[PATCH 2/9] drm/xe: Convert xe_gem_fault to use direct xe_pm_runtime calls

[Matthew Auld]

On 04/03/2024 18:21, Rodrigo Vivi wrote:
> The gem page fault is one of the outer bound protections where
> we want to ensure that the hardware is in D0 before proceeding
> with memory access. Let's convert it towards the xe_pm_runtime
> functions directly so we can then convert the mem_access to be
> inner protection only and then Kill it for good.
> 
> Signed-off-by: Rodrigo Vivi <rodrigo.vivi at intel.com>

Not strictly related to this, but FYI there is:

https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/1100
https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/1300

Which is on the GPU fault path. Looks like VM is maybe nuked before the 
worker can process the fault from the GuC? In that case there no RPM ref.

> ---
>   drivers/gpu/drm/xe/xe_bo.c | 5 +++--
>   1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_bo.c b/drivers/gpu/drm/xe/xe_bo.c
> index 6603a0ea79c5..def68528cd40 100644
> --- a/drivers/gpu/drm/xe/xe_bo.c
> +++ b/drivers/gpu/drm/xe/xe_bo.c
> @@ -22,6 +22,7 @@
>   #include "xe_gt.h"
>   #include "xe_map.h"
>   #include "xe_migrate.h"
> +#include "xe_pm.h"
>   #include "xe_preempt_fence.h"
>   #include "xe_res_cursor.h"
>   #include "xe_trace.h"
> @@ -1144,7 +1145,7 @@ static vm_fault_t xe_gem_fault(struct vm_fault *vmf)
>   	int idx, r = 0;
>   
>   	if (needs_rpm)
> -		xe_device_mem_access_get(xe);
> +		xe_pm_runtime_get(xe);
>   
>   	ret = ttm_bo_vm_reserve(tbo, vmf);
>   	if (ret)
> @@ -1184,7 +1185,7 @@ static vm_fault_t xe_gem_fault(struct vm_fault *vmf)
>   	dma_resv_unlock(tbo->base.resv);
>   out:
>   	if (needs_rpm)
> -		xe_device_mem_access_put(xe);
> +		xe_pm_runtime_put(xe);
>   
>   	return ret;
>   }