[PATCH RFC v2 14/18] dmaengine: idxd: add mdev type as a new wq type

[Dave Jiang <dave.jiang@xxxxxxxxx>]

Add "mdev" wq type and support helpers. The mdev wq type marks the wq
to be utilized as a VFIO mediated device.

Signed-off-by: Dave Jiang <dave.jiang@xxxxxxxxx>
Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx>
---
 drivers/dma/idxd/idxd.h  |    2 ++
 drivers/dma/idxd/sysfs.c |   13 +++++++++++--
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/drivers/dma/idxd/idxd.h b/drivers/dma/idxd/idxd.h
index 1e4d9ec9b00d..1f03019bb45d 100644
--- a/drivers/dma/idxd/idxd.h
+++ b/drivers/dma/idxd/idxd.h
@@ -71,6 +71,7 @@ enum idxd_wq_type {
 	IDXD_WQT_NONE = 0,
 	IDXD_WQT_KERNEL,
 	IDXD_WQT_USER,
+	IDXD_WQT_MDEV,
 };
 
 struct idxd_cdev {
@@ -308,6 +309,7 @@ void idxd_cleanup_sysfs(struct idxd_device *idxd);
 int idxd_register_driver(void);
 void idxd_unregister_driver(void);
 struct bus_type *idxd_get_bus_type(struct idxd_device *idxd);
+bool is_idxd_wq_mdev(struct idxd_wq *wq);
 
 /* device interrupt control */
 irqreturn_t idxd_irq_handler(int vec, void *data);
diff --git a/drivers/dma/idxd/sysfs.c b/drivers/dma/idxd/sysfs.c
index cdf2b5aac314..d3b0a95b0d1d 100644
--- a/drivers/dma/idxd/sysfs.c
+++ b/drivers/dma/idxd/sysfs.c
@@ -14,6 +14,7 @@ static char *idxd_wq_type_names[] = {
 	[IDXD_WQT_NONE]		= "none",
 	[IDXD_WQT_KERNEL]	= "kernel",
 	[IDXD_WQT_USER]		= "user",
+	[IDXD_WQT_MDEV]		= "mdev",
 };
 
 static void idxd_conf_device_release(struct device *dev)
@@ -69,6 +70,11 @@ static inline bool is_idxd_wq_cdev(struct idxd_wq *wq)
 	return wq->type == IDXD_WQT_USER;
 }
 
+inline bool is_idxd_wq_mdev(struct idxd_wq *wq)
+{
+	return wq->type == IDXD_WQT_MDEV ? true : false;
+}
+
 static int idxd_config_bus_match(struct device *dev,
 				 struct device_driver *drv)
 {
@@ -1095,8 +1101,9 @@ static ssize_t wq_type_show(struct device *dev,
 		return sprintf(buf, "%s\n",
 			       idxd_wq_type_names[IDXD_WQT_KERNEL]);
 	case IDXD_WQT_USER:
-		return sprintf(buf, "%s\n",
-			       idxd_wq_type_names[IDXD_WQT_USER]);
+		return sprintf(buf, "%s\n", idxd_wq_type_names[IDXD_WQT_USER]);
+	case IDXD_WQT_MDEV:
+		return sprintf(buf, "%s\n", idxd_wq_type_names[IDXD_WQT_MDEV]);
 	case IDXD_WQT_NONE:
 	default:
 		return sprintf(buf, "%s\n",
@@ -1123,6 +1130,8 @@ static ssize_t wq_type_store(struct device *dev,
 		wq->type = IDXD_WQT_KERNEL;
 	else if (sysfs_streq(buf, idxd_wq_type_names[IDXD_WQT_USER]))
 		wq->type = IDXD_WQT_USER;
+	else if (sysfs_streq(buf, idxd_wq_type_names[IDXD_WQT_MDEV]))
+		wq->type = IDXD_WQT_MDEV;
 	else
 		return -EINVAL;