[PATCH 1/4] drm/amdgpu/gmc9: rework stolen vga memory handling

[Zhang, Jerry (Junwei)]

On 08/30/2018 10:53 PM, Alex Deucher wrote:
> No functional change, just rework it in order to adjust the
> behavior on a per asic level.  The problem is that on vega10,
> something corrupts the lower 8 MB of vram on the second
> resume from S3.  This does not seem to affect Raven, other
> gmc9 based asics need testing.
>
> Signed-off-by: Alex Deucher <alexander.deucher at amd.com>

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

> ---
>   drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c | 48 +++++++++++++++++++++--------------
>   1 file changed, 29 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
> index 04d50893a6f2..46cff7d8b375 100644
> --- a/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
> @@ -692,6 +692,28 @@ static int gmc_v9_0_ecc_available(struct amdgpu_device *adev)
>   	return lost_sheep == 0;
>   }
>
> +static bool gmc_v9_0_keep_stolen_memory(struct amdgpu_device *adev)
> +{
> +
> +	/*
> +	 * TODO:
> +	 * Currently there is a bug where some memory client outside
> +	 * of the driver writes to first 8M of VRAM on S3 resume,
> +	 * this overrides GART which by default gets placed in first 8M and
> +	 * causes VM_FAULTS once GTT is accessed.
> +	 * Keep the stolen memory reservation until the while this is not solved.
> +	 * Also check code in gmc_v9_0_get_vbios_fb_size and gmc_v9_0_late_init
> +	 */
> +	switch (adev->asic_type) {
> +	case CHIP_RAVEN:
> +	case CHIP_VEGA10:
> +	case CHIP_VEGA12:
> +	case CHIP_VEGA20:
> +	default:
> +		return true;
> +	}
> +}
> +
>   static int gmc_v9_0_late_init(void *handle)
>   {
>   	struct amdgpu_device *adev = (struct amdgpu_device *)handle;
> @@ -708,10 +730,8 @@ static int gmc_v9_0_late_init(void *handle)
>   	unsigned i;
>   	int r;
>
> -	/*
> -	 * TODO - Uncomment once GART corruption issue is fixed.
> -	 */
> -	/* amdgpu_bo_late_init(adev); */
> +	if (!gmc_v9_0_keep_stolen_memory(adev))
> +		amdgpu_bo_late_init(adev);
>
>   	for(i = 0; i < adev->num_rings; ++i) {
>   		struct amdgpu_ring *ring = adev->rings[i];
> @@ -848,18 +868,16 @@ static int gmc_v9_0_gart_init(struct amdgpu_device *adev)
>
>   static unsigned gmc_v9_0_get_vbios_fb_size(struct amdgpu_device *adev)
>   {
> -#if 0
>   	u32 d1vga_control = RREG32_SOC15(DCE, 0, mmD1VGA_CONTROL);
> -#endif
>   	unsigned size;
>
>   	/*
>   	 * TODO Remove once GART corruption is resolved
>   	 * Check related code in gmc_v9_0_sw_fini
>   	 * */
> -	size = 9 * 1024 * 1024;
> +	if (gmc_v9_0_keep_stolen_memory(adev))
> +		return 9 * 1024 * 1024;
>
> -#if 0
>   	if (REG_GET_FIELD(d1vga_control, D1VGA_CONTROL, D1VGA_MODE_ENABLE)) {
>   		size = 9 * 1024 * 1024; /* reserve 8MB for vga emulator and 1 MB for FB */
>   	} else {
> @@ -876,6 +894,7 @@ static unsigned gmc_v9_0_get_vbios_fb_size(struct amdgpu_device *adev)
>   			break;
>   		case CHIP_VEGA10:
>   		case CHIP_VEGA12:
> +		case CHIP_VEGA20:
>   		default:
>   			viewport = RREG32_SOC15(DCE, 0, mmSCL0_VIEWPORT_SIZE);
>   			size = (REG_GET_FIELD(viewport, SCL0_VIEWPORT_SIZE, VIEWPORT_HEIGHT) *
> @@ -888,7 +907,6 @@ static unsigned gmc_v9_0_get_vbios_fb_size(struct amdgpu_device *adev)
>   	if ((adev->gmc.real_vram_size - size) < (8 * 1024 * 1024))
>   		return 0;
>
> -#endif
>   	return size;
>   }
>
> @@ -1000,16 +1018,8 @@ static int gmc_v9_0_sw_fini(void *handle)
>   	amdgpu_gem_force_release(adev);
>   	amdgpu_vm_manager_fini(adev);
>
> -	/*
> -	* TODO:
> -	* Currently there is a bug where some memory client outside
> -	* of the driver writes to first 8M of VRAM on S3 resume,
> -	* this overrides GART which by default gets placed in first 8M and
> -	* causes VM_FAULTS once GTT is accessed.
> -	* Keep the stolen memory reservation until the while this is not solved.
> -	* Also check code in gmc_v9_0_get_vbios_fb_size and gmc_v9_0_late_init
> -	*/
> -	amdgpu_bo_free_kernel(&adev->stolen_vga_memory, NULL, NULL);
> +	if (gmc_v9_0_keep_stolen_memory(adev))
> +		amdgpu_bo_free_kernel(&adev->stolen_vga_memory, NULL, NULL);
>
>   	amdgpu_gart_table_vram_free(adev);
>   	amdgpu_bo_fini(adev);
>