From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751600AbcFNKra (ORCPT ); Tue, 14 Jun 2016 06:47:30 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:48397 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750805AbcFNKr3 (ORCPT ); Tue, 14 Jun 2016 06:47:29 -0400 X-IBM-Helo: d23dlp03.au.ibm.com X-IBM-MailFrom: shreyas@linux.vnet.ibm.com X-IBM-RcptTo: linux-kernel@vger.kernel.org;linux-pm@vger.kernel.org Date: Tue, 14 Jun 2016 16:17:12 +0530 From: Shreyas B Prabhu User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.1.0 MIME-Version: 1.0 To: Daniel Lezcano CC: mpe@ellerman.id.au, benh@au1.ibm.com, paulus@ozlabs.org, mikey@neuling.org, ego@linux.vnet.ibm.com, maddy@linux.vnet.ibm.com, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, "Rafael J. Wysocki" , Rob Herring , Lorenzo Pieralisi , linux-pm@vger.kernel.org Subject: Re: [PATCH v6 10/11] cpuidle/powernv: Add support for POWER ISA v3 idle states References: <1465404871-5406-1-git-send-email-shreyas@linux.vnet.ibm.com> <1465404871-5406-11-git-send-email-shreyas@linux.vnet.ibm.com> <20160613153446.GF10634@linaro.org> In-Reply-To: <20160613153446.GF10634@linaro.org> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16061410-0048-0000-0000-0000019279A9 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 16061410-0049-0000-0000-000045EFB10B Message-Id: <575FE0B0.4030309@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2016-06-14_04:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=2 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1604210000 definitions=main-1606140121 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/13/2016 09:04 PM, Daniel Lezcano wrote: > On Wed, Jun 08, 2016 at 11:54:30AM -0500, Shreyas B. Prabhu wrote: >> POWER ISA v3 defines a new idle processor core mechanism. In summary, >> a) new instruction named stop is added. >> b) new per thread SPR named PSSCR is added which controls the behavior >> of stop instruction. >> >> Supported idle states and value to be written to PSSCR register to enter >> any idle state is exposed via ibm,cpu-idle-state-names and >> ibm,cpu-idle-state-psscr respectively. To enter an idle state, >> platform provided power_stop() needs to be invoked with the appropriate >> PSSCR value. >> >> This patch adds support for this new mechanism in cpuidle powernv driver. >> >> Cc: Rafael J. Wysocki >> Cc: Daniel Lezcano >> Cc: Rob Herring >> Cc: Lorenzo Pieralisi >> Cc: linux-pm@vger.kernel.org >> Cc: Michael Ellerman >> Cc: Paul Mackerras >> Cc: linuxppc-dev@lists.ozlabs.org >> Reviewed-by: Gautham R. Shenoy >> Signed-off-by: Shreyas B. Prabhu >> --- > > [ ... ] > >> + rc = of_property_read_string_array(power_mgt, >> + "ibm,cpu-idle-state-names", names, >> + dt_idle_states); >> + if (rc < 0) { >> + pr_warn("cpuidle-powernv: missing ibm,cpu-idle-state-names in DT\n"); >> + goto out_free_latency; >> + } >> + >> + /* >> + * If the idle states use stop instruction, probe for psscr values >> + * which are necessary to specify required stop level. >> + */ >> + if (flags[0] & (OPAL_PM_STOP_INST_FAST | OPAL_PM_STOP_INST_DEEP)) { >> + psscr_val = kcalloc(dt_idle_states, sizeof(*psscr_val), >> + GFP_KERNEL); > > if (!psscr_val) check missing. I ignored adding this check because this is part of initcall and we are unlikely to run out of memory at this state. But I'll add the check in next version. > >> + rc = of_property_read_u64_array(power_mgt, >> + "ibm,cpu-idle-state-psscr", >> + psscr_val, dt_idle_states); >> + if (rc) { >> + pr_warn("cpuidle-powernv: missing ibm,cpu-idle-states-psscr in DT\n"); >> + goto out_free_psscr; >> + } >> + } >> residency_ns = kzalloc(sizeof(*residency_ns) * dt_idle_states, GFP_KERNEL); > > if (!residency_ns) check missing. > > I suppose the code is relying on 'of_property_read_u32_array' to check it, > right ? I'll add the NULL check for existing kzalloc's in the file as well in the next version. Thanks, Shreyas