Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753864AbdFMOG0 (ORCPT ); Tue, 13 Jun 2017 10:06:26 -0400 Received: from mail-il-dmz.mellanox.com ([193.47.165.129]:50601 "EHLO mellanox.co.il" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753389AbdFMOEK (ORCPT ); Tue, 13 Jun 2017 10:04:10 -0400 From: Noam Camus To: linux-snps-arc@lists.infradead.org Cc: linux-kernel@vger.kernel.org, Noam Camus Subject: [PATCH v2 08/12] ARC: [plat-eznps] new command line argument for HW scheduler at MTM Date: Tue, 13 Jun 2017 17:03:52 +0300 Message-Id: <1497362636-30353-9-git-send-email-noamca@mellanox.com> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1497362636-30353-1-git-send-email-noamca@mellanox.com> References: <1497362636-30353-1-git-send-email-noamca@mellanox.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3295 Lines: 109 From: Noam Camus 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 HE scheduler. Signed-off-by: Noam Camus --- Documentation/admin-guide/kernel-parameters.txt | 9 ++++ arch/arc/plat-eznps/mtm.c | 49 ++++++++++++++++++++++- 2 files changed, 56 insertions(+), 2 deletions(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 15f79c2..5b551f7 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -2693,6 +2693,15 @@ 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 59a0162..dd1ea1f 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 int do_memory_error(unsigned long address, struct pt_regs *regs) { @@ -129,7 +132,7 @@ 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); @@ -140,3 +143,45 @@ void mtm_enable_core(unsigned int cpu) */ cpu_relax(); } + +/* Handle an out of bounds mtm hs counter value */ +static void __init handle_mtm_hs_ctr_out_of_bounds_error(uint8_t val) +{ + pr_err("** The value of mtm_hs_ctr is out of bounds!\n" + "** It must be in the range [%d,%d] (inclusive)\n" + "Setting mtm_hs_ctr to %d\n", MT_HS_CNT_MIN, MT_HS_CNT_MAX, val); + + mtm_hs_ctr = val; +} + +/* Verify and set the value of the mtm hs counter */ +static int __init set_mtm_hs_ctr(char *ctr_str) +{ + int ret; + long hs_ctr; + + ret = kstrtol(ctr_str, 0, &hs_ctr); + if (ret) { + pr_err("** Error parsing the value of mtm_hs_ctr\n" + "** Make sure you entered a valid integer value\n" + "Setting mtm_hs_ctr to default value: %d\n", + MT_HS_CNT_MAX); + mtm_hs_ctr = MT_HS_CNT_MAX; + return -EINVAL; + } + + if (hs_ctr > MT_HS_CNT_MAX) { + handle_mtm_hs_ctr_out_of_bounds_error(MT_HS_CNT_MAX); + return -EDOM; + } + + if (hs_ctr < MT_HS_CNT_MIN) { + handle_mtm_hs_ctr_out_of_bounds_error(MT_HS_CNT_MIN); + return -EDOM; + } + + mtm_hs_ctr = hs_ctr; + + return 0; +} +early_param("nps_mtm_hs_ctr", set_mtm_hs_ctr); -- 1.7.1