Re: [PATCH v2 03/12] drm/xe: Add xe_device_asid_to_vm helper

[Matt Atwood <matthew.s.atwood@intel.com>]

On Tue, Nov 04, 2025 at 11:56:07AM -0800, Matthew Brost wrote:
> Introduce the xe_device_asid_to_vm helper, which can be used throughout
> the driver to resolve the VM from a given ASID.
> 
> Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Matt Atwood <matthew.s.atwood@intel.com>
> ---
>  drivers/gpu/drm/xe/xe_device.c | 25 +++++++++++++++++++++++++
>  drivers/gpu/drm/xe/xe_device.h |  4 ++++
>  2 files changed, 29 insertions(+)
> 
> diff --git a/drivers/gpu/drm/xe/xe_device.c b/drivers/gpu/drm/xe/xe_device.c
> index 86d5960476af..57907904c49d 100644
> --- a/drivers/gpu/drm/xe/xe_device.c
> +++ b/drivers/gpu/drm/xe/xe_device.c
> @@ -1290,3 +1290,28 @@ void xe_device_declare_wedged(struct xe_device *xe)
>  		drm_dev_wedged_event(&xe->drm, xe->wedged.method, NULL);
>  	}
>  }
> +
> +/**
> + * xe_device_asid_to_vm() - Find VM from ASID
> + * @xe: the &xe_device
> + * @asid: Address space ID
> + *
> + * Find a VM from ASID and take a reference to VM which caller must drop.
> + * Reclaim safe.
> + *
> + * Return: VM on success, ERR_PTR on failure
> + */
> +struct xe_vm *xe_device_asid_to_vm(struct xe_device *xe, u32 asid)
> +{
> +	struct xe_vm *vm;
> +
> +	down_read(&xe->usm.lock);
> +	vm = xa_load(&xe->usm.asid_to_vm, asid);
> +	if (vm)
> +		xe_vm_get(vm);
> +	else
> +		vm = ERR_PTR(-EINVAL);
> +	up_read(&xe->usm.lock);
> +
> +	return vm;
> +}
> diff --git a/drivers/gpu/drm/xe/xe_device.h b/drivers/gpu/drm/xe/xe_device.h
> index 32cc6323b7f6..538202eebc16 100644
> --- a/drivers/gpu/drm/xe/xe_device.h
> +++ b/drivers/gpu/drm/xe/xe_device.h
> @@ -6,6 +6,8 @@
>  #ifndef _XE_DEVICE_H_
>  #define _XE_DEVICE_H_
>  
> +struct xe_vm;
> +
>  #include <drm/drm_util.h>
>  
>  #include "xe_device_types.h"
> @@ -195,6 +197,8 @@ void xe_file_put(struct xe_file *xef);
>  
>  int xe_is_injection_active(void);
>  
> +struct xe_vm *xe_device_asid_to_vm(struct xe_device *xe, u32 asid);
> +
>  /*
>   * Occasionally it is seen that the G2H worker starts running after a delay of more than
>   * a second even after being queued and activated by the Linux workqueue subsystem. This
> -- 
> 2.34.1
>