2 files changed, 57 insertions, 2 deletions

diff --git a/drivers/scsi/cxlflash/ocxl_hw.c b/drivers/scsi/cxlflash/ocxl_hw.c
index 576a39e6b198..655377d17a70 100644
--- a/drivers/scsi/cxlflash/ocxl_hw.c
+++ b/drivers/scsi/cxlflash/ocxl_hw.c
@@ -16,6 +16,7 @@
 #include <linux/idr.h>
 #include <linux/module.h>
 #include <linux/mount.h>
+#include <linux/poll.h>
 
 #include <misc/ocxl.h>
 
@@ -452,6 +453,7 @@ static void *ocxlflash_dev_context_init(struct pci_dev *pdev, void *afu_cookie)
 	}
 
 	spin_lock_init(&ctx->slock);
+	init_waitqueue_head(&ctx->wq);
 
 	ctx->pe = rc;
 	ctx->master = false;
@@ -892,10 +894,57 @@ err1:
 	goto out;
 }
 
+/**
+ * ctx_event_pending() - check for any event pending on the context
+ * @ctx:	Context to be checked.
+ *
+ * Return: true if there is an event pending, false if none pending
+ */
+static inline bool ctx_event_pending(struct ocxlflash_context *ctx)
+{
+	if (ctx->pending_irq)
+		return true;
+
+	return false;
+}
+
+/**
+ * afu_poll() - poll the AFU for events on the context
+ * @file:	File associated with the adapter context.
+ * @poll:	Poll structure from the user.
+ *
+ * Return: poll mask
+ */
+static unsigned int afu_poll(struct file *file, struct poll_table_struct *poll)
+{
+	struct ocxlflash_context *ctx = file->private_data;
+	struct device *dev = ctx->hw_afu->dev;
+	ulong lock_flags;
+	int mask = 0;
+
+	poll_wait(file, &ctx->wq, poll);
+
+	spin_lock_irqsave(&ctx->slock, lock_flags);
+	if (ctx_event_pending(ctx))
+		mask |= POLLIN | POLLRDNORM;
+	else
+		mask |= POLLERR;
+	spin_unlock_irqrestore(&ctx->slock, lock_flags);
+
+	dev_dbg(dev, "%s: Poll wait completed for pe %i mask %i\n",
+		__func__, ctx->pe, mask);
+
+	return mask;
+}
+
 static const struct file_operations ocxl_afu_fops = {
 	.owner		= THIS_MODULE,
+	.poll		= afu_poll,
 };
 
+#define PATCH_FOPS(NAME)						\
+	do { if (!fops->NAME) fops->NAME = ocxl_afu_fops.NAME; } while (0)
+
 /**
  * ocxlflash_get_fd() - get file descriptor for an adapter context
  * @ctx_cookie:	Adapter context.
@@ -933,8 +982,10 @@ static struct file *ocxlflash_get_fd(void *ctx_cookie,
 	}
 	fdtmp = rc;
 
-	/* Use default ops if there is no fops */
-	if (!fops)
+	/* Patch the file ops that are not defined */
+	if (fops) {
+		PATCH_FOPS(poll);
+	} else /* Use default ops */
 		fops = (struct file_operations *)&ocxl_afu_fops;
 
 	name = kasprintf(GFP_KERNEL, "ocxlflash:%d", ctx->pe);
@@ -998,6 +1049,8 @@ static irqreturn_t ocxlflash_afu_irq(int irq, void *data)
 	set_bit(i - 1, &ctx->irq_bitmap);
 	ctx->pending_irq = true;
 	spin_unlock(&ctx->slock);
+
+	wake_up_all(&ctx->wq);
 out:
 	return IRQ_HANDLED;
 }
diff --git a/drivers/scsi/cxlflash/ocxl_hw.h b/drivers/scsi/cxlflash/ocxl_hw.h
index 2eb53901daf3..acd280135989 100644
--- a/drivers/scsi/cxlflash/ocxl_hw.h
+++ b/drivers/scsi/cxlflash/ocxl_hw.h
@@ -56,6 +56,8 @@ struct ocxlflash_context {
 	u64 psn_size;			/* Process mapping size */
 
 	spinlock_t slock;		/* Protects irq/fault/event updates */
+	wait_queue_head_t wq;		/* Wait queue for poll and interrupts */
+
 	struct ocxlflash_irqs *irqs;	/* Pointer to array of structures */
 	int num_irqs;			/* Number of interrupts */
 	bool pending_irq;		/* Pending interrupt on the context */