From mboxrd@z Thu Jan 1 00:00:00 1970 From: Preeti U Murthy Subject: [PATCH] cpuidle/powernv: Populate cpuidle state details by querying the device-tree Date: Tue, 14 Oct 2014 13:23:00 +0530 Message-ID: <20141014075259.11810.50996.stgit@preeti.in.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: Received: from e9.ny.us.ibm.com ([32.97.182.139]:59958 "EHLO e9.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754201AbaJNHxO (ORCPT ); Tue, 14 Oct 2014 03:53:14 -0400 Received: from /spool/local by e9.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 14 Oct 2014 03:53:13 -0400 Received: from b01cxnp23034.gho.pok.ibm.com (b01cxnp23034.gho.pok.ibm.com [9.57.198.29]) by d01dlp02.pok.ibm.com (Postfix) with ESMTP id CBEEF6E8046 for ; Tue, 14 Oct 2014 03:41:54 -0400 (EDT) Received: from d01av03.pok.ibm.com (d01av03.pok.ibm.com [9.56.224.217]) by b01cxnp23034.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id s9E7rA6o7799262 for ; Tue, 14 Oct 2014 07:53:10 GMT Received: from d01av03.pok.ibm.com (localhost [127.0.0.1]) by d01av03.pok.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id s9E7r9ib017297 for ; Tue, 14 Oct 2014 03:53:10 -0400 Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: mpe@ellerman.id.au, rjw@rjwysocki.net, benh@kernel.crashing.org Cc: shreyas@linux.vnet.ibm.com, linuxppc-dev@lists.ozlabs.org, linux-pm@vger.kernel.org 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: devicetree@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: Michael Ellerman Cc: Benjamin Herrenschmidt Signed-off-by: Preeti U. Murthy Signed-off-by: Shreyas B. Prabhu --- drivers/cpuidle/cpuidle-powernv.c | 27 ++++++++++++++++++++++----- 1 file changed, 22 insertions(+), 5 deletions(-) diff --git a/drivers/cpuidle/cpuidle-powernv.c b/drivers/cpuidle/cpuidle-powernv.c index fa79392..b57681d 100644 --- a/drivers/cpuidle/cpuidle-powernv.c +++ b/drivers/cpuidle/cpuidle-powernv.c @@ -165,7 +165,8 @@ 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 */ @@ -182,18 +183,32 @@ 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 + * 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++; } @@ -204,8 +219,10 @@ 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++; }