ARC: SMP support

xiaomi-sm8450/android_kernel_xiaomi_sm8450

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>

This commit is contained in:

Vineet Gupta

2013-01-18 15:12:23 +05:30

parent 0ef88a54aa

commit 41195d236e

23 changed files with 960 additions and 2 deletions

									
										6

arch/arc/mm/tlb.c
									
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				@@ -474,6 +474,12 @@ void __init arc_mmu_init(void)

					/* Enable the MMU */

					write_aux_reg(ARC_REG_PID, MMU_ENABLE);

					/* In smp we use this reg for interrupt 1 scratch */

				#ifndef CONFIG_SMP

					/* swapper_pg_dir is the pgd for the kernel, used by vmalloc */

					write_aux_reg(ARC_REG_SCRATCH_DATA0, swapper_pg_dir);

				#endif

				}

				/*

ARC: SMP support

6 arch/arc/mm/tlb.c Unescape Escape View File

6

arch/arc/mm/tlb.c

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