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, 14 insertions, 0 deletions

diff --git a/arch/powerpc/include/asm/mpic.h b/arch/powerpc/include/asm/mpic.h
index e14d35d572af..c0f9ef90f0b8 100644
--- a/arch/powerpc/include/asm/mpic.h
+++ b/arch/powerpc/include/asm/mpic.h
@@ -118,6 +118,9 @@
 #define MPIC_MAX_CPUS           32
 #define MPIC_MAX_ISU            32
 
+#define MPIC_MAX_ERR      32
+#define MPIC_FSL_ERR_INT  16
+
 /*
  * Tsi108 implementation of MPIC has many differences from the original one
  */
@@ -270,6 +273,7 @@ struct mpic
         struct irq_chip         hc_ipi;
 #endif
         struct irq_chip         hc_tm;
+        struct irq_chip         hc_err;
         const char              *name;
         /* Flags */
         unsigned int            flags;
@@ -283,6 +287,8 @@ struct mpic
         /* vector numbers used for internal sources (ipi/timers) */
         unsigned int            ipi_vecs[4];
         unsigned int            timer_vecs[8];
+        /* vector numbers used for FSL MPIC error interrupts */
+        unsigned int            err_int_vecs[MPIC_MAX_ERR];
 
         /* Spurious vector to program into unused sources */
         unsigned int            spurious_vec;
@@ -306,6 +312,9 @@ struct mpic
         struct mpic_reg_bank    cpuregs[MPIC_MAX_CPUS];
         struct mpic_reg_bank    isus[MPIC_MAX_ISU];
 
+        /* ioremap'ed base for error interrupt registers */
+        u32 __iomem     *err_regs;
+
         /* Protected sources */
         unsigned long           *protected;
 
@@ -370,6 +379,11 @@ struct mpic
 #define MPIC_NO_RESET                   0x00004000
 /* Freescale MPIC (compatible includes "fsl,mpic") */
 #define MPIC_FSL                        0x00008000
+/* Freescale MPIC supports EIMR (error interrupt mask register).
+ * This flag is set for MPIC version >= 4.1 (version determined
+ * from the BRR1 register).
+*/
+#define MPIC_FSL_HAS_EIMR               0x00010000
 
 /* MPIC HW modification ID */
 #define MPIC_REGSET_MASK                0xf0000000