| Message ID | 20230913163823.7880-26-james.morse@arm.com (mailing list archive) |
|---|---|
| State | Handled Elsewhere |
| Headers | show |
| Series | ACPI/arm64: add support for virtual cpuhotplug | expand |
| Context | Check | Description |
|---|---|---|
| conchuod/cover_letter | success | Series has a cover letter |
| conchuod/tree_selection | success | Guessed tree name to be for-next at HEAD 0bb80ecc33a8 |
| conchuod/fixes_present | success | Fixes tag not required for -next series |
| conchuod/maintainers_pattern | success | MAINTAINERS pattern errors before the patch: 5 and now 5 |
| conchuod/verify_signedoff | success | Signed-off-by tag matches author and committer |
| conchuod/kdoc | success | Errors and warnings before: 0 this patch: 0 |
| conchuod/build_rv64_clang_allmodconfig | success | Errors and warnings before: 9 this patch: 9 |
| conchuod/module_param | success | Was 0 now: 0 |
| conchuod/build_rv64_gcc_allmodconfig | success | Errors and warnings before: 9 this patch: 9 |
| conchuod/build_rv32_defconfig | success | Build OK |
| conchuod/dtb_warn_rv64 | success | Errors and warnings before: 25 this patch: 25 |
| conchuod/header_inline | success | No static functions without inline keyword in header files |
| conchuod/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 13 lines checked |
| conchuod/build_rv64_nommu_k210_defconfig | success | Build OK |
| conchuod/verify_fixes | success | No Fixes tag |
| conchuod/build_rv64_nommu_virt_defconfig | success | Build OK |
On Wed, 13 Sep 2023 16:38:13 +0000 James Morse <james.morse@arm.com> wrote: > LoongArch provides its own arch_unregister_cpu(). This clears the > hotpluggable flag, then unregisters the CPU. > > It isn't necessary to clear the hotpluggable flag when unregistering > a cpu. unregister_cpu() writes NULL to the percpu cpu_sys_devices > pointer, meaning cpu_is_hotpluggable() will return false, as > get_cpu_device() has returned NULL. Thought that looked odd earlier but didn't care enough to dig. Seem unlikely state would persist for an unregistered cpu. Great to see confirmation. > > Remove arch_unregister_cpu() and use the __weak version. > > Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> > --- > arch/loongarch/kernel/topology.c | 9 --------- > 1 file changed, 9 deletions(-) > > diff --git a/arch/loongarch/kernel/topology.c b/arch/loongarch/kernel/topology.c > index 8e4441c1ff39..5a75e2cc0848 100644 > --- a/arch/loongarch/kernel/topology.c > +++ b/arch/loongarch/kernel/topology.c > @@ -16,13 +16,4 @@ int arch_register_cpu(int cpu) > return register_cpu(c, cpu); > } > EXPORT_SYMBOL(arch_register_cpu); > - > -void arch_unregister_cpu(int cpu) > -{ > - struct cpu *c = &per_cpu(cpu_devices, cpu); > - > - c->hotpluggable = 0; > - unregister_cpu(c); > -} > -EXPORT_SYMBOL(arch_unregister_cpu); > #endif
On 9/14/23 02:38, James Morse wrote: > LoongArch provides its own arch_unregister_cpu(). This clears the > hotpluggable flag, then unregisters the CPU. > > It isn't necessary to clear the hotpluggable flag when unregistering > a cpu. unregister_cpu() writes NULL to the percpu cpu_sys_devices > pointer, meaning cpu_is_hotpluggable() will return false, as > get_cpu_device() has returned NULL. > > Remove arch_unregister_cpu() and use the __weak version. > > Signed-off-by: James Morse <james.morse@arm.com> > --- > arch/loongarch/kernel/topology.c | 9 --------- > 1 file changed, 9 deletions(-) > I think arch/x86/kernel/topology.c::arch_unregister_cpu() can be dropped either. Reviewed-by: Gavin Shan <gshan@redhat.com> > diff --git a/arch/loongarch/kernel/topology.c b/arch/loongarch/kernel/topology.c > index 8e4441c1ff39..5a75e2cc0848 100644 > --- a/arch/loongarch/kernel/topology.c > +++ b/arch/loongarch/kernel/topology.c > @@ -16,13 +16,4 @@ int arch_register_cpu(int cpu) > return register_cpu(c, cpu); > } > EXPORT_SYMBOL(arch_register_cpu); > - > -void arch_unregister_cpu(int cpu) > -{ > - struct cpu *c = &per_cpu(cpu_devices, cpu); > - > - c->hotpluggable = 0; > - unregister_cpu(c); > -} > -EXPORT_SYMBOL(arch_unregister_cpu); > #endif Thanks, Gavin
On Thu, Sep 14, 2023 at 03:41:11PM +0100, Jonathan Cameron wrote: > On Wed, 13 Sep 2023 16:38:13 +0000 > James Morse <james.morse@arm.com> wrote: > > > LoongArch provides its own arch_unregister_cpu(). This clears the > > hotpluggable flag, then unregisters the CPU. > > > > It isn't necessary to clear the hotpluggable flag when unregistering > > a cpu. unregister_cpu() writes NULL to the percpu cpu_sys_devices > > pointer, meaning cpu_is_hotpluggable() will return false, as > > get_cpu_device() has returned NULL. > > Thought that looked odd earlier but didn't care enough to dig. > Seem unlikely state would persist for an unregistered cpu. > Great to see confirmation. Would it make sense to move this immedaitely after "LoongArch: Switch over to GENERIC_CPU_DEVICES" ?
diff --git a/arch/loongarch/kernel/topology.c b/arch/loongarch/kernel/topology.c index 8e4441c1ff39..5a75e2cc0848 100644 --- a/arch/loongarch/kernel/topology.c +++ b/arch/loongarch/kernel/topology.c @@ -16,13 +16,4 @@ int arch_register_cpu(int cpu) return register_cpu(c, cpu); } EXPORT_SYMBOL(arch_register_cpu); - -void arch_unregister_cpu(int cpu) -{ - struct cpu *c = &per_cpu(cpu_devices, cpu); - - c->hotpluggable = 0; - unregister_cpu(c); -} -EXPORT_SYMBOL(arch_unregister_cpu); #endif
LoongArch provides its own arch_unregister_cpu(). This clears the hotpluggable flag, then unregisters the CPU. It isn't necessary to clear the hotpluggable flag when unregistering a cpu. unregister_cpu() writes NULL to the percpu cpu_sys_devices pointer, meaning cpu_is_hotpluggable() will return false, as get_cpu_device() has returned NULL. Remove arch_unregister_cpu() and use the __weak version. Signed-off-by: James Morse <james.morse@arm.com> --- arch/loongarch/kernel/topology.c | 9 --------- 1 file changed, 9 deletions(-)