[MIPS] Compile __do_IRQ() when really needed

__do_IRQ() is needed only by irq handlers that can't use
default handlers defined in kernel/irq/chip.c.

For others platforms there's no need to compile this function
since it won't be used. For those platforms this patch defines
GENERIC_HARDIRQS_NO__DO_IRQ symbol which is used exactly for
this purpose.

Futhermore for platforms which do not use __do_IRQ(), end()
method which is part of the 'irq_chip' structure is not used.
This patch simply removes this method in this case.

Signed-off-by: Franck Bui-Huu <fbuihuu@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 9 insertions, 0 deletions

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 4d64960be035..d8af858fe3f5 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -242,6 +242,7 @@ config LASAT
         select SYS_SUPPORTS_32BIT_KERNEL
         select SYS_SUPPORTS_64BIT_KERNEL if EXPERIMENTAL
         select SYS_SUPPORTS_LITTLE_ENDIAN
+        select GENERIC_HARDIRQS_NO__DO_IRQ
 
 config MIPS_ATLAS
         bool "MIPS Atlas board"
@@ -265,6 +266,7 @@ config MIPS_ATLAS
         select SYS_SUPPORTS_BIG_ENDIAN
         select SYS_SUPPORTS_LITTLE_ENDIAN
         select SYS_SUPPORTS_MULTITHREADING if EXPERIMENTAL
+        select GENERIC_HARDIRQS_NO__DO_IRQ
         help
           This enables support for the MIPS Technologies Atlas evaluation
           board.
@@ -419,6 +421,7 @@ config MOMENCO_OCELOT_C
         select SYS_SUPPORTS_32BIT_KERNEL
         select SYS_SUPPORTS_64BIT_KERNEL
         select SYS_SUPPORTS_BIG_ENDIAN
+        select GENERIC_HARDIRQS_NO__DO_IRQ
         help
           The Ocelot is a MIPS-based Single Board Computer (SBC) made by
           Momentum Computer <http://www.momenco.com/>.
@@ -569,6 +572,7 @@ config SGI_IP27
         select SYS_SUPPORTS_BIG_ENDIAN
         select SYS_SUPPORTS_NUMA
         select SYS_SUPPORTS_SMP
+        select GENERIC_HARDIRQS_NO__DO_IRQ
         help
           This are the SGI Origin 200, Origin 2000 and Onyx 2 Graphics
           workstations.  To compile a Linux kernel that runs on these, say Y
@@ -835,6 +839,10 @@ config SCHED_NO_NO_OMIT_FRAME_POINTER
         bool
         default y
 
+config GENERIC_HARDIRQS_NO__DO_IRQ
+        bool
+        default n
+
 #
 # Select some configuration options automatically based on user selections.
 #
@@ -996,6 +1004,7 @@ config SOC_PNX8550
         select HW_HAS_PCI
         select SYS_HAS_CPU_MIPS32_R1
         select SYS_SUPPORTS_32BIT_KERNEL
+        select GENERIC_HARDIRQS_NO__DO_IRQ
 
 config SWAP_IO_SPACE
         bool