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 <hanjun....@linaro.org>
> ---
> 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.
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