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Subject[PATCH v3 1/7] ACPI / processor: Introduce invalid_logical_cpuid()
Date
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.guo@linaro.org>
---
drivers/acpi/acpi_processor.c | 5 +++--
drivers/acpi/processor_pdc.c | 5 +----
include/linux/acpi.h | 5 +++++
3 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c
index 58f335c..ac6bda0 100644
--- a/drivers/acpi/acpi_processor.c
+++ b/drivers/acpi/acpi_processor.c
@@ -275,7 +275,8 @@ static int acpi_processor_get_info(struct acpi_device *device)
* Handle UP system running SMP kernel, with no CPU
* entry in MADT
*/
- if ((cpu_index == -1) && (num_online_cpus() == 1))
+ if (invalid_logical_cpuid(cpu_index)
+ && (num_online_cpus() == 1))
cpu_index = 0;
}
pr->id = cpu_index;
@@ -285,7 +286,7 @@ 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..7cfbda4 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);
}

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);
--
1.9.1


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