ocxl: move event_fd handling to frontend

Event_fd is only used in the driver frontend, so it does not
need to exist in the backend code. Relocate it to the frontend
and provide an opaque mechanism for consumers instead.

Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
Acked-by: Frederic Barrat <fbarrat@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

1 files changed, 42 insertions, 32 deletions

diff --git a/drivers/misc/ocxl/afu_irq.c b/drivers/misc/ocxl/afu_irq.c
index 2d410cd6f817..70f8f1c3929d 100644
--- a/drivers/misc/ocxl/afu_irq.c
+++ b/drivers/misc/ocxl/afu_irq.c
@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0+
 // Copyright 2017 IBM Corp.
 #include <linux/interrupt.h>
-#include <linux/eventfd.h>
+#include <asm/pnv-ocxl.h>
 #include "ocxl_internal.h"
 #include "trace.h"
 
@@ -11,7 +11,9 @@ struct afu_irq {
 	unsigned int virq;
 	char *name;
 	u64 trigger_page;
-	struct eventfd_ctx *ev_ctx;
+	irqreturn_t (*handler)(void *private);
+	void (*free_private)(void *private);
+	void *private;
 };
 
 int ocxl_irq_offset_to_id(struct ocxl_context *ctx, u64 offset)
@@ -24,14 +26,44 @@ u64 ocxl_irq_id_to_offset(struct ocxl_context *ctx, int irq_id)
 	return ctx->afu->irq_base_offset + (irq_id << PAGE_SHIFT);
 }
 
+int ocxl_irq_set_handler(struct ocxl_context *ctx, int irq_id,
+		irqreturn_t (*handler)(void *private),
+		void (*free_private)(void *private),
+		void *private)
+{
+	struct afu_irq *irq;
+	int rc;
+
+	mutex_lock(&ctx->irq_lock);
+	irq = idr_find(&ctx->irq_idr, irq_id);
+	if (!irq) {
+		rc = -EINVAL;
+		goto unlock;
+	}
+
+	irq->handler = handler;
+	irq->private = private;
+	irq->free_private = free_private;
+
+	rc = 0;
+	// Fall through to unlock
+
+unlock:
+	mutex_unlock(&ctx->irq_lock);
+	return rc;
+}
+EXPORT_SYMBOL_GPL(ocxl_irq_set_handler);
+
 static irqreturn_t afu_irq_handler(int virq, void *data)
 {
 	struct afu_irq *irq = (struct afu_irq *) data;
 
 	trace_ocxl_afu_irq_receive(virq);
-	if (irq->ev_ctx)
-		eventfd_signal(irq->ev_ctx, 1);
-	return IRQ_HANDLED;
+
+	if (irq->handler)
+		return irq->handler(irq->private);
+
+	return IRQ_HANDLED; // Just drop it on the ground
 }
 
 static int setup_afu_irq(struct ocxl_context *ctx, struct afu_irq *irq)
@@ -117,6 +149,7 @@ err_unlock:
 	kfree(irq);
 	return rc;
 }
+EXPORT_SYMBOL_GPL(ocxl_afu_irq_alloc);
 
 static void afu_irq_free(struct afu_irq *irq, struct ocxl_context *ctx)
 {
@@ -126,8 +159,8 @@ static void afu_irq_free(struct afu_irq *irq, struct ocxl_context *ctx)
 				ocxl_irq_id_to_offset(ctx, irq->id),
 				1 << PAGE_SHIFT, 1);
 	release_afu_irq(irq);
-	if (irq->ev_ctx)
-		eventfd_ctx_put(irq->ev_ctx);
+	if (irq->free_private)
+		irq->free_private(irq->private);
 	ocxl_link_free_irq(ctx->afu->fn->link, irq->hw_irq);
 	kfree(irq);
 }
@@ -148,6 +181,7 @@ int ocxl_afu_irq_free(struct ocxl_context *ctx, int irq_id)
 	mutex_unlock(&ctx->irq_lock);
 	return 0;
 }
+EXPORT_SYMBOL_GPL(ocxl_afu_irq_free);
 
 void ocxl_afu_irq_free_all(struct ocxl_context *ctx)
 {
@@ -160,31 +194,6 @@ void ocxl_afu_irq_free_all(struct ocxl_context *ctx)
 	mutex_unlock(&ctx->irq_lock);
 }
 
-int ocxl_afu_irq_set_fd(struct ocxl_context *ctx, int irq_id, int eventfd)
-{
-	struct afu_irq *irq;
-	struct eventfd_ctx *ev_ctx;
-	int rc = 0;
-
-	mutex_lock(&ctx->irq_lock);
-	irq = idr_find(&ctx->irq_idr, irq_id);
-	if (!irq) {
-		rc = -EINVAL;
-		goto unlock;
-	}
-
-	ev_ctx = eventfd_ctx_fdget(eventfd);
-	if (IS_ERR(ev_ctx)) {
-		rc = -EINVAL;
-		goto unlock;
-	}
-
-	irq->ev_ctx = ev_ctx;
-unlock:
-	mutex_unlock(&ctx->irq_lock);
-	return rc;
-}
-
 u64 ocxl_afu_irq_get_addr(struct ocxl_context *ctx, int irq_id)
 {
 	struct afu_irq *irq;
@@ -197,3 +206,4 @@ u64 ocxl_afu_irq_get_addr(struct ocxl_context *ctx, int irq_id)
 	mutex_unlock(&ctx->irq_lock);
 	return addr;
 }
+EXPORT_SYMBOL_GPL(ocxl_afu_irq_get_addr);