* [PATCH v2 0/1] drm/amd/display: add DCN support for ARM64
@ 2022-10-27 14:45 Ao Zhong
2022-10-27 14:45 ` [PATCH v2 1/1] " Ao Zhong
0 siblings, 1 reply; 3+ messages in thread
From: Ao Zhong @ 2022-10-27 14:45 UTC (permalink / raw)
To: Harry Wentland, Leo Li, Rodrigo Siqueira, Arnd Bergmann,
Nathan Chancellor, Alex Deucher, Stephen Rothwell,
Christian König
Cc: Ao Zhong, linux-arm-kernel, amd-gfx
Hello everyone,
Recently I got a SBSA ARM64 workstation, and try to use it as my daily
drive machine after installing an AMD RX6400 graphics card.
Since the newer AMD GPUs require DCN (Display Core Next) support to work
properly, DCN is not supported on ARM64 platforms. Because some code in
DCN needs to use FPU, and aarch64 has no soft floating-point toolchain.
Displaycore developers have started isolating code that needs to use
FPU, and most of the code has been isolated. In the process of trying to
enable DCN support for the ARM64 platform, I found that there are two
remaining code blocks that are not isolated. Due to -mgeneral-regs-only
is enabled by default to compile the kernel on the ARM64 platform, these
two code blocks will cause the compilation to fail after enabling DCN
support.
I have submitted two patches to isolate the remaining two code blocks
that need to use the FPU.
Links: https://patchwork.freedesktop.org/patch/508813/
Links: https://patchwork.freedesktop.org/patch/508816/
After merging these two patches, we can enable DCN support for ARM64
platform.
I removed -mgeneral-regs-only CFLAG in the dml/Makefile for the code
that needs to use hardware FPU, and add a control mechanism in
amdgpu_dm/dc_fpu.c for ARM Neon.
Change Since V1:
replace $(dml_rcflags_arm64) with $(dml_rcflags) in dml/Makefile
Ao Zhong (1):
drm/amd/display: add DCN support for ARM64
drivers/gpu/drm/amd/display/Kconfig | 2 +-
.../gpu/drm/amd/display/amdgpu_dm/dc_fpu.c | 6 ++++++
drivers/gpu/drm/amd/display/dc/dml/Makefile | 21 ++++++++++++++++++-
3 files changed, 27 insertions(+), 2 deletions(-)
--
2.37.4
^ permalink raw reply [flat|nested] 3+ messages in thread
* [PATCH v2 1/1] drm/amd/display: add DCN support for ARM64
2022-10-27 14:45 [PATCH v2 0/1] drm/amd/display: add DCN support for ARM64 Ao Zhong
@ 2022-10-27 14:45 ` Ao Zhong
2022-10-27 15:07 ` Arnd Bergmann
0 siblings, 1 reply; 3+ messages in thread
From: Ao Zhong @ 2022-10-27 14:45 UTC (permalink / raw)
To: Harry Wentland, Leo Li, Rodrigo Siqueira, Arnd Bergmann,
Nathan Chancellor, Alex Deucher, Stephen Rothwell,
Christian König
Cc: Ao Zhong, linux-arm-kernel, amd-gfx
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@gmail.com>
---
drivers/gpu/drm/amd/display/Kconfig | 2 +-
.../gpu/drm/amd/display/amdgpu_dm/dc_fpu.c | 6 ++++++
drivers/gpu/drm/amd/display/dc/dml/Makefile | 21 ++++++++++++++++++-
3 files changed, 27 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/amd/display/Kconfig b/drivers/gpu/drm/amd/display/Kconfig
index 0142affcdaa3..a7f1c4e51719 100644
--- a/drivers/gpu/drm/amd/display/Kconfig
+++ b/drivers/gpu/drm/amd/display/Kconfig
@@ -6,7 +6,7 @@ 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)
+ select DRM_AMD_DC_DCN if (X86 || PPC64 || (ARM64 && KERNEL_MODE_NEON))
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..4e6e1fc0650f 100644
--- a/drivers/gpu/drm/amd/display/dc/dml/Makefile
+++ b/drivers/gpu/drm/amd/display/dc/dml/Makefile
@@ -33,6 +33,12 @@ ifdef CONFIG_PPC64
dml_ccflags := -mhard-float -maltivec
endif
+ifdef CONFIG_ARM64
+ifdef CONFIG_DRM_AMD_DC_DCN
+dml_rcflags := -mgeneral-regs-only
+endif
+endif
+
ifdef CONFIG_CC_IS_GCC
ifeq ($(call cc-ifversion, -lt, 0701, y), y)
IS_OLD_GCC = 1
@@ -88,7 +94,6 @@ 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 := $(dml_rcflags)
@@ -105,6 +110,20 @@ CFLAGS_REMOVE_$(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 := $(dml_rcflags)
+ifdef CONFIG_ARM64
+CFLAGS_REMOVE_$(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 := $(dml_rcflags)
+endif
endif
CFLAGS_$(AMDDALPATH)/dc/dml/dml1_display_rq_dlg_calc.o := $(dml_ccflags)
CFLAGS_$(AMDDALPATH)/dc/dml/display_rq_dlg_helpers.o := $(dml_ccflags)
--
2.37.4
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH v2 1/1] drm/amd/display: add DCN support for ARM64
2022-10-27 14:45 ` [PATCH v2 1/1] " Ao Zhong
@ 2022-10-27 15:07 ` Arnd Bergmann
0 siblings, 0 replies; 3+ messages in thread
From: Arnd Bergmann @ 2022-10-27 15:07 UTC (permalink / raw)
To: Ao Zhong, Harry Wentland, Leo Li, Rodrigo Siqueira,
Nathan Chancellor, Alex Deucher, Stephen Rothwell,
Christian König
Cc: linux-arm-kernel, amd-gfx
On Thu, Oct 27, 2022, at 16:45, Ao Zhong wrote:
> After moving all FPU code to the DML folder, we can enable DCN support
> for the ARM64 platform. Remove the -mgeneral-regs-only CFLAG from the
> code in the DML folder that needs to use hardware FPU, and add a control
> mechanism for ARM Neon.
>
> Signed-off-by: Ao Zhong <hacc1225@gmail.com>
>
> +ifdef CONFIG_ARM64
> +ifdef CONFIG_DRM_AMD_DC_DCN
> +dml_rcflags := -mgeneral-regs-only
> +endif
> +endif
I don't think the CONFIG_DRM_AMD_DC_DCN check is needed here,
if the dml_ccflags doesn't have this.
> +ifdef CONFIG_ARM64
> +CFLAGS_REMOVE_$(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 :=
> $(dml_rcflags)
Similarly, this bit should not need a check for CONFIG_ARM64.
> +CFLAGS_REMOVE_$(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 :=
> $(dml_rcflags)
> +endif
> endif
> CFLAGS_$(AMDDALPATH)/dc/dml/dml1_display_rq_dlg_calc.o :=
> $(dml_ccflags)
> CFLAGS_$(AMDDALPATH)/dc/dml/display_rq_dlg_helpers.o := $(dml_ccflags)
Having the #endif for the CONFIG_DRM_AMD_DC_DCN list is
a bit confusing (this is the preexisting state, not your
change).I'd probably drop the CONFIG_DRM_AMD_DC_DCN check
for the per-file cflags entirely.
Arnd
^ permalink raw reply [flat|nested] 3+ messages in thread
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2022-10-27 14:45 [PATCH v2 0/1] drm/amd/display: add DCN support for ARM64 Ao Zhong
2022-10-27 14:45 ` [PATCH v2 1/1] " Ao Zhong
2022-10-27 15:07 ` Arnd Bergmann
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