Commit 932df741 authored by Lin Ming's avatar Lin Ming Committed by Len Brown
Browse files

ACPI: processor: fix processor_physically_present in UP kernel 

Usually, there are multiple processors defined in ACPI table, for
example

    Scope (_PR)
    {
        Processor (CPU0, 0x00, 0x00000410, 0x06) {}
        Processor (CPU1, 0x01, 0x00000410, 0x06) {}
        Processor (CPU2, 0x02, 0x00000410, 0x06) {}
        Processor (CPU3, 0x03, 0x00000410, 0x06) {}
    }

processor_physically_present(...) will be called to check whether those
processors are physically present.

Currently we have below codes in processor_physically_present,

cpuid = acpi_get_cpuid(...);
if ((cpuid == -1) && (num_possible_cpus() > 1))
        return false;
return true;

In UP kernel, acpi_get_cpuid(...) always return -1 and
num_possible_cpus() always return 1, so
processor_physically_present(...) always returns true for all passed in
processor handles.

This is wrong for UP processor or SMP processor running UP kernel.

This patch removes the !SMP version of acpi_get_cpuid(), so both UP and
SMP kernel use the same acpi_get_cpuid function.

And for UP kernel, only processor 0 is valid.

https://bugzilla.kernel.org/show_bug.cgi?id=16548
https://bugzilla.kernel.org/show_bug.cgi?id=16357



Tested-by: default avatarAnton Kochkov <anton.kochkov@gmail.com>
Tested-by: default avatarAmbroz Bizjak <ambrop7@gmail.com>
Signed-off-by: default avatarLin Ming <ming.m.lin@intel.com>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent 61c4f2c8

drivers/acpi/processor_core.c

+9 −3
Original line number Diff line number Diff line
@@ -37,7 +37,6 @@ static struct dmi_system_id __initdata processor_idle_dmi_table[] = { 
	{},

};



#ifdef CONFIG_SMP

static int map_lapic_id(struct acpi_subtable_header *entry,

		 u32 acpi_id, int *apic_id)

{
@@ -165,7 +164,9 @@ static int map_mat_entry(acpi_handle handle, int type, u32 acpi_id) 


int acpi_get_cpuid(acpi_handle handle, int type, u32 acpi_id)

{

#ifdef CONFIG_SMP

	int i;

#endif

	int apic_id = -1;



	apic_id = map_mat_entry(handle, type, acpi_id);
@@ -174,14 +175,19 @@ int acpi_get_cpuid(acpi_handle handle, int type, u32 acpi_id) 
	if (apic_id == -1)

		return apic_id;



#ifdef CONFIG_SMP

	for_each_possible_cpu(i) {

		if (cpu_physical_id(i) == apic_id)

			return i;

	}

#else

	/* In UP kernel, only processor 0 is valid */

	if (apic_id == 0)

		return apic_id;

#endif

	return -1;

}

EXPORT_SYMBOL_GPL(acpi_get_cpuid);

#endif



static bool __init processor_physically_present(acpi_handle handle)

{
@@ -217,7 +223,7 @@ 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) && (num_possible_cpus() > 1))

	if (cpuid == -1)

		return false;



	return true;

include/acpi/processor.h

+0 −7
Original line number Diff line number Diff line
@@ -310,14 +310,7 @@ static inline int acpi_processor_get_bios_limit(int cpu, unsigned int *limit) 


/* in processor_core.c */

void acpi_processor_set_pdc(acpi_handle handle);

#ifdef CONFIG_SMP

int acpi_get_cpuid(acpi_handle, int type, u32 acpi_id);

#else

static inline int acpi_get_cpuid(acpi_handle handle, int type, u32 acpi_id)

{

	return -1;

}

#endif



/* in processor_throttling.c */

int acpi_processor_tstate_has_changed(struct acpi_processor *pr);