From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A314DC433E0 for ; Wed, 29 Jul 2020 06:47:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 817F820809 for ; Wed, 29 Jul 2020 06:47:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727058AbgG2Grv (ORCPT ); Wed, 29 Jul 2020 02:47:51 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:64048 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726367AbgG2Grv (ORCPT ); Wed, 29 Jul 2020 02:47:51 -0400 Received: from pps.filterd (m0098399.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 06T6WBgB109475; Wed, 29 Jul 2020 02:47:48 -0400 Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com with ESMTP id 32jp1meruj-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 29 Jul 2020 02:47:48 -0400 Received: from m0098399.ppops.net (m0098399.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.36/8.16.0.36) with SMTP id 06T6f9a3135796; Wed, 29 Jul 2020 02:47:47 -0400 Received: from ppma04dal.us.ibm.com (7a.29.35a9.ip4.static.sl-reverse.com [169.53.41.122]) by mx0a-001b2d01.pphosted.com with ESMTP id 32jp1meru6-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 29 Jul 2020 02:47:47 -0400 Received: from pps.filterd (ppma04dal.us.ibm.com [127.0.0.1]) by ppma04dal.us.ibm.com (8.16.0.42/8.16.0.42) with SMTP id 06T6UML0029829; Wed, 29 Jul 2020 06:47:46 GMT Received: from b03cxnp08028.gho.boulder.ibm.com (b03cxnp08028.gho.boulder.ibm.com [9.17.130.20]) by ppma04dal.us.ibm.com with ESMTP id 32gcq1fjea-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 29 Jul 2020 06:47:46 +0000 Received: from b03ledav004.gho.boulder.ibm.com (b03ledav004.gho.boulder.ibm.com [9.17.130.235]) by b03cxnp08028.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 06T6ljTL1245830 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 29 Jul 2020 06:47:45 GMT Received: from b03ledav004.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 743307805E; Wed, 29 Jul 2020 06:47:45 +0000 (GMT) Received: from b03ledav004.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id BC01878060; Wed, 29 Jul 2020 06:47:44 +0000 (GMT) Received: from sofia.ibm.com (unknown [9.85.85.173]) by b03ledav004.gho.boulder.ibm.com (Postfix) with ESMTP; Wed, 29 Jul 2020 06:47:44 +0000 (GMT) Received: by sofia.ibm.com (Postfix, from userid 1000) id A8AAC2E2FF4; Wed, 29 Jul 2020 12:17:39 +0530 (IST) From: "Gautham R. Shenoy" To: Nicholas Piggin , Anton Blanchard , Nathan Lynch , Michael Ellerman , Michael Neuling , Vaidyanathan Srinivasan Cc: linuxppc-dev@ozlabs.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, "Gautham R. Shenoy" Subject: [PATCH v2 2/3] cpuidle-pseries: Add function to parse extended CEDE records Date: Wed, 29 Jul 2020 12:17:33 +0530 Message-Id: <1596005254-25753-3-git-send-email-ego@linux.vnet.ibm.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1596005254-25753-1-git-send-email-ego@linux.vnet.ibm.com> References: <1596005254-25753-1-git-send-email-ego@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235,18.0.687 definitions=2020-07-29_02:2020-07-28,2020-07-29 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 malwarescore=0 clxscore=1015 priorityscore=1501 phishscore=0 mlxlogscore=999 bulkscore=0 impostorscore=0 suspectscore=0 lowpriorityscore=0 mlxscore=0 spamscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2007290041 Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org From: "Gautham R. Shenoy" Currently we use CEDE with latency-hint 0 as the only other idle state on a dedicated LPAR apart from the polling "snooze" state. The platform might support additional extended CEDE idle states, which can be discovered through the "ibm,get-system-parameter" rtas-call made with CEDE_LATENCY_TOKEN. This patch adds a function to obtain information about the extended CEDE idle states from the platform and parse the contents to populate an array of extended CEDE states. These idle states thus discovered will be added to the cpuidle framework in the next patch. dmesg on a POWER9 LPAR, demonstrating the output of parsing the extended CEDE latency parameters. [ 5.913180] xcede : xcede_record_size = 10 [ 5.913183] xcede : Record 0 : hint = 1, latency =0x400 tb-ticks, Wake-on-irq = 1 [ 5.913188] xcede : Record 1 : hint = 2, latency =0x3e8000 tb-ticks, Wake-on-irq = 0 [ 5.913193] cpuidle : Skipping the 2 Extended CEDE idle states Reviewed-by: Vaidyanathan Srinivasan Signed-off-by: Gautham R. Shenoy --- drivers/cpuidle/cpuidle-pseries.c | 129 +++++++++++++++++++++++++++++++++++++- 1 file changed, 127 insertions(+), 2 deletions(-) diff --git a/drivers/cpuidle/cpuidle-pseries.c b/drivers/cpuidle/cpuidle-pseries.c index 88e71c3..b1dc24d 100644 --- a/drivers/cpuidle/cpuidle-pseries.c +++ b/drivers/cpuidle/cpuidle-pseries.c @@ -21,6 +21,7 @@ #include #include #include +#include static struct cpuidle_driver pseries_idle_driver = { .name = "pseries_idle", @@ -86,9 +87,120 @@ static void check_and_cede_processor(void) } } -#define NR_CEDE_STATES 1 /* CEDE with latency-hint 0 */ +struct xcede_latency_records { + u8 latency_hint; + u64 wakeup_latency_tb_ticks; + u8 responsive_to_irqs; +}; + +/* + * XCEDE : Extended CEDE states discovered through the + * "ibm,get-systems-parameter" rtas-call with the token + * CEDE_LATENCY_TOKEN + */ +#define MAX_XCEDE_STATES 4 +#define XCEDE_LATENCY_RECORD_SIZE 10 +#define XCEDE_LATENCY_PARAM_MAX_LENGTH (2 + 2 + \ + (MAX_XCEDE_STATES * XCEDE_LATENCY_RECORD_SIZE)) + +#define CEDE_LATENCY_TOKEN 45 + +#define NR_CEDE_STATES (MAX_XCEDE_STATES + 1) /* CEDE with latency-hint 0 */ #define NR_DEDICATED_STATES (NR_CEDE_STATES + 1) /* Includes snooze */ +struct xcede_latency_records xcede_records[MAX_XCEDE_STATES]; +unsigned int nr_xcede_records; +char xcede_parameters[XCEDE_LATENCY_PARAM_MAX_LENGTH]; + +static int parse_cede_parameters(void) +{ + int ret = -1, i; + u16 payload_length; + u8 xcede_record_size; + u32 total_xcede_records_size; + char *payload; + + memset(xcede_parameters, 0, XCEDE_LATENCY_PARAM_MAX_LENGTH); + + ret = rtas_call(rtas_token("ibm,get-system-parameter"), 3, 1, + NULL, CEDE_LATENCY_TOKEN, __pa(xcede_parameters), + XCEDE_LATENCY_PARAM_MAX_LENGTH); + + if (ret) { + pr_err("xcede: Error parsing CEDE_LATENCY_TOKEN\n"); + return ret; + } + + payload_length = be16_to_cpu(*(__be16 *)(&xcede_parameters[0])); + payload = &xcede_parameters[2]; + + /* + * If the platform supports the cede latency settings + * information system parameter it must provide the following + * information in the NULL terminated parameter string: + * + * a. The first byte is the length “N” of each cede + * latency setting record minus one (zero indicates a length + * of 1 byte). + * + * b. For each supported cede latency setting a cede latency + * setting record consisting of the first “N” bytes as per + * the following table. + * + * ----------------------------- + * | Field | Field | + * | Name | Length | + * ----------------------------- + * | Cede Latency | 1 Byte | + * | Specifier Value | | + * ----------------------------- + * | Maximum wakeup | | + * | latency in | 8 Bytes| + * | tb-ticks | | + * ----------------------------- + * | Responsive to | | + * | external | 1 Byte | + * | interrupts | | + * ----------------------------- + * + * This version has cede latency record size = 10. + */ + xcede_record_size = (u8)payload[0] + 1; + + if (xcede_record_size != XCEDE_LATENCY_RECORD_SIZE) { + pr_err("xcede : Expected record-size %d. Observed size %d.\n", + XCEDE_LATENCY_RECORD_SIZE, xcede_record_size); + return -EINVAL; + } + + pr_info("xcede : xcede_record_size = %d\n", xcede_record_size); + + /* + * Since the payload_length includes the last NULL byte and + * the xcede_record_size, the remaining bytes correspond to + * array of all cede_latency settings. + */ + total_xcede_records_size = payload_length - 2; + nr_xcede_records = total_xcede_records_size / xcede_record_size; + + payload++; + for (i = 0; i < nr_xcede_records; i++) { + struct xcede_latency_records *record = &xcede_records[i]; + + record->latency_hint = (u8)payload[0]; + record->wakeup_latency_tb_ticks = + be64_to_cpu(*(__be64 *)(&payload[1])); + record->responsive_to_irqs = (u8)payload[9]; + payload += xcede_record_size; + pr_info("xcede : Record %d : hint = %u, latency =0x%llx tb-ticks, Wake-on-irq = %u\n", + i, record->latency_hint, + record->wakeup_latency_tb_ticks, + record->responsive_to_irqs); + } + + return 0; +} + u8 cede_latency_hint[NR_DEDICATED_STATES]; static int dedicated_cede_loop(struct cpuidle_device *dev, struct cpuidle_driver *drv, @@ -219,6 +331,19 @@ static int pseries_cpuidle_driver_init(void) return 0; } +static int add_pseries_idle_states(void) +{ + int nr_states = 2; /* By default we have snooze, CEDE */ + + if (parse_cede_parameters()) + return nr_states; + + pr_info("cpuidle : Skipping the %d Extended CEDE idle states\n", + nr_xcede_records); + + return nr_states; +} + /* * pseries_idle_probe() * Choose state table for shared versus dedicated partition @@ -241,7 +366,7 @@ static int pseries_idle_probe(void) max_idle_state = ARRAY_SIZE(shared_states); } else { cpuidle_state_table = dedicated_states; - max_idle_state = ARRAY_SIZE(dedicated_states); + max_idle_state = add_pseries_idle_states(); } } else return -ENODEV; -- 1.9.4