ocxl: Access interrupt trigger page from xive directly

We can access the trigger page through standard APIs so let's use it
and avoid saving it when allocating the interrupt. It will also allow
to simplify allocation in a later patch.
Signed-off-by: Frederic Barrat <fbarrat@linux.ibm.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Acked-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200403153838.29224-3-fbarrat@linux.ibm.com

drivers/misc/ocxl/afu_irq.c

@@ -2,6 +2,7 @@
 // Copyright 2017 IBM Corp.
 #include <linux/interrupt.h>
 #include <asm/pnv-ocxl.h>
+#include <asm/xive.h>
 #include "ocxl_internal.h"
 #include "trace.h"
 
@@ -196,13 +197,16 @@ void ocxl_afu_irq_free_all(struct ocxl_context *ctx)
 
 u64 ocxl_afu_irq_get_addr(struct ocxl_context *ctx, int irq_id)
 {
+	struct xive_irq_data *xd;
 	struct afu_irq *irq;
 	u64 addr = 0;
 
 	mutex_lock(&ctx->irq_lock);
 	irq = idr_find(&ctx->irq_idr, irq_id);
-	if (irq)
-		addr = irq->trigger_page;
+	if (irq) {
+		xd = irq_get_handler_data(irq->virq);
+		addr = xd ? xd->trig_page : 0;
+	}
 	mutex_unlock(&ctx->irq_lock);
 	return addr;
 }