On 2018-08-27 12:53 PM, Christian König wrote:
> Helper to figure out the location of the AGP BAR.
>
> Signed-off-by: Christian König <christian.koenig at amd.com>
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c | 42 +++++++++++++++++++++++++
> drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.h | 5 +++
> 2 files changed, 47 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c
> index 4331a0e25cdc..eed5352f3136 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c
> @@ -141,3 +141,45 @@ 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 fina a place for the AGP BAR in the MC address
s/fina/find
> + * space.
> + *
> + * AGP BAR will be assigned the largest available hole in the address space.
I'd add a comment that this function must be called after
amdgpu_gmc_vram_location and amdgpu_gmc_gart_location.
> + */
> +void amdgpu_gmc_agp_location(struct amdgpu_device *adev, struct amdgpu_gmc *mc)
> +{
> + const uint64_t sixteen_gb = 1ULL << 34;
> + u64 size_af, size_bf;
> +
> + if (mc->vram_start > mc->gart_start) {
> + size_bf = mc->vram_start - mc->gart_end + 1;
> + size_af = mc->mc_mask - mc->vram_end;
> + } else {
> + size_bf = mc->vram_start;
> + size_af = mc->mc_mask - mc->gart_end;
> + }
> +
> + size_bf &= ~(sixteen_gb - 1);
> + size_af &= ~(sixteen_gb - 1);
This is not correct. E.g. vram_end = 12GB, gart_start = 28GB, size =
16GB. agp_start will be rounded up to 16GB and AGP will run into the
GART aperture.
You need to align the addresses before calculating the sizes.
Regards,
 Felix
> +
> + if (size_bf > size_af) {
> + mc->agp_start = mc->vram_start > mc->gart_start ?
> + mc->gart_start : 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 72fcc9338f5e..163110fe375d 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.h
> @@ -81,6 +81,9 @@ 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;
> @@ -138,5 +141,7 @@ 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
