[PATCH v2 5/7] fpga: sec-mgr: expose sec-mgr update size

[Russ Weight]

Extend the Intel 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@xxxxxxxxx>
Reviewed-by: Tom Rix <trix@xxxxxxxxxx>
---
v2:
  - Bumped documentation date and version
---
 Documentation/ABI/testing/sysfs-class-ifpga-sec-mgr | 11 +++++++++++
 drivers/fpga/ifpga-sec-mgr.c                        | 10 ++++++++++
 2 files changed, 21 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-class-ifpga-sec-mgr b/Documentation/ABI/testing/sysfs-class-ifpga-sec-mgr
index 1f9f2c215e0c..ec51135fcb6a 100644
--- a/Documentation/ABI/testing/sysfs-class-ifpga-sec-mgr
+++ b/Documentation/ABI/testing/sysfs-class-ifpga-sec-mgr
@@ -90,6 +90,17 @@ Description:	Read-only. Returns a string describing the current
 		as it will be signaled by sysfs_notify() on each
 		state change.
 
+What: 		/sys/class/ifpga_sec_mgr/ifpga_secX/update/remaining_size
+Date:		Oct 2020
+KernelVersion:  5.11
+Contact:	Russ Weight <russell.h.weight@xxxxxxxxx>
+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/ifpga_sec_mgr/ifpga_secX/update/error
 Date:		Oct 2020
 KernelVersion:  5.11
diff --git a/drivers/fpga/ifpga-sec-mgr.c b/drivers/fpga/ifpga-sec-mgr.c
index 456ea0b71e3d..d8ac863c1159 100644
--- a/drivers/fpga/ifpga-sec-mgr.c
+++ b/drivers/fpga/ifpga-sec-mgr.c
@@ -350,6 +350,15 @@ 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 ifpga_sec_mgr *imgr = to_sec_mgr(dev);
+
+	return sprintf(buf, "%u\n", imgr->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)
 {
@@ -386,6 +395,7 @@ 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,
 };
 
-- 
2.17.1