| Message ID | 20240418135412.14730-4-Jonathan.Cameron@huawei.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | ACPI/arm64: add support for virtual cpu hotplug | expand |
On Thu, Apr 18, 2024 at 3:55 PM Jonathan Cameron <Jonathan.Cameron@huawei.com> wrote: > > The ACPI bus scan will only result in acpi_processor_add() being called > if _STA has already been checked and the result is that the > processor is enabled and present. Hence drop this additional check. > > Suggested-by: Rafael J. Wysocki <rafael@kernel.org> > Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> LGTM, so Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > --- > v7: No change > v6: New patch to drop this unnecessary code. Now I think we only > need to explicitly read STA to print a warning in the ARM64 > arch_unregister_cpu() path where we want to know if the > present bit has been unset as well. > --- > drivers/acpi/acpi_processor.c | 6 ------ > 1 file changed, 6 deletions(-) > > diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c > index 7fc924aeeed0..ba0a6f0ac841 100644 > --- a/drivers/acpi/acpi_processor.c > +++ b/drivers/acpi/acpi_processor.c > @@ -186,17 +186,11 @@ static void __init acpi_pcc_cpufreq_init(void) {} > #ifdef CONFIG_ACPI_HOTPLUG_CPU > static int acpi_processor_hotadd_init(struct acpi_processor *pr) > { > - unsigned long long sta; > - acpi_status status; > int ret; > > if (invalid_phys_cpuid(pr->phys_id)) > return -ENODEV; > > - status = acpi_evaluate_integer(pr->handle, "_STA", NULL, &sta); > - if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_PRESENT)) > - return -ENODEV; > - > cpu_maps_update_begin(); > cpus_write_lock(); > > --
On 2024/4/18 21:53, Jonathan Cameron wrote: > The ACPI bus scan will only result in acpi_processor_add() being called > if _STA has already been checked and the result is that the > processor is enabled and present. Hence drop this additional check. > > Suggested-by: Rafael J. Wysocki <rafael@kernel.org> > Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> > > --- > v7: No change > v6: New patch to drop this unnecessary code. Now I think we only > need to explicitly read STA to print a warning in the ARM64 > arch_unregister_cpu() path where we want to know if the > present bit has been unset as well. > --- > drivers/acpi/acpi_processor.c | 6 ------ > 1 file changed, 6 deletions(-) > > diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c > index 7fc924aeeed0..ba0a6f0ac841 100644 > --- a/drivers/acpi/acpi_processor.c > +++ b/drivers/acpi/acpi_processor.c > @@ -186,17 +186,11 @@ static void __init acpi_pcc_cpufreq_init(void) {} > #ifdef CONFIG_ACPI_HOTPLUG_CPU > static int acpi_processor_hotadd_init(struct acpi_processor *pr) > { > - unsigned long long sta; > - acpi_status status; > int ret; > > if (invalid_phys_cpuid(pr->phys_id)) > return -ENODEV; > > - status = acpi_evaluate_integer(pr->handle, "_STA", NULL, &sta); > - if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_PRESENT)) > - return -ENODEV; > - > cpu_maps_update_begin(); > cpus_write_lock(); Since the status bits were checked before acpi_processor_add() being called, do we need to remove the if (!acpi_device_is_enabled(device)) check in acpi_processor_add() as well? Thanks Hanjun
On Tue, Apr 23, 2024 at 8:49 AM Hanjun Guo <guohanjun@huawei.com> wrote: > > On 2024/4/18 21:53, Jonathan Cameron wrote: > > The ACPI bus scan will only result in acpi_processor_add() being called > > if _STA has already been checked and the result is that the > > processor is enabled and present. Hence drop this additional check. > > > > Suggested-by: Rafael J. Wysocki <rafael@kernel.org> > > Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> > > > > --- > > v7: No change > > v6: New patch to drop this unnecessary code. Now I think we only > > need to explicitly read STA to print a warning in the ARM64 > > arch_unregister_cpu() path where we want to know if the > > present bit has been unset as well. > > --- > > drivers/acpi/acpi_processor.c | 6 ------ > > 1 file changed, 6 deletions(-) > > > > diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c > > index 7fc924aeeed0..ba0a6f0ac841 100644 > > --- a/drivers/acpi/acpi_processor.c > > +++ b/drivers/acpi/acpi_processor.c > > @@ -186,17 +186,11 @@ static void __init acpi_pcc_cpufreq_init(void) {} > > #ifdef CONFIG_ACPI_HOTPLUG_CPU > > static int acpi_processor_hotadd_init(struct acpi_processor *pr) > > { > > - unsigned long long sta; > > - acpi_status status; > > int ret; > > > > if (invalid_phys_cpuid(pr->phys_id)) > > return -ENODEV; > > > > - status = acpi_evaluate_integer(pr->handle, "_STA", NULL, &sta); > > - if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_PRESENT)) > > - return -ENODEV; > > - > > cpu_maps_update_begin(); > > cpus_write_lock(); > > Since the status bits were checked before acpi_processor_add() being > called, do we need to remove the if (!acpi_device_is_enabled(device)) > check in acpi_processor_add() as well? No, because its caller only checks the present bit. The function itself checks the enabled bit.
On 2024/4/23 17:31, Rafael J. Wysocki wrote: > On Tue, Apr 23, 2024 at 8:49 AM Hanjun Guo <guohanjun@huawei.com> wrote: >> >> On 2024/4/18 21:53, Jonathan Cameron wrote: >>> The ACPI bus scan will only result in acpi_processor_add() being called >>> if _STA has already been checked and the result is that the >>> processor is enabled and present. Hence drop this additional check. >>> >>> Suggested-by: Rafael J. Wysocki <rafael@kernel.org> >>> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> >>> >>> --- >>> v7: No change >>> v6: New patch to drop this unnecessary code. Now I think we only >>> need to explicitly read STA to print a warning in the ARM64 >>> arch_unregister_cpu() path where we want to know if the >>> present bit has been unset as well. >>> --- >>> drivers/acpi/acpi_processor.c | 6 ------ >>> 1 file changed, 6 deletions(-) >>> >>> diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c >>> index 7fc924aeeed0..ba0a6f0ac841 100644 >>> --- a/drivers/acpi/acpi_processor.c >>> +++ b/drivers/acpi/acpi_processor.c >>> @@ -186,17 +186,11 @@ static void __init acpi_pcc_cpufreq_init(void) {} >>> #ifdef CONFIG_ACPI_HOTPLUG_CPU >>> static int acpi_processor_hotadd_init(struct acpi_processor *pr) >>> { >>> - unsigned long long sta; >>> - acpi_status status; >>> int ret; >>> >>> if (invalid_phys_cpuid(pr->phys_id)) >>> return -ENODEV; >>> >>> - status = acpi_evaluate_integer(pr->handle, "_STA", NULL, &sta); >>> - if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_PRESENT)) >>> - return -ENODEV; >>> - >>> cpu_maps_update_begin(); >>> cpus_write_lock(); >> >> Since the status bits were checked before acpi_processor_add() being >> called, do we need to remove the if (!acpi_device_is_enabled(device)) >> check in acpi_processor_add() as well? > > No, because its caller only checks the present bit. The function > itself checks the enabled bit. Thanks for the pointer, I can see the detail in the acpi_bus_attach() now, Reviewed-by: Hanjun Guo <guohanjun@huawei.com> Thanks Hanjun
On 4/18/24 23:53, Jonathan Cameron wrote: > The ACPI bus scan will only result in acpi_processor_add() being called > if _STA has already been checked and the result is that the > processor is enabled and present. Hence drop this additional check. > > Suggested-by: Rafael J. Wysocki <rafael@kernel.org> > Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> > > --- > v7: No change > v6: New patch to drop this unnecessary code. Now I think we only > need to explicitly read STA to print a warning in the ARM64 > arch_unregister_cpu() path where we want to know if the > present bit has been unset as well. > --- > drivers/acpi/acpi_processor.c | 6 ------ > 1 file changed, 6 deletions(-) > Reviewed-by: Gavin Shan <gshan@redhat.com>
diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c index 7fc924aeeed0..ba0a6f0ac841 100644 --- a/drivers/acpi/acpi_processor.c +++ b/drivers/acpi/acpi_processor.c @@ -186,17 +186,11 @@ static void __init acpi_pcc_cpufreq_init(void) {} #ifdef CONFIG_ACPI_HOTPLUG_CPU static int acpi_processor_hotadd_init(struct acpi_processor *pr) { - unsigned long long sta; - acpi_status status; int ret; if (invalid_phys_cpuid(pr->phys_id)) return -ENODEV; - status = acpi_evaluate_integer(pr->handle, "_STA", NULL, &sta); - if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_PRESENT)) - return -ENODEV; - cpu_maps_update_begin(); cpus_write_lock();
The ACPI bus scan will only result in acpi_processor_add() being called if _STA has already been checked and the result is that the processor is enabled and present. Hence drop this additional check. Suggested-by: Rafael J. Wysocki <rafael@kernel.org> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> --- v7: No change v6: New patch to drop this unnecessary code. Now I think we only need to explicitly read STA to print a warning in the ARM64 arch_unregister_cpu() path where we want to know if the present bit has been unset as well. --- drivers/acpi/acpi_processor.c | 6 ------ 1 file changed, 6 deletions(-)