1 files changed, 463 insertions, 49 deletions

diff --git a/drivers/platform/x86/dell-smbios.c b/drivers/platform/x86/dell-smbios.c
index 0a5723468bff..6a60db515bda 100644
--- a/drivers/platform/x86/dell-smbios.c
+++ b/drivers/platform/x86/dell-smbios.c
@@ -12,33 +12,119 @@
  *  it under the terms of the GNU General Public License version 2 as
  *  published by the Free Software Foundation.
  */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/capability.h>
 #include <linux/dmi.h>
 #include <linux/err.h>
-#include <linux/gfp.h>
 #include <linux/mutex.h>
+#include <linux/platform_device.h>
 #include <linux/slab.h>
-#include <linux/io.h>
-#include "../../firmware/dcdbas.h"
 #include "dell-smbios.h"
 
-struct calling_interface_structure {
-	struct dmi_header header;
-	u16 cmdIOAddress;
-	u8 cmdIOCode;
-	u32 supportedCmds;
-	struct calling_interface_token tokens[];
-} __packed;
-
-static struct calling_interface_buffer *buffer;
-static DEFINE_MUTEX(buffer_mutex);
-
-static int da_command_address;
-static int da_command_code;
+static u32 da_supported_commands;
 static int da_num_tokens;
+static struct platform_device *platform_device;
 static struct calling_interface_token *da_tokens;
+static struct device_attribute *token_location_attrs;
+static struct device_attribute *token_value_attrs;
+static struct attribute **token_attrs;
+static DEFINE_MUTEX(smbios_mutex);
+
+struct smbios_device {
+	struct list_head list;
+	struct device *device;
+	int (*call_fn)(struct calling_interface_buffer *);
+};
+
+struct smbios_call {
+	u32 need_capability;
+	int cmd_class;
+	int cmd_select;
+};
+
+/* calls that are whitelisted for given capabilities */
+static struct smbios_call call_whitelist[] = {
+	/* generally tokens are allowed, but may be further filtered or
+	 * restricted by token blacklist or whitelist
+	 */
+	{CAP_SYS_ADMIN,	CLASS_TOKEN_READ,	SELECT_TOKEN_STD},
+	{CAP_SYS_ADMIN,	CLASS_TOKEN_READ,	SELECT_TOKEN_AC},
+	{CAP_SYS_ADMIN,	CLASS_TOKEN_READ,	SELECT_TOKEN_BAT},
+	{CAP_SYS_ADMIN,	CLASS_TOKEN_WRITE,	SELECT_TOKEN_STD},
+	{CAP_SYS_ADMIN,	CLASS_TOKEN_WRITE,	SELECT_TOKEN_AC},
+	{CAP_SYS_ADMIN,	CLASS_TOKEN_WRITE,	SELECT_TOKEN_BAT},
+	/* used by userspace: fwupdate */
+	{CAP_SYS_ADMIN, CLASS_ADMIN_PROP,	SELECT_ADMIN_PROP},
+	/* used by userspace: fwupd */
+	{CAP_SYS_ADMIN,	CLASS_INFO,		SELECT_DOCK},
+	{CAP_SYS_ADMIN,	CLASS_FLASH_INTERFACE,	SELECT_FLASH_INTERFACE},
+};
+
+/* calls that are explicitly blacklisted */
+static struct smbios_call call_blacklist[] = {
+	{0x0000, 01, 07}, /* manufacturing use */
+	{0x0000, 06, 05}, /* manufacturing use */
+	{0x0000, 11, 03}, /* write once */
+	{0x0000, 11, 07}, /* write once */
+	{0x0000, 11, 11}, /* write once */
+	{0x0000, 19, -1}, /* diagnostics */
+	/* handled by kernel: dell-laptop */
+	{0x0000, CLASS_INFO, SELECT_RFKILL},
+	{0x0000, CLASS_KBD_BACKLIGHT, SELECT_KBD_BACKLIGHT},
+};
+
+struct token_range {
+	u32 need_capability;
+	u16 min;
+	u16 max;
+};
+
+/* tokens that are whitelisted for given capabilities */
+static struct token_range token_whitelist[] = {
+	/* used by userspace: fwupdate */
+	{CAP_SYS_ADMIN,	CAPSULE_EN_TOKEN,	CAPSULE_DIS_TOKEN},
+	/* can indicate to userspace that WMI is needed */
+	{0x0000,	WSMT_EN_TOKEN,		WSMT_DIS_TOKEN}
+};
+
+/* tokens that are explicitly blacklisted */
+static struct token_range token_blacklist[] = {
+	{0x0000, 0x0058, 0x0059}, /* ME use */
+	{0x0000, 0x00CD, 0x00D0}, /* raid shadow copy */
+	{0x0000, 0x013A, 0x01FF}, /* sata shadow copy */
+	{0x0000, 0x0175, 0x0176}, /* write once */
+	{0x0000, 0x0195, 0x0197}, /* diagnostics */
+	{0x0000, 0x01DC, 0x01DD}, /* manufacturing use */
+	{0x0000, 0x027D, 0x0284}, /* diagnostics */
+	{0x0000, 0x02E3, 0x02E3}, /* manufacturing use */
+	{0x0000, 0x02FF, 0x02FF}, /* manufacturing use */
+	{0x0000, 0x0300, 0x0302}, /* manufacturing use */
+	{0x0000, 0x0325, 0x0326}, /* manufacturing use */
+	{0x0000, 0x0332, 0x0335}, /* fan control */
+	{0x0000, 0x0350, 0x0350}, /* manufacturing use */
+	{0x0000, 0x0363, 0x0363}, /* manufacturing use */
+	{0x0000, 0x0368, 0x0368}, /* manufacturing use */
+	{0x0000, 0x03F6, 0x03F7}, /* manufacturing use */
+	{0x0000, 0x049E, 0x049F}, /* manufacturing use */
+	{0x0000, 0x04A0, 0x04A3}, /* disagnostics */
+	{0x0000, 0x04E6, 0x04E7}, /* manufacturing use */
+	{0x0000, 0x4000, 0x7FFF}, /* internal BIOS use */
+	{0x0000, 0x9000, 0x9001}, /* internal BIOS use */
+	{0x0000, 0xA000, 0xBFFF}, /* write only */
+	{0x0000, 0xEFF0, 0xEFFF}, /* internal BIOS use */
+	/* handled by kernel: dell-laptop */
+	{0x0000, BRIGHTNESS_TOKEN,	BRIGHTNESS_TOKEN},
+	{0x0000, KBD_LED_OFF_TOKEN,	KBD_LED_AUTO_TOKEN},
+	{0x0000, KBD_LED_AC_TOKEN,	KBD_LED_AC_TOKEN},
+	{0x0000, KBD_LED_AUTO_25_TOKEN,	KBD_LED_AUTO_75_TOKEN},
+	{0x0000, KBD_LED_AUTO_100_TOKEN,	KBD_LED_AUTO_100_TOKEN},
+	{0x0000, GLOBAL_MIC_MUTE_ENABLE,	GLOBAL_MIC_MUTE_DISABLE},
+};
+
+static LIST_HEAD(smbios_device_list);
 
 int dell_smbios_error(int value)
 {
@@ -55,42 +141,175 @@ int dell_smbios_error(int value)
 }
 EXPORT_SYMBOL_GPL(dell_smbios_error);
 
-struct calling_interface_buffer *dell_smbios_get_buffer(void)
+int dell_smbios_register_device(struct device *d, void *call_fn)
 {
-	mutex_lock(&buffer_mutex);
-	dell_smbios_clear_buffer();
-	return buffer;
+	struct smbios_device *priv;
+
+	priv = devm_kzalloc(d, sizeof(struct smbios_device), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+	get_device(d);
+	priv->device = d;
+	priv->call_fn = call_fn;
+	mutex_lock(&smbios_mutex);
+	list_add_tail(&priv->list, &smbios_device_list);
+	mutex_unlock(&smbios_mutex);
+	dev_dbg(d, "Added device: %s\n", d->driver->name);
+	return 0;
 }
-EXPORT_SYMBOL_GPL(dell_smbios_get_buffer);
+EXPORT_SYMBOL_GPL(dell_smbios_register_device);
 
-void dell_smbios_clear_buffer(void)
+void dell_smbios_unregister_device(struct device *d)
 {
-	memset(buffer, 0, sizeof(struct calling_interface_buffer));
+	struct smbios_device *priv;
+
+	mutex_lock(&smbios_mutex);
+	list_for_each_entry(priv, &smbios_device_list, list) {
+		if (priv->device == d) {
+			list_del(&priv->list);
+			put_device(d);
+			break;
+		}
+	}
+	mutex_unlock(&smbios_mutex);
+	dev_dbg(d, "Remove device: %s\n", d->driver->name);
 }
-EXPORT_SYMBOL_GPL(dell_smbios_clear_buffer);
+EXPORT_SYMBOL_GPL(dell_smbios_unregister_device);
 
-void dell_smbios_release_buffer(void)
+int dell_smbios_call_filter(struct device *d,
+			    struct calling_interface_buffer *buffer)
 {
-	mutex_unlock(&buffer_mutex);
+	u16 t = 0;
+	int i;
+
+	/* can't make calls over 30 */
+	if (buffer->cmd_class > 30) {
+		dev_dbg(d, "class too big: %u\n", buffer->cmd_class);
+		return -EINVAL;
+	}
+
+	/* supported calls on the particular system */
+	if (!(da_supported_commands & (1 << buffer->cmd_class))) {
+		dev_dbg(d, "invalid command, supported commands: 0x%8x\n",
+			da_supported_commands);
+		return -EINVAL;
+	}
+
+	/* match against call blacklist  */
+	for (i = 0; i < ARRAY_SIZE(call_blacklist); i++) {
+		if (buffer->cmd_class != call_blacklist[i].cmd_class)
+			continue;
+		if (buffer->cmd_select != call_blacklist[i].cmd_select &&
+		    call_blacklist[i].cmd_select != -1)
+			continue;
+		dev_dbg(d, "blacklisted command: %u/%u\n",
+			buffer->cmd_class, buffer->cmd_select);
+		return -EINVAL;
+	}
+
+	/* if a token call, find token ID */
+
+	if ((buffer->cmd_class == CLASS_TOKEN_READ ||
+	     buffer->cmd_class == CLASS_TOKEN_WRITE) &&
+	     buffer->cmd_select < 3) {
+		/* find the matching token ID */
+		for (i = 0; i < da_num_tokens; i++) {
+			if (da_tokens[i].location != buffer->input[0])
+				continue;
+			t = da_tokens[i].tokenID;
+			break;
+		}
+
+		/* token call; but token didn't exist */
+		if (!t) {
+			dev_dbg(d, "token at location %04x doesn't exist\n",
+				buffer->input[0]);
+			return -EINVAL;
+		}
+
+		/* match against token blacklist */
+		for (i = 0; i < ARRAY_SIZE(token_blacklist); i++) {
+			if (!token_blacklist[i].min || !token_blacklist[i].max)
+				continue;
+			if (t >= token_blacklist[i].min &&
+			    t <= token_blacklist[i].max)
+				return -EINVAL;
+		}
+
+		/* match against token whitelist */
+		for (i = 0; i < ARRAY_SIZE(token_whitelist); i++) {
+			if (!token_whitelist[i].min || !token_whitelist[i].max)
+				continue;
+			if (t < token_whitelist[i].min ||
+			    t > token_whitelist[i].max)
+				continue;
+			if (!token_whitelist[i].need_capability ||
+			    capable(token_whitelist[i].need_capability)) {
+				dev_dbg(d, "whitelisted token: %x\n", t);
+				return 0;
+			}
+
+		}
+	}
+	/* match against call whitelist */
+	for (i = 0; i < ARRAY_SIZE(call_whitelist); i++) {
+		if (buffer->cmd_class != call_whitelist[i].cmd_class)
+			continue;
+		if (buffer->cmd_select != call_whitelist[i].cmd_select)
+			continue;
+		if (!call_whitelist[i].need_capability ||
+		    capable(call_whitelist[i].need_capability)) {
+			dev_dbg(d, "whitelisted capable command: %u/%u\n",
+			buffer->cmd_class, buffer->cmd_select);
+			return 0;
+		}
+		dev_dbg(d, "missing capability %d for %u/%u\n",
+			call_whitelist[i].need_capability,
+			buffer->cmd_class, buffer->cmd_select);
+
+	}
+
+	/* not in a whitelist, only allow processes with capabilities */
+	if (capable(CAP_SYS_RAWIO)) {
+		dev_dbg(d, "Allowing %u/%u due to CAP_SYS_RAWIO\n",
+			buffer->cmd_class, buffer->cmd_select);
+		return 0;
+	}
+
+	return -EACCES;
 }
-EXPORT_SYMBOL_GPL(dell_smbios_release_buffer);
+EXPORT_SYMBOL_GPL(dell_smbios_call_filter);
 
-void dell_smbios_send_request(int class, int select)
+int dell_smbios_call(struct calling_interface_buffer *buffer)
 {
-	struct smi_cmd command;
+	int (*call_fn)(struct calling_interface_buffer *) = NULL;
+	struct device *selected_dev = NULL;
+	struct smbios_device *priv;
+	int ret;
 
-	command.magic = SMI_CMD_MAGIC;
-	command.command_address = da_command_address;
-	command.command_code = da_command_code;
-	command.ebx = virt_to_phys(buffer);
-	command.ecx = 0x42534931;
+	mutex_lock(&smbios_mutex);
+	list_for_each_entry(priv, &smbios_device_list, list) {
+		if (!selected_dev || priv->device->id >= selected_dev->id) {
+			dev_dbg(priv->device, "Trying device ID: %d\n",
+				priv->device->id);
+			call_fn = priv->call_fn;
+			selected_dev = priv->device;
+		}
+	}
+
+	if (!selected_dev) {
+		ret = -ENODEV;
+		pr_err("No dell-smbios drivers are loaded\n");
+		goto out_smbios_call;
+	}
 
-	buffer->class = class;
-	buffer->select = select;
+	ret = call_fn(buffer);
 
-	dcdbas_smi_request(&command);
+out_smbios_call:
+	mutex_unlock(&smbios_mutex);
+	return ret;
 }
-EXPORT_SYMBOL_GPL(dell_smbios_send_request);
+EXPORT_SYMBOL_GPL(dell_smbios_call);
 
 struct calling_interface_token *dell_smbios_find_token(int tokenid)
 {
@@ -139,8 +358,7 @@ static void __init parse_da_table(const struct dmi_header *dm)
 	if (dm->length < 17)
 		return;
 
-	da_command_address = table->cmdIOAddress;
-	da_command_code = table->cmdIOCode;
+	da_supported_commands = table->supportedCmds;
 
 	new_da_tokens = krealloc(da_tokens, (da_num_tokens + tokens) *
 				 sizeof(struct calling_interface_token),
@@ -156,6 +374,27 @@ static void __init parse_da_table(const struct dmi_header *dm)
 	da_num_tokens += tokens;
 }
 
+static void zero_duplicates(struct device *dev)
+{
+	int i, j;
+
+	for (i = 0; i < da_num_tokens; i++) {
+		if (da_tokens[i].tokenID == 0)
+			continue;
+		for (j = i+1; j < da_num_tokens; j++) {
+			if (da_tokens[j].tokenID == 0)
+				continue;
+			if (da_tokens[i].tokenID == da_tokens[j].tokenID) {
+				dev_dbg(dev, "Zeroing dup token ID %x(%x/%x)\n",
+					da_tokens[j].tokenID,
+					da_tokens[j].location,
+					da_tokens[j].value);
+				da_tokens[j].tokenID = 0;
+			}
+		}
+	}
+}
+
 static void __init find_tokens(const struct dmi_header *dm, void *dummy)
 {
 	switch (dm->type) {
@@ -169,10 +408,160 @@ static void __init find_tokens(const struct dmi_header *dm, void *dummy)
 	}
 }
 
+static int match_attribute(struct device *dev,
+			   struct device_attribute *attr)
+{
+	int i;
+
+	for (i = 0; i < da_num_tokens * 2; i++) {
+		if (!token_attrs[i])
+			continue;
+		if (strcmp(token_attrs[i]->name, attr->attr.name) == 0)
+			return i/2;
+	}
+	dev_dbg(dev, "couldn't match: %s\n", attr->attr.name);
+	return -EINVAL;
+}
+
+static ssize_t location_show(struct device *dev,
+			     struct device_attribute *attr, char *buf)
+{
+	int i;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	i = match_attribute(dev, attr);
+	if (i > 0)
+		return scnprintf(buf, PAGE_SIZE, "%08x", da_tokens[i].location);
+	return 0;
+}
+
+static ssize_t value_show(struct device *dev,
+			  struct device_attribute *attr, char *buf)
+{
+	int i;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	i = match_attribute(dev, attr);
+	if (i > 0)
+		return scnprintf(buf, PAGE_SIZE, "%08x", da_tokens[i].value);
+	return 0;
+}
+
+static struct attribute_group smbios_attribute_group = {
+	.name = "tokens"
+};
+
+static struct platform_driver platform_driver = {
+	.driver = {
+		.name = "dell-smbios",
+	},
+};
+
+static int build_tokens_sysfs(struct platform_device *dev)
+{
+	char *location_name;
+	char *value_name;
+	size_t size;
+	int ret;
+	int i, j;
+
+	/* (number of tokens  + 1 for null terminated */
+	size = sizeof(struct device_attribute) * (da_num_tokens + 1);
+	token_location_attrs = kzalloc(size, GFP_KERNEL);
+	if (!token_location_attrs)
+		return -ENOMEM;
+	token_value_attrs = kzalloc(size, GFP_KERNEL);
+	if (!token_value_attrs)
+		goto out_allocate_value;
+
+	/* need to store both location and value + terminator*/
+	size = sizeof(struct attribute *) * ((2 * da_num_tokens) + 1);
+	token_attrs = kzalloc(size, GFP_KERNEL);
+	if (!token_attrs)
+		goto out_allocate_attrs;
+
+	for (i = 0, j = 0; i < da_num_tokens; i++) {
+		/* skip empty */
+		if (da_tokens[i].tokenID == 0)
+			continue;
+		/* add location */
+		location_name = kasprintf(GFP_KERNEL, "%04x_location",
+					  da_tokens[i].tokenID);
+		if (location_name == NULL)
+			goto out_unwind_strings;
+		sysfs_attr_init(&token_location_attrs[i].attr);
+		token_location_attrs[i].attr.name = location_name;
+		token_location_attrs[i].attr.mode = 0444;
+		token_location_attrs[i].show = location_show;
+		token_attrs[j++] = &token_location_attrs[i].attr;
+
+		/* add value */
+		value_name = kasprintf(GFP_KERNEL, "%04x_value",
+				       da_tokens[i].tokenID);
+		if (value_name == NULL)
+			goto loop_fail_create_value;
+		sysfs_attr_init(&token_value_attrs[i].attr);
+		token_value_attrs[i].attr.name = value_name;
+		token_value_attrs[i].attr.mode = 0444;
+		token_value_attrs[i].show = value_show;
+		token_attrs[j++] = &token_value_attrs[i].attr;
+		continue;
+
+loop_fail_create_value:
+		kfree(value_name);
+		goto out_unwind_strings;
+	}
+	smbios_attribute_group.attrs = token_attrs;
+
+	ret = sysfs_create_group(&dev->dev.kobj, &smbios_attribute_group);
+	if (ret)
+		goto out_unwind_strings;
+	return 0;
+
+out_unwind_strings:
+	for (i = i-1; i > 0; i--) {
+		kfree(token_location_attrs[i].attr.name);
+		kfree(token_value_attrs[i].attr.name);
+	}
+	kfree(token_attrs);
+out_allocate_attrs:
+	kfree(token_value_attrs);
+out_allocate_value:
+	kfree(token_location_attrs);
+
+	return -ENOMEM;
+}
+
+static void free_group(struct platform_device *pdev)
+{
+	int i;
+
+	sysfs_remove_group(&pdev->dev.kobj,
+				&smbios_attribute_group);
+	for (i = 0; i < da_num_tokens; i++) {
+		kfree(token_location_attrs[i].attr.name);
+		kfree(token_value_attrs[i].attr.name);
+	}
+	kfree(token_attrs);
+	kfree(token_value_attrs);
+	kfree(token_location_attrs);
+}
+
 static int __init dell_smbios_init(void)
 {
+	const struct dmi_device *valid;
 	int ret;
 
+	valid = dmi_find_device(DMI_DEV_TYPE_OEM_STRING, "Dell System", NULL);
+	if (!valid) {
+		pr_err("Unable to run on non-Dell system\n");
+		return -ENODEV;
+	}
+
 	dmi_walk(find_tokens, NULL);
 
 	if (!da_tokens)  {
@@ -180,27 +569,52 @@ static int __init dell_smbios_init(void)
 		return -ENODEV;
 	}
 
-	/*
-	 * Allocate buffer below 4GB for SMI data--only 32-bit physical addr
-	 * is passed to SMI handler.
-	 */
-	buffer = (void *)__get_free_page(GFP_KERNEL | GFP_DMA32);
-	if (!buffer) {
+	ret = platform_driver_register(&platform_driver);
+	if (ret)
+		goto fail_platform_driver;
+
+	platform_device = platform_device_alloc("dell-smbios", 0);
+	if (!platform_device) {
 		ret = -ENOMEM;
-		goto fail_buffer;
+		goto fail_platform_device_alloc;
 	}
+	ret = platform_device_add(platform_device);
+	if (ret)
+		goto fail_platform_device_add;
+
+	/* duplicate tokens will cause problems building sysfs files */
+	zero_duplicates(&platform_device->dev);
+
+	ret = build_tokens_sysfs(platform_device);
+	if (ret)
+		goto fail_create_group;
 
 	return 0;
 
-fail_buffer:
+fail_create_group:
+	platform_device_del(platform_device);
+
+fail_platform_device_add:
+	platform_device_put(platform_device);
+
+fail_platform_device_alloc:
+	platform_driver_unregister(&platform_driver);
+
+fail_platform_driver:
 	kfree(da_tokens);
 	return ret;
 }
 
 static void __exit dell_smbios_exit(void)
 {
+	mutex_lock(&smbios_mutex);
+	if (platform_device) {
+		free_group(platform_device);
+		platform_device_unregister(platform_device);
+		platform_driver_unregister(&platform_driver);
+	}
 	kfree(da_tokens);
-	free_page((unsigned long)buffer);
+	mutex_unlock(&smbios_mutex);
 }
 
 subsys_initcall(dell_smbios_init);