From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758375AbbEELgH (ORCPT ); Tue, 5 May 2015 07:36:07 -0400 Received: from v094114.home.net.pl ([79.96.170.134]:53061 "HELO v094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1758353AbbEELgB (ORCPT ); Tue, 5 May 2015 07:36:01 -0400 From: "Rafael J. Wysocki" To: Hanjun Guo Cc: Will Deacon , Catalin Marinas , Boris Ostrovsky , Stefano Stabellini , Lorenzo Pieralisi , Sudeep Holla , linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, linaro-acpi@lists.linaro.org Subject: Re: [PATCH v2 3/7] ACPI / processor: Introduce invalid_logical_cpuid() Date: Tue, 05 May 2015 14:01:02 +0200 Message-ID: <1905565.04MrkTmlaM@vostro.rjw.lan> User-Agent: KMail/4.11.5 (Linux/4.0.0+; KDE/4.11.5; x86_64; ; ) In-Reply-To: <1430793998-21631-4-git-send-email-hanjun.guo@linaro.org> References: <1430793998-21631-1-git-send-email-hanjun.guo@linaro.org> <1430793998-21631-4-git-send-email-hanjun.guo@linaro.org> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tuesday, May 05, 2015 10:46:34 AM Hanjun Guo wrote: > In ACPI processor drivers, we use direct comparisons of cpu logical > id with -1 which are error prone in case logical cpuid is accidentally > assinged an error code and prevents us from returning an error-encoding > cpuid directly in some cases. > > So introduce invalid_logical_cpuid() to identify cpu with invalid > logical cpu num, then it will be used to replace the direct comparisons > with -1. > > Signed-off-by: Hanjun Guo > --- > drivers/acpi/acpi_processor.c | 4 ++-- > drivers/acpi/processor_pdc.c | 5 +---- > include/linux/acpi.h | 5 +++++ > 3 files changed, 8 insertions(+), 6 deletions(-) > > diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c > index 95492d0..62c846b 100644 > --- a/drivers/acpi/acpi_processor.c > +++ b/drivers/acpi/acpi_processor.c > @@ -274,7 +274,7 @@ static int acpi_processor_get_info(struct acpi_device *device) > * Handle UP system running SMP kernel, with no CPU > * entry in MADT > */ > - if ((pr->id == -1) && (num_online_cpus() == 1)) > + if (invalid_logical_cpuid(pr->id) && (num_online_cpus() == 1)) > pr->id = 0; > } > > @@ -283,7 +283,7 @@ static int acpi_processor_get_info(struct acpi_device *device) > * less than the max # of CPUs. They should be ignored _iff > * they are physically not present. > */ > - if (pr->id == -1) { > + if (invalid_logical_cpuid(pr->id)) { > int ret = acpi_processor_hotadd_init(pr); > if (ret) > return ret; > diff --git a/drivers/acpi/processor_pdc.c b/drivers/acpi/processor_pdc.c > index e5dd808..6dd98d0 100644 > --- a/drivers/acpi/processor_pdc.c > +++ b/drivers/acpi/processor_pdc.c > @@ -52,10 +52,7 @@ static bool __init processor_physically_present(acpi_handle handle) > type = (acpi_type == ACPI_TYPE_DEVICE) ? 1 : 0; > cpuid = acpi_get_cpuid(handle, type, acpi_id); > > - if (cpuid == -1) > - return false; > - > - return true; > + return invalid_logical_cpuid(cpuid) ? false : true; What about return !invalid_logical_cpuid(cpuid); > } > > static void acpi_set_pdc_bits(u32 *buf) > diff --git a/include/linux/acpi.h b/include/linux/acpi.h > index e4da5e3..913b49f 100644 > --- a/include/linux/acpi.h > +++ b/include/linux/acpi.h > @@ -158,6 +158,11 @@ typedef u32 phys_cpuid_t; > #define PHYS_CPUID_INVALID (phys_cpuid_t)(-1) > #endif > > +static inline bool invalid_logical_cpuid(u32 cpuid) > +{ > + return (int)cpuid < 0; > +} > + > #ifdef CONFIG_ACPI_HOTPLUG_CPU > /* Arch dependent functions for cpu hotplug support */ > int acpi_map_cpu(acpi_handle handle, phys_cpuid_t physid, int *pcpu); > -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center.