From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e39.co.us.ibm.com (e39.co.us.ibm.com [32.97.110.160]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 640E31A05E7 for ; Wed, 1 Oct 2014 17:46:01 +1000 (EST) Received: from /spool/local by e39.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 1 Oct 2014 01:45:58 -0600 Received: from b03cxnp07028.gho.boulder.ibm.com (b03cxnp07028.gho.boulder.ibm.com [9.17.130.15]) by d03dlp01.boulder.ibm.com (Postfix) with ESMTP id 4D88C1FF0040 for ; Wed, 1 Oct 2014 01:34:41 -0600 (MDT) 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 s917hqSp1311154 for ; Wed, 1 Oct 2014 09:43:52 +0200 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 s917jtkv014622 for ; Wed, 1 Oct 2014 01:45:55 -0600 From: "Shreyas B. Prabhu" To: linux-kernel@vger.kernel.org Subject: [PATCH v2] cpuidle/powernv: Populate cpuidle state details by querying the device-tree Date: Wed, 1 Oct 2014 13:15:02 +0530 Message-Id: <1412149502-2729-1-git-send-email-shreyas@linux.vnet.ibm.com> Cc: devicetree@vger.kernel.org, linux-pm@vger.kernel.org, "Rafael J. Wysocki" , Grant Likely , Rob Herring , "Shreyas B. Prabhu" , Preeti U Murthy , linuxppc-dev@lists.ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Preeti U Murthy We hard code the metrics relevant for cpuidle states in the kernel today. Instead pick them up from the device tree so that they remain relevant and updated for the system that the kernel is running on. Cc: linux-pm@vger.kernel.org Cc: Rafael J. Wysocki Cc: Rob Herring Cc: Grant Likely Cc: devicetree@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: Michael Ellerman Signed-off-by: Preeti U. Murthy Signed-off-by: Shreyas B. Prabhu --- v2: Rebased on 3.17-rc7 Separated from 'powerpc/powernv: Support for fastsleep and winkle' v1: Initial post https://lkml.org/lkml/2014/8/25/456 diff --git a/drivers/cpuidle/cpuidle-powernv.c b/drivers/cpuidle/cpuidle-powernv.c index a64be57..2426a4b 100644 --- a/drivers/cpuidle/cpuidle-powernv.c +++ b/drivers/cpuidle/cpuidle-powernv.c @@ -163,7 +163,8 @@ static int powernv_add_idle_states(void) int nr_idle_states = 1; /* Snooze */ int dt_idle_states; const __be32 *idle_state_flags; - u32 len_flags, flags; + const __be32 *idle_state_latency; + u32 len_flags, flags, latency_ns; int i; /* Currently we have snooze statically defined */ @@ -180,18 +181,32 @@ static int powernv_add_idle_states(void) 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"); + return nr_idle_states; + } + dt_idle_states = len_flags / sizeof(u32); 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 best case + * target residency to be 10x exit_latency + */ + latency_ns = be32_to_cpu(idle_state_latency[i]); if (flags & IDLE_USE_INST_NAP) { /* 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 = CPUIDLE_FLAG_TIME_VALID; - powernv_states[nr_idle_states].exit_latency = 10; - powernv_states[nr_idle_states].target_residency = 100; + 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].enter = &nap_loop; nr_idle_states++; } @@ -202,8 +217,10 @@ static int powernv_add_idle_states(void) strcpy(powernv_states[nr_idle_states].desc, "FastSleep"); powernv_states[nr_idle_states].flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TIMER_STOP; - powernv_states[nr_idle_states].exit_latency = 300; - powernv_states[nr_idle_states].target_residency = 1000000; + 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].enter = &fastsleep_loop; nr_idle_states++; }