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authorVineet Gupta <vgupta@synopsys.com>2013-01-18 15:12:23 +0530
committerVineet Gupta <vgupta@synopsys.com>2013-02-15 23:16:02 +0530
commit41195d236e84458bebd4fdc218610a92231ac791 (patch)
treec0049630c1a21a071c9c942086041029ebdf2866 /arch/arc/mm/tlb.c
parent0ef88a54aa341f754707414500158addbf35c780 (diff)
downloadlinux-41195d236e84458bebd4fdc218610a92231ac791.tar.bz2
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>
Diffstat (limited to 'arch/arc/mm/tlb.c')
-rw-r--r--arch/arc/mm/tlb.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/arc/mm/tlb.c b/arch/arc/mm/tlb.c
index 232a0ff80a5e..e96030c13b52 100644
--- a/arch/arc/mm/tlb.c
+++ b/arch/arc/mm/tlb.c
@@ -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
}
/*