powerpc/fsl_msi: Use chip_data not handler_data

handler_data should be reserved for flow handlers on the dependent
irq, not consumed by the parent irq code that is part of the irq_chip
code.  The msi_data pointer was already set in msidesc->irqhost->hostdata
and being copied to irq_data->chipdata in the msidesc->irqhost->map()
method called via create_irq_mapping, so we can obtain the pointer
from there and free the instance it in teardown_msi_irqs.

Also remove the unnecessary cast of irq_get_handler_data in the
cascade handler, which is the demux flow handler of the parent
msi interrupt.  (This is the expected usage for handler_data).
Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/sysdev/fsl_msi.c

@@ -110,7 +110,7 @@ static void fsl_teardown_msi_irqs(struct pci_dev *pdev)
 	list_for_each_entry(entry, &pdev->msi_list, list) {
 		if (entry->irq == NO_IRQ)
 			continue;
-		msi_data = irq_get_handler_data(entry->irq);
+		msi_data = irq_get_chip_data(entry->irq);
 		irq_set_msi_desc(entry->irq, NULL);
 		msi_bitmap_free_hwirqs(&msi_data->bitmap,
 				       virq_to_hw(entry->irq), 1);
@@ -168,7 +168,7 @@ static int fsl_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
 			rc = -ENOSPC;
 			goto out_free;
 		}
-		irq_set_handler_data(virq, msi_data);
+		/* chip_data is msi_data via host->hostdata in host->map() */
 		irq_set_msi_desc(virq, entry);
 
 		fsl_compose_msi_msg(pdev, hwirq, &msg, msi_data);
@@ -193,7 +193,7 @@ static void fsl_msi_cascade(unsigned int irq, struct irq_desc *desc)
 	u32 have_shift = 0;
 	struct fsl_msi_cascade_data *cascade_data;
 
-	cascade_data = (struct fsl_msi_cascade_data *)irq_get_handler_data(irq);
+	cascade_data = irq_get_handler_data(irq);
 	msi_data = cascade_data->msi_data;
 
 	raw_spin_lock(&desc->lock);