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| author | James Morse <james.morse@arm.com> | 2021-03-29 13:58:59 +0100 |
|---|---|---|
| committer | Russell King (Oracle) <rmk+kernel@armlinux.org.uk> | 2023-08-29 15:29:55 +0100 |
| commit | 4195a899b447bfd1cf1349d81cca7005091f9103 (patch) | |
| tree | 6d2a34354b581f0ebfe303589e8e487a58cd0b97 | |
| parent | 6f376abea52d366bcca1067ae68bcb990fdf8182 (diff) | |
drivers: base: Use present CPUs in GENERIC_CPU_DEVICES
The four ACPI architectures only create sysfs entries using register_cpu()
for present CPUs, whereas GENERIC_CPU_DEVICES does this for possible CPUs.
Only two of the eight architectures that use GENERIC_CPU_DEVICES have a
distinction between present and possible CPUs.
To allow all four ACPI architectures to use GENERIC_CPU_DEVICES, change
it to use for_each_present_cpu().
The following architectures use GENERIC_CPU_DEVICES but are not SMP,
so possible == present:
* m68k
* microblaze
* nios2
The following architectures use GENERIC_CPU_DEVICES and consider
possible == present:
* csky: setup_smp()
* hexagon: compare smp_start_cpus() and smp_prepare_cpus()
* parisc: smp_prepare_boot_cpu() marks the boot cpu as present,
processor_probe() sets possible for all CPUs and present for all CPUs
except the boot cpu.
um appears to be a subarchitecture of x86.
The remaining architecture using GENERIC_CPU_DEVICES is openrisc,
where smp_init_cpus() makes all CPUs < NR_CPUS possible, whereas
smp_prepare_cpus() only makes CPUs < setup_max_cpus present. After this
change, openrisc systems that boot with max_cpus=1 would not see other
CPUs present in sysfs. This should not be a problem as these CPUs can't
bre brought online as _cpu_up() checks cpu_present().
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
| -rw-r--r-- | drivers/base/cpu.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c index fe6690ecf563..4a65a728c8c4 100644 --- a/drivers/base/cpu.c +++ b/drivers/base/cpu.c @@ -501,7 +501,7 @@ static void __init cpu_dev_register_generic(void) #ifdef CONFIG_GENERIC_CPU_DEVICES int i; - for_each_possible_cpu(i) { + for_each_present_cpu(i) { if (register_cpu(&per_cpu(cpu_devices, i), i)) panic("Failed to register CPU device"); } |