diff mbox

[V10,4/9] vfio: platform: add support for ACPI probe

Message ID 1468883367-2854-5-git-send-email-okaya@codeaurora.org (mailing list archive)
State Not Applicable, archived
Headers show

Commit Message

Sinan Kaya July 18, 2016, 11:09 p.m. UTC
The code is using the compatible DT string to associate a reset driver
with the actual device itself. The compatible string does not exist on
ACPI based systems. HID is the unique identifier for a device driver
instead.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
---
 drivers/vfio/platform/vfio_platform_common.c  | 69 +++++++++++++++++++++++++--
 drivers/vfio/platform/vfio_platform_private.h |  1 +
 2 files changed, 65 insertions(+), 5 deletions(-)

Comments

Alex Williamson July 19, 2016, midnight UTC | #1
On Mon, 18 Jul 2016 19:09:22 -0400
Sinan Kaya <okaya@codeaurora.org> wrote:

> The code is using the compatible DT string to associate a reset driver
> with the actual device itself. The compatible string does not exist on
> ACPI based systems. HID is the unique identifier for a device driver
> instead.
> 
> Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
> ---
>  drivers/vfio/platform/vfio_platform_common.c  | 69 +++++++++++++++++++++++++--
>  drivers/vfio/platform/vfio_platform_private.h |  1 +
>  2 files changed, 65 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c
> index 6be92c3..a5299f6 100644
> --- a/drivers/vfio/platform/vfio_platform_common.c
> +++ b/drivers/vfio/platform/vfio_platform_common.c
> @@ -13,6 +13,7 @@
>   */
>  
>  #include <linux/device.h>
> +#include <linux/acpi.h>
>  #include <linux/iommu.h>
>  #include <linux/module.h>
>  #include <linux/mutex.h>
> @@ -49,6 +50,32 @@ static vfio_platform_reset_fn_t vfio_platform_lookup_reset(const char *compat,
>  	return reset_fn;
>  }
>  
> +static int vfio_platform_acpi_probe(struct vfio_platform_device *vdev,
> +				    struct device *dev)
> +{
> +	struct acpi_device *adev;
> +
> +	if (acpi_disabled)
> +		return -EPERM;
> +
> +	adev = ACPI_COMPANION(dev);

I didn't necessarily have a problem with this being set in the
declaration.

> +	if (!adev) {
> +		pr_err("VFIO: ACPI companion device not found for %s\n",
> +			vdev->name);
> +		return -ENODEV;
> +	}
> +
> +#ifdef CONFIG_ACPI
> +	vdev->acpihid = acpi_device_hid(adev);
> +	if (!vdev->acpihid) {
> +		pr_err("VFIO: cannot find ACPI HID for %s\n",
> +		       vdev->name);
> +		return -EINVAL;
> +	}
> +#endif
> +	return WARN_ON(!vdev->acpihid) ? -ENOENT : 0;

?!?!  The point was that that entire if{} branch is unnecessary.  The
WARN_ON handles the (impossible) case of !vdev->acpihid.  We just need:

#ifdef CONFIG_ACPI
	vdev->acpihid = acpi_device_hid(adev);
#endif
	return WARN_ON(!vdev->acpihid) ? -ENOENT : 0;

nit, might make sense to replace EPERM with ENOENT and use EINVAL here.

> +}
> +
>  static bool vfio_platform_has_reset(struct vfio_platform_device *vdev)
>  {
>  	return vdev->of_reset ? true : false;
> @@ -547,6 +574,37 @@ static const struct vfio_device_ops vfio_platform_ops = {
>  	.mmap		= vfio_platform_mmap,
>  };
>  
> +int vfio_platform_of_probe(struct vfio_platform_device *vdev,
> +			   struct device *dev)
> +{
> +	int ret;
> +
> +	ret = device_property_read_string(dev, "compatible",
> +					  &vdev->compat);
> +	if (ret)
> +		pr_err("VFIO: cannot retrieve compat for %s\n",
> +			vdev->name);
> +
> +	return ret;
> +}
> +
> +/*
> + * There can be two kernel build combinations. One build where
> + * ACPI is not selected in Kconfig and another one with the ACPI Kconfig.
> + *
> + * In the first case, vfio_platform_acpi_probe will return since
> + * acpi_disabled is 1. DT user will not see any kind of messages from
> + * ACPI.
> + *
> + * In the second case, both DT and ACPI is compiled in but the system is
> + * booting with any of these combinations.
> + *
> + * If the firmware is DT type, then acpi_disabled is 1. The ACPI probe routine
> + * terminates immediately without any messages.
> + *
> + * If the firmware is ACPI type, then acpi_disabled is 0. All other checks are
> + * valid checks. We cannot claim that this system is DT.
> + */
>  int vfio_platform_probe_common(struct vfio_platform_device *vdev,
>  			       struct device *dev)
>  {
> @@ -556,11 +614,12 @@ int vfio_platform_probe_common(struct vfio_platform_device *vdev,
>  	if (!vdev)
>  		return -EINVAL;
>  
> -	ret = device_property_read_string(dev, "compatible", &vdev->compat);
> -	if (ret) {
> -		pr_err("VFIO: cannot retrieve compat for %s\n", vdev->name);
> -		return -EINVAL;
> -	}
> +	ret = vfio_platform_acpi_probe(vdev, dev);
> +	if (ret)
> +		ret = vfio_platform_of_probe(vdev, dev);
> +
> +	if (ret)
> +		return ret;
>  
>  	vdev->device = dev;
>  
> diff --git a/drivers/vfio/platform/vfio_platform_private.h b/drivers/vfio/platform/vfio_platform_private.h
> index 71ed7d1..ba9e4f8 100644
> --- a/drivers/vfio/platform/vfio_platform_private.h
> +++ b/drivers/vfio/platform/vfio_platform_private.h
> @@ -58,6 +58,7 @@ struct vfio_platform_device {
>  	struct mutex			igate;
>  	struct module			*parent_module;
>  	const char			*compat;
> +	const char			*acpihid;
>  	struct module			*reset_module;
>  	struct device			*device;
>  

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Sinan Kaya July 19, 2016, 12:16 a.m. UTC | #2
On 2016-07-18 20:00, Alex Williamson wrote:
> On Mon, 18 Jul 2016 19:09:22 -0400
> Sinan Kaya <okaya@codeaurora.org> wrote:
> 
>> The code is using the compatible DT string to associate a reset driver
>> with the actual device itself. The compatible string does not exist on
>> ACPI based systems. HID is the unique identifier for a device driver
>> instead.
>> 
>> Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
>> ---
>>  drivers/vfio/platform/vfio_platform_common.c  | 69 
>> +++++++++++++++++++++++++--
>>  drivers/vfio/platform/vfio_platform_private.h |  1 +
>>  2 files changed, 65 insertions(+), 5 deletions(-)
>> 
>> diff --git a/drivers/vfio/platform/vfio_platform_common.c 
>> b/drivers/vfio/platform/vfio_platform_common.c
>> index 6be92c3..a5299f6 100644
>> --- a/drivers/vfio/platform/vfio_platform_common.c
>> +++ b/drivers/vfio/platform/vfio_platform_common.c
>> @@ -13,6 +13,7 @@
>>   */
>> 
>>  #include <linux/device.h>
>> +#include <linux/acpi.h>
>>  #include <linux/iommu.h>
>>  #include <linux/module.h>
>>  #include <linux/mutex.h>
>> @@ -49,6 +50,32 @@ static vfio_platform_reset_fn_t 
>> vfio_platform_lookup_reset(const char *compat,
>>  	return reset_fn;
>>  }
>> 
>> +static int vfio_platform_acpi_probe(struct vfio_platform_device 
>> *vdev,
>> +				    struct device *dev)
>> +{
>> +	struct acpi_device *adev;
>> +
>> +	if (acpi_disabled)
>> +		return -EPERM;
>> +
>> +	adev = ACPI_COMPANION(dev);
> 
> I didn't necessarily have a problem with this being set in the
> declaration.

I think this is better. If ACPI is disabled, it is dangerous to call an 
ACPI API.


> 
>> +	if (!adev) {
>> +		pr_err("VFIO: ACPI companion device not found for %s\n",
>> +			vdev->name);
>> +		return -ENODEV;
>> +	}
>> +
>> +#ifdef CONFIG_ACPI
>> +	vdev->acpihid = acpi_device_hid(adev);
>> +	if (!vdev->acpihid) {
>> +		pr_err("VFIO: cannot find ACPI HID for %s\n",
>> +		       vdev->name);
>> +		return -EINVAL;
>> +	}
>> +#endif
>> +	return WARN_ON(!vdev->acpihid) ? -ENOENT : 0;
> 
> ?!?!  The point was that that entire if{} branch is unnecessary.  The
> WARN_ON handles the (impossible) case of !vdev->acpihid.  We just need:
> 
> #ifdef CONFIG_ACPI
> 	vdev->acpihid = acpi_device_hid(adev);
> #endif
> 	return WARN_ON(!vdev->acpihid) ? -ENOENT : 0;
> 

OK, got it now. I thought you were trying to get rid of #else

> nit, might make sense to replace EPERM with ENOENT and use EINVAL here.
> 

Sure, will take carr of it.

Anything else I need to take care of?

>> +}
>> +
>>  static bool vfio_platform_has_reset(struct vfio_platform_device 
>> *vdev)
>>  {
>>  	return vdev->of_reset ? true : false;
>> @@ -547,6 +574,37 @@ static const struct vfio_device_ops 
>> vfio_platform_ops = {
>>  	.mmap		= vfio_platform_mmap,
>>  };
>> 
>> +int vfio_platform_of_probe(struct vfio_platform_device *vdev,
>> +			   struct device *dev)
>> +{
>> +	int ret;
>> +
>> +	ret = device_property_read_string(dev, "compatible",
>> +					  &vdev->compat);
>> +	if (ret)
>> +		pr_err("VFIO: cannot retrieve compat for %s\n",
>> +			vdev->name);
>> +
>> +	return ret;
>> +}
>> +
>> +/*
>> + * There can be two kernel build combinations. One build where
>> + * ACPI is not selected in Kconfig and another one with the ACPI 
>> Kconfig.
>> + *
>> + * In the first case, vfio_platform_acpi_probe will return since
>> + * acpi_disabled is 1. DT user will not see any kind of messages from
>> + * ACPI.
>> + *
>> + * In the second case, both DT and ACPI is compiled in but the system 
>> is
>> + * booting with any of these combinations.
>> + *
>> + * If the firmware is DT type, then acpi_disabled is 1. The ACPI 
>> probe routine
>> + * terminates immediately without any messages.
>> + *
>> + * If the firmware is ACPI type, then acpi_disabled is 0. All other 
>> checks are
>> + * valid checks. We cannot claim that this system is DT.
>> + */
>>  int vfio_platform_probe_common(struct vfio_platform_device *vdev,
>>  			       struct device *dev)
>>  {
>> @@ -556,11 +614,12 @@ int vfio_platform_probe_common(struct 
>> vfio_platform_device *vdev,
>>  	if (!vdev)
>>  		return -EINVAL;
>> 
>> -	ret = device_property_read_string(dev, "compatible", &vdev->compat);
>> -	if (ret) {
>> -		pr_err("VFIO: cannot retrieve compat for %s\n", vdev->name);
>> -		return -EINVAL;
>> -	}
>> +	ret = vfio_platform_acpi_probe(vdev, dev);
>> +	if (ret)
>> +		ret = vfio_platform_of_probe(vdev, dev);
>> +
>> +	if (ret)
>> +		return ret;
>> 
>>  	vdev->device = dev;
>> 
>> diff --git a/drivers/vfio/platform/vfio_platform_private.h 
>> b/drivers/vfio/platform/vfio_platform_private.h
>> index 71ed7d1..ba9e4f8 100644
>> --- a/drivers/vfio/platform/vfio_platform_private.h
>> +++ b/drivers/vfio/platform/vfio_platform_private.h
>> @@ -58,6 +58,7 @@ struct vfio_platform_device {
>>  	struct mutex			igate;
>>  	struct module			*parent_module;
>>  	const char			*compat;
>> +	const char			*acpihid;
>>  	struct module			*reset_module;
>>  	struct device			*device;
>> 
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Alex Williamson July 19, 2016, 12:24 a.m. UTC | #3
On Mon, 18 Jul 2016 20:16:50 -0400
okaya@codeaurora.org wrote:

> On 2016-07-18 20:00, Alex Williamson wrote:
> > On Mon, 18 Jul 2016 19:09:22 -0400
> > Sinan Kaya <okaya@codeaurora.org> wrote:
> >   
> >> The code is using the compatible DT string to associate a reset driver
> >> with the actual device itself. The compatible string does not exist on
> >> ACPI based systems. HID is the unique identifier for a device driver
> >> instead.
> >> 
> >> Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
> >> ---
> >>  drivers/vfio/platform/vfio_platform_common.c  | 69 
> >> +++++++++++++++++++++++++--
> >>  drivers/vfio/platform/vfio_platform_private.h |  1 +
> >>  2 files changed, 65 insertions(+), 5 deletions(-)
> >> 
> >> diff --git a/drivers/vfio/platform/vfio_platform_common.c 
> >> b/drivers/vfio/platform/vfio_platform_common.c
> >> index 6be92c3..a5299f6 100644
> >> --- a/drivers/vfio/platform/vfio_platform_common.c
> >> +++ b/drivers/vfio/platform/vfio_platform_common.c
> >> @@ -13,6 +13,7 @@
> >>   */
> >> 
> >>  #include <linux/device.h>
> >> +#include <linux/acpi.h>
> >>  #include <linux/iommu.h>
> >>  #include <linux/module.h>
> >>  #include <linux/mutex.h>
> >> @@ -49,6 +50,32 @@ static vfio_platform_reset_fn_t 
> >> vfio_platform_lookup_reset(const char *compat,
> >>  	return reset_fn;
> >>  }
> >> 
> >> +static int vfio_platform_acpi_probe(struct vfio_platform_device 
> >> *vdev,
> >> +				    struct device *dev)
> >> +{
> >> +	struct acpi_device *adev;
> >> +
> >> +	if (acpi_disabled)
> >> +		return -EPERM;
> >> +
> >> +	adev = ACPI_COMPANION(dev);  
> > 
> > I didn't necessarily have a problem with this being set in the
> > declaration.  
> 
> I think this is better. If ACPI is disabled, it is dangerous to call an 
> ACPI API.

Ok, fair enough.

> >   
> >> +	if (!adev) {
> >> +		pr_err("VFIO: ACPI companion device not found for %s\n",
> >> +			vdev->name);
> >> +		return -ENODEV;
> >> +	}
> >> +
> >> +#ifdef CONFIG_ACPI
> >> +	vdev->acpihid = acpi_device_hid(adev);
> >> +	if (!vdev->acpihid) {
> >> +		pr_err("VFIO: cannot find ACPI HID for %s\n",
> >> +		       vdev->name);
> >> +		return -EINVAL;
> >> +	}
> >> +#endif
> >> +	return WARN_ON(!vdev->acpihid) ? -ENOENT : 0;  
> > 
> > ?!?!  The point was that that entire if{} branch is unnecessary.  The
> > WARN_ON handles the (impossible) case of !vdev->acpihid.  We just need:
> > 
> > #ifdef CONFIG_ACPI
> > 	vdev->acpihid = acpi_device_hid(adev);
> > #endif
> > 	return WARN_ON(!vdev->acpihid) ? -ENOENT : 0;
> >   
> 
> OK, got it now. I thought you were trying to get rid of #else
> 
> > nit, might make sense to replace EPERM with ENOENT and use EINVAL here.
> >   
> 
> Sure, will take carr of it.
> 
> Anything else I need to take care of?

Not that I see, maybe just send a new version of this patch if the
changes don't trickle through too much.  Thanks,

Alex

 
> >> +}
> >> +
> >>  static bool vfio_platform_has_reset(struct vfio_platform_device 
> >> *vdev)
> >>  {
> >>  	return vdev->of_reset ? true : false;
> >> @@ -547,6 +574,37 @@ static const struct vfio_device_ops 
> >> vfio_platform_ops = {
> >>  	.mmap		= vfio_platform_mmap,
> >>  };
> >> 
> >> +int vfio_platform_of_probe(struct vfio_platform_device *vdev,
> >> +			   struct device *dev)
> >> +{
> >> +	int ret;
> >> +
> >> +	ret = device_property_read_string(dev, "compatible",
> >> +					  &vdev->compat);
> >> +	if (ret)
> >> +		pr_err("VFIO: cannot retrieve compat for %s\n",
> >> +			vdev->name);
> >> +
> >> +	return ret;
> >> +}
> >> +
> >> +/*
> >> + * There can be two kernel build combinations. One build where
> >> + * ACPI is not selected in Kconfig and another one with the ACPI 
> >> Kconfig.
> >> + *
> >> + * In the first case, vfio_platform_acpi_probe will return since
> >> + * acpi_disabled is 1. DT user will not see any kind of messages from
> >> + * ACPI.
> >> + *
> >> + * In the second case, both DT and ACPI is compiled in but the system 
> >> is
> >> + * booting with any of these combinations.
> >> + *
> >> + * If the firmware is DT type, then acpi_disabled is 1. The ACPI 
> >> probe routine
> >> + * terminates immediately without any messages.
> >> + *
> >> + * If the firmware is ACPI type, then acpi_disabled is 0. All other 
> >> checks are
> >> + * valid checks. We cannot claim that this system is DT.
> >> + */
> >>  int vfio_platform_probe_common(struct vfio_platform_device *vdev,
> >>  			       struct device *dev)
> >>  {
> >> @@ -556,11 +614,12 @@ int vfio_platform_probe_common(struct 
> >> vfio_platform_device *vdev,
> >>  	if (!vdev)
> >>  		return -EINVAL;
> >> 
> >> -	ret = device_property_read_string(dev, "compatible", &vdev->compat);
> >> -	if (ret) {
> >> -		pr_err("VFIO: cannot retrieve compat for %s\n", vdev->name);
> >> -		return -EINVAL;
> >> -	}
> >> +	ret = vfio_platform_acpi_probe(vdev, dev);
> >> +	if (ret)
> >> +		ret = vfio_platform_of_probe(vdev, dev);
> >> +
> >> +	if (ret)
> >> +		return ret;
> >> 
> >>  	vdev->device = dev;
> >> 
> >> diff --git a/drivers/vfio/platform/vfio_platform_private.h 
> >> b/drivers/vfio/platform/vfio_platform_private.h
> >> index 71ed7d1..ba9e4f8 100644
> >> --- a/drivers/vfio/platform/vfio_platform_private.h
> >> +++ b/drivers/vfio/platform/vfio_platform_private.h
> >> @@ -58,6 +58,7 @@ struct vfio_platform_device {
> >>  	struct mutex			igate;
> >>  	struct module			*parent_module;
> >>  	const char			*compat;
> >> +	const char			*acpihid;
> >>  	struct module			*reset_module;
> >>  	struct device			*device;
> >>   

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Sinan Kaya July 19, 2016, 2:49 p.m. UTC | #4
On 7/18/2016 8:24 PM, Alex Williamson wrote:
>>> nit, might make sense to replace EPERM with ENOENT and use EINVAL here.
>>> > >   
>> > 
>> > Sure, will take carr of it.
>> > 
>> > Anything else I need to take care of?
> Not that I see, maybe just send a new version of this patch if the
> changes don't trickle through too much.  Thanks,

I posted V11 with the discussed change. 

[PATCH V11 0/9] vfio, platform: add ACPI support

Do you see this making to 4.8 kernel?
Alex Williamson July 19, 2016, 3:28 p.m. UTC | #5
On Tue, 19 Jul 2016 10:49:54 -0400
Sinan Kaya <okaya@codeaurora.org> wrote:

> On 7/18/2016 8:24 PM, Alex Williamson wrote:
> >>> nit, might make sense to replace EPERM with ENOENT and use EINVAL here.  
> >>> > >     
> >> > 
> >> > Sure, will take carr of it.
> >> > 
> >> > Anything else I need to take care of?  
> > Not that I see, maybe just send a new version of this patch if the
> > changes don't trickle through too much.  Thanks,  
> 
> I posted V11 with the discussed change. 
> 
> [PATCH V11 0/9] vfio, platform: add ACPI support
> 
> Do you see this making to 4.8 kernel?


I hope so, I'll try to get it into my next branch within the next day
or so.  Thanks,

Alex
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Sinan Kaya July 19, 2016, 3:29 p.m. UTC | #6
On 7/19/2016 11:28 AM, Alex Williamson wrote:
> On Tue, 19 Jul 2016 10:49:54 -0400
> Sinan Kaya <okaya@codeaurora.org> wrote:
> 
>> On 7/18/2016 8:24 PM, Alex Williamson wrote:
>>>>> nit, might make sense to replace EPERM with ENOENT and use EINVAL here.  
>>>>>>>     
>>>>>
>>>>> Sure, will take carr of it.
>>>>>
>>>>> Anything else I need to take care of?  
>>> Not that I see, maybe just send a new version of this patch if the
>>> changes don't trickle through too much.  Thanks,  
>>
>> I posted V11 with the discussed change. 
>>
>> [PATCH V11 0/9] vfio, platform: add ACPI support
>>
>> Do you see this making to 4.8 kernel?
> 
> 
> I hope so, I'll try to get it into my next branch within the next day
> or so.  Thanks,
> 
> Alex
> 

Thank you.
diff mbox

Patch

diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c
index 6be92c3..a5299f6 100644
--- a/drivers/vfio/platform/vfio_platform_common.c
+++ b/drivers/vfio/platform/vfio_platform_common.c
@@ -13,6 +13,7 @@ 
  */
 
 #include <linux/device.h>
+#include <linux/acpi.h>
 #include <linux/iommu.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
@@ -49,6 +50,32 @@  static vfio_platform_reset_fn_t vfio_platform_lookup_reset(const char *compat,
 	return reset_fn;
 }
 
+static int vfio_platform_acpi_probe(struct vfio_platform_device *vdev,
+				    struct device *dev)
+{
+	struct acpi_device *adev;
+
+	if (acpi_disabled)
+		return -EPERM;
+
+	adev = ACPI_COMPANION(dev);
+	if (!adev) {
+		pr_err("VFIO: ACPI companion device not found for %s\n",
+			vdev->name);
+		return -ENODEV;
+	}
+
+#ifdef CONFIG_ACPI
+	vdev->acpihid = acpi_device_hid(adev);
+	if (!vdev->acpihid) {
+		pr_err("VFIO: cannot find ACPI HID for %s\n",
+		       vdev->name);
+		return -EINVAL;
+	}
+#endif
+	return WARN_ON(!vdev->acpihid) ? -ENOENT : 0;
+}
+
 static bool vfio_platform_has_reset(struct vfio_platform_device *vdev)
 {
 	return vdev->of_reset ? true : false;
@@ -547,6 +574,37 @@  static const struct vfio_device_ops vfio_platform_ops = {
 	.mmap		= vfio_platform_mmap,
 };
 
+int vfio_platform_of_probe(struct vfio_platform_device *vdev,
+			   struct device *dev)
+{
+	int ret;
+
+	ret = device_property_read_string(dev, "compatible",
+					  &vdev->compat);
+	if (ret)
+		pr_err("VFIO: cannot retrieve compat for %s\n",
+			vdev->name);
+
+	return ret;
+}
+
+/*
+ * There can be two kernel build combinations. One build where
+ * ACPI is not selected in Kconfig and another one with the ACPI Kconfig.
+ *
+ * In the first case, vfio_platform_acpi_probe will return since
+ * acpi_disabled is 1. DT user will not see any kind of messages from
+ * ACPI.
+ *
+ * In the second case, both DT and ACPI is compiled in but the system is
+ * booting with any of these combinations.
+ *
+ * If the firmware is DT type, then acpi_disabled is 1. The ACPI probe routine
+ * terminates immediately without any messages.
+ *
+ * If the firmware is ACPI type, then acpi_disabled is 0. All other checks are
+ * valid checks. We cannot claim that this system is DT.
+ */
 int vfio_platform_probe_common(struct vfio_platform_device *vdev,
 			       struct device *dev)
 {
@@ -556,11 +614,12 @@  int vfio_platform_probe_common(struct vfio_platform_device *vdev,
 	if (!vdev)
 		return -EINVAL;
 
-	ret = device_property_read_string(dev, "compatible", &vdev->compat);
-	if (ret) {
-		pr_err("VFIO: cannot retrieve compat for %s\n", vdev->name);
-		return -EINVAL;
-	}
+	ret = vfio_platform_acpi_probe(vdev, dev);
+	if (ret)
+		ret = vfio_platform_of_probe(vdev, dev);
+
+	if (ret)
+		return ret;
 
 	vdev->device = dev;
 
diff --git a/drivers/vfio/platform/vfio_platform_private.h b/drivers/vfio/platform/vfio_platform_private.h
index 71ed7d1..ba9e4f8 100644
--- a/drivers/vfio/platform/vfio_platform_private.h
+++ b/drivers/vfio/platform/vfio_platform_private.h
@@ -58,6 +58,7 @@  struct vfio_platform_device {
 	struct mutex			igate;
 	struct module			*parent_module;
 	const char			*compat;
+	const char			*acpihid;
 	struct module			*reset_module;
 	struct device			*device;