diff options
Diffstat (limited to 'drivers/platform/x86/dell/dell-smbios-base.c')
| -rw-r--r-- | drivers/platform/x86/dell/dell-smbios-base.c | 652 |
1 files changed, 652 insertions, 0 deletions
diff --git a/drivers/platform/x86/dell/dell-smbios-base.c b/drivers/platform/x86/dell/dell-smbios-base.c new file mode 100644 index 000000000..e61bfaf8b --- /dev/null +++ b/drivers/platform/x86/dell/dell-smbios-base.c @@ -0,0 +1,652 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Common functions for kernel modules using Dell SMBIOS + * + * Copyright (c) Red Hat <mjg@redhat.com> + * Copyright (c) 2014 Gabriele Mazzotta <gabriele.mzt@gmail.com> + * Copyright (c) 2014 Pali Rohár <pali@kernel.org> + * + * Based on documentation in the libsmbios package: + * Copyright (C) 2005-2014 Dell Inc. + */ +#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/mutex.h> +#include <linux/platform_device.h> +#include <linux/slab.h> +#include "dell-smbios.h" + +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 *arg); +}; + +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, 1, 7}, /* manufacturing use */ + {0x0000, 6, 5}, /* manufacturing use */ + {0x0000, 11, 3}, /* write once */ + {0x0000, 11, 7}, /* 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) +{ + switch (value) { + case 0: /* Completed successfully */ + return 0; + case -1: /* Completed with error */ + return -EIO; + case -2: /* Function not supported */ + return -ENXIO; + default: /* Unknown error */ + return -EINVAL; + } +} +EXPORT_SYMBOL_GPL(dell_smbios_error); + +int dell_smbios_register_device(struct device *d, void *call_fn) +{ + 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_register_device); + +void dell_smbios_unregister_device(struct device *d) +{ + 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_unregister_device); + +int dell_smbios_call_filter(struct device *d, + struct calling_interface_buffer *buffer) +{ + 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) { + /* tokens enabled ? */ + if (!da_tokens) { + dev_dbg(d, "no token support on this system\n"); + return -EINVAL; + } + + /* 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_call_filter); + +int dell_smbios_call(struct calling_interface_buffer *buffer) +{ + int (*call_fn)(struct calling_interface_buffer *) = NULL; + struct device *selected_dev = NULL; + struct smbios_device *priv; + int ret; + + 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; + } + + ret = call_fn(buffer); + +out_smbios_call: + mutex_unlock(&smbios_mutex); + return ret; +} +EXPORT_SYMBOL_GPL(dell_smbios_call); + +struct calling_interface_token *dell_smbios_find_token(int tokenid) +{ + int i; + + if (!da_tokens) + return NULL; + + for (i = 0; i < da_num_tokens; i++) { + if (da_tokens[i].tokenID == tokenid) + return &da_tokens[i]; + } + + return NULL; +} +EXPORT_SYMBOL_GPL(dell_smbios_find_token); + +static BLOCKING_NOTIFIER_HEAD(dell_laptop_chain_head); + +int dell_laptop_register_notifier(struct notifier_block *nb) +{ + return blocking_notifier_chain_register(&dell_laptop_chain_head, nb); +} +EXPORT_SYMBOL_GPL(dell_laptop_register_notifier); + +int dell_laptop_unregister_notifier(struct notifier_block *nb) +{ + return blocking_notifier_chain_unregister(&dell_laptop_chain_head, nb); +} +EXPORT_SYMBOL_GPL(dell_laptop_unregister_notifier); + +void dell_laptop_call_notifier(unsigned long action, void *data) +{ + blocking_notifier_call_chain(&dell_laptop_chain_head, action, data); +} +EXPORT_SYMBOL_GPL(dell_laptop_call_notifier); + +static void __init parse_da_table(const struct dmi_header *dm) +{ + /* Final token is a terminator, so we don't want to copy it */ + int tokens = (dm->length-11)/sizeof(struct calling_interface_token)-1; + struct calling_interface_token *new_da_tokens; + struct calling_interface_structure *table = + container_of(dm, struct calling_interface_structure, header); + + /* + * 4 bytes of table header, plus 7 bytes of Dell header + * plus at least 6 bytes of entry + */ + + if (dm->length < 17) + return; + + da_supported_commands = table->supportedCmds; + + new_da_tokens = krealloc(da_tokens, (da_num_tokens + tokens) * + sizeof(struct calling_interface_token), + GFP_KERNEL); + + if (!new_da_tokens) + return; + da_tokens = new_da_tokens; + + memcpy(da_tokens+da_num_tokens, table->tokens, + sizeof(struct calling_interface_token) * tokens); + + 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) { + case 0xd4: /* Indexed IO */ + case 0xd5: /* Protected Area Type 1 */ + case 0xd6: /* Protected Area Type 2 */ + break; + case 0xda: /* Calling interface */ + parse_da_table(dm); + break; + } +} + +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 sysfs_emit(buf, "%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 sysfs_emit(buf, "%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(location_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: + while (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) +{ + int ret, wmi, smm; + + if (!dmi_find_device(DMI_DEV_TYPE_OEM_STRING, "Dell System", NULL) && + !dmi_find_device(DMI_DEV_TYPE_OEM_STRING, "www.dell.com", NULL)) { + pr_err("Unable to run on non-Dell system\n"); + return -ENODEV; + } + + dmi_walk(find_tokens, NULL); + + 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_platform_device_alloc; + } + ret = platform_device_add(platform_device); + if (ret) + goto fail_platform_device_add; + + /* register backends */ + wmi = init_dell_smbios_wmi(); + if (wmi) + pr_debug("Failed to initialize WMI backend: %d\n", wmi); + smm = init_dell_smbios_smm(); + if (smm) + pr_debug("Failed to initialize SMM backend: %d\n", smm); + if (wmi && smm) { + pr_err("No SMBIOS backends available (wmi: %d, smm: %d)\n", + wmi, smm); + ret = -ENODEV; + goto fail_create_group; + } + + if (da_tokens) { + /* duplicate tokens will cause problems building sysfs files */ + zero_duplicates(&platform_device->dev); + + ret = build_tokens_sysfs(platform_device); + if (ret) + goto fail_sysfs; + } + + return 0; + +fail_sysfs: + free_group(platform_device); + +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) +{ + exit_dell_smbios_wmi(); + exit_dell_smbios_smm(); + mutex_lock(&smbios_mutex); + if (platform_device) { + if (da_tokens) + free_group(platform_device); + platform_device_unregister(platform_device); + platform_driver_unregister(&platform_driver); + } + kfree(da_tokens); + mutex_unlock(&smbios_mutex); +} + +module_init(dell_smbios_init); +module_exit(dell_smbios_exit); + +MODULE_AUTHOR("Matthew Garrett <mjg@redhat.com>"); +MODULE_AUTHOR("Gabriele Mazzotta <gabriele.mzt@gmail.com>"); +MODULE_AUTHOR("Pali Rohár <pali@kernel.org>"); +MODULE_AUTHOR("Mario Limonciello <mario.limonciello@outlook.com>"); +MODULE_DESCRIPTION("Common functions for kernel modules using Dell SMBIOS"); +MODULE_LICENSE("GPL"); |