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

[Rodrigo Siqueira Jordao]

On 2022-11-01 12:31, Nathan Chancellor wrote:
> On Tue, Nov 01, 2022 at 10:36:08AM -0400, Rodrigo Siqueira Jordao wrote:
>>
>>
>> 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.
> 
> Yes, this version looks good to me, as the code can no longer be built
> for arm64 when using clang.
> 
> Cheers,
> Nathan

I just merged this patch to amd-staging-drm-next.

Thanks
Siqueira