2 files changed, 97 insertions, 24 deletions

diff --git a/drivers/dma/idxd/cdev.c b/drivers/dma/idxd/cdev.c
index 5c8e964e671b..e07411053e21 100644
--- a/drivers/dma/idxd/cdev.c
+++ b/drivers/dma/idxd/cdev.c
@@ -24,6 +24,13 @@ struct idxd_cdev_context {
 };
 
 /*
+ * Since user file names are global in DSA devices, define their ida's as
+ * global to avoid conflict file names.
+ */
+static DEFINE_IDA(file_ida);
+static DEFINE_MUTEX(ida_lock);
+
+/*
  * ictx is an array based off of accelerator types. enum idxd_type
  * is used as index
  */
@@ -39,7 +46,60 @@ struct idxd_user_context {
 	struct mm_struct *mm;
 	unsigned int flags;
 	struct iommu_sva *sva;
+	struct idxd_dev idxd_dev;
 	u64 counters[COUNTER_MAX];
+	int id;
+};
+
+static void idxd_cdev_evl_drain_pasid(struct idxd_wq *wq, u32 pasid);
+static void idxd_xa_pasid_remove(struct idxd_user_context *ctx);
+
+static inline struct idxd_user_context *dev_to_uctx(struct device *dev)
+{
+	struct idxd_dev *idxd_dev = confdev_to_idxd_dev(dev);
+
+	return container_of(idxd_dev, struct idxd_user_context, idxd_dev);
+}
+
+static void idxd_file_dev_release(struct device *dev)
+{
+	struct idxd_user_context *ctx = dev_to_uctx(dev);
+	struct idxd_wq *wq = ctx->wq;
+	struct idxd_device *idxd = wq->idxd;
+	int rc;
+
+	mutex_lock(&ida_lock);
+	ida_free(&file_ida, ctx->id);
+	mutex_unlock(&ida_lock);
+
+	/* Wait for in-flight operations to complete. */
+	if (wq_shared(wq)) {
+		idxd_device_drain_pasid(idxd, ctx->pasid);
+	} else {
+		if (device_user_pasid_enabled(idxd)) {
+			/* The wq disable in the disable pasid function will drain the wq */
+			rc = idxd_wq_disable_pasid(wq);
+			if (rc < 0)
+				dev_err(dev, "wq disable pasid failed.\n");
+		} else {
+			idxd_wq_drain(wq);
+		}
+	}
+
+	if (ctx->sva) {
+		idxd_cdev_evl_drain_pasid(wq, ctx->pasid);
+		iommu_sva_unbind_device(ctx->sva);
+		idxd_xa_pasid_remove(ctx);
+	}
+	kfree(ctx);
+	mutex_lock(&wq->wq_lock);
+	idxd_wq_put(wq);
+	mutex_unlock(&wq->wq_lock);
+}
+
+static struct device_type idxd_cdev_file_type = {
+	.name = "idxd_file",
+	.release = idxd_file_dev_release,
 };
 
 static void idxd_cdev_dev_release(struct device *dev)
@@ -107,10 +167,11 @@ static int idxd_cdev_open(struct inode *inode, struct file *filp)
 	struct idxd_user_context *ctx;
 	struct idxd_device *idxd;
 	struct idxd_wq *wq;
-	struct device *dev;
+	struct device *dev, *fdev;
 	int rc = 0;
 	struct iommu_sva *sva;
 	unsigned int pasid;
+	struct idxd_cdev *idxd_cdev;
 
 	wq = inode_wq(inode);
 	idxd = wq->idxd;
@@ -166,10 +227,41 @@ static int idxd_cdev_open(struct inode *inode, struct file *filp)
 		}
 	}
 
+	idxd_cdev = wq->idxd_cdev;
+	mutex_lock(&ida_lock);
+	ctx->id = ida_alloc(&file_ida, GFP_KERNEL);
+	mutex_unlock(&ida_lock);
+	if (ctx->id < 0) {
+		dev_warn(dev, "ida alloc failure\n");
+		goto failed_ida;
+	}
+	ctx->idxd_dev.type  = IDXD_DEV_CDEV_FILE;
+	fdev = user_ctx_dev(ctx);
+	device_initialize(fdev);
+	fdev->parent = cdev_dev(idxd_cdev);
+	fdev->bus = &dsa_bus_type;
+	fdev->type = &idxd_cdev_file_type;
+
+	rc = dev_set_name(fdev, "file%d", ctx->id);
+	if (rc < 0) {
+		dev_warn(dev, "set name failure\n");
+		goto failed_dev_name;
+	}
+
+	rc = device_add(fdev);
+	if (rc < 0) {
+		dev_warn(dev, "file device add failure\n");
+		goto failed_dev_add;
+	}
+
 	idxd_wq_get(wq);
 	mutex_unlock(&wq->wq_lock);
 	return 0;
 
+failed_dev_add:
+failed_dev_name:
+	put_device(fdev);
+failed_ida:
 failed_set_pasid:
 	if (device_user_pasid_enabled(idxd))
 		idxd_xa_pasid_remove(ctx);
@@ -217,34 +309,12 @@ static int idxd_cdev_release(struct inode *node, struct file *filep)
 	struct idxd_wq *wq = ctx->wq;
 	struct idxd_device *idxd = wq->idxd;
 	struct device *dev = &idxd->pdev->dev;
-	int rc;
 
 	dev_dbg(dev, "%s called\n", __func__);
 	filep->private_data = NULL;
 
-	/* Wait for in-flight operations to complete. */
-	if (wq_shared(wq)) {
-		idxd_device_drain_pasid(idxd, ctx->pasid);
-	} else {
-		if (device_user_pasid_enabled(idxd)) {
-			/* The wq disable in the disable pasid function will drain the wq */
-			rc = idxd_wq_disable_pasid(wq);
-			if (rc < 0)
-				dev_err(dev, "wq disable pasid failed.\n");
-		} else {
-			idxd_wq_drain(wq);
-		}
-	}
+	device_unregister(user_ctx_dev(ctx));
 
-	if (ctx->sva) {
-		idxd_cdev_evl_drain_pasid(wq, ctx->pasid);
-		iommu_sva_unbind_device(ctx->sva);
-		idxd_xa_pasid_remove(ctx);
-	}
-	kfree(ctx);
-	mutex_lock(&wq->wq_lock);
-	idxd_wq_put(wq);
-	mutex_unlock(&wq->wq_lock);
 	return 0;
 }
 
@@ -375,6 +445,7 @@ void idxd_wq_del_cdev(struct idxd_wq *wq)
 	struct idxd_cdev *idxd_cdev;
 
 	idxd_cdev = wq->idxd_cdev;
+	ida_destroy(&file_ida);
 	wq->idxd_cdev = NULL;
 	cdev_device_del(&idxd_cdev->cdev, cdev_dev(idxd_cdev));
 	put_device(cdev_dev(idxd_cdev));
diff --git a/drivers/dma/idxd/idxd.h b/drivers/dma/idxd/idxd.h
index 9fb26d017285..bd544eb2ddcb 100644
--- a/drivers/dma/idxd/idxd.h
+++ b/drivers/dma/idxd/idxd.h
@@ -32,6 +32,7 @@ enum idxd_dev_type {
 	IDXD_DEV_GROUP,
 	IDXD_DEV_ENGINE,
 	IDXD_DEV_CDEV,
+	IDXD_DEV_CDEV_FILE,
 	IDXD_DEV_MAX_TYPE,
 };
 
@@ -405,6 +406,7 @@ enum idxd_completion_status {
 #define engine_confdev(engine) &engine->idxd_dev.conf_dev
 #define group_confdev(group) &group->idxd_dev.conf_dev
 #define cdev_dev(cdev) &cdev->idxd_dev.conf_dev
+#define user_ctx_dev(ctx) (&(ctx)->idxd_dev.conf_dev)
 
 #define confdev_to_idxd_dev(dev) container_of(dev, struct idxd_dev, conf_dev)
 #define idxd_dev_to_idxd(idxd_dev) container_of(idxd_dev, struct idxd_device, idxd_dev)