[PATCH 2/7] drm/amdgpu: add amdgpu module parameter for zfb

[Christian König]

Am 15.05.2018 um 16:50 schrieb Alex Deucher:
> From: Feifei Xu <Feifei.Xu at amd.com>
>
> Users can pass in an array to decide enable/disable Zero Frame Buffer.
> zfb[0] = zfb_size(MB), zfb[1] = zfb_phys_addr(MB).
> If zbf_size > 0, zfb is enabled. Otherwise disabled.
> Usage for example:
>      modprobe amdgpu zfb=256,4096

I still vote for using the CMA instead of this hack for that.

Should be trivial to implement and is far less error prone than manually 
messing with memory configuration.

Christian.

>
> Signed-off-by: Feifei Xu <Feifei.Xu at amd.com>
> Acked-by: John Bridgman <john.bridgman at amd.com>
> Reviewed-by: Alex Deucher <alexander.deucher at amd.com>
> Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu.h     | 1 +
>   drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c | 4 ++++
>   2 files changed, 5 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> index 2d7500921c0b..dc55b73cbeed 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> @@ -130,6 +130,7 @@ extern int amdgpu_compute_multipipe;
>   extern int amdgpu_gpu_recovery;
>   extern int amdgpu_emu_mode;
>   extern uint amdgpu_smu_memory_pool_size;
> +extern ulong amdgpu_zfb[];
>   
>   #ifdef CONFIG_DRM_AMDGPU_SI
>   extern int amdgpu_si_support;
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> index 739e7e09c8b0..a7a81ddab721 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> @@ -134,6 +134,7 @@ int amdgpu_compute_multipipe = -1;
>   int amdgpu_gpu_recovery = -1; /* auto */
>   int amdgpu_emu_mode = 0;
>   uint amdgpu_smu_memory_pool_size = 0;
> +ulong amdgpu_zfb[2] = {0,4096UL}; /* {0,0x100000000} */
>   
>   MODULE_PARM_DESC(vramlimit, "Restrict VRAM for testing, in megabytes");
>   module_param_named(vramlimit, amdgpu_vram_limit, int, 0600);
> @@ -292,6 +293,9 @@ module_param_named(gpu_recovery, amdgpu_gpu_recovery, int, 0444);
>   MODULE_PARM_DESC(emu_mode, "Emulation mode, (1 = enable, 0 = disable)");
>   module_param_named(emu_mode, amdgpu_emu_mode, int, 0444);
>   
> +MODULE_PARM_DESC(zfb,
> +    "Enable Zero Frame Buffer feature (zfb will be set like xxxx,xxxx(zfb_size MB,zfb_phys_addr MB),default disabled)");
> +module_param_array_named(zfb, amdgpu_zfb, ulong, NULL, 0444);
>   #ifdef CONFIG_DRM_AMDGPU_SI
>   
>   #if defined(CONFIG_DRM_RADEON) || defined(CONFIG_DRM_RADEON_MODULE)