From patchwork Thu Oct 29 19:02:58 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Borislav Petkov X-Patchwork-Id: 315258 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=-12.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, 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 CA234C55179 for ; Thu, 29 Oct 2020 19:03:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6AC252075E for ; Thu, 29 Oct 2020 19:03:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=alien8.de header.i=@alien8.de header.b="rRIPC++y" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726120AbgJ2TDW (ORCPT ); Thu, 29 Oct 2020 15:03:22 -0400 Received: from mail.skyhub.de ([5.9.137.197]:44282 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725778AbgJ2TDN (ORCPT ); Thu, 29 Oct 2020 15:03:13 -0400 Received: from zn.tnic (p200300ec2f0ce9003d743c4902fedd6b.dip0.t-ipconnect.de [IPv6:2003:ec:2f0c:e900:3d74:3c49:2fe:dd6b]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id DDBC11EC04DF; Thu, 29 Oct 2020 20:03:11 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1603998192; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=6cXGQZ8AQHng+4XungGa7nZ70/GyrbVXVlX6fuu7CYg=; b=rRIPC++yKmVFUu1skX92udzN+vwHCb5zUfQQcJ6G1j6X5MmtkrPMtK1GV7VVsrUHVSZz7s KauTClOAL2TRKP7hcQ6UjYf7vgqWpSgmUY/5P+9IVh/bv/wxazaIL2IyX6lclnQO8lcF/b OF7Xouy80KJI7dVpPwXTUbHIoClZ6SI= From: Borislav Petkov To: X86 ML Cc: Thomas Renninger , Shuah Khan , Len Brown , linux-pm@vger.kernel.org, LKML Subject: [PATCH v1 3/4] tools/power/x86_energy_perf_policy: Read energy_perf_bias from sysfs Date: Thu, 29 Oct 2020 20:02:58 +0100 Message-Id: <20201029190259.3476-4-bp@alien8.de> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20201029190259.3476-1-bp@alien8.de> References: <20201029190259.3476-1-bp@alien8.de> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org From: Borislav Petkov ... and stop poking at the MSR directly. Signed-off-by: Borislav Petkov --- .../x86_energy_perf_policy.c | 109 ++++++++++++++++-- 1 file changed, 99 insertions(+), 10 deletions(-) diff --git a/tools/power/x86/x86_energy_perf_policy/x86_energy_perf_policy.c b/tools/power/x86/x86_energy_perf_policy/x86_energy_perf_policy.c index 3fe1eed900d4..ad6aed1fabf8 100644 --- a/tools/power/x86/x86_energy_perf_policy/x86_energy_perf_policy.c +++ b/tools/power/x86/x86_energy_perf_policy/x86_energy_perf_policy.c @@ -91,6 +91,9 @@ unsigned int has_hwp_request_pkg; /* IA32_HWP_REQUEST_PKG */ unsigned int bdx_highest_ratio; +#define PATH_TO_CPU "/sys/devices/system/cpu/" +#define SYSFS_PATH_MAX 255 + /* * maintain compatibility with original implementation, but don't document it: */ @@ -668,6 +671,48 @@ int put_msr(int cpu, int offset, unsigned long long new_msr) return 0; } +static unsigned int read_sysfs(const char *path, char *buf, size_t buflen) +{ + ssize_t numread; + int fd; + + fd = open(path, O_RDONLY); + if (fd == -1) + return 0; + + numread = read(fd, buf, buflen - 1); + if (numread < 1) { + close(fd); + return 0; + } + + buf[numread] = '\0'; + close(fd); + + return (unsigned int) numread; +} + +static unsigned int write_sysfs(const char *path, char *buf, size_t buflen) +{ + ssize_t numwritten; + int fd; + + fd = open(path, O_WRONLY); + if (fd == -1) + return 0; + + numwritten = write(fd, buf, buflen - 1); + if (numwritten < 1) { + perror("write failed\n"); + close(fd); + return -1; + } + + close(fd); + + return (unsigned int) numwritten; +} + void print_hwp_cap(int cpu, struct msr_hwp_cap *cap, char *str) { if (cpu != -1) @@ -745,17 +790,61 @@ void write_hwp_request(int cpu, struct msr_hwp_request *hwp_req, unsigned int ms put_msr(cpu, msr_offset, msr); } +static int get_epb(int cpu) +{ + char path[SYSFS_PATH_MAX]; + char linebuf[3]; + char *endp; + long val; + + if (!has_epb) + return -1; + + snprintf(path, sizeof(path), PATH_TO_CPU "cpu%u/power/energy_perf_bias", cpu); + + if (!read_sysfs(path, linebuf, 3)) + return -1; + + val = strtol(linebuf, &endp, 0); + if (endp == linebuf || errno == ERANGE) + return -1; + + return (int)val; +} + +static int set_epb(int cpu, int val) +{ + char path[SYSFS_PATH_MAX]; + char linebuf[3]; + char *endp; + int ret; + + if (!has_epb) + return -1; + + snprintf(path, sizeof(path), PATH_TO_CPU "cpu%u/power/energy_perf_bias", cpu); + snprintf(linebuf, sizeof(linebuf), "%d", val); + + ret = write_sysfs(path, linebuf, 3); + if (ret <= 0) + return -1; + + val = strtol(linebuf, &endp, 0); + if (endp == linebuf || errno == ERANGE) + return -1; + + return (int)val; +} + int print_cpu_msrs(int cpu) { - unsigned long long msr; struct msr_hwp_request req; struct msr_hwp_cap cap; + int epb; - if (has_epb) { - get_msr(cpu, MSR_IA32_ENERGY_PERF_BIAS, &msr); - - printf("cpu%d: EPB %u\n", cpu, (unsigned int) msr); - } + epb = get_epb(cpu); + if (epb >= 0) + printf("cpu%d: EPB %u\n", cpu, (unsigned int) epb); if (!has_hwp) return 0; @@ -1038,15 +1127,15 @@ int enable_hwp_on_cpu(int cpu) int update_cpu_msrs(int cpu) { unsigned long long msr; - + int epb; if (update_epb) { - get_msr(cpu, MSR_IA32_ENERGY_PERF_BIAS, &msr); - put_msr(cpu, MSR_IA32_ENERGY_PERF_BIAS, new_epb); + epb = get_epb(cpu); + set_epb(cpu, new_epb); if (verbose) printf("cpu%d: ENERGY_PERF_BIAS old: %d new: %d\n", - cpu, (unsigned int) msr, (unsigned int) new_epb); + cpu, epb, (unsigned int) new_epb); } if (update_turbo) {