ARC: SMP support
ARC common code to enable a SMP system + ISS provided SMP extensions.
ARC700 natively lacks SMP support, hence some of the core features are
are only enabled if SoCs have the necessary h/w pixie-dust. This
includes:
-Inter Processor Interrupts (IPI)
-Cache coherency
-load-locked/store-conditional
...
The low level exception handling would be completely broken in SMP
because we don't have hardware assisted stack switching. Thus a fair bit
of this code is repurposing the MMU_SCRATCH reg for event handler
prologues to keep them re-entrant.
Many thanks to Rajeshwar Ranga for his initial "major" contributions to
SMP Port (back in 2008), and to Noam Camus and Gilad Ben-Yossef for help
with resurrecting that in 3.2 kernel (2012).
Note that this platform code is again singleton design pattern - so
multiple SMP platforms won't build at the moment - this deficiency is
addressed in subsequent patches within this series.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Rajeshwar Ranga <rajeshwar.ranga@gmail.com>
Cc: Noam Camus <noamc@ezchip.com>
Cc: Gilad Ben-Yossef <gilad@benyossef.com>
diff --git a/arch/arc/plat-arcfpga/Kconfig b/arch/arc/plat-arcfpga/Kconfig
index 7af3a4e..38752bf 100644
--- a/arch/arc/plat-arcfpga/Kconfig
+++ b/arch/arc/plat-arcfpga/Kconfig
@@ -13,6 +13,7 @@
config ARC_BOARD_ANGEL4
bool "ARC Angel4"
+ select ISS_SMP_EXTN if SMP
help
ARC Angel4 FPGA Ref Platform (Xilinx Virtex Based)
@@ -21,6 +22,19 @@
help
ARC ML509 FPGA Ref Platform (Xilinx Virtex-5 Based)
+config ISS_SMP_EXTN
+ bool "ARC SMP Extensions (ISS Models only)"
+ default n
+ depends on SMP
+ select ARC_HAS_COH_RTSC
+ help
+ SMP Extensions to ARC700, in a "simulation only" Model, supported in
+ ARC ISS (Instruction Set Simulator).
+ The SMP extensions include:
+ -IDU (Interrupt Distribution Unit)
+ -XTL (To enable CPU start/stop/set-PC for another CPU)
+ It doesn't provide coherent Caches and/or Atomic Ops (LLOCK/SCOND)
+
endchoice
config ARC_SERIAL_BAUD