firmware_loader: Add firmware-upload support

Extend the firmware subsystem to support a persistent sysfs interface that
userspace may use to initiate a firmware update. For example, FPGA based
PCIe cards load firmware and FPGA images from local FLASH when the card
boots. The images in FLASH may be updated with new images provided by the
user at his/her convenience.

A device driver may call firmware_upload_register() to expose persistent
"loading" and "data" sysfs files. These files are used in the same way as
the fallback sysfs "loading" and "data" files. When 0 is written to
"loading" to complete the write of firmware data, the data is transferred
to the lower-level driver using pre-registered call-back functions. The
data transfer is done in the context of a kernel worker thread.

Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Tianfei zhang <tianfei.zhang@intel.com>
Tested-by: Matthew Gerlach <matthew.gerlach@linux.intel.com>
Signed-off-by: Russ Weight <russell.h.weight@intel.com>
Link: https://lore.kernel.org/r/20220421212204.36052-5-russell.h.weight@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 49 insertions, 0 deletions

diff --git a/drivers/base/firmware_loader/sysfs_upload.h b/drivers/base/firmware_loader/sysfs_upload.h
new file mode 100644
index 000000000000..18bd4d99f064
--- /dev/null
+++ b/drivers/base/firmware_loader/sysfs_upload.h
@@ -0,0 +1,49 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __FIRMWARE_UPLOAD_H
+#define __FIRMWARE_UPLOAD_H
+
+#include <linux/device.h>
+
+/**
+ * enum fw_upload_prog - firmware upload progress codes
+ * @FW_UPLOAD_PROG_IDLE: there is no firmware upload in progress
+ * @FW_UPLOAD_PROG_RECEIVING: worker thread is receiving firmware data
+ * @FW_UPLOAD_PROG_PREPARING: target device is preparing for firmware upload
+ * @FW_UPLOAD_PROG_TRANSFERRING: data is being copied to the device
+ * @FW_UPLOAD_PROG_PROGRAMMING: device is performing the firmware update
+ * @FW_UPLOAD_PROG_MAX: Maximum progress code marker
+ */
+enum fw_upload_prog {
+	FW_UPLOAD_PROG_IDLE,
+	FW_UPLOAD_PROG_RECEIVING,
+	FW_UPLOAD_PROG_PREPARING,
+	FW_UPLOAD_PROG_TRANSFERRING,
+	FW_UPLOAD_PROG_PROGRAMMING,
+	FW_UPLOAD_PROG_MAX
+};
+
+struct fw_upload_priv {
+	struct fw_upload *fw_upload;
+	struct module *module;
+	const char *name;
+	const struct fw_upload_ops *ops;
+	struct mutex lock;		  /* protect data structure contents */
+	struct work_struct work;
+	const u8 *data;			  /* pointer to update data */
+	u32 remaining_size;		  /* size remaining to transfer */
+	enum fw_upload_prog progress;
+	enum fw_upload_prog err_progress; /* progress at time of failure */
+	enum fw_upload_err err_code;	  /* security manager error code */
+};
+
+#ifdef CONFIG_FW_UPLOAD
+int fw_upload_start(struct fw_sysfs *fw_sysfs);
+umode_t fw_upload_is_visible(struct kobject *kobj, struct attribute *attr, int n);
+#else
+static inline int fw_upload_start(struct fw_sysfs *fw_sysfs)
+{
+	return 0;
+}
+#endif
+
+#endif /* __FIRMWARE_UPLOAD_H */