From 35b55ef2b8f5aeedf349a1fe2ad8b11d5974f3f1 Mon Sep 17 00:00:00 2001 From: Noam Camus Date: Thu, 15 Jun 2017 11:43:57 +0300 Subject: [PATCH] ARC: [plat-eznps] new command line argument for HW scheduler at MTM We add ability for all cores at NPS SoC to control the number of cycles HW thread can execute before it is replace with another eligible HW thread within the same core. The replacement is done by the HW scheduler. Signed-off-by: Noam Camus Signed-off-by: Vineet Gupta [vgupta: simplified handlign of out of range argument value] --- Documentation/admin-guide/kernel-parameters.txt | 9 +++++++++ arch/arc/plat-eznps/mtm.c | 27 +++++++++++++++++++++++-- 2 files changed, 34 insertions(+), 2 deletions(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index d9c171c..1c0a995 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -2750,6 +2750,15 @@ If the dependencies are under your control, you can turn on cpu0_hotplug. + nps_mtm_hs_ctr= [KNL,ARC] + This parameter sets the maximum duration, in + cycles, each HW thread of the CTOP can run + without interruptions, before HW switches it. + The actual maximum duration is 16 times this + parameter's value. + Format: integer between 1 and 255 + Default: 255 + nptcg= [IA-64] Override max number of concurrent global TLB purges which is reported from either PAL_VM_SUMMARY or SAL PALO. diff --git a/arch/arc/plat-eznps/mtm.c b/arch/arc/plat-eznps/mtm.c index dcbf8f6..8a13f0a 100644 --- a/arch/arc/plat-eznps/mtm.c +++ b/arch/arc/plat-eznps/mtm.c @@ -21,10 +21,13 @@ #include #include -#define MT_CTRL_HS_CNT 0xFF +#define MT_HS_CNT_MIN 0x01 +#define MT_HS_CNT_MAX 0xFF #define MT_CTRL_ST_CNT 0xF #define NPS_NUM_HW_THREADS 0x10 +static int mtm_hs_ctr = MT_HS_CNT_MAX; + #ifdef CONFIG_EZNPS_MEM_ERROR_ALIGN int do_memory_error(unsigned long address, struct pt_regs *regs) { @@ -127,7 +130,7 @@ void mtm_enable_core(unsigned int cpu) /* Enable HW schedule, stall counter, mtm */ mt_ctrl.value = 0; mt_ctrl.hsen = 1; - mt_ctrl.hs_cnt = MT_CTRL_HS_CNT; + mt_ctrl.hs_cnt = mtm_hs_ctr; mt_ctrl.mten = 1; write_aux_reg(CTOP_AUX_MT_CTRL, mt_ctrl.value); @@ -138,3 +141,23 @@ void mtm_enable_core(unsigned int cpu) */ cpu_relax(); } + +/* Verify and set the value of the mtm hs counter */ +static int __init set_mtm_hs_ctr(char *ctr_str) +{ + long hs_ctr; + int ret; + + ret = kstrtol(ctr_str, 0, &hs_ctr); + + if (ret || hs_ctr > MT_HS_CNT_MAX || hs_ctr < MT_HS_CNT_MIN) { + pr_err("** Invalid @nps_mtm_hs_ctr [%d] needs to be [%d:%d] (incl)\n", + hs_ctr, MT_HS_CNT_MIN, MT_HS_CNT_MAX); + return -EINVAL; + } + + mtm_hs_ctr = hs_ctr; + + return 0; +} +early_param("nps_mtm_hs_ctr", set_mtm_hs_ctr); -- 2.7.4