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tools/wmi: add a sample for dell smbios communication over WMI
This application uses the character device /dev/wmi/dell-smbios to perform SMBIOS communications from userspace. It offers demonstrations of a few simple tasks: - Running a class/select command - Querying a token value - Activating a token Signed-off-by: Mario Limonciello <[email protected]> Reviewed-by: Edward O'Callaghan <[email protected]> Signed-off-by: Darren Hart (VMware) <[email protected]>
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@@ -3997,6 +3997,7 @@ M: Mario Limonciello <[email protected]> | |
| L: [email protected] | ||
| S: Maintained | ||
| F: drivers/platform/x86/dell-smbios-wmi.c | ||
| F: tools/wmi/dell-smbios-example.c | ||
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| DELL LAPTOP DRIVER | ||
| M: Matthew Garrett <[email protected]> | ||
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| PREFIX ?= /usr | ||
| SBINDIR ?= sbin | ||
| INSTALL ?= install | ||
| CFLAGS += -D__EXPORTED_HEADERS__ -I../../include/uapi -I../../include | ||
| CC = $(CROSS_COMPILE)gcc | ||
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| TARGET = dell-smbios-example | ||
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| all: $(TARGET) | ||
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| %: %.c | ||
| $(CC) $(CFLAGS) $(LDFLAGS) -o $@ $< | ||
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| clean: | ||
| $(RM) $(TARGET) | ||
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| install: dell-smbios-example | ||
| $(INSTALL) -D -m 755 $(TARGET) $(DESTDIR)$(PREFIX)/$(SBINDIR)/$(TARGET) |
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| /* | ||
| * Sample application for SMBIOS communication over WMI interface | ||
| * Performs the following: | ||
| * - Simple cmd_class/cmd_select lookup for TPM information | ||
| * - Simple query of known tokens and their values | ||
| * - Simple activation of a token | ||
| * | ||
| * Copyright (C) 2017 Dell, Inc. | ||
| * | ||
| * This program is free software; you can redistribute it and/or modify | ||
| * it under the terms of the GNU General Public License version 2 as | ||
| * published by the Free Software Foundation. | ||
| */ | ||
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| #include <errno.h> | ||
| #include <fcntl.h> | ||
| #include <stdio.h> | ||
| #include <stdlib.h> | ||
| #include <sys/ioctl.h> | ||
| #include <unistd.h> | ||
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| /* if uapi header isn't installed, this might not yet exist */ | ||
| #ifndef __packed | ||
| #define __packed __attribute__((packed)) | ||
| #endif | ||
| #include <linux/wmi.h> | ||
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| /* It would be better to discover these using udev, but for a simple | ||
| * application they're hardcoded | ||
| */ | ||
| static const char *ioctl_devfs = "/dev/wmi/dell-smbios"; | ||
| static const char *token_sysfs = | ||
| "/sys/bus/platform/devices/dell-smbios.0/tokens"; | ||
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| static void show_buffer(struct dell_wmi_smbios_buffer *buffer) | ||
| { | ||
| printf("Call: %x/%x [%x,%x,%x,%x]\nResults: [%8x,%8x,%8x,%8x]\n", | ||
| buffer->std.cmd_class, buffer->std.cmd_select, | ||
| buffer->std.input[0], buffer->std.input[1], | ||
| buffer->std.input[2], buffer->std.input[3], | ||
| buffer->std.output[0], buffer->std.output[1], | ||
| buffer->std.output[2], buffer->std.output[3]); | ||
| } | ||
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| static int run_wmi_smbios_cmd(struct dell_wmi_smbios_buffer *buffer) | ||
| { | ||
| int fd; | ||
| int ret; | ||
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| fd = open(ioctl_devfs, O_NONBLOCK); | ||
| ret = ioctl(fd, DELL_WMI_SMBIOS_CMD, buffer); | ||
| close(fd); | ||
| return ret; | ||
| } | ||
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| static int find_token(__u16 token, __u16 *location, __u16 *value) | ||
| { | ||
| char location_sysfs[60]; | ||
| char value_sysfs[57]; | ||
| char buf[4096]; | ||
| FILE *f; | ||
| int ret; | ||
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| ret = sprintf(value_sysfs, "%s/%04x_value", token_sysfs, token); | ||
| if (ret < 0) { | ||
| printf("sprintf value failed\n"); | ||
| return 2; | ||
| } | ||
| f = fopen(value_sysfs, "rb"); | ||
| if (!f) { | ||
| printf("failed to open %s\n", value_sysfs); | ||
| return 2; | ||
| } | ||
| fread(buf, 1, 4096, f); | ||
| fclose(f); | ||
| *value = (__u16) strtol(buf, NULL, 16); | ||
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| ret = sprintf(location_sysfs, "%s/%04x_location", token_sysfs, token); | ||
| if (ret < 0) { | ||
| printf("sprintf location failed\n"); | ||
| return 1; | ||
| } | ||
| f = fopen(location_sysfs, "rb"); | ||
| if (!f) { | ||
| printf("failed to open %s\n", location_sysfs); | ||
| return 2; | ||
| } | ||
| fread(buf, 1, 4096, f); | ||
| fclose(f); | ||
| *location = (__u16) strtol(buf, NULL, 16); | ||
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| if (*location) | ||
| return 0; | ||
| return 2; | ||
| } | ||
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| static int token_is_active(__u16 *location, __u16 *cmpvalue, | ||
| struct dell_wmi_smbios_buffer *buffer) | ||
| { | ||
| int ret; | ||
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| buffer->std.cmd_class = CLASS_TOKEN_READ; | ||
| buffer->std.cmd_select = SELECT_TOKEN_STD; | ||
| buffer->std.input[0] = *location; | ||
| ret = run_wmi_smbios_cmd(buffer); | ||
| if (ret != 0 || buffer->std.output[0] != 0) | ||
| return ret; | ||
| ret = (buffer->std.output[1] == *cmpvalue); | ||
| return ret; | ||
| } | ||
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| static int query_token(__u16 token, struct dell_wmi_smbios_buffer *buffer) | ||
| { | ||
| __u16 location; | ||
| __u16 value; | ||
| int ret; | ||
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| ret = find_token(token, &location, &value); | ||
| if (ret != 0) { | ||
| printf("unable to find token %04x\n", token); | ||
| return 1; | ||
| } | ||
| return token_is_active(&location, &value, buffer); | ||
| } | ||
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| static int activate_token(struct dell_wmi_smbios_buffer *buffer, | ||
| __u16 token) | ||
| { | ||
| __u16 location; | ||
| __u16 value; | ||
| int ret; | ||
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| ret = find_token(token, &location, &value); | ||
| if (ret != 0) { | ||
| printf("unable to find token %04x\n", token); | ||
| return 1; | ||
| } | ||
| buffer->std.cmd_class = CLASS_TOKEN_WRITE; | ||
| buffer->std.cmd_select = SELECT_TOKEN_STD; | ||
| buffer->std.input[0] = location; | ||
| buffer->std.input[1] = 1; | ||
| ret = run_wmi_smbios_cmd(buffer); | ||
| return ret; | ||
| } | ||
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| static int query_buffer_size(__u64 *buffer_size) | ||
| { | ||
| FILE *f; | ||
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| f = fopen(ioctl_devfs, "rb"); | ||
| if (!f) | ||
| return -EINVAL; | ||
| fread(buffer_size, sizeof(__u64), 1, f); | ||
| fclose(f); | ||
| return EXIT_SUCCESS; | ||
| } | ||
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| int main(void) | ||
| { | ||
| struct dell_wmi_smbios_buffer *buffer; | ||
| int ret; | ||
| __u64 value = 0; | ||
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| ret = query_buffer_size(&value); | ||
| if (ret == EXIT_FAILURE || !value) { | ||
| printf("Unable to read buffer size\n"); | ||
| goto out; | ||
| } | ||
| printf("Detected required buffer size %lld\n", value); | ||
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| buffer = malloc(value); | ||
| if (buffer == NULL) { | ||
| printf("failed to alloc memory for ioctl\n"); | ||
| ret = -ENOMEM; | ||
| goto out; | ||
| } | ||
| buffer->length = value; | ||
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| /* simple SMBIOS call for looking up TPM info */ | ||
| buffer->std.cmd_class = CLASS_FLASH_INTERFACE; | ||
| buffer->std.cmd_select = SELECT_FLASH_INTERFACE; | ||
| buffer->std.input[0] = 2; | ||
| ret = run_wmi_smbios_cmd(buffer); | ||
| if (ret) { | ||
| printf("smbios ioctl failed: %d\n", ret); | ||
| ret = EXIT_FAILURE; | ||
| goto out; | ||
| } | ||
| show_buffer(buffer); | ||
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| /* query some tokens */ | ||
| ret = query_token(CAPSULE_EN_TOKEN, buffer); | ||
| printf("UEFI Capsule enabled token is: %d\n", ret); | ||
| ret = query_token(CAPSULE_DIS_TOKEN, buffer); | ||
| printf("UEFI Capsule disabled token is: %d\n", ret); | ||
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| /* activate UEFI capsule token if disabled */ | ||
| if (ret) { | ||
| printf("Enabling UEFI capsule token"); | ||
| if (activate_token(buffer, CAPSULE_EN_TOKEN)) { | ||
| printf("activate failed\n"); | ||
| ret = -1; | ||
| goto out; | ||
| } | ||
| } | ||
| ret = EXIT_SUCCESS; | ||
| out: | ||
| free(buffer); | ||
| return ret; | ||
| } |