Commit fb57fc78 authored by Jithu Joseph's avatar Jithu Joseph Committed by Hans de Goede
Browse files

platform/x86/intel/ifs: Read IFS firmware image 



Driver probe routine allocates structure to communicate status
and parameters between functions in the driver. Also call
load_ifs_binary() to load the scan image file.

There is a separate scan image file for each processor family,
model, stepping combination. This is read from the static path:

  /lib/firmware/intel/ifs/{ff-mm-ss}.scan

Step 1 in loading is to generate the correct path and use
request_firmware_direct() to load into memory.

Subsequent patches will use the IFS MSR interfaces to copy
the image to BIOS reserved memory and validate the SHA256
checksums.

Reviewed-by: default avatarDan Williams <dan.j.williams@intel.com>
Signed-off-by: default avatarJithu Joseph <jithu.joseph@intel.com>
Co-developed-by: default avatarTony Luck <tony.luck@intel.com>
Signed-off-by: default avatarTony Luck <tony.luck@intel.com>
Acked-by: default avatarHans de Goede <hdegoede@redhat.com>
Reviewed-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: default avatarThomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20220506225410.1652287-6-tony.luck@intel.com


Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
parent 67896ef1

drivers/platform/x86/intel/ifs/Makefile

+1 −1
Original line number Diff line number Diff line 
obj-$(CONFIG_INTEL_IFS)		+= intel_ifs.o



intel_ifs-objs			:= core.o
 
intel_ifs-objs			:= core.o load.o

drivers/platform/x86/intel/ifs/core.c

+21 −1
Original line number Diff line number Diff line
@@ -6,6 +6,8 @@ 


#include <asm/cpu_device_id.h>



#include "ifs.h"



#define X86_MATCH(model)				\

	X86_MATCH_VENDOR_FAM_MODEL_FEATURE(INTEL, 6,	\

		INTEL_FAM6_##model, X86_FEATURE_CORE_CAPABILITIES, NULL)
@@ -16,6 +18,17 @@ static const struct x86_cpu_id ifs_cpu_ids[] __initconst = { 
};

MODULE_DEVICE_TABLE(x86cpu, ifs_cpu_ids);



static struct ifs_device ifs_device = {

	.data = {

		.integrity_cap_bit = MSR_INTEGRITY_CAPS_PERIODIC_BIST_BIT,

	},

	.misc = {

		.name = "intel_ifs_0",

		.nodename = "intel_ifs/0",

		.minor = MISC_DYNAMIC_MINOR,

	},

};



static int __init ifs_init(void)

{

	const struct x86_cpu_id *m;
@@ -34,11 +47,18 @@ static int __init ifs_init(void) 
	if (rdmsrl_safe(MSR_INTEGRITY_CAPS, &msrval))

		return -ENODEV;



	if ((msrval & BIT(ifs_device.data.integrity_cap_bit)) &&

	    !misc_register(&ifs_device.misc)) {

		ifs_load_firmware(ifs_device.misc.this_device);

		return 0;

	}



	return -ENODEV;

}



static void __exit ifs_exit(void)

{

	misc_deregister(&ifs_device.misc);

}



module_init(ifs_init);

drivers/platform/x86/intel/ifs/ifs.h

0 → 100644
+25 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0-only */

/* Copyright(c) 2022 Intel Corporation. */



#ifndef _IFS_H_

#define _IFS_H_



#include <linux/device.h>

#include <linux/miscdevice.h>



/**

 * struct ifs_data - attributes related to intel IFS driver

 * @integrity_cap_bit: MSR_INTEGRITY_CAPS bit enumerating this test

 */

struct ifs_data {

	int	integrity_cap_bit;

};



struct ifs_device {

	struct ifs_data data;

	struct miscdevice misc;

};



void ifs_load_firmware(struct device *dev);



#endif

drivers/platform/x86/intel/ifs/load.c

0 → 100644
+28 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-only

/* Copyright(c) 2022 Intel Corporation. */



#include <linux/firmware.h>



#include "ifs.h"



/*

 * Load ifs image. Before loading ifs module, the ifs image must be located

 * in /lib/firmware/intel/ifs and named as {family/model/stepping}.{testname}.

 */

void ifs_load_firmware(struct device *dev)

{

	const struct firmware *fw;

	char scan_path[32];

	int ret;



	snprintf(scan_path, sizeof(scan_path), "intel/ifs/%02x-%02x-%02x.scan",

		 boot_cpu_data.x86, boot_cpu_data.x86_model, boot_cpu_data.x86_stepping);



	ret = request_firmware_direct(&fw, scan_path, dev);

	if (ret) {

		dev_err(dev, "ifs file %s load failed\n", scan_path);

		return;

	}



	release_firmware(fw);

}