[PATCH v2] cpuidle/cpuidle-big_little: fix reading cpu id part number
From: Juri Lelli <hidden>
Date: 2014-08-14 08:28:26
Also in:
linux-pm, lkml
Subsystem:
arm port, cpu idle time management framework, cpuidle driver - arm big little, the rest · Maintainers:
Russell King, "Rafael J. Wysocki", Daniel Lezcano, Lorenzo Pieralisi, Linus Torvalds
Commit af040ffc9ba1 ("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: Juri Lelli <redacted>
Signed-off-by: Lorenzo Pieralisi <redacted>
Cc: Russell King <redacted>
Cc: Daniel Lezcano <redacted>
Cc: "Rafael J. Wysocki" <redacted>
Cc: Will Deacon <redacted>
Cc: Chao Xie <redacted>
Cc: Stephen Warren <redacted>
Cc: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Cc: Rob Herring <redacted>
Cc: Jonathan Austin <redacted>
Cc: Chao Xie Linux <redacted>
Cc: Juri Lelli <redacted>
Cc: linux-pm at vger.kernel.org
Cc: linux-arm-kernel at lists.infradead.org
Cc: linux-kernel at vger.kernel.org
---
arch/arm/include/asm/cputype.h | 3 ++-
arch/arm/include/asm/smp_plat.h | 15 +++++++++++++++
drivers/cpuidle/cpuidle-big_little.c | 13 +++----------
3 files changed, 20 insertions(+), 11 deletions(-)
diff --git a/arch/arm/include/asm/cputype.h b/arch/arm/include/asm/cputype.h
index 963a251..819777d 100644
--- a/arch/arm/include/asm/cputype.h
+++ b/arch/arm/include/asm/cputype.h@@ -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)
diff --git a/arch/arm/include/asm/smp_plat.h b/arch/arm/include/asm/smp_plat.h
index a252c0b..0ad7d49 100644
--- a/arch/arm/include/asm/smp_plat.h
+++ b/arch/arm/include/asm/smp_plat.h@@ -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
diff --git a/drivers/cpuidle/cpuidle-big_little.c b/drivers/cpuidle/cpuidle-big_little.c
index 344d79fa..ef94c3b 100644
--- a/drivers/cpuidle/cpuidle-big_little.c
+++ b/drivers/cpuidle/cpuidle-big_little.c@@ -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;
--
2.0.4