powerpc/mpic: FSL MPIC error interrupt support.

All SOC device error interrupts are muxed and delivered to the core
as a single MPIC error interrupt. Currently all the device drivers
requiring access to device errors have to register for the MPIC error
interrupt as a shared interrupt.

With this patch we add interrupt demuxing capability in the mpic driver,
allowing device drivers to register for their individual error interrupts.
This is achieved by handling error interrupts in a cascaded fashion.

MPIC error interrupt is handled by the "error_int_handler", which
subsequently demuxes it using the EISR and delivers it to the respective
drivers.

The error interrupt capability is dependent on the MPIC EIMR register,
which was introduced in FSL MPIC version 4.1 (P4080 rev2). So, error
interrupt demuxing capability is dependent on the MPIC version and can
be used for versions >= 4.1.

Signed-off-by: Varun Sethi <Varun.Sethi@freescale.com>
Signed-off-by: Bogdan Hamciuc <bogdan.hamciuc@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

1 files changed, 22 insertions, 0 deletions

diff --git a/arch/powerpc/sysdev/mpic.h b/arch/powerpc/sysdev/mpic.h
index 13f3e8913a93..24bf07a63924 100644
--- a/arch/powerpc/sysdev/mpic.h
+++ b/arch/powerpc/sysdev/mpic.h
@@ -40,4 +40,26 @@ extern int mpic_set_affinity(struct irq_data *d,
                              const struct cpumask *cpumask, bool force);
 extern void mpic_reset_core(int cpu);
 
+#ifdef CONFIG_FSL_SOC
+extern int mpic_map_error_int(struct mpic *mpic, unsigned int virq, irq_hw_number_t  hw);
+extern void mpic_err_int_init(struct mpic *mpic, irq_hw_number_t irqnum);
+extern int mpic_setup_error_int(struct mpic *mpic, int intvec);
+#else
+static inline int mpic_map_error_int(struct mpic *mpic, unsigned int virq, irq_hw_number_t  hw)
+{
+        return 0;
+}
+
+
+static inline void mpic_err_int_init(struct mpic *mpic, irq_hw_number_t irqnum)
+{
+        return;
+}
+
+static inline int mpic_setup_error_int(struct mpic *mpic, int intvec)
+{
+        return -1;
+}
+#endif
+
 #endif /* _POWERPC_SYSDEV_MPIC_H */