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: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jithu Joseph <jithu.joseph@intel.com>
Co-developed-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20220506225410.1652287-6-tony.luck@intel.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

1 files changed, 28 insertions, 0 deletions

diff --git a/drivers/platform/x86/intel/ifs/load.c b/drivers/platform/x86/intel/ifs/load.c
new file mode 100644
index 000000000000..9fb71d38c819
--- /dev/null
+++ b/drivers/platform/x86/intel/ifs/load.c
@@ -0,0 +1,28 @@
+// 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);
+}