* host control action to perform on shutdown. It is safe to
* use smi_data_buf at this point because the system has finished
* shutting down and no userspace apps are running.
*/
static void dcdbas_host_control(void)
{
struct apm_cmd *apm_cmd;
u8 action;
if (host_control_action == HC_ACTION_NONE)
return;
action = host_control_action;
host_control_action = HC_ACTION_NONE;
if (!smi_data_buf) {
dev_dbg(&dcdbas_pdev->dev, "%s: no SMI buffer\n", __FUNCTION__);
return;
}
if (smi_data_buf_size < sizeof(struct apm_cmd)) {
dev_dbg(&dcdbas_pdev->dev, "%s: SMI buffer too small\n",
__FUNCTION__);
return;
}
apm_cmd = (struct apm_cmd *)smi_data_buf;
/* power off takes precedence */
if (action & HC_ACTION_HOST_CONTROL_POWEROFF) {
apm_cmd->command = ESM_APM_POWER_CYCLE;
apm_cmd->reserved = 0;
*((s16 *)&apm_cmd->parameters.shortreq.parm[0]) = (s16) 0;
host_control_smi();
} else if (action & HC_ACTION_HOST_CONTROL_POWERCYCLE) {
apm_cmd->command = ESM_APM_POWER_CYCLE;
apm_cmd->reserved = 0;
*((s16 *)&apm_cmd->parameters.shortreq.parm[0]) = (s16) 20;
host_control_smi();
}
}
/**
* dcdbas_reboot_notify: handle reboot notification for host control
*/
static int dcdbas_reboot_notify(struct notifier_block *nb, unsigned long code,
void *unused)
{
static unsigned int notify_cnt = 0;
switch (code) {
case SYS_DOWN:
case SYS_HALT:
case SYS_POWER_OFF:
if (host_control_on_shutdown) {
/* firmware is going to perform host control action */
if (++notify_cnt == 2) {
printk(KERN_WARNING
"Please wait for shutdown "
"action to complete...\n");
dcdbas_host_control();
}
/*
* register again and initiate the host control
* action on the second notification to allow
* everyone that registered to be notified
*/
register_reboot_notifier(nb);
}
break;
}
return NOTIFY_DONE;
}
static struct notifier_block dcdbas_reboot_nb = {
.notifier_call = dcdbas_reboot_notify,
.next = NULL,
.priority = 0
};
static DCDBAS_BIN_ATTR_RW(smi_data);
static struct bin_attribute *dcdbas_bin_attrs[] = {
&bin_attr_smi_data,
NULL
};
static DCDBAS_DEV_ATTR_RW(smi_data_buf_size);
static DCDBAS_DEV_ATTR_RO(smi_data_buf_phys_addr);
static DCDBAS_DEV_ATTR_WO(smi_request);
static DCDBAS_DEV_ATTR_RW(host_control_action);
static DCDBAS_DEV_ATTR_RW(host_control_smi_type);
static DCDBAS_DEV_ATTR_RW(host_control_on_shutdown);
static struct device_attribute *dcdbas_dev_attrs[] = {
&dev_attr_smi_data_buf_size,
&dev_attr_smi_data_buf_phys_addr,
&dev_attr_smi_request,
&dev_attr_host_control_action,
&dev_attr_host_control_smi_type,
&dev_attr_host_control_on_shutdown,
NULL
};
/**
* dcdbas_init: initialize driver
*/
static int __init dcdbas_init(void)
{
int i;
host_control_action = HC_ACTION_NONE;
host_control_smi_type = HC_SMITYPE_NONE;
dcdbas_pdev = platform_device_register_simple(DRIVER_NAME, -1, NULL, 0);
if (IS_ERR(dcdbas_pdev))
return PTR_ERR(dcdbas_pdev);
/*
* BIOS SMI calls require buffer addresses be in 32-bit address space.
* This is done by setting the DMA mask below.
*/
dcdbas_pdev->dev.coherent_dma_mask = DMA_32BIT_MASK;
dcdbas_pdev->dev.dma_mask = &dcdbas_pdev->dev.coherent_dma_mask;
register_reboot_notifier(&dcdbas_reboot_nb);
for (i = 0; dcdbas_bin_attrs[i]; i++)
sysfs_create_bin_file(&dcdbas_pdev->dev.kobj,
dcdbas_bin_attrs[i]);
for (i = 0; dcdbas_dev_attrs[i]; i++)
device_create_file(&dcdbas_pdev->dev, dcdbas_dev_attrs[i]);
dev_info(&dcdbas_pdev->dev, "%s (version %s)\n",
DRIVER_DESCRIPTION, DRIVER_VERSION);
return 0;
}
/**
* dcdbas_exit: perform driver cleanup
*/
static void __exit dcdbas_exit(void)
{
/*
* make sure functions that use dcdbas_pdev are called
* before platform_device_unregister
*/
unregister_reboot_notifier(&dcdbas_reboot_nb);
smi_data_buf_free();
platform_device_unregister(dcdbas_pdev);
}
module_init(dcdbas_init);
module_exit(dcdbas_exit);
MODULE_DESCRIPTION(DRIVER_DESCRIPTION " (version " DRIVER_VERSION ")");
MODULE_VERSION(DRIVER_VERSION);
MODULE_AUTHOR("Dell Inc.");
MODULE_LICENSE("GPL");
