[PATCH 3/7] drm/amdgpu: add amdgpu_gmc_agp_location v2

[Zhang, Jerry (Junwei)]

On 08/29/2018 10:08 PM, Christian König wrote:
> Helper to figure out the location of the AGP BAR.
>
> v2: fix a couple of bugs
>
> Signed-off-by: Christian König <christian.koenig at amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c | 43 +++++++++++++++++++++++++
>   drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.h |  5 +++
>   2 files changed, 48 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c
> index c6bcc4715373..1d201fd3f4af 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c
> @@ -143,3 +143,46 @@ void amdgpu_gmc_gart_location(struct amdgpu_device *adev, struct amdgpu_gmc *mc)
>   	dev_info(adev->dev, "GART: %lluM 0x%016llX - 0x%016llX\n",
>   			mc->gart_size >> 20, mc->gart_start, mc->gart_end);
>   }
> +
> +/**
> + * amdgpu_gmc_agp_location - try to find AGP location
> + * @adev: amdgpu device structure holding all necessary informations
> + * @mc: memory controller structure holding memory informations
> + *
> + * Function will place try to find a place for the AGP BAR in the MC address
> + * space.
> + *
> + * AGP BAR will be assigned the largest available hole in the address space.
> + * Should be called after VRAM and GART locations are setup.
> + */
> +void amdgpu_gmc_agp_location(struct amdgpu_device *adev, struct amdgpu_gmc *mc)
> +{
> +	const uint64_t sixteen_gb = 1ULL << 34;
> +	const uint64_t sixteen_gb_mask = ~(sixteen_gb - 1);
> +	u64 size_af, size_bf;
> +
> +	if (mc->vram_start > mc->gart_start) {
> +		size_bf = (mc->vram_start & sixteen_gb_mask) -
> +			ALIGN(mc->gart_end + 1, sixteen_gb);
> +		size_af = mc->mc_mask + 1 - ALIGN(mc->vram_end, sixteen_gb);
> +	} else {
> +		size_bf = mc->vram_start & sixteen_gb_mask;
> +		size_af = (mc->gart_start & sixteen_gb_mask) -
> +			ALIGN(mc->vram_end, sixteen_gb);

we may need ALIGN(mc->vram_end + 1, sixteen_gb) for size_af.

> +	}
> +
> +	if (size_bf > size_af) {
> +		mc->agp_start = mc->vram_start > mc->gart_start ?
> +			mc->gart_end + 1 : 0;
> +		mc->agp_size = size_bf;
> +	} else {
> +		mc->agp_start = (mc->vram_start > mc->gart_start ?
> +			mc->vram_end : mc->gart_end) + 1,
> +		mc->agp_size = size_af;
> +	}
> +
> +	mc->agp_start = ALIGN(mc->agp_start, sixteen_gb);
> +	mc->agp_end = mc->agp_start + mc->agp_size - 1;
> +	dev_info(adev->dev, "AGP: %lluM 0x%016llX - 0x%016llX\n",
> +			mc->agp_size >> 20, mc->agp_start, mc->agp_end);
> +}
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.h
> index 48715dd5808a..c9985e7dc9e5 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.h
> @@ -94,6 +94,9 @@ struct amdgpu_gmc {
>   	 * about vram size near mc fb location */
>   	u64			mc_vram_size;
>   	u64			visible_vram_size;
> +	u64			agp_size;
> +	u64			agp_start;
> +	u64			agp_end;
>   	u64			gart_size;
>   	u64			gart_start;
>   	u64			gart_end;
> @@ -164,5 +167,7 @@ void amdgpu_gmc_vram_location(struct amdgpu_device *adev, struct amdgpu_gmc *mc,
>   			      u64 base);
>   void amdgpu_gmc_gart_location(struct amdgpu_device *adev,
>   			      struct amdgpu_gmc *mc);
> +void amdgpu_gmc_agp_location(struct amdgpu_device *adev,
> +			     struct amdgpu_gmc *mc);
>
>   #endif
>