drivers/irqchip: Use new macro ACPI_DECLARE_SUBTABLE_PROBE_ENTRY

In an effort to enable -Wcast-function-type in the top-level Makefile to
support Control Flow Integrity builds, there are the need to remove all
the function callback casts.

To do this, modify the IRQCHIP_ACPI_DECLARE macro to use the new defined
macro ACPI_DECLARE_SUBTABLE_PROBE_ENTRY instead of the macro
ACPI_DECLARE_PROBE_ENTRY. This is necessary to be able to initialize the
the acpi_probe_entry struct using the probe_subtbl field instead of the
probe_table field and avoid function cast mismatches.

Also, modify the prototype of the functions used by the invocation of the
IRQCHIP_ACPI_DECLARE macro to match all the parameters.
Co-developed-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Oscar Carter <oscar.carter@gmx.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/20200530143430.5203-3-oscar.carter@gmx.com

drivers/irqchip/irq-gic-v3.c

@@ -2116,7 +2116,7 @@ static void __init gic_acpi_setup_kvm_info(void)
 }
 
 static int __init
-gic_acpi_init(struct acpi_subtable_header *header, const unsigned long end)
+gic_acpi_init(union acpi_subtable_headers *header, const unsigned long end)
 {
 	struct acpi_madt_generic_distributor *dist;
 	struct fwnode_handle *domain_handle;

drivers/irqchip/irq-gic.c

@@ -1592,7 +1592,7 @@ static void __init gic_acpi_setup_kvm_info(void)
 	gic_set_kvm_info(&gic_v2_kvm_info);
 }
 
-static int __init gic_v2_acpi_init(struct acpi_subtable_header *header,
+static int __init gic_v2_acpi_init(union acpi_subtable_headers *header,
 				   const unsigned long end)
 {
 	struct acpi_madt_generic_distributor *dist;

include/linux/irqchip.h

@@ -39,8 +39,9 @@
  * @fn: initialization function
  */
 #define IRQCHIP_ACPI_DECLARE(name, subtable, validate, data, fn)	\
-	ACPI_DECLARE_PROBE_ENTRY(irqchip, name, ACPI_SIG_MADT, 		\
-				 subtable, validate, data, fn)
+	ACPI_DECLARE_SUBTABLE_PROBE_ENTRY(irqchip, name,		\
+					  ACPI_SIG_MADT, subtable,	\
+					  validate, data, fn)
 
 #ifdef CONFIG_IRQCHIP
 void irqchip_init(void);