| Message ID | 20240430142434.10471-7-Jonathan.Cameron@huawei.com |
|---|---|
| State | New |
| Headers | show |
| Series | ACPI/arm64: add support for virtual cpu hotplug | expand |
On Tue, Apr 30, 2024 at 4:27 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> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> One nit below. > --- > v9: Add back a blank line accidentally removed in code move. > Fix up error returns so that the new cleanup in processor_add() > is triggered on detection of the bios bug. > Combined with the previous 2 patches, should solve the leak > that Gavin identified. > --- > drivers/acpi/acpi_processor.c | 80 +++++++++++++++++++++-------------- > 1 file changed, 49 insertions(+), 31 deletions(-) > > diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c > index 16e36e55a560..4a79b42d649e 100644 > --- a/drivers/acpi/acpi_processor.c > +++ b/drivers/acpi/acpi_processor.c > @@ -183,8 +183,38 @@ static void __init acpi_pcc_cpufreq_init(void) {} > #endif /* CONFIG_X86 */ > > /* Initialization */ > +static DEFINE_PER_CPU(void *, processor_device_array); > + > +static bool 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); > + return false; > + } > + /* > + * 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; > + > + return true; > +} > + > #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; > > @@ -198,8 +228,16 @@ static int acpi_processor_hotadd_init(struct acpi_processor *pr) > if (ret) > goto out; > > + if (!acpi_processor_set_per_cpu(pr, device)) { > + ret = -EINVAL; > + acpi_unmap_cpu(pr->id); > + goto out; > + } > + > ret = arch_register_cpu(pr->id); > if (ret) { > + /* Leave the processor device array in place to detect buggy bios */ > + per_cpu(processors, pr->id) = NULL; > acpi_unmap_cpu(pr->id); > goto out; > } > @@ -217,7 +255,8 @@ 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; > } > @@ -316,10 +355,13 @@ 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); > + int ret = acpi_processor_hotadd_init(pr, device); > > if (ret) > return ret; > + } else { > + if (!acpi_processor_set_per_cpu(pr, device)) > + return -EINVAL; > } This looks a bit odd. I would make acpi_processor_set_per_cpu() return 0 on success and -EINVAL on failure and the above would become if (invalid_logical_cpuid(pr->id) || !cpu_present(pr->id)) ret = acpi_processor_hotadd_init(pr, device); else ret = acpi_processor_set_per_cpu(pr, device); if (ret) return ret; (and of course ret needs to be defined at the beginning of the function). > > /* > @@ -365,8 +407,6 @@ 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 +435,6 @@ static int acpi_processor_add(struct acpi_device *device, > if (result) /* Processor is not physically present or unavailable */ > goto err_clear_driver_data; > > - 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_clear_driver_data; > - } > - /* > - * 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; > @@ -470,10 +488,6 @@ 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(); > > @@ -481,6 +495,10 @@ 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(); > > -- > 2.39.2 >
On Tue, 7 May 2024 21:04:26 +0200 "Rafael J. Wysocki" <rafael@kernel.org> wrote: > On Tue, Apr 30, 2024 at 4:27 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> > > Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > > One nit below. Thanks. Given timing, this is looking like 6.11 material. I'll tidy this up and post a v10 in a couple of weeks (so around rc1 time). Maybe we'll pick up some more tags for the ARM specific bits in the meantime. Thanks for all your help! Jonathan > > > --- > > v9: Add back a blank line accidentally removed in code move. > > Fix up error returns so that the new cleanup in processor_add() > > is triggered on detection of the bios bug. > > Combined with the previous 2 patches, should solve the leak > > that Gavin identified. > > --- > > drivers/acpi/acpi_processor.c | 80 +++++++++++++++++++++-------------- > > 1 file changed, 49 insertions(+), 31 deletions(-) > > > > diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c > > index 16e36e55a560..4a79b42d649e 100644 > > --- a/drivers/acpi/acpi_processor.c > > +++ b/drivers/acpi/acpi_processor.c > > @@ -183,8 +183,38 @@ static void __init acpi_pcc_cpufreq_init(void) {} > > #endif /* CONFIG_X86 */ > > > > /* Initialization */ > > +static DEFINE_PER_CPU(void *, processor_device_array); > > + > > +static bool 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); > > + return false; > > + } > > + /* > > + * 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; > > + > > + return true; > > +} > > + > > #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; > > > > @@ -198,8 +228,16 @@ static int acpi_processor_hotadd_init(struct acpi_processor *pr) > > if (ret) > > goto out; > > > > + if (!acpi_processor_set_per_cpu(pr, device)) { > > + ret = -EINVAL; > > + acpi_unmap_cpu(pr->id); > > + goto out; > > + } > > + > > ret = arch_register_cpu(pr->id); > > if (ret) { > > + /* Leave the processor device array in place to detect buggy bios */ > > + per_cpu(processors, pr->id) = NULL; > > acpi_unmap_cpu(pr->id); > > goto out; > > } > > @@ -217,7 +255,8 @@ 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; > > } > > @@ -316,10 +355,13 @@ 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); > > + int ret = acpi_processor_hotadd_init(pr, device); > > > > if (ret) > > return ret; > > + } else { > > + if (!acpi_processor_set_per_cpu(pr, device)) > > + return -EINVAL; > > } > > This looks a bit odd. > > I would make acpi_processor_set_per_cpu() return 0 on success and > -EINVAL on failure and the above would become > > if (invalid_logical_cpuid(pr->id) || !cpu_present(pr->id)) > ret = acpi_processor_hotadd_init(pr, device); > else > ret = acpi_processor_set_per_cpu(pr, device); > > if (ret) > return ret; > > (and of course ret needs to be defined at the beginning of the function). > > > > > /* > > @@ -365,8 +407,6 @@ 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 +435,6 @@ static int acpi_processor_add(struct acpi_device *device, > > if (result) /* Processor is not physically present or unavailable */ > > goto err_clear_driver_data; > > > > - 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_clear_driver_data; > > - } > > - /* > > - * 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; > > @@ -470,10 +488,6 @@ 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(); > > > > @@ -481,6 +495,10 @@ 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(); > > > > -- > > 2.39.2 > >
diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c index 16e36e55a560..4a79b42d649e 100644 --- a/drivers/acpi/acpi_processor.c +++ b/drivers/acpi/acpi_processor.c @@ -183,8 +183,38 @@ static void __init acpi_pcc_cpufreq_init(void) {} #endif /* CONFIG_X86 */ /* Initialization */ +static DEFINE_PER_CPU(void *, processor_device_array); + +static bool 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); + return false; + } + /* + * 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; + + return true; +} + #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; @@ -198,8 +228,16 @@ static int acpi_processor_hotadd_init(struct acpi_processor *pr) if (ret) goto out; + if (!acpi_processor_set_per_cpu(pr, device)) { + ret = -EINVAL; + acpi_unmap_cpu(pr->id); + goto out; + } + ret = arch_register_cpu(pr->id); if (ret) { + /* Leave the processor device array in place to detect buggy bios */ + per_cpu(processors, pr->id) = NULL; acpi_unmap_cpu(pr->id); goto out; } @@ -217,7 +255,8 @@ 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; } @@ -316,10 +355,13 @@ 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); + int ret = acpi_processor_hotadd_init(pr, device); if (ret) return ret; + } else { + if (!acpi_processor_set_per_cpu(pr, device)) + return -EINVAL; } /* @@ -365,8 +407,6 @@ 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 +435,6 @@ static int acpi_processor_add(struct acpi_device *device, if (result) /* Processor is not physically present or unavailable */ goto err_clear_driver_data; - 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_clear_driver_data; - } - /* - * 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; @@ -470,10 +488,6 @@ 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(); @@ -481,6 +495,10 @@ 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> --- v9: Add back a blank line accidentally removed in code move. Fix up error returns so that the new cleanup in processor_add() is triggered on detection of the bios bug. Combined with the previous 2 patches, should solve the leak that Gavin identified. --- drivers/acpi/acpi_processor.c | 80 +++++++++++++++++++++-------------- 1 file changed, 49 insertions(+), 31 deletions(-)