[PATCH v4 1/1] drm/amd/display: add DCN support for ARM64

[Rodrigo Siqueira Jordao]

On 2022-10-31 15:37, Ao Zhong wrote:
> After moving all FPU code to the DML folder, we can enable DCN support
> for the ARM64 platform. Remove the -mgeneral-regs-only CFLAG from the
> code in the DML folder that needs to use hardware FPU, and add a control
> mechanism for ARM Neon.
> 
> Signed-off-by: Ao Zhong <hacc1225 at gmail.com>
> ---
>   drivers/gpu/drm/amd/display/Kconfig           |  3 ++-
>   .../gpu/drm/amd/display/amdgpu_dm/dc_fpu.c    |  6 ++++++
>   drivers/gpu/drm/amd/display/dc/dml/Makefile   | 20 +++++++++++++++----
>   3 files changed, 24 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/amd/display/Kconfig b/drivers/gpu/drm/amd/display/Kconfig
> index 0142affcdaa3..843a55a6a3ac 100644
> --- a/drivers/gpu/drm/amd/display/Kconfig
> +++ b/drivers/gpu/drm/amd/display/Kconfig
> @@ -6,7 +6,8 @@ config DRM_AMD_DC
>   	bool "AMD DC - Enable new display engine"
>   	default y
>   	select SND_HDA_COMPONENT if SND_HDA_CORE
> -	select DRM_AMD_DC_DCN if (X86 || PPC64)
> +	# !CC_IS_CLANG: https://github.com/ClangBuiltLinux/linux/issues/1752
> +	select DRM_AMD_DC_DCN if (X86 || PPC64 || (ARM64 && KERNEL_MODE_NEON && !CC_IS_CLANG))
>   	help
>   	  Choose this option if you want to use the new display engine
>   	  support for AMDGPU. This adds required support for Vega and
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/dc_fpu.c b/drivers/gpu/drm/amd/display/amdgpu_dm/dc_fpu.c
> index ab0c6d191038..1743ca0a3641 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/dc_fpu.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/dc_fpu.c
> @@ -31,6 +31,8 @@
>   #elif defined(CONFIG_PPC64)
>   #include <asm/switch_to.h>
>   #include <asm/cputable.h>
> +#elif defined(CONFIG_ARM64)
> +#include <asm/neon.h>
>   #endif
>   
>   /**
> @@ -99,6 +101,8 @@ void dc_fpu_begin(const char *function_name, const int line)
>   			preempt_disable();
>   			enable_kernel_fp();
>   		}
> +#elif defined(CONFIG_ARM64)
> +		kernel_neon_begin();
>   #endif
>   	}
>   
> @@ -136,6 +140,8 @@ void dc_fpu_end(const char *function_name, const int line)
>   			disable_kernel_fp();
>   			preempt_enable();
>   		}
> +#elif defined(CONFIG_ARM64)
> +		kernel_neon_end();
>   #endif
>   	}
>   
> diff --git a/drivers/gpu/drm/amd/display/dc/dml/Makefile b/drivers/gpu/drm/amd/display/dc/dml/Makefile
> index d0c6cf61c676..d4e93bed1c8e 100644
> --- a/drivers/gpu/drm/amd/display/dc/dml/Makefile
> +++ b/drivers/gpu/drm/amd/display/dc/dml/Makefile
> @@ -33,6 +33,10 @@ ifdef CONFIG_PPC64
>   dml_ccflags := -mhard-float -maltivec
>   endif
>   
> +ifdef CONFIG_ARM64
> +dml_rcflags := -mgeneral-regs-only
> +endif
> +
>   ifdef CONFIG_CC_IS_GCC
>   ifeq ($(call cc-ifversion, -lt, 0701, y), y)
>   IS_OLD_GCC = 1
> @@ -55,8 +59,6 @@ frame_warn_flag := -Wframe-larger-than=2048
>   endif
>   
>   CFLAGS_$(AMDDALPATH)/dc/dml/display_mode_lib.o := $(dml_ccflags)
> -
> -ifdef CONFIG_DRM_AMD_DC_DCN
>   CFLAGS_$(AMDDALPATH)/dc/dml/display_mode_vba.o := $(dml_ccflags)
>   CFLAGS_$(AMDDALPATH)/dc/dml/dcn10/dcn10_fpu.o := $(dml_ccflags)
>   CFLAGS_$(AMDDALPATH)/dc/dml/dcn20/dcn20_fpu.o := $(dml_ccflags)
> @@ -88,7 +90,6 @@ CFLAGS_$(AMDDALPATH)/dc/dml/calcs/dcn_calcs.o := $(dml_ccflags)
>   CFLAGS_$(AMDDALPATH)/dc/dml/calcs/dcn_calc_auto.o := $(dml_ccflags)
>   CFLAGS_$(AMDDALPATH)/dc/dml/calcs/dcn_calc_math.o := $(dml_ccflags) -Wno-tautological-compare
>   CFLAGS_REMOVE_$(AMDDALPATH)/dc/dml/display_mode_vba.o := $(dml_rcflags)
> -CFLAGS_REMOVE_$(AMDDALPATH)/dc/dml/dcn2x/dcn2x.o := $(dml_rcflags)
>   CFLAGS_REMOVE_$(AMDDALPATH)/dc/dml/dcn20/display_mode_vba_20.o := $(dml_rcflags)
>   CFLAGS_REMOVE_$(AMDDALPATH)/dc/dml/dcn20/display_rq_dlg_calc_20.o := $(dml_rcflags)
>   CFLAGS_REMOVE_$(AMDDALPATH)/dc/dml/dcn20/display_mode_vba_20v2.o := $(dml_rcflags)
> @@ -105,7 +106,18 @@ CFLAGS_REMOVE_$(AMDDALPATH)/dc/dml/dcn32/display_mode_vba_util_32.o := $(dml_rcf
>   CFLAGS_REMOVE_$(AMDDALPATH)/dc/dml/dcn301/dcn301_fpu.o := $(dml_rcflags)
>   CFLAGS_REMOVE_$(AMDDALPATH)/dc/dml/display_mode_lib.o := $(dml_rcflags)
>   CFLAGS_REMOVE_$(AMDDALPATH)/dc/dml/dsc/rc_calc_fpu.o  := $(dml_rcflags)
> -endif
> +CFLAGS_REMOVE_$(AMDDALPATH)/dc/dml/dcn10/dcn10_fpu.o := $(dml_rcflags)
> +CFLAGS_REMOVE_$(AMDDALPATH)/dc/dml/dcn20/dcn20_fpu.o := $(dml_rcflags)
> +CFLAGS_REMOVE_$(AMDDALPATH)/dc/dml/dcn314/display_mode_vba_314.o := $(dml_rcflags)
> +CFLAGS_REMOVE_$(AMDDALPATH)/dc/dml/dcn314/display_rq_dlg_calc_314.o := $(dml_rcflags)
> +CFLAGS_REMOVE_$(AMDDALPATH)/dc/dml/dcn314/dcn314_fpu.o := $(dml_rcflags)
> +CFLAGS_REMOVE_$(AMDDALPATH)/dc/dml/dcn30/dcn30_fpu.o := $(dml_rcflags)
> +CFLAGS_REMOVE_$(AMDDALPATH)/dc/dml/dcn32/dcn32_fpu.o := $(dml_rcflags)
> +CFLAGS_REMOVE_$(AMDDALPATH)/dc/dml/dcn321/dcn321_fpu.o := $(dml_rcflags)
> +CFLAGS_REMOVE_$(AMDDALPATH)/dc/dml/dcn31/dcn31_fpu.o := $(dml_rcflags)
> +CFLAGS_REMOVE_$(AMDDALPATH)/dc/dml/dcn302/dcn302_fpu.o := $(dml_rcflags)
> +CFLAGS_REMOVE_$(AMDDALPATH)/dc/dml/dcn303/dcn303_fpu.o := $(dml_rcflags)
> +CFLAGS_REMOVE_$(AMDDALPATH)/dc/dml/calcs/dcn_calc_math.o := $(dml_rcflags)
>   CFLAGS_$(AMDDALPATH)/dc/dml/dml1_display_rq_dlg_calc.o := $(dml_ccflags)
>   CFLAGS_$(AMDDALPATH)/dc/dml/display_rq_dlg_helpers.o := $(dml_ccflags)
>   CFLAGS_REMOVE_$(AMDDALPATH)/dc/dml/dml1_display_rq_dlg_calc.o := $(dml_rcflags)

lgtm,

Reviewed-by: Rodrigo Siqueira <Rodrigo.Siqueira at amd.com>

Nathan,

If it is ok for you, I can merge this change.

Thanks
Siqueira