Add cpuid Linux kernel module for ARM CPUs

CMakeLists.txt

@@ -9,13 +9,16 @@ project(
   LANGUAGES C ASM_MASM
   VERSION ${VERSION})
 
+# CMake modules
+list(APPEND CMAKE_MODULE_PATH "${PROJECT_SOURCE_DIR}/cmake")
+
 if(MSVC)
   set(LIBCPUID_SHARED OFF)
 else()
   set(LIBCPUID_SHARED ON)
 endif()
 option(BUILD_SHARED_LIBS "Build shared lib" ${LIBCPUID_SHARED})
-
+option(LIBCPUID_DRIVERS "Enable kernel drivers" ON)
 option(LIBCPUID_TESTS "Enable building tests" OFF)
 
 set(CMAKE_CXX_STANDARD 11)
@@ -47,8 +50,6 @@ elseif(${CMAKE_SYSTEM_NAME} STREQUAL "FreeBSD")
 endif()
 
 # Global variables
-list(APPEND CMAKE_MODULE_PATH "${PROJECT_SOURCE_DIR}/cmake")
-
 if(UNIX)
   include(GNUInstallDirs)
   set(prefix "${CMAKE_INSTALL_PREFIX}")
@@ -64,6 +65,9 @@ endif(UNIX)
 # Include subdirectories
 add_subdirectory(libcpuid)
 add_subdirectory(cpuid_tool)
+if(LIBCPUID_DRIVERS)
+  add_subdirectory(drivers)
+endif()
 if(LIBCPUID_TESTS)
   add_subdirectory(tests)
 endif()

cmake/FindLinuxKernelHeaders.cmake

@@ -0,0 +1,24 @@
+# Find the kernel release
+execute_process(
+  COMMAND uname -r
+  OUTPUT_VARIABLE KERNEL_RELEASE
+  OUTPUT_STRIP_TRAILING_WHITESPACE
+)
+message(STATUS "Kernel release: ${KERNEL_RELEASE}")
+
+# Find the headers
+set(KERNELHEADERS_DIR "/usr/lib/modules/${KERNEL_RELEASE}/build")
+if(IS_DIRECTORY "${KERNELHEADERS_DIR}")
+  message(STATUS "Kernel headers: ${KERNELHEADERS_DIR}")
+  file(GLOB KERNELHEADERS_ARCH_INCLUDE_DIR LIST_DIRECTORIES true "${KERNELHEADERS_DIR}/arch/*/include")
+  set(KERNELHEADERS_INCLUDE_DIRS
+    "${KERNELHEADERS_DIR}/include"
+    "${KERNELHEADERS_ARCH_INCLUDE_DIR}"
+    CACHE PATH "Kernel headers include dirs"
+  )
+  set(KERNELHEADERS_FOUND 1 CACHE STRING "Set to 1 if kernel headers were found")
+else()
+  set(KERNELHEADERS_FOUND 0 CACHE STRING "Set to 1 if kernel headers were found")
+endif()
+
+mark_as_advanced(KERNELHEADERS_FOUND)

drivers/.gitignore

@@ -0,0 +1,8 @@
+!*/*/Makefile.in
+*.cmd
+*.o.d
+*.ko
+*.mod
+*.mod.c
+Module.symvers
+modules.order

drivers/CMakeLists.txt

@@ -0,0 +1,4 @@
+# Include "arm" directory only for ARM CPUs
+if(("${CMAKE_SYSTEM_PROCESSOR}" MATCHES "^armv.*") OR ("${CMAKE_SYSTEM_PROCESSOR}" STREQUAL "aarch64"))
+  add_subdirectory(arm)
+endif()

drivers/arm/CMakeLists.txt

@@ -0,0 +1,8 @@
+option(LIBCPUID_DRIVER_DEBUG "Debug kernel module" OFF)
+if(LIBCPUID_DRIVER_DEBUG)
+  add_definitions(-DLIBCPUID_DRIVER_DEBUG)
+endif(LIBCPUID_DRIVER_DEBUG)
+
+if("${CMAKE_SYSTEM_NAME}" STREQUAL "Linux")
+  add_subdirectory(linux)
+endif()

drivers/arm/linux/CMakeLists.txt

@@ -0,0 +1,38 @@
+set(DRIVER_NAME "cpuid")
+option(LIBCPUID_DRIVER_ARM_LINUX_DKMS "Use DKMS for CPUID kernel module for ARM" ON)
+
+if(LIBCPUID_DRIVER_ARM_LINUX_DKMS)
+  message(STATUS "Deploying DKMS configuration for CPUID kernel module...")
+  set(LIBCPUID_SRC_DIR "/usr/src/${CMAKE_PROJECT_NAME}-${PROJECT_VERSION}")
+
+  configure_file(dkms.conf.in "${CMAKE_CURRENT_BINARY_DIR}/dkms.conf")
+  configure_file(Makefile.in  "${CMAKE_CURRENT_BINARY_DIR}/Makefile_dkms")
+  install(FILES
+    cpuid.c
+    "${CMAKE_SOURCE_DIR}/libcpuid/libcpuid_arm_driver.h"
+    "${CMAKE_CURRENT_BINARY_DIR}/dkms.conf"
+    DESTINATION "${LIBCPUID_SRC_DIR}/"
+  )
+  install(FILES
+    "${CMAKE_CURRENT_BINARY_DIR}/Makefile_dkms"
+    DESTINATION "${LIBCPUID_SRC_DIR}"
+    RENAME "Makefile"
+  )
+else(LIBCPUID_DRIVER_ARM_LINUX_DKMS)
+  find_package(LinuxKernelHeaders REQUIRED)
+
+  set(DRIVER_SOURCE "${DRIVER_NAME}.c")
+  set(DRIVER_OBJECT "${DRIVER_NAME}.o")
+  set(DRIVER_MODULE "${DRIVER_NAME}.ko")
+  set(KBUILD_CMD "${CMAKE_MAKE_PROGRAM}" EXTRA_CFLAGS="-I${CMAKE_SOURCE_DIR}/libcpuid" -C "${KERNELHEADERS_DIR}" "src=${CMAKE_CURRENT_SOURCE_DIR}" "M=${CMAKE_CURRENT_BINARY_DIR}")
+
+  add_custom_command(OUTPUT "${DRIVER_MODULE}"
+    COMMAND ${KBUILD_CMD} modules
+    WORKING_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}"
+    DEPENDS "${DRIVER_SOURCE}"
+    COMMENT "Building CPUID kernel module for ARM..."
+    VERBATIM
+  )
+
+  add_custom_target(driver-arm-cpuid ALL DEPENDS "${DRIVER_MODULE}")
+endif(LIBCPUID_DRIVER_ARM_LINUX_DKMS)

drivers/arm/linux/Makefile.in

@@ -0,0 +1,9 @@
+obj-m += @DRIVER_NAME@.o
+
+all: modules
+
+modules:
+	@$(MAKE) -C /lib/modules/$(shell uname -r)/build M=$(PWD) modules
+
+clean:
+	@$(MAKE) -C /lib/modules/$(shell uname -r)/build M=$(PWD) clean

drivers/arm/linux/cpuid.c

@@ -0,0 +1,266 @@
+/*
+ * Copyright 2024  Veselin Georgiev,
+ * anrieffNOSPAM @ mgail_DOT.com (convert to gmail)
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/* This kernel module is inpired on msr: https://github.com/torvalds/linux/blob/master/arch/x86/kernel/msr.c */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/fcntl.h>
+#include <linux/init.h>
+#include <linux/poll.h>
+#include <linux/smp.h>
+#include <linux/major.h>
+#include <linux/fs.h>
+#include <linux/device.h>
+#include <linux/cpu.h>
+#include <linux/version.h>
+
+#include "libcpuid_arm_driver.h"
+
+
+#ifdef LIBCPUID_DRIVER_DEBUG
+# define	DPRINTF(format, ...) pr_info(format, __VA_ARGS__)
+#else
+# define	DPRINTF(...)
+#endif
+
+#if defined(__arm__)
+# define cpuid_read_sysreg(aarch32, aarch64, value) asm volatile("mrc " aarch32 : "=r" (value))
+#elif defined(__aarch64__)
+# define cpuid_read_sysreg(aarch32, aarch64, value) asm volatile("mrs %0, " aarch64 : "=r" (value))
+#else
+# error This platform is not supported by this kernel module
+#endif
+
+static enum cpuhp_state cpuhp_cpuid_state;
+
+#if (LINUX_VERSION_CODE < KERNEL_VERSION(6, 2, 0))
+static char *cpuid_devnode(struct device *dev, umode_t *mode)
+#else
+static char *cpuid_devnode(const struct device *dev, umode_t *mode)
+#endif /* Linux 6.2 */
+{
+	return kasprintf(GFP_KERNEL, "cpu/%u/cpuid", MINOR(dev->devt));
+}
+
+#if (LINUX_VERSION_CODE < KERNEL_VERSION(6, 6, 0))
+static struct class *cpuid_class;
+#else
+static const struct class cpuid_class = {
+	.name		= "cpuid",
+	.devnode	= cpuid_devnode,
+};
+#endif /* Linux 6.6 */
+
+static void __read_reg_on_cpu(void *info)
+{
+	struct read_reg_t *read_reg = info;
+
+	DPRINTF("[cpuid,%d]: operating on request %d\n", __LINE__, read_reg->request);
+	read_reg->value_64b = 0;
+	switch(read_reg->request)
+	{
+		case REQ_MIDR:     cpuid_read_sysreg("p15, 0, %0, c0, c0, 0", AARCH64_REG_MIDR_EL1,   read_reg->value_64b); break;
+		case REQ_MPIDR:    cpuid_read_sysreg("p15, 0, %0, c0, c0, 5", AARCH64_REG_MPIDR_EL1,  read_reg->value_64b); break;
+		case REQ_REVIDR:   cpuid_read_sysreg("p15, 0, %0, c0, c0, 6", AARCH64_REG_REVIDR_EL1, read_reg->value_64b); break;
+		case REQ_ID_AFR0:  cpuid_read_sysreg("p15, 0, %0, c0, c1, 3", AARCH64_REG_ID_AFR0,    read_reg->value_32b); break;
+		case REQ_ID_DFR0:  cpuid_read_sysreg("p15, 0, %0, c0, c1, 2", AARCH64_REG_ID_DFR0,    read_reg->value_32b); break;
+		case REQ_ID_DFR1:  cpuid_read_sysreg("p15, 0, %0, c0, c3, 5", AARCH64_REG_ID_DFR1,    read_reg->value_32b); break;
+		case REQ_ID_ISAR0: cpuid_read_sysreg("p15, 0, %0, c0, c2, 0", AARCH64_REG_ID_ISAR0,   read_reg->value_32b); break;
+		case REQ_ID_ISAR1: cpuid_read_sysreg("p15, 0, %0, c0, c2, 1", AARCH64_REG_ID_ISAR1,   read_reg->value_32b); break;
+		case REQ_ID_ISAR2: cpuid_read_sysreg("p15, 0, %0, c0, c2, 2", AARCH64_REG_ID_ISAR2,   read_reg->value_32b); break;
+		case REQ_ID_ISAR3: cpuid_read_sysreg("p15, 0, %0, c0, c2, 3", AARCH64_REG_ID_ISAR3,   read_reg->value_32b); break;
+		case REQ_ID_ISAR4: cpuid_read_sysreg("p15, 0, %0, c0, c2, 4", AARCH64_REG_ID_ISAR4,   read_reg->value_32b); break;
+		case REQ_ID_ISAR5: cpuid_read_sysreg("p15, 0, %0, c0, c2, 5", AARCH64_REG_ID_ISAR5,   read_reg->value_32b); break;
+		case REQ_ID_ISAR6: cpuid_read_sysreg("p15, 0, %0, c0, c2, 7", AARCH64_REG_ID_ISAR6,   read_reg->value_32b); break;
+		case REQ_ID_MMFR0: cpuid_read_sysreg("p15, 0, %0, c0, c1, 4", AARCH64_REG_ID_MMFR0,   read_reg->value_32b); break;
+		case REQ_ID_MMFR1: cpuid_read_sysreg("p15, 0, %0, c0, c1, 5", AARCH64_REG_ID_MMFR1,   read_reg->value_32b); break;
+		case REQ_ID_MMFR2: cpuid_read_sysreg("p15, 0, %0, c0, c1, 6", AARCH64_REG_ID_MMFR2,   read_reg->value_32b); break;
+		case REQ_ID_MMFR3: cpuid_read_sysreg("p15, 0, %0, c0, c1, 7", AARCH64_REG_ID_MMFR3,   read_reg->value_32b); break;
+		case REQ_ID_MMFR4: cpuid_read_sysreg("p15, 0, %0, c0, c2, 6", AARCH64_REG_ID_MMFR4,   read_reg->value_32b); break;
+		case REQ_ID_MMFR5: cpuid_read_sysreg("p15, 0, %0, c0, c3, 6", AARCH64_REG_ID_MMFR5,   read_reg->value_32b); break;
+		case REQ_ID_PFR0:  cpuid_read_sysreg("p15, 0, %0, c0, c1, 0", AARCH64_REG_ID_PFR0,    read_reg->value_32b); break;
+		case REQ_ID_PFR1:  cpuid_read_sysreg("p15, 0, %0, c0, c1, 1", AARCH64_REG_ID_PFR1,    read_reg->value_32b); break;
+		case REQ_ID_PFR2:  cpuid_read_sysreg("p15, 0, %0, c0, c3, 4", AARCH64_REG_ID_PFR2,    read_reg->value_32b); break;
+#if defined(__aarch64__)
+		case REQ_ID_AA64AFR0:  cpuid_read_sysreg(NULL, AARCH64_REG_ID_AA64AFR0_EL1,  read_reg->value_64b); break;
+		case REQ_ID_AA64AFR1:  cpuid_read_sysreg(NULL, AARCH64_REG_ID_AA64AFR1_EL1,  read_reg->value_64b); break;
+		case REQ_ID_AA64DFR0:  cpuid_read_sysreg(NULL, AARCH64_REG_ID_AA64DFR0_EL1,  read_reg->value_64b); break;
+		case REQ_ID_AA64DFR1:  cpuid_read_sysreg(NULL, AARCH64_REG_ID_AA64DFR1_EL1,  read_reg->value_64b); break;
+		case REQ_ID_AA64ISAR0: cpuid_read_sysreg(NULL, AARCH64_REG_ID_AA64ISAR0_EL1, read_reg->value_64b); break;
+		case REQ_ID_AA64ISAR1: cpuid_read_sysreg(NULL, AARCH64_REG_ID_AA64ISAR1_EL1, read_reg->value_64b); break;
+		case REQ_ID_AA64ISAR2: cpuid_read_sysreg(NULL, AARCH64_REG_ID_AA64ISAR2_EL1, read_reg->value_64b); break;
+		case REQ_ID_AA64MMFR0: cpuid_read_sysreg(NULL, AARCH64_REG_ID_AA64MMFR0_EL1, read_reg->value_64b); break;
+		case REQ_ID_AA64MMFR1: cpuid_read_sysreg(NULL, AARCH64_REG_ID_AA64MMFR1_EL1, read_reg->value_64b); break;
+		case REQ_ID_AA64MMFR2: cpuid_read_sysreg(NULL, AARCH64_REG_ID_AA64MMFR2_EL1, read_reg->value_64b); break;
+		case REQ_ID_AA64MMFR3: cpuid_read_sysreg(NULL, AARCH64_REG_ID_AA64MMFR3_EL1, read_reg->value_64b); break;
+		case REQ_ID_AA64MMFR4: cpuid_read_sysreg(NULL, AARCH64_REG_ID_AA64MMFR4_EL1, read_reg->value_64b); break;
+		case REQ_ID_AA64PFR0:  cpuid_read_sysreg(NULL, AARCH64_REG_ID_AA64PFR0_EL1,  read_reg->value_64b); break;
+		case REQ_ID_AA64PFR1:  cpuid_read_sysreg(NULL, AARCH64_REG_ID_AA64PFR1_EL1,  read_reg->value_64b); break;
+		case REQ_ID_AA64PFR2:  cpuid_read_sysreg(NULL, AARCH64_REG_ID_AA64PFR2_EL1,  read_reg->value_64b); break;
+		case REQ_ID_AA64SMFR0: cpuid_read_sysreg(NULL, AARCH64_REG_ID_AA64SMFR0_EL1, read_reg->value_64b); break;
+		case REQ_ID_AA64ZFR0:  cpuid_read_sysreg(NULL, AARCH64_REG_ID_AA64ZFR0_EL1,  read_reg->value_64b); break;
+#endif /* __aarch64__ */
+		default:
+			read_reg->request = REQ_INVALID;
+			pr_warn("[cpuid,%d]: unknown operation requested: %d", __LINE__, read_reg->request);
+			break;
+	}
+
+	DPRINTF("[cpuid,%d]: set value 0x%016llX\n", __LINE__, read_reg->value_64b);
+}
+
+static long cpuid_ioctl(struct file *file, unsigned int ioc, unsigned long arg)
+{
+	u32 __user *uregs = (u32 __user *)arg;
+	int err = 0;
+	struct read_reg_t read_reg;
+	const int cpu = iminor(file_inode(file));
+
+	DPRINTF("[cpuid,%d]: received ioctl %u for cpu number %d\n", __LINE__, ioc, cpu);
+	switch (ioc) {
+		case ARM_IOC_READ_REG:
+			if (!(file->f_mode & FMODE_READ)) {
+				err = -EBADF;
+				break;
+			}
+			if (copy_from_user(&read_reg, uregs, sizeof(read_reg))) {
+				err = -EFAULT;
+				break;
+			}
+			err = smp_call_function_single(cpu, __read_reg_on_cpu, &read_reg, 1);
+			if (err)
+				break;
+			if (copy_to_user(uregs, &read_reg, sizeof(read_reg)))
+				err = -EFAULT;
+			break;
+
+		default:
+			err = -ENOTTY;
+			break;
+	}
+
+	return err;
+}
+
+/*
+ * File operations we support
+ */
+static const struct file_operations cpuid_fops = {
+	.owner = THIS_MODULE,
+	.unlocked_ioctl = cpuid_ioctl,
+	.compat_ioctl = cpuid_ioctl,
+};
+
+static int cpuid_device_create(unsigned int cpu)
+{
+	struct device *dev;
+
+#if (LINUX_VERSION_CODE < KERNEL_VERSION(6, 6, 0))
+	dev = device_create(cpuid_class, NULL, MKDEV(CPUID_MAJOR, cpu), NULL, "cpuid%d", cpu);
+#else
+	dev = device_create(&cpuid_class, NULL, MKDEV(CPUID_MAJOR, cpu), NULL, "cpuid%d", cpu);
+#endif /* Linux 6.6 */
+
+	return PTR_ERR_OR_ZERO(dev);
+}
+
+static int cpuid_device_destroy(unsigned int cpu)
+{
+#if (LINUX_VERSION_CODE < KERNEL_VERSION(6, 6, 0))
+	device_destroy(cpuid_class, MKDEV(CPUID_MAJOR, cpu));
+#else
+	device_destroy(&cpuid_class, MKDEV(CPUID_MAJOR, cpu));
+#endif
+	return 0;
+}
+
+static int __init cpuid_init(void)
+{
+	int err;
+
+	DPRINTF("[cpuid,%d]: load module\n", __LINE__);
+	if (__register_chrdev(CPUID_MAJOR, 0, NR_CPUS, "cpu/cpuid", &cpuid_fops)) {
+		pr_err("unable to get major %d for cpuid\n", CPUID_MAJOR);
+		return -EBUSY;
+	}
+#if (LINUX_VERSION_CODE < KERNEL_VERSION(6, 6, 0))
+# if (LINUX_VERSION_CODE < KERNEL_VERSION(6, 4, 0))
+	cpuid_class = class_create(THIS_MODULE, "cpuid");
+# else
+	cpuid_class = class_create("cpuid");
+# endif /* Linux 6.4 */
+	if (IS_ERR(cpuid_class)) {
+		err = PTR_ERR(cpuid_class);
+		goto out_chrdev;
+	}
+	cpuid_class->devnode = cpuid_devnode;
+#else
+	err = class_register(&cpuid_class);
+	if (err)
+		goto out_chrdev;
+#endif /* Linux 6.6 */
+
+#if defined(__aarch64__)
+	err  = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "arm64/cpuid:online", cpuid_device_create, cpuid_device_destroy);
+#else
+	err  = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "arm/cpuid:online", cpuid_device_create, cpuid_device_destroy);
+#endif
+	if (err < 0)
+		goto out_class;
+	cpuhp_cpuid_state = err;
+	return 0;
+
+out_class:
+#if (LINUX_VERSION_CODE < KERNEL_VERSION(6, 6, 0))
+	class_destroy(cpuid_class);
+#else
+	class_unregister(&cpuid_class);
+#endif /* Linux 6.6 */
+out_chrdev:
+	__unregister_chrdev(CPUID_MAJOR, 0, NR_CPUS, "cpu/cpuid");
+	return err;
+}
+module_init(cpuid_init);
+
+static void __exit cpuid_exit(void)
+{
+	DPRINTF("[cpuid,%d]: unload module\n", __LINE__);
+	cpuhp_remove_state(cpuhp_cpuid_state);
+#if (LINUX_VERSION_CODE < KERNEL_VERSION(6, 6, 0))
+	class_destroy(cpuid_class);
+#else
+	class_unregister(&cpuid_class);
+#endif /* Linux 6.6 */
+	__unregister_chrdev(CPUID_MAJOR, 0, NR_CPUS, "cpu/cpuid");
+}
+module_exit(cpuid_exit)
+
+MODULE_AUTHOR("The Tumultuous Unicorn Of Darkness");
+MODULE_DESCRIPTION("ARM registers driver for libcpuid");
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_VERSION("0.1");

drivers/arm/linux/dkms.conf.in

@@ -0,0 +1,7 @@
+PACKAGE_NAME="@CMAKE_PROJECT_NAME@"
+PACKAGE_VERSION="@PROJECT_VERSION@"
+MAKE="make"
+CLEAN="make clean"
+BUILT_MODULE_NAME[0]="@DRIVER_NAME@"
+DEST_MODULE_LOCATION[0]="/kernel/drivers/misc/@DRIVER_NAME@"
+AUTOINSTALL="yes"