From patchwork Wed Jan 28 02:13:06 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Preeti U Murthy X-Patchwork-Id: 433752 X-Patchwork-Delegate: michael@ellerman.id.au Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id BC30F14021A for ; Wed, 28 Jan 2015 13:15:01 +1100 (AEDT) Received: from ozlabs.org (ozlabs.org [103.22.144.67]) by lists.ozlabs.org (Postfix) with ESMTP id 963831A0DBB for ; Wed, 28 Jan 2015 13:15:01 +1100 (AEDT) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Received: from e38.co.us.ibm.com (e38.co.us.ibm.com [32.97.110.159]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id A077B1A06F7 for ; Wed, 28 Jan 2015 13:14:04 +1100 (AEDT) Received: from /spool/local by e38.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Tue, 27 Jan 2015 19:13:59 -0700 Received: from b03cxnp07028.gho.boulder.ibm.com (b03cxnp07028.gho.boulder.ibm.com [9.17.130.15]) by d03dlp02.boulder.ibm.com (Postfix) with ESMTP id 0899A3E4003F for ; Tue, 27 Jan 2015 19:13:59 -0700 (MST) Received: from d03av02.boulder.ibm.com (d03av02.boulder.ibm.com [9.17.195.168]) by b03cxnp07028.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id t0S2CU5C20185100 for ; Tue, 27 Jan 2015 19:12:39 -0700 Received: from d03av02.boulder.ibm.com (localhost [127.0.0.1]) by d03av02.boulder.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id t0S2DP9R016495 for ; Tue, 27 Jan 2015 19:13:26 -0700 Received: from preeti.in.ibm.com ([9.77.192.8]) by d03av02.boulder.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with ESMTP id t0S2DMiU016054; Tue, 27 Jan 2015 19:13:23 -0700 Subject: [PATCH V2] cpuidle/powernv: Read target_residency value of idle states from DT if available From: Preeti U Murthy To: mpe@ellerman.id.au Date: Wed, 28 Jan 2015 07:43:06 +0530 Message-ID: <20150128021044.11166.81418.stgit@preeti.in.ibm.com> User-Agent: StGit/0.17-dirty MIME-Version: 1.0 X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15012802-0029-0000-0000-00000781BDB2 Cc: rafael.j.wysocki@intel.com, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" The device tree now exposes the residency values for different idle states. Read these values instead of calculating residency from the latency values. The values exposed in the DT are validated for optimal power efficiency. However to maintain compatibility with the older firmware code which does not expose residency values, use default values as a fallback mechanism. While at it, handle some cleanups. Signed-off-by: Preeti U Murthy Acked-by: Stewart Smith Acked-by: Michael Ellerman --- Changes from V1: https://lkml.org/lkml/2015/1/19/221 1. Used a better API for reading the DT property values. 2. Code cleanups drivers/cpuidle/cpuidle-powernv.c | 57 ++++++++++++++++++++----------------- 1 file changed, 31 insertions(+), 26 deletions(-) diff --git a/drivers/cpuidle/cpuidle-powernv.c b/drivers/cpuidle/cpuidle-powernv.c index 223d505..29fdbe7 100644 --- a/drivers/cpuidle/cpuidle-powernv.c +++ b/drivers/cpuidle/cpuidle-powernv.c @@ -13,6 +13,7 @@ #include #include #include +#include #include #include @@ -161,9 +162,9 @@ static int powernv_add_idle_states(void) int nr_idle_states = 1; /* Snooze */ int dt_idle_states; const __be32 *idle_state_flags; - const __be32 *idle_state_latency; - u32 len_flags, flags, latency_ns; - int i; + u32 len_flags, flags; + u32 *latency_ns, *residency_ns; + int i, rc; /* Currently we have snooze statically defined */ @@ -175,53 +176,57 @@ static int powernv_add_idle_states(void) idle_state_flags = of_get_property(power_mgt, "ibm,cpu-idle-state-flags", &len_flags); if (!idle_state_flags) { - pr_warn("DT-PowerMgmt: missing ibm,cpu-idle-state-flags\n"); + pr_warn("cpuidle-powernv : missing ibm,cpu-idle-state-flags in DT\n"); return nr_idle_states; } - idle_state_latency = of_get_property(power_mgt, - "ibm,cpu-idle-state-latencies-ns", NULL); - if (!idle_state_latency) { - pr_warn("DT-PowerMgmt: missing ibm,cpu-idle-state-latencies-ns\n"); + dt_idle_states = len_flags / sizeof(u32); + + latency_ns = kzalloc(sizeof(*latency_ns) * dt_idle_states, GFP_KERNEL); + rc = of_property_read_u32_array(power_mgt, + "ibm,cpu-idle-state-latencies-ns", latency_ns, dt_idle_states); + if (rc) { + pr_warn("cpuidle-powernv: missing ibm,cpu-idle-state-latencies-ns in DT\n"); return nr_idle_states; } - dt_idle_states = len_flags / sizeof(u32); + residency_ns = kzalloc(sizeof(*residency_ns) * dt_idle_states, GFP_KERNEL); + rc = of_property_read_u32_array(power_mgt, + "ibm,cpu-idle-state-residency-ns", residency_ns, dt_idle_states); for (i = 0; i < dt_idle_states; i++) { flags = be32_to_cpu(idle_state_flags[i]); - - /* Cpuidle accepts exit_latency in us and we estimate - * target residency to be 10x exit_latency + /* + * Cpuidle accepts exit_latency and target_residency in us. + * Use default target_residency values if f/w does not expose it. */ - latency_ns = be32_to_cpu(idle_state_latency[i]); if (flags & OPAL_PM_NAP_ENABLED) { /* Add NAP state */ strcpy(powernv_states[nr_idle_states].name, "Nap"); strcpy(powernv_states[nr_idle_states].desc, "Nap"); powernv_states[nr_idle_states].flags = 0; - powernv_states[nr_idle_states].exit_latency = - ((unsigned int)latency_ns) / 1000; - powernv_states[nr_idle_states].target_residency = - ((unsigned int)latency_ns / 100); + powernv_states[nr_idle_states].target_residency = 100; powernv_states[nr_idle_states].enter = &nap_loop; - nr_idle_states++; - } - - if (flags & OPAL_PM_SLEEP_ENABLED || + } else if (flags & OPAL_PM_SLEEP_ENABLED || flags & OPAL_PM_SLEEP_ENABLED_ER1) { /* Add FASTSLEEP state */ strcpy(powernv_states[nr_idle_states].name, "FastSleep"); strcpy(powernv_states[nr_idle_states].desc, "FastSleep"); powernv_states[nr_idle_states].flags = CPUIDLE_FLAG_TIMER_STOP; - powernv_states[nr_idle_states].exit_latency = - ((unsigned int)latency_ns) / 1000; - powernv_states[nr_idle_states].target_residency = - ((unsigned int)latency_ns / 100); + powernv_states[nr_idle_states].target_residency = 300000; powernv_states[nr_idle_states].enter = &fastsleep_loop; - nr_idle_states++; } + + powernv_states[nr_idle_states].exit_latency = + ((unsigned int)latency_ns[i]) / 1000; + + if (!rc) { + powernv_states[nr_idle_states].target_residency = + ((unsigned int)residency_ns[i]) / 1000; + } + + nr_idle_states++; } return nr_idle_states;