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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=unavailable 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 4192BC433E0 for ; Tue, 7 Jul 2020 11:12:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2CA33207C4 for ; Tue, 7 Jul 2020 11:12:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728143AbgGGLMH (ORCPT ); Tue, 7 Jul 2020 07:12:07 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:54962 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727981AbgGGLMH (ORCPT ); Tue, 7 Jul 2020 07:12:07 -0400 Received: from pps.filterd (m0098396.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 067B3boZ042928; Tue, 7 Jul 2020 07:12:03 -0400 Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com with ESMTP id 324hfqu59d-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 07 Jul 2020 07:12:03 -0400 Received: from m0098396.ppops.net (m0098396.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.36/8.16.0.36) with SMTP id 067B3jEN043597; Tue, 7 Jul 2020 07:12:03 -0400 Received: from ppma03dal.us.ibm.com (b.bd.3ea9.ip4.static.sl-reverse.com [169.62.189.11]) by mx0a-001b2d01.pphosted.com with ESMTP id 324hfqu596-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 07 Jul 2020 07:12:02 -0400 Received: from pps.filterd (ppma03dal.us.ibm.com [127.0.0.1]) by ppma03dal.us.ibm.com (8.16.0.42/8.16.0.42) with SMTP id 067AxEpD027871; Tue, 7 Jul 2020 11:12:02 GMT Received: from b03cxnp07029.gho.boulder.ibm.com (b03cxnp07029.gho.boulder.ibm.com [9.17.130.16]) by ppma03dal.us.ibm.com with ESMTP id 324aejecmu-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 07 Jul 2020 11:12:02 +0000 Received: from b03ledav005.gho.boulder.ibm.com (b03ledav005.gho.boulder.ibm.com [9.17.130.236]) by b03cxnp07029.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 067BC07D20054370 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 7 Jul 2020 11:12:00 GMT Received: from b03ledav005.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id BEF38BE04F; Tue, 7 Jul 2020 11:12:00 +0000 (GMT) Received: from b03ledav005.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 11B65BE054; Tue, 7 Jul 2020 11:12:00 +0000 (GMT) Received: from sofia.ibm.com (unknown [9.85.70.202]) by b03ledav005.gho.boulder.ibm.com (Postfix) with ESMTP; Tue, 7 Jul 2020 11:12:00 +0000 (GMT) Received: by sofia.ibm.com (Postfix, from userid 1000) id 66CE42E48C5; Tue, 7 Jul 2020 16:41:54 +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 2/5] cpuidle-pseries: Add function to parse extended CEDE records Date: Tue, 7 Jul 2020 16:41:36 +0530 Message-Id: <1594120299-31389-3-git-send-email-ego@linux.vnet.ibm.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1594120299-31389-1-git-send-email-ego@linux.vnet.ibm.com> References: <1594120299-31389-1-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=2020-07-07_07:2020-07-07,2020-07-07 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 bulkscore=0 impostorscore=0 clxscore=1015 cotscore=-2147483648 lowpriorityscore=0 adultscore=0 mlxlogscore=999 priorityscore=1501 phishscore=0 mlxscore=0 spamscore=0 suspectscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2004280000 definitions=main-2007070085 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 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 39d4bb6..c13549b 100644 --- a/drivers/cpuidle/cpuidle-pseries.c +++ b/drivers/cpuidle/cpuidle-pseries.c @@ -21,6 +21,7 @@ #include #include #include +#include struct cpuidle_driver pseries_idle_driver = { .name = "pseries_idle", @@ -105,9 +106,120 @@ 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, @@ -238,6 +350,19 @@ 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 @@ -260,7 +385,7 @@ 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