[PATCH 05/12] fpga: sec-mgr: expose sec-mgr update size

[Moritz Fischer <mdf@kernel.org>]

From: Russ Weight <russell.h.weight@intel.com>

Extend the FPGA Security Manager class driver to include
an update/remaining_size sysfs node that can be read to
determine how much data remains to be transferred to the
secure update engine. This file can be used to monitor
progress during the "writing" phase of an update.

Signed-off-by: Russ Weight <russell.h.weight@intel.com>
Reviewed-by: Tom Rix <trix@redhat.com>
Signed-off-by: Moritz Fischer <mdf@kernel.org>
---
 Documentation/ABI/testing/sysfs-class-fpga-sec-mgr | 11 +++++++++++
 drivers/fpga/fpga-sec-mgr.c                        | 10 ++++++++++
 2 files changed, 21 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-class-fpga-sec-mgr b/Documentation/ABI/testing/sysfs-class-fpga-sec-mgr
index 24890d04521f..c5d0b9d7c7e4 100644
--- a/Documentation/ABI/testing/sysfs-class-fpga-sec-mgr
+++ b/Documentation/ABI/testing/sysfs-class-fpga-sec-mgr
@@ -28,6 +28,17 @@ Description:	Read-only. Returns a string describing the current
 		as it will be signaled by sysfs_notify() on each
 		state change.
 
+What: 		/sys/class/fpga_sec_mgr/fpga_secX/update/remaining_size
+Date:		June 2021
+KernelVersion:	5.14
+Contact:	Russ Weight <russell.h.weight@intel.com>
+Description:	Read-only. Returns the size of data that remains to
+		be written to the secure update engine. The size
+		value is initialized to the full size of the file
+		image and the value is updated periodically during
+		the "writing" phase of the update.
+		Format: "%u".
+
 What: 		/sys/class/fpga_sec_mgr/fpga_secX/update/error
 Date:		June 2021
 KernelVersion:	5.14
diff --git a/drivers/fpga/fpga-sec-mgr.c b/drivers/fpga/fpga-sec-mgr.c
index 903385779a1f..bc6b35cc7237 100644
--- a/drivers/fpga/fpga-sec-mgr.c
+++ b/drivers/fpga/fpga-sec-mgr.c
@@ -198,6 +198,15 @@ error_show(struct device *dev, struct device_attribute *attr, char *buf)
 }
 static DEVICE_ATTR_RO(error);
 
+static ssize_t remaining_size_show(struct device *dev,
+				   struct device_attribute *attr, char *buf)
+{
+	struct fpga_sec_mgr *smgr = to_sec_mgr(dev);
+
+	return sysfs_emit(buf, "%u\n", smgr->remaining_size);
+}
+static DEVICE_ATTR_RO(remaining_size);
+
 static ssize_t filename_store(struct device *dev, struct device_attribute *attr,
 			      const char *buf, size_t count)
 {
@@ -234,6 +243,7 @@ static struct attribute *sec_mgr_update_attrs[] = {
 	&dev_attr_filename.attr,
 	&dev_attr_status.attr,
 	&dev_attr_error.attr,
+	&dev_attr_remaining_size.attr,
 	NULL,
 };
 
-- 
2.31.1