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Commit eba1c718 authored by Juri Lelli's avatar Juri Lelli Committed by Russell King
Browse files

ARM: 8130/1: cpuidle/cpuidle-big_little: fix reading cpu id part number 



Commit af040ffc ("ARM: make it easier to check the CPU part number
correctly") changed ARM_CPU_PART_X masks, and the way they are returned and
checked against. Usage of read_cpuid_part_number() is now deprecated, and
calling places updated accordingly. This actually broke cpuidle-big_little
initialization, as bl_idle_driver_init() performs a check using an hardcoded
mask on cpu_id.

Create an interface to perform the check (that is now even easier to read).
Define also a proper mask (ARM_CPU_PART_MASK) that makes this kind of checks
cleaner and helps preventing bugs in the future. Update usage accordingly.

Signed-off-by: default avatarJuri Lelli <juri.lelli@arm.com>
Signed-off-by: default avatarLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 2c32c65e

arch/arm/include/asm/cputype.h

+2 −1
Original line number Diff line number Diff line
@@ -74,6 +74,7 @@ 
#define ARM_CPU_PART_CORTEX_A12		0x4100c0d0

#define ARM_CPU_PART_CORTEX_A17		0x4100c0e0

#define ARM_CPU_PART_CORTEX_A15		0x4100c0f0

#define ARM_CPU_PART_MASK		0xff00fff0



#define ARM_CPU_XSCALE_ARCH_MASK	0xe000

#define ARM_CPU_XSCALE_ARCH_V1		0x2000
@@ -179,7 +180,7 @@ static inline unsigned int __attribute_const__ read_cpuid_implementor(void) 
 */

static inline unsigned int __attribute_const__ read_cpuid_part(void)

{

	return read_cpuid_id() & 0xff00fff0;

	return read_cpuid_id() & ARM_CPU_PART_MASK;

}



static inline unsigned int __attribute_const__ __deprecated read_cpuid_part_number(void)

arch/arm/include/asm/smp_plat.h

+15 −0
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ 
#include <linux/cpumask.h>

#include <linux/err.h>



#include <asm/cpu.h>

#include <asm/cputype.h>



/*
@@ -25,6 +26,20 @@ static inline bool is_smp(void) 
#endif

}



/**

 * smp_cpuid_part() - return part id for a given cpu

 * @cpu:	logical cpu id.

 *

 * Return: part id of logical cpu passed as argument.

 */

static inline unsigned int smp_cpuid_part(int cpu)

{

	struct cpuinfo_arm *cpu_info = &per_cpu(cpu_data, cpu);



	return is_smp() ? cpu_info->cpuid & ARM_CPU_PART_MASK :

			  read_cpuid_part();

}



/* all SMP configurations have the extended CPUID registers */

#ifndef CONFIG_MMU

#define tlb_ops_need_broadcast()	0

drivers/cpuidle/cpuidle-big_little.c

+3 −10
Original line number Diff line number Diff line
@@ -138,25 +138,18 @@ static int bl_enter_powerdown(struct cpuidle_device *dev, 
	return idx;

}



static int __init bl_idle_driver_init(struct cpuidle_driver *drv, int cpu_id)

static int __init bl_idle_driver_init(struct cpuidle_driver *drv, int part_id)

{

	struct cpuinfo_arm *cpu_info;

	struct cpumask *cpumask;

	unsigned long cpuid;

	int cpu;



	cpumask = kzalloc(cpumask_size(), GFP_KERNEL);

	if (!cpumask)

		return -ENOMEM;



	for_each_possible_cpu(cpu) {

		cpu_info = &per_cpu(cpu_data, cpu);

		cpuid = is_smp() ? cpu_info->cpuid : read_cpuid_id();



		/* read cpu id part number */

		if ((cpuid & 0xFFF0) == cpu_id)

	for_each_possible_cpu(cpu)

		if (smp_cpuid_part(cpu) == part_id)

			cpumask_set_cpu(cpu, cpumask);

	}



	drv->cpumask = cpumask;