MIPS: GIC: Generalise check for pending interrupts

Move most of the functionality of gic_get_int() into a new function
gic_get_int_mask() which takes a bitmask of interrupts in which the
caller is interested, and returns the subset which are pending for the
current CPU.

This allows CP0 IRQ dispatch routines to check only the GIC interrupts
which are routed to a particular CPU interrupt input.

gic_get_int() is reimplemented using gic_get_int_mask() and is retained
for use by any platforms for which gic_get_int() is sufficient.

Signed-off-by: Jeffrey Deans <jeffrey.deans@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7376/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/include/asm/gic.h

@@ -373,6 +373,7 @@ extern unsigned int plat_ipi_call_int_xlate(unsigned int);
 extern unsigned int plat_ipi_resched_int_xlate(unsigned int);
 extern void gic_bind_eic_interrupt(int irq, int set);
 extern unsigned int gic_get_timer_pending(void);
+extern void gic_get_int_mask(unsigned long *dst, const unsigned long *src);
 extern unsigned int gic_get_int(void);
 extern void gic_enable_interrupt(int irq_vec);
 extern void gic_disable_interrupt(int irq_vec);

arch/mips/kernel/irq-gic.c

@@ -189,7 +189,7 @@ unsigned int gic_compare_int(void)
 		return 0;
 }
 
-unsigned int gic_get_int(void)
+void gic_get_int_mask(unsigned long *dst, const unsigned long *src)
 {
 	unsigned int i;
 	unsigned long *pending, *intrmask, *pcpu_mask;
@@ -214,8 +214,17 @@ unsigned int gic_get_int(void)
 
 	bitmap_and(pending, pending, intrmask, GIC_NUM_INTRS);
 	bitmap_and(pending, pending, pcpu_mask, GIC_NUM_INTRS);
+	bitmap_and(dst, src, pending, GIC_NUM_INTRS);
+}
 
-	return find_first_bit(pending, GIC_NUM_INTRS);
+unsigned int gic_get_int(void)
+{
+	DECLARE_BITMAP(interrupts, GIC_NUM_INTRS);
+
+	bitmap_fill(interrupts, GIC_NUM_INTRS);
+	gic_get_int_mask(interrupts, interrupts);
+
+	return find_first_bit(interrupts, GIC_NUM_INTRS);
 }
 
 static void gic_mask_irq(struct irq_data *d)