Commit 35b55ef2 authored by Noam Camus's avatar Noam Camus Committed by Vineet Gupta
Browse files

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: default avatarNoam Camus <>
Signed-off-by: default avatarVineet Gupta <>
[vgupta: simplified handlign of out of range argument value]
parent 18ee4bec
......@@ -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
......@@ -21,10 +21,13 @@
#include <plat/mtm.h>
#include <plat/smp.h>
#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;
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)
/* 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",
return -EINVAL;
mtm_hs_ctr = hs_ctr;
return 0;
early_param("nps_mtm_hs_ctr", set_mtm_hs_ctr);
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