linux-kernel - [PATCH v3 05/11] platform/x86/intel/ifs: Read IFS firmware image

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Date:   Tue, 19 Apr 2022 09:38:53 -0700
From:   Tony Luck <tony.luck@...el.com>
To:     hdegoede@...hat.com, markgross@...nel.org
Cc:     tglx@...utronix.de, mingo@...hat.com, bp@...en8.de,
        dave.hansen@...ux.intel.com, x86@...nel.org, hpa@...or.com,
        corbet@....net, gregkh@...uxfoundation.org,
        andriy.shevchenko@...ux.intel.com, jithu.joseph@...el.com,
        ashok.raj@...el.com, tony.luck@...el.com, rostedt@...dmis.org,
        dan.j.williams@...el.com, linux-kernel@...r.kernel.org,
        linux-doc@...r.kernel.org, platform-driver-x86@...r.kernel.org,
        patches@...ts.linux.dev, ravi.v.shankar@...el.com
Subject: [PATCH v3 05/11] platform/x86/intel/ifs: Read IFS firmware image

From: Jithu Joseph <jithu.joseph@...el.com>

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: Dan Williams <dan.j.williams@...el.com>
Signed-off-by: Jithu Joseph <jithu.joseph@...el.com>
Co-developed-by: Tony Luck <tony.luck@...el.com>
Signed-off-by: Tony Luck <tony.luck@...el.com>
---
 drivers/platform/x86/intel/ifs/Makefile |  2 +-
 drivers/platform/x86/intel/ifs/core.c   | 23 ++++++++++++++++++
 drivers/platform/x86/intel/ifs/ifs.h    | 19 +++++++++++++++
 drivers/platform/x86/intel/ifs/load.c   | 31 +++++++++++++++++++++++++
 4 files changed, 74 insertions(+), 1 deletion(-)
 create mode 100644 drivers/platform/x86/intel/ifs/ifs.h
 create mode 100644 drivers/platform/x86/intel/ifs/load.c

diff --git a/drivers/platform/x86/intel/ifs/Makefile b/drivers/platform/x86/intel/ifs/Makefile
index bf8adc57892c..eab0cc81f38e 100644
--- a/drivers/platform/x86/intel/ifs/Makefile
+++ b/drivers/platform/x86/intel/ifs/Makefile
@@ -2,4 +2,4 @@ obj-$(CONFIG_INTEL_IFS_DEVICE)	+= intel_ifs_device.o
 
 obj-$(CONFIG_INTEL_IFS)		+= intel_ifs.o
 
-intel_ifs-objs			:= core.o
+intel_ifs-objs			:= core.o load.o
diff --git a/drivers/platform/x86/intel/ifs/core.c b/drivers/platform/x86/intel/ifs/core.c
index eb34b877dac0..139449f11a64 100644
--- a/drivers/platform/x86/intel/ifs/core.c
+++ b/drivers/platform/x86/intel/ifs/core.c
@@ -4,7 +4,30 @@
 #include <linux/module.h>
 #include <linux/platform_device.h>
 
+#include "ifs.h"
+
+static int ifs_probe(struct platform_device *pdev)
+{
+	struct ifs_data *ifsd;
+
+	ifsd = devm_kzalloc(&pdev->dev, sizeof(*ifsd), GFP_KERNEL);
+	if (!ifsd)
+		return -ENOMEM;
+
+	dev_set_drvdata(&pdev->dev, ifsd);
+
+	switch (pdev->id) {
+	case 0:
+		/* Load IFS binary to BIOS reserved memory area */
+		ifsd->loaded = !load_ifs_binary(&pdev->dev);
+		break;
+	}
+
+	return 0;
+}
+
 static struct platform_driver intel_ifs_driver = {
+	.probe = ifs_probe,
 	.driver = {
 		.name = "intel_ifs",
 	},
diff --git a/drivers/platform/x86/intel/ifs/ifs.h b/drivers/platform/x86/intel/ifs/ifs.h
new file mode 100644
index 000000000000..dacc8b6ce159
--- /dev/null
+++ b/drivers/platform/x86/intel/ifs/ifs.h
@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* Copyright(c) 2022 Intel Corporation. */
+
+#ifndef _IFS_H_
+#define _IFS_H_
+
+/**
+ * struct ifs_data - attributes related to intel IFS driver
+ * @loaded_version: stores the currently loaded ifs image version.
+ * @loaded: If a valid test binary has been loaded into the memory
+ */
+struct ifs_data {
+	int loaded_version;
+	bool loaded;
+};
+
+int load_ifs_binary(struct device *dev);
+
+#endif
diff --git a/drivers/platform/x86/intel/ifs/load.c b/drivers/platform/x86/intel/ifs/load.c
new file mode 100644
index 000000000000..fa6c64707a73
--- /dev/null
+++ b/drivers/platform/x86/intel/ifs/load.c
@@ -0,0 +1,31 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright(c) 2022 Intel Corporation. */
+
+#include <linux/firmware.h>
+#include <linux/platform_device.h>
+
+static const char *ifs_path = "intel/ifs/";
+
+/*
+ * 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}.
+ */
+int load_ifs_binary(struct device *dev)
+{
+	const struct firmware *fw;
+	char scan_path[256];
+	int ret;
+
+	snprintf(scan_path, sizeof(scan_path), "%s%02x-%02x-%02x.scan", ifs_path,
+		 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 ret;
+	}
+
+	release_firmware(fw);
+
+	return ret;
+}
-- 
2.35.1