| Message ID | 20240418135412.14730-5-Jonathan.Cameron@huawei.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | ACPI/arm64: add support for virtual cpu hotplug | expand |
On Thu, Apr 18, 2024 at 3:56 PM Jonathan Cameron <Jonathan.Cameron@huawei.com> wrote: > > Make the per_cpu(processors, cpu) entries available earlier so that > they are available in arch_register_cpu() as ARM64 will need access > to the acpi_handle to distinguish between acpi_processor_add() > and earlier registration attempts (which will fail as _STA cannot > be checked). > > Reorder the remove flow to clear this per_cpu() after > arch_unregister_cpu() has completed, allowing it to be used in > there as well. > > Note that on x86 for the CPU hotplug case, the pr->id prior to > acpi_map_cpu() may be invalid. Thus the per_cpu() structures > must be initialized after that call or after checking the ID > is valid (not hotplug path). > > Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> > --- > v7: Swap order with acpi_unmap_cpu() in acpi_processor_remove() > to keep it in reverse order of the setup path. (thanks Salil) > Fix an issue with placement of CONFIG_ACPI_HOTPLUG_CPU guards. > v6: As per discussion in v5 thread, don't use the cpu->dev and > make this data available earlier by moving the assignment checks > int acpi_processor_get_info(). > --- > drivers/acpi/acpi_processor.c | 78 +++++++++++++++++++++-------------- > 1 file changed, 46 insertions(+), 32 deletions(-) > > diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c > index ba0a6f0ac841..ac7ddb30f10e 100644 > --- a/drivers/acpi/acpi_processor.c > +++ b/drivers/acpi/acpi_processor.c > @@ -183,8 +183,36 @@ static void __init acpi_pcc_cpufreq_init(void) {} > #endif /* CONFIG_X86 */ > > /* Initialization */ > +static DEFINE_PER_CPU(void *, processor_device_array); > + > +static void acpi_processor_set_per_cpu(struct acpi_processor *pr, > + struct acpi_device *device) > +{ > + BUG_ON(pr->id >= nr_cpu_ids); > + /* > + * Buggy BIOS check. > + * ACPI id of processors can be reported wrongly by the BIOS. > + * Don't trust it blindly > + */ > + if (per_cpu(processor_device_array, pr->id) != NULL && > + per_cpu(processor_device_array, pr->id) != device) { > + dev_warn(&device->dev, > + "BIOS reported wrong ACPI id %d for the processor\n", > + pr->id); > + /* Give up, but do not abort the namespace scan. */ > + return; In this case the caller should make acpi_pricessor_add() return 0, I think, because otherwise it will attempt to acpi_bind_one() "pr" to "device" which will confuse things. So I would make this return false to indicate that. Or just fold it into the caller and do the error handling there.
> @@ -232,6 +263,7 @@ static int acpi_processor_get_info(struct acpi_device *device) > acpi_status status = AE_OK; > static int cpu0_initialized; > unsigned long long value; > + int ret; > > acpi_processor_errata(); > > @@ -316,10 +348,12 @@ static int acpi_processor_get_info(struct acpi_device *device) > * because cpuid <-> apicid mapping is persistent now. > */ > if (invalid_logical_cpuid(pr->id) || !cpu_present(pr->id)) { > - int ret = acpi_processor_hotadd_init(pr); > + ret = acpi_processor_hotadd_init(pr, device); > > if (ret) > - return ret; > + goto err; > + } else { > + acpi_processor_set_per_cpu(pr, device); > } > > /* > @@ -357,6 +391,10 @@ static int acpi_processor_get_info(struct acpi_device *device) > arch_fix_phys_package_id(pr->id, value); > > return 0; > + > +err: > + per_cpu(processors, pr->id) = NULL; ... > + return ret; > } > > /* > @@ -365,8 +403,6 @@ static int acpi_processor_get_info(struct acpi_device *device) > * (cpu_data(cpu)) values, like CPU feature flags, family, model, etc. > * Such things have to be put in and set up by the processor driver's .probe(). > */ > -static DEFINE_PER_CPU(void *, processor_device_array); > - > static int acpi_processor_add(struct acpi_device *device, > const struct acpi_device_id *id) > { > @@ -395,28 +431,6 @@ static int acpi_processor_add(struct acpi_device *device, > if (result) /* Processor is not physically present or unavailable */ > return 0; > > - BUG_ON(pr->id >= nr_cpu_ids); > - > - /* > - * Buggy BIOS check. > - * ACPI id of processors can be reported wrongly by the BIOS. > - * Don't trust it blindly > - */ > - if (per_cpu(processor_device_array, pr->id) != NULL && > - per_cpu(processor_device_array, pr->id) != device) { > - dev_warn(&device->dev, > - "BIOS reported wrong ACPI id %d for the processor\n", > - pr->id); > - /* Give up, but do not abort the namespace scan. */ > - goto err; > - } > - /* > - * processor_device_array is not cleared on errors to allow buggy BIOS > - * checks. > - */ > - per_cpu(processor_device_array, pr->id) = device; > - per_cpu(processors, pr->id) = pr; Nit: seems we need to remove the duplicated per_cpu(processors, pr->id) = NULL; in acpi_processor_add(): --- a/drivers/acpi/acpi_processor.c +++ b/drivers/acpi/acpi_processor.c @@ -446,7 +446,6 @@ static int acpi_processor_add(struct acpi_device *device, err: free_cpumask_var(pr->throttling.shared_cpu_map); device->driver_data = NULL; - per_cpu(processors, pr->id) = NULL; err_free_pr: kfree(pr); return result; Thanks Hanjun
diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c index ba0a6f0ac841..ac7ddb30f10e 100644 --- a/drivers/acpi/acpi_processor.c +++ b/drivers/acpi/acpi_processor.c @@ -183,8 +183,36 @@ static void __init acpi_pcc_cpufreq_init(void) {} #endif /* CONFIG_X86 */ /* Initialization */ +static DEFINE_PER_CPU(void *, processor_device_array); + +static void acpi_processor_set_per_cpu(struct acpi_processor *pr, + struct acpi_device *device) +{ + BUG_ON(pr->id >= nr_cpu_ids); + /* + * Buggy BIOS check. + * ACPI id of processors can be reported wrongly by the BIOS. + * Don't trust it blindly + */ + if (per_cpu(processor_device_array, pr->id) != NULL && + per_cpu(processor_device_array, pr->id) != device) { + dev_warn(&device->dev, + "BIOS reported wrong ACPI id %d for the processor\n", + pr->id); + /* Give up, but do not abort the namespace scan. */ + return; + } + /* + * processor_device_array is not cleared on errors to allow buggy BIOS + * checks. + */ + per_cpu(processor_device_array, pr->id) = device; + per_cpu(processors, pr->id) = pr; +} + #ifdef CONFIG_ACPI_HOTPLUG_CPU -static int acpi_processor_hotadd_init(struct acpi_processor *pr) +static int acpi_processor_hotadd_init(struct acpi_processor *pr, + struct acpi_device *device) { int ret; @@ -198,6 +226,8 @@ static int acpi_processor_hotadd_init(struct acpi_processor *pr) if (ret) goto out; + acpi_processor_set_per_cpu(pr, device); + ret = arch_register_cpu(pr->id); if (ret) { acpi_unmap_cpu(pr->id); @@ -217,7 +247,8 @@ static int acpi_processor_hotadd_init(struct acpi_processor *pr) return ret; } #else -static inline int acpi_processor_hotadd_init(struct acpi_processor *pr) +static inline int acpi_processor_hotadd_init(struct acpi_processor *pr, + struct acpi_device *device) { return -ENODEV; } @@ -232,6 +263,7 @@ static int acpi_processor_get_info(struct acpi_device *device) acpi_status status = AE_OK; static int cpu0_initialized; unsigned long long value; + int ret; acpi_processor_errata(); @@ -316,10 +348,12 @@ static int acpi_processor_get_info(struct acpi_device *device) * because cpuid <-> apicid mapping is persistent now. */ if (invalid_logical_cpuid(pr->id) || !cpu_present(pr->id)) { - int ret = acpi_processor_hotadd_init(pr); + ret = acpi_processor_hotadd_init(pr, device); if (ret) - return ret; + goto err; + } else { + acpi_processor_set_per_cpu(pr, device); } /* @@ -357,6 +391,10 @@ static int acpi_processor_get_info(struct acpi_device *device) arch_fix_phys_package_id(pr->id, value); return 0; + +err: + per_cpu(processors, pr->id) = NULL; + return ret; } /* @@ -365,8 +403,6 @@ static int acpi_processor_get_info(struct acpi_device *device) * (cpu_data(cpu)) values, like CPU feature flags, family, model, etc. * Such things have to be put in and set up by the processor driver's .probe(). */ -static DEFINE_PER_CPU(void *, processor_device_array); - static int acpi_processor_add(struct acpi_device *device, const struct acpi_device_id *id) { @@ -395,28 +431,6 @@ static int acpi_processor_add(struct acpi_device *device, if (result) /* Processor is not physically present or unavailable */ return 0; - BUG_ON(pr->id >= nr_cpu_ids); - - /* - * Buggy BIOS check. - * ACPI id of processors can be reported wrongly by the BIOS. - * Don't trust it blindly - */ - if (per_cpu(processor_device_array, pr->id) != NULL && - per_cpu(processor_device_array, pr->id) != device) { - dev_warn(&device->dev, - "BIOS reported wrong ACPI id %d for the processor\n", - pr->id); - /* Give up, but do not abort the namespace scan. */ - goto err; - } - /* - * processor_device_array is not cleared on errors to allow buggy BIOS - * checks. - */ - per_cpu(processor_device_array, pr->id) = device; - per_cpu(processors, pr->id) = pr; - dev = get_cpu_device(pr->id); if (!dev) { result = -ENODEV; @@ -469,10 +483,6 @@ static void acpi_processor_remove(struct acpi_device *device) device_release_driver(pr->dev); acpi_unbind_one(pr->dev); - /* Clean up. */ - per_cpu(processor_device_array, pr->id) = NULL; - per_cpu(processors, pr->id) = NULL; - cpu_maps_update_begin(); cpus_write_lock(); @@ -480,6 +490,10 @@ static void acpi_processor_remove(struct acpi_device *device) arch_unregister_cpu(pr->id); acpi_unmap_cpu(pr->id); + /* Clean up. */ + per_cpu(processor_device_array, pr->id) = NULL; + per_cpu(processors, pr->id) = NULL; + cpus_write_unlock(); cpu_maps_update_done();
Make the per_cpu(processors, cpu) entries available earlier so that they are available in arch_register_cpu() as ARM64 will need access to the acpi_handle to distinguish between acpi_processor_add() and earlier registration attempts (which will fail as _STA cannot be checked). Reorder the remove flow to clear this per_cpu() after arch_unregister_cpu() has completed, allowing it to be used in there as well. Note that on x86 for the CPU hotplug case, the pr->id prior to acpi_map_cpu() may be invalid. Thus the per_cpu() structures must be initialized after that call or after checking the ID is valid (not hotplug path). Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> --- v7: Swap order with acpi_unmap_cpu() in acpi_processor_remove() to keep it in reverse order of the setup path. (thanks Salil) Fix an issue with placement of CONFIG_ACPI_HOTPLUG_CPU guards. v6: As per discussion in v5 thread, don't use the cpu->dev and make this data available earlier by moving the assignment checks int acpi_processor_get_info(). --- drivers/acpi/acpi_processor.c | 78 +++++++++++++++++++++-------------- 1 file changed, 46 insertions(+), 32 deletions(-)