From 3f9cd874dcc8705b53c03431f0ae46c94e572349 Mon Sep 17 00:00:00 2001 From: Elad Kanfi Date: Thu, 15 Jun 2017 11:44:01 +0300 Subject: ARC: [plat-eznps] avoid toggling of DPC register HW bug description: in case of HW thread context switch the dpc configuration of the exiting thread is dragged one cycle into the next thread. In order to avoid the consequences of this bug, the DPC register is set to an initial value, and not changed afterwards. Signed-off-by: Elad Kanfi Signed-off-by: Noam Camus Signed-off-by: Vineet Gupta --- arch/arc/plat-eznps/include/plat/ctop.h | 1 + arch/arc/plat-eznps/mtm.c | 12 ++++++++++++ 2 files changed, 13 insertions(+) diff --git a/arch/arc/plat-eznps/include/plat/ctop.h b/arch/arc/plat-eznps/include/plat/ctop.h index 7729d3d18300..0c7d11022d0f 100644 --- a/arch/arc/plat-eznps/include/plat/ctop.h +++ b/arch/arc/plat-eznps/include/plat/ctop.h @@ -39,6 +39,7 @@ #define CTOP_AUX_LOGIC_CORE_ID (CTOP_AUX_BASE + 0x018) #define CTOP_AUX_MT_CTRL (CTOP_AUX_BASE + 0x020) #define CTOP_AUX_HW_COMPLY (CTOP_AUX_BASE + 0x024) +#define CTOP_AUX_DPC (CTOP_AUX_BASE + 0x02C) #define CTOP_AUX_LPC (CTOP_AUX_BASE + 0x030) #define CTOP_AUX_EFLAGS (CTOP_AUX_BASE + 0x080) #define CTOP_AUX_IACK (CTOP_AUX_BASE + 0x088) diff --git a/arch/arc/plat-eznps/mtm.c b/arch/arc/plat-eznps/mtm.c index 8a13f0ac49fb..2388de3d09ef 100644 --- a/arch/arc/plat-eznps/mtm.c +++ b/arch/arc/plat-eznps/mtm.c @@ -110,6 +110,18 @@ void mtm_enable_core(unsigned int cpu) int i; struct nps_host_reg_aux_mt_ctrl mt_ctrl; struct nps_host_reg_mtm_cfg mtm_cfg; + struct nps_host_reg_aux_dpc dpc; + + /* + * Initializing dpc register in each CPU. + * Overwriting the init value of the DPC + * register so that CMEM and FMT virtual address + * spaces are accessible, and Data Plane HW + * facilities are enabled. + */ + dpc.ien = 1; + dpc.men = 1; + write_aux_reg(CTOP_AUX_DPC, dpc.value); if (NPS_CPU_TO_THREAD_NUM(cpu) != 0) return; -- cgit v1.2.3-59-g8ed1b