[PATCH v2] cpuidle/cpuidle-big_little: fix reading cpu id part number
From: Lorenzo Pieralisi <hidden>
Date: 2014-08-15 10:07:14
Also in:
linux-pm, lkml
On Thu, Aug 14, 2014 at 09:27:45AM +0100, Juri Lelli wrote:
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.If Russell does not have any additional comments you can send it to his patch system. Thanks, Lorenzo
quoted hunk ↗ jump to hunk
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() 0diff --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