diff mbox series

[v9,06/19] ACPI: processor: Move checks and availability of acpi_processor earlier

Message ID 20240430142434.10471-7-Jonathan.Cameron@huawei.com (mailing list archive)
State New, archived
Headers show
Series ACPI/arm64: add support for virtual cpu hotplug | expand

Commit Message

Jonathan Cameron April 30, 2024, 2:24 p.m. UTC
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(-)

Comments

Gavin Shan May 1, 2024, 10:33 a.m. UTC | #1
On 5/1/24 00:24, Jonathan Cameron 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>
> 
> ---
> 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(-)
> 

It would be nice for acpi_processor_set_per_cpu() to return errno,
explained as below. The patch looks good to me in either me.

Reviewed-by: Gavin Shan <gshan@redhat.com>

> 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;
> +}
> +

I think it'd better for acpi_processor_set_per_cpu() to return errno. -EINVAL
is returned if a mismatched ACPI device is found, and 0 is returned on success.

With the improvement, the callers needn't to translate boolen to errno.

>   #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;
> +	}
> +

If errno is returned from acpi_processor_set_per_cpu(), this chunk of code becomes:

	ret = acpi_processor_set_per_cpu(pr, device);
	if (ret) {
		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;
>   	}
>   

		ret = acpi_processor_set_per_cpu(pr, device);
		if (ret)
			return ret;

>   	/*
> @@ -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();
>   

Thanks,
Gavin
Rafael J. Wysocki May 7, 2024, 7:04 p.m. UTC | #2
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
>
Jonathan Cameron May 8, 2024, 8:44 a.m. UTC | #3
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 mbox series

Patch

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();