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

Tony Luck
2022-04-19T16:42:04Z

From: Jithu Joseph <jithu.joseph@intel.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@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>
---
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