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

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 <juri.lelli@arm.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 3 insertions, 10 deletions

diff --git a/drivers/cpuidle/cpuidle-big_little.c b/drivers/cpuidle/cpuidle-big_little.c
index 344d79fa3407..ef94c3b81f18 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;