[PATCH] dcdbas: add Dell Systems Management Base Driver with sysfs support

This patch adds the Dell Systems Management Base Driver with sysfs support.

This driver has been tested with Dell OpenManage.

Signed-off-by: Doug Warzecha <Douglas_Warzecha@dell.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 596 insertions, 0 deletions

diff --git a/drivers/firmware/dcdbas.c b/drivers/firmware/dcdbas.c
new file mode 100644
index 000000000000..955537fe9958
--- /dev/null
+++ b/drivers/firmware/dcdbas.c
@@ -0,0 +1,596 @@
+/*
+ *  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/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		"5.6.0-1"
+#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)
+{
+	platform_device_unregister(dcdbas_pdev);
+	unregister_reboot_notifier(&dcdbas_reboot_nb);
+	smi_data_buf_free();
+}
+
+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");
+