Re: [RFC 07/15] drm/xe: Move ASID to FAULT VM lookup to xe_device

[Matthew Brost <matthew.brost@intel.com>]

On Wed, Mar 18, 2026 at 01:14:48PM +0530, Himal Prasad Ghimiray wrote:
> Move xe_pagefault_asid_to_vm() to xe_device.c as
> xe_device_asid_to_fault_vm() for reuse in access counter handling.
> 
> Signed-off-by: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>
> ---
>  drivers/gpu/drm/xe/xe_device.c    | 25 +++++++++++++++++++++++++
>  drivers/gpu/drm/xe/xe_device.h    |  1 +
>  drivers/gpu/drm/xe/xe_pagefault.c | 16 +---------------
>  3 files changed, 27 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_device.c b/drivers/gpu/drm/xe/xe_device.c
> index 8773c2d2f69a..ba2f0e345257 100644
> --- a/drivers/gpu/drm/xe/xe_device.c
> +++ b/drivers/gpu/drm/xe/xe_device.c
> @@ -1399,3 +1399,28 @@ struct xe_vm *xe_device_asid_to_vm(struct xe_device *xe, u32 asid)
>  
>  	return vm;
>  }
> +
> +/**
> + * xe_device_asid_to_fault_vm() - Find FAULT VM from ASID
> + * @xe: the &xe_device
> + * @asid: Address space ID
> + *
> + * Find a FAULTING 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_fault_vm(struct xe_device *xe, u32 asid)

I think the recently merged xe_pagefault_save_to_vm() function can reuse
this function now too.

Patch LGTM to though.

Matt

> +{
> +	struct xe_vm *vm;
> +
> +	down_read(&xe->usm.lock);
> +	vm = xa_load(&xe->usm.asid_to_vm, asid);
> +	if (vm && xe_vm_in_fault_mode(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 c4d267002661..e746f5c7cce0 100644
> --- a/drivers/gpu/drm/xe/xe_device.h
> +++ b/drivers/gpu/drm/xe/xe_device.h
> @@ -209,6 +209,7 @@ int xe_is_injection_active(void);
>  bool xe_is_xe_file(const struct file *file);
>  
>  struct xe_vm *xe_device_asid_to_vm(struct xe_device *xe, u32 asid);
> +struct xe_vm *xe_device_asid_to_fault_vm(struct xe_device *xe, u32 asid);
>  
>  /*
>   * Occasionally it is seen that the G2H worker starts running after a delay of more than
> diff --git a/drivers/gpu/drm/xe/xe_pagefault.c b/drivers/gpu/drm/xe/xe_pagefault.c
> index 8c159e3512ee..a4ee9393e4af 100644
> --- a/drivers/gpu/drm/xe/xe_pagefault.c
> +++ b/drivers/gpu/drm/xe/xe_pagefault.c
> @@ -121,20 +121,6 @@ xe_pagefault_access_is_atomic(enum xe_pagefault_access_type access_type)
>  	return (access_type & XE_PAGEFAULT_ACCESS_TYPE_MASK) == XE_PAGEFAULT_ACCESS_TYPE_ATOMIC;
>  }
>  
> -static struct xe_vm *xe_pagefault_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_in_fault_mode(vm))
> -		xe_vm_get(vm);
> -	else
> -		vm = ERR_PTR(-EINVAL);
> -	up_read(&xe->usm.lock);
> -
> -	return vm;
> -}
>  
>  static int xe_pagefault_service(struct xe_pagefault *pf)
>  {
> @@ -149,7 +135,7 @@ static int xe_pagefault_service(struct xe_pagefault *pf)
>  	if (pf->consumer.fault_type_level == XE_PAGEFAULT_TYPE_LEVEL_NACK)
>  		return -EFAULT;
>  
> -	vm = xe_pagefault_asid_to_vm(xe, pf->consumer.asid);
> +	vm = xe_device_asid_to_fault_vm(xe, pf->consumer.asid);
>  	if (IS_ERR(vm))
>  		return PTR_ERR(vm);
>  
> -- 
> 2.34.1
>