Commit 9d64fc08 authored by Mario Limonciello's avatar Mario Limonciello Committed by Darren Hart (VMware)
Browse files

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: default avatarMario Limonciello <mario.limonciello@dell.com>
Reviewed-by: default avatarEdward O'Callaghan <quasisec@google.com>
Signed-off-by: default avatarDarren Hart (VMware) <dvhart@infradead.org>
parent f2645fa3

MAINTAINERS

+1 −0
Original line number Diff line number Diff line
@@ -3997,6 +3997,7 @@ M: Mario Limonciello <mario.limonciello@dell.com> 
L:	platform-driver-x86@vger.kernel.org

S:	Maintained

F:	drivers/platform/x86/dell-smbios-wmi.c

F:	tools/wmi/dell-smbios-example.c



DELL LAPTOP DRIVER

M:	Matthew Garrett <mjg59@srcf.ucam.org>

tools/Makefile

+8 −6
Original line number Diff line number Diff line
@@ -29,6 +29,7 @@ help: 
	@echo '  usb                    - USB testing tools'

	@echo '  virtio                 - vhost test module'

	@echo '  vm                     - misc vm tools'

	@echo '  wmi			- WMI interface examples'

	@echo '  x86_energy_perf_policy - Intel energy policy tool'

	@echo ''

	@echo 'You can do:'
@@ -57,7 +58,7 @@ acpi: FORCE 
cpupower: FORCE

	$(call descend,power/$@)



cgroup firewire hv guest spi usb virtio vm net iio gpio objtool leds: FORCE

cgroup firewire hv guest spi usb virtio vm net iio gpio objtool leds wmi: FORCE

	$(call descend,$@)



liblockdep: FORCE
@@ -92,7 +93,7 @@ kvm_stat: FORCE 
all: acpi cgroup cpupower gpio hv firewire liblockdep \

		perf selftests spi turbostat usb \

		virtio vm net x86_energy_perf_policy \

		tmon freefall iio objtool kvm_stat

		tmon freefall iio objtool kvm_stat wmi



acpi_install:

	$(call descend,power/$(@:_install=),install)
@@ -100,7 +101,7 @@ acpi_install: 
cpupower_install:

	$(call descend,power/$(@:_install=),install)



cgroup_install firewire_install gpio_install hv_install iio_install perf_install spi_install usb_install virtio_install vm_install net_install objtool_install:

cgroup_install firewire_install gpio_install hv_install iio_install perf_install spi_install usb_install virtio_install vm_install net_install objtool_install wmi_install:

	$(call descend,$(@:_install=),install)



liblockdep_install:
@@ -125,7 +126,8 @@ install: acpi_install cgroup_install cpupower_install gpio_install \ 
		hv_install firewire_install iio_install liblockdep_install \

		perf_install selftests_install turbostat_install usb_install \

		virtio_install vm_install net_install x86_energy_perf_policy_install \

		tmon_install freefall_install objtool_install kvm_stat_install

		tmon_install freefall_install objtool_install kvm_stat_install \

		wmi_install



acpi_clean:

	$(call descend,power/acpi,clean)
@@ -133,7 +135,7 @@ acpi_clean: 
cpupower_clean:

	$(call descend,power/cpupower,clean)



cgroup_clean hv_clean firewire_clean spi_clean usb_clean virtio_clean vm_clean net_clean iio_clean gpio_clean objtool_clean leds_clean:

cgroup_clean hv_clean firewire_clean spi_clean usb_clean virtio_clean vm_clean wmi_clean net_clean iio_clean gpio_clean objtool_clean leds_clean:

	$(call descend,$(@:_clean=),clean)



liblockdep_clean:
@@ -171,6 +173,6 @@ clean: acpi_clean cgroup_clean cpupower_clean hv_clean firewire_clean \ 
		perf_clean selftests_clean turbostat_clean spi_clean usb_clean virtio_clean \

		vm_clean net_clean iio_clean x86_energy_perf_policy_clean tmon_clean \

		freefall_clean build_clean libbpf_clean libsubcmd_clean liblockdep_clean \

		gpio_clean objtool_clean leds_clean

		gpio_clean objtool_clean leds_clean wmi_clean



.PHONY: FORCE

tools/wmi/Makefile

0 → 100644
+18 −0
Original line number Diff line number Diff line 
PREFIX ?= /usr

SBINDIR ?= sbin

INSTALL ?= install

CFLAGS += -D__EXPORTED_HEADERS__ -I../../include/uapi -I../../include

CC = $(CROSS_COMPILE)gcc



TARGET = dell-smbios-example



all: $(TARGET)



%: %.c

	$(CC) $(CFLAGS) $(LDFLAGS) -o $@ $<



clean:

	$(RM) $(TARGET)



install: dell-smbios-example

	$(INSTALL) -D -m 755 $(TARGET) $(DESTDIR)$(PREFIX)/$(SBINDIR)/$(TARGET)

tools/wmi/dell-smbios-example.c

0 → 100644
+210 −0
Original line number Diff line number Diff line 
/*

 *  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.

 */



#include <errno.h>

#include <fcntl.h>

#include <stdio.h>

#include <stdlib.h>

#include <sys/ioctl.h>

#include <unistd.h>



/* if uapi header isn't installed, this might not yet exist */

#ifndef __packed

#define __packed __attribute__((packed))

#endif

#include <linux/wmi.h>



/* 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";



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]);

}



static int run_wmi_smbios_cmd(struct dell_wmi_smbios_buffer *buffer)

{

	int fd;

	int ret;



	fd = open(ioctl_devfs, O_NONBLOCK);

	ret = ioctl(fd, DELL_WMI_SMBIOS_CMD, buffer);

	close(fd);

	return ret;

}



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;



	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);



	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);



	if (*location)

		return 0;

	return 2;

}



static int token_is_active(__u16 *location, __u16 *cmpvalue,

			   struct dell_wmi_smbios_buffer *buffer)

{

	int ret;



	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;

}



static int query_token(__u16 token, struct dell_wmi_smbios_buffer *buffer)

{

	__u16 location;

	__u16 value;

	int ret;



	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);

}



static int activate_token(struct dell_wmi_smbios_buffer *buffer,

		   __u16 token)

{

	__u16 location;

	__u16 value;

	int ret;



	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;

}



static int query_buffer_size(__u64 *buffer_size)

{

	FILE *f;



	f = fopen(ioctl_devfs, "rb");

	if (!f)

		return -EINVAL;

	fread(buffer_size, sizeof(__u64), 1, f);

	fclose(f);

	return EXIT_SUCCESS;

}



int main(void)

{

	struct dell_wmi_smbios_buffer *buffer;

	int ret;

	__u64 value = 0;



	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);



	buffer = malloc(value);

	if (buffer == NULL) {

		printf("failed to alloc memory for ioctl\n");

		ret = -ENOMEM;

		goto out;

	}

	buffer->length = value;



	/* 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);



	/* 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);



	/* 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;

}

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