[PATCH 2/7] drm/amdgpu: put GART away from VRAM v2

[Zhang, Jerry (Junwei)]

On 08/29/2018 10:08 PM, Christian König wrote:
> Always try to put the GART away from where VRAM is.
>
> v2: correctly handle the 4GB limitation
>
> Signed-off-by: Christian König <christian.koenig at amd.com>

Fix my concern :)

Reviewed-by: Junwei Zhang <Jerry.Zhang at amd.com>

> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c | 8 +++++---
>   1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c
> index 265ec6807130..c6bcc4715373 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c
> @@ -116,6 +116,7 @@ void amdgpu_gmc_vram_location(struct amdgpu_device *adev, struct amdgpu_gmc *mc,
>    */
>   void amdgpu_gmc_gart_location(struct amdgpu_device *adev, struct amdgpu_gmc *mc)
>   {
> +	const uint64_t four_gb = 0x100000000ULL;
>   	u64 size_af, size_bf;
>
>   	mc->gart_size += adev->pm.smu_prv_buffer_size;
> @@ -124,8 +125,7 @@ void amdgpu_gmc_gart_location(struct amdgpu_device *adev, struct amdgpu_gmc *mc)
>   	 * the GART base on a 4GB boundary as well.
>   	 */
>   	size_bf = mc->vram_start;
> -	size_af = adev->gmc.mc_mask + 1 -
> -		ALIGN(mc->vram_end + 1, 0x100000000ULL);
> +	size_af = adev->gmc.mc_mask + 1 - ALIGN(mc->vram_end + 1, four_gb);
>
>   	if (mc->gart_size > max(size_bf, size_af)) {
>   		dev_warn(adev->dev, "limiting GART\n");
> @@ -136,7 +136,9 @@ void amdgpu_gmc_gart_location(struct amdgpu_device *adev, struct amdgpu_gmc *mc)
>   	    (size_af < mc->gart_size))
>   		mc->gart_start = 0;
>   	else
> -		mc->gart_start = ALIGN(mc->vram_end + 1, 0x100000000ULL);
> +		mc->gart_start = mc->mc_mask - mc->gart_size + 1;
> +
> +	mc->gart_start &= four_gb - 1;
>   	mc->gart_end = mc->gart_start + mc->gart_size - 1;
>   	dev_info(adev->dev, "GART: %lluM 0x%016llX - 0x%016llX\n",
>   			mc->gart_size >> 20, mc->gart_start, mc->gart_end);
>