[Intel-gfx] [PATCH RFC 2/4] drm/i915: IOMMU based SVM implementation v13

[Chris Wilson]

On Mon, Aug 15, 2016 at 02:48:05PM +0300, Mika Kuoppala wrote:
> @@ -891,6 +894,8 @@ struct i915_gem_context {
>  	unsigned long flags;
>  #define CONTEXT_NO_ZEROMAP		BIT(0)
>  #define CONTEXT_NO_ERROR_CAPTURE	BIT(1)
> +#define CONTEXT_SVM			BIT(2)
> +
>  	unsigned hw_id;
>  	u32 user_handle;
>  
> @@ -909,6 +914,9 @@ struct i915_gem_context {
>  	struct atomic_notifier_head status_notifier;
>  	bool execlists_force_single_submission;
>  
> +	u32 pasid; /* svm, 20 bits */

Doesn't this conflict with hw_id for execlists.

> +	struct task_struct *task;

We don't need the task, we need the mm.

Holding the task is not sufficient.

>  	struct list_head link;
>  
>  	u8 remap_slice;
> @@ -2001,6 +2009,8 @@ struct drm_i915_private {
>  
>  	struct i915_runtime_pm pm;
>  
> +	bool svm_available;

No better home / community?

> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> index 7e08c774a1aa..45d67b54c018 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -4304,6 +4304,13 @@ i915_gem_init_hw(struct drm_device *dev)
>  		}
>  	}
>  
> +	if (INTEL_GEN(dev) >= 8) {
> +		if (intel_init_svm(dev))

init_hw ?

This looks more like one off early driver init.

> +			DRM_DEBUG_DRIVER("Initialized Intel SVM support\n");
> +		else
> +			DRM_ERROR("Failed to enable Intel SVM support\n");
> +	}
> +

-- 
Chris Wilson, Intel Open Source Technology Centre