[PATCH v16 4/5] fpga: image-load: add status ioctl

[Russ Weight]

Extend the FPGA Image Load framework to include an FPGA_IMAGE_LOAD_STATUS
IOCTL that can be used to monitor the progress of an ongoing image upload.
The status returned includes how much data remains to be transferred, the
progress of the image upload, and error information in the case of a
failure.

Signed-off-by: Russ Weight <russell.h.weight@xxxxxxxxx>
---
V16:
 - Minor changes to adapt in changes in prevoius patches.
V15:
 - This patch is new to the patchset and provides an FPGA_IMAGE_LOAD_STATUS
   IOCTL to return the current values for: remaining_size, progress,
   err_progress, and err_code.
 - This patch has elements of the following three patches from the previous
   patch-set:
     [PATCH v14 3/6] fpga: sec-mgr: expose sec-mgr update status
     [PATCH v14 4/6] fpga: sec-mgr: expose sec-mgr update errors
     [PATCH v14 5/6] fpga: sec-mgr: expose sec-mgr update size
 - Changed file, symbol, and config names to reflect the new driver name
 - There are some minor changes to locking to enable this ioctl to return
   coherent data.
---
 Documentation/fpga/fpga-image-load.rst |  6 +++
 drivers/fpga/fpga-image-load.c         | 54 ++++++++++++++++++++++----
 include/linux/fpga/fpga-image-load.h   |  1 +
 include/uapi/linux/fpga-image-load.h   | 18 +++++++++
 4 files changed, 71 insertions(+), 8 deletions(-)

diff --git a/Documentation/fpga/fpga-image-load.rst b/Documentation/fpga/fpga-image-load.rst
index 22a455421bb4..572e18afebb9 100644
--- a/Documentation/fpga/fpga-image-load.rst
+++ b/Documentation/fpga/fpga-image-load.rst
@@ -34,3 +34,9 @@ being updated. This is an exclusive operation; an attempt to start
 concurrent image loads for the same device will fail with EBUSY. An eventfd
 file descriptor parameter is provided to this IOCTL. It will be signalled
 at the completion of the image upload.
+
+FPGA_IMAGE_LOAD_STATUS:
+
+Collect status for an on-going image upload. The status returned includes
+how much data remains to be transferred, the progress of the image load,
+and error information in the case of a failure.
diff --git a/drivers/fpga/fpga-image-load.c b/drivers/fpga/fpga-image-load.c
index 09164a0258a5..2e9a5a041535 100644
--- a/drivers/fpga/fpga-image-load.c
+++ b/drivers/fpga/fpga-image-load.c
@@ -24,9 +24,25 @@ static dev_t fpga_image_devt;
 
 #define WRITE_BLOCK_SIZE 0x4000	/* Default write-block size is 0x4000 bytes */
 
-static void fpga_image_dev_error(struct fpga_image_load *imgld, u32 err_code)
+static void fpga_image_update_progress(struct fpga_image_load *imgld,
+				       u32 new_progress)
 {
+	mutex_lock(&imgld->lock);
+	imgld->progress = new_progress;
+	mutex_unlock(&imgld->lock);
+}
+
+static void fpga_image_set_error(struct fpga_image_load *imgld, u32 err_code)
+{
+	mutex_lock(&imgld->lock);
+	imgld->err_progress = imgld->progress;
 	imgld->err_code = err_code;
+	mutex_unlock(&imgld->lock);
+}
+
+static void fpga_image_dev_error(struct fpga_image_load *imgld, u32 err_code)
+{
+	fpga_image_set_error(imgld, err_code);
 	imgld->ops->cancel(imgld);
 }
 
@@ -46,24 +62,24 @@ static void fpga_image_do_load(struct work_struct *work)
 	imgld = container_of(work, struct fpga_image_load, work);
 
 	if (imgld->driver_unload) {
-		imgld->err_code = FPGA_IMAGE_ERR_CANCELED;
+		fpga_image_set_error(imgld, FPGA_IMAGE_ERR_CANCELED);
 		goto idle_exit;
 	}
 
 	get_device(&imgld->dev);
 	if (!try_module_get(imgld->dev.parent->driver->owner)) {
-		imgld->err_code = FPGA_IMAGE_ERR_BUSY;
+		fpga_image_set_error(imgld, FPGA_IMAGE_ERR_BUSY);
 		goto putdev_exit;
 	}
 
-	imgld->progress = FPGA_IMAGE_PROG_PREPARING;
+	fpga_image_update_progress(imgld, FPGA_IMAGE_PROG_PREPARING);
 	ret = imgld->ops->prepare(imgld);
 	if (ret != FPGA_IMAGE_ERR_NONE) {
 		fpga_image_dev_error(imgld, ret);
 		goto modput_exit;
 	}
 
-	imgld->progress = FPGA_IMAGE_PROG_WRITING;
+	fpga_image_update_progress(imgld, FPGA_IMAGE_PROG_WRITING);
 	while (imgld->remaining_size) {
 		/*
 		 * The write_blk() op has the option to use the blk_size
@@ -89,7 +105,7 @@ static void fpga_image_do_load(struct work_struct *work)
 		cond_resched();
 	}
 
-	imgld->progress = FPGA_IMAGE_PROG_PROGRAMMING;
+	fpga_image_update_progress(imgld, FPGA_IMAGE_PROG_PROGRAMMING);
 	ret = imgld->ops->poll_complete(imgld);
 	if (ret != FPGA_IMAGE_ERR_NONE)
 		fpga_image_dev_error(imgld, ret);
@@ -171,20 +187,42 @@ static int fpga_image_load_ioctl_write(struct fpga_image_load *imgld,
 	return ret;
 }
 
+static int fpga_image_load_ioctl_status(struct fpga_image_load *imgld,
+					unsigned long arg)
+{
+	struct fpga_image_status status;
+
+	memset(&status, 0, sizeof(status));
+	status.progress = imgld->progress;
+	status.remaining_size = imgld->remaining_size;
+	status.err_progress = imgld->err_progress;
+	status.err_code = imgld->err_code;
+
+	if (copy_to_user((void __user *)arg, &status, sizeof(status)))
+		return -EFAULT;
+
+	return 0;
+}
+
 static long fpga_image_load_ioctl(struct file *filp, unsigned int cmd,
 				  unsigned long arg)
 {
 	struct fpga_image_load *imgld = filp->private_data;
 	int ret = -ENOTTY;
 
+	mutex_lock(&imgld->lock);
+
 	switch (cmd) {
 	case FPGA_IMAGE_LOAD_WRITE:
-		mutex_lock(&imgld->lock);
 		ret = fpga_image_load_ioctl_write(imgld, arg);
-		mutex_unlock(&imgld->lock);
+		break;
+	case FPGA_IMAGE_LOAD_STATUS:
+		ret = fpga_image_load_ioctl_status(imgld, arg);
 		break;
 	}
 
+	mutex_unlock(&imgld->lock);
+
 	return ret;
 }
 
diff --git a/include/linux/fpga/fpga-image-load.h b/include/linux/fpga/fpga-image-load.h
index 7d39daa4d921..8b58365893fc 100644
--- a/include/linux/fpga/fpga-image-load.h
+++ b/include/linux/fpga/fpga-image-load.h
@@ -51,6 +51,7 @@ struct fpga_image_load {
 	const u8 *data;			/* pointer to update data */
 	u32 remaining_size;		/* size remaining to transfer */
 	u32 progress;
+	u32 err_progress;		/* progress at time of error */
 	u32 err_code;			/* image load error code */
 	bool driver_unload;
 	struct eventfd_ctx *finished;
diff --git a/include/uapi/linux/fpga-image-load.h b/include/uapi/linux/fpga-image-load.h
index 152a8e1c031f..dc0c9f1d78b1 100644
--- a/include/uapi/linux/fpga-image-load.h
+++ b/include/uapi/linux/fpga-image-load.h
@@ -52,4 +52,22 @@ struct fpga_image_write {
 
 #define FPGA_IMAGE_LOAD_WRITE	_IOW(FPGA_IMAGE_LOAD_MAGIC, 0, struct fpga_image_write)
 
+/**
+ * FPGA_IMAGE_LOAD_STATUS - _IOR(FPGA_IMAGE_LOAD_MAGIC, 1,
+ *				 struct fpga_image_status)
+ *
+ * Request status information for an ongoing update.
+ *
+ * Return: 0 on success, -errno on failure.
+ */
+struct fpga_image_status {
+	/* Output */
+	__u32 remaining_size;	/* size remaining to transfer */
+	__u32 progress;		/* current progress of image load */
+	__u32 err_progress;	/* progress at time of error */
+	__u32 err_code;		/* error code */
+};
+
+#define FPGA_IMAGE_LOAD_STATUS	_IOR(FPGA_IMAGE_LOAD_MAGIC, 1, struct fpga_image_status)
+
 #endif /* _UAPI_LINUX_FPGA_IMAGE_LOAD_H */
-- 
2.25.1