[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");
+