amdgpu: Enable initial DCN support on POWER

DCN requires floating point support to operate.  Add the appropriate
x86/ppc64 guards and FPU / AltiVec / VSX context switches to DCN.

Note that the current DC20 code doesn't contain all required FPU
wrappers on x86 or POWER, so this patch is insufficient to fully
enable DC20 on POWER.

v2: s/X86_64/X86/g to retain previous behavior.
Signed-off-by: Timothy Pearson <tpearson@raptorengineering.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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 && !(KCOV_INSTRUMENT_ALL && KCOV_ENABLE_COMPARISONS)
+	select DRM_AMD_DC_DCN if (X86 || PPC64) && !(KCOV_INSTRUMENT_ALL && KCOV_ENABLE_COMPARISONS)
 	help
 	  Choose this option if you want to use the new display engine
 	  support for AMDGPU. This adds required support for Vega and

drivers/gpu/drm/amd/display/dc/calcs/Makefile

 #
 # Copyright 2017 Advanced Micro Devices, Inc.
+# Copyright 2019 Raptor Engineering, LLC
 #
 # Permission is hereby granted, free of charge, to any person obtaining a
 # copy of this software and associated documentation files (the "Software"),
@@ -24,7 +25,13 @@
 # It calculates Bandwidth and Watermarks values for HW programming
 #
 
+ifdef CONFIG_X86
 calcs_ccflags := -mhard-float -msse
+endif
+
+ifdef CONFIG_PPC64
+calcs_ccflags := -mhard-float -maltivec
+endif
 
 ifdef CONFIG_CC_IS_GCC
 ifeq ($(call cc-ifversion, -lt, 0701, y), y)
@@ -32,6 +39,7 @@ IS_OLD_GCC = 1
 endif
 endif
 
+ifdef CONFIG_X86
 ifdef IS_OLD_GCC
 # Stack alignment mismatch, proceed with caution.
 # GCC < 7.1 cannot compile code using `double` and -mpreferred-stack-boundary=3
@@ -40,6 +48,7 @@ calcs_ccflags += -mpreferred-stack-boundary=4
 else
 calcs_ccflags += -msse2
 endif
+endif
 
 CFLAGS_$(AMDDALPATH)/dc/calcs/dcn_calcs.o := $(calcs_ccflags)
 CFLAGS_$(AMDDALPATH)/dc/calcs/dcn_calc_auto.o := $(calcs_ccflags)

drivers/gpu/drm/amd/display/dc/calcs/dcn_calcs.c

 /*
  * Copyright 2017 Advanced Micro Devices, Inc.
+ * Copyright 2019 Raptor Engineering, LLC
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Software"),

drivers/gpu/drm/amd/display/dc/dcn20/Makefile

@@ -9,7 +9,13 @@ DCN20 = dcn20_resource.o dcn20_init.o dcn20_hwseq.o dcn20_dpp.o dcn20_dpp_cm.o d
 
 DCN20 += dcn20_dsc.o
 
+ifdef CONFIG_X86
 CFLAGS_$(AMDDALPATH)/dc/dcn20/dcn20_resource.o := -mhard-float -msse
+endif
+
+ifdef CONFIG_PPC64
+CFLAGS_$(AMDDALPATH)/dc/dcn20/dcn20_resource.o := -mhard-float -maltivec
+endif
 
 ifdef CONFIG_CC_IS_GCC
 ifeq ($(call cc-ifversion, -lt, 0701, y), y)
@@ -17,6 +23,7 @@ IS_OLD_GCC = 1
 endif
 endif
 
+ifdef CONFIG_X86
 ifdef IS_OLD_GCC
 # Stack alignment mismatch, proceed with caution.
 # GCC < 7.1 cannot compile code using `double` and -mpreferred-stack-boundary=3
@@ -25,6 +32,7 @@ CFLAGS_$(AMDDALPATH)/dc/dcn20/dcn20_resource.o += -mpreferred-stack-boundary=4
 else
 CFLAGS_$(AMDDALPATH)/dc/dcn20/dcn20_resource.o += -msse2
 endif
+endif
 
 AMD_DAL_DCN20 = $(addprefix $(AMDDALPATH)/dc/dcn20/,$(DCN20))
 

drivers/gpu/drm/amd/display/dc/dcn21/Makefile

@@ -5,7 +5,13 @@
 DCN21 = dcn21_init.o dcn21_hubp.o dcn21_hubbub.o dcn21_resource.o \
 	 dcn21_hwseq.o dcn21_link_encoder.o
 
+ifdef CONFIG_X86
 CFLAGS_$(AMDDALPATH)/dc/dcn21/dcn21_resource.o := -mhard-float -msse
+endif
+
+ifdef CONFIG_PPC64
+CFLAGS_$(AMDDALPATH)/dc/dcn21/dcn21_resource.o := -mhard-float -maltivec
+endif
 
 ifdef CONFIG_CC_IS_GCC
 ifeq ($(call cc-ifversion, -lt, 0701, y), y)
@@ -13,6 +19,7 @@ IS_OLD_GCC = 1
 endif
 endif
 
+ifdef CONFIG_X86
 ifdef IS_OLD_GCC
 # Stack alignment mismatch, proceed with caution.
 # GCC < 7.1 cannot compile code using `double` and -mpreferred-stack-boundary=3
@@ -21,6 +28,7 @@ CFLAGS_$(AMDDALPATH)/dc/dcn21/dcn21_resource.o += -mpreferred-stack-boundary=4
 else
 CFLAGS_$(AMDDALPATH)/dc/dcn21/dcn21_resource.o += -msse2
 endif
+endif
 
 AMD_DAL_DCN21 = $(addprefix $(AMDDALPATH)/dc/dcn21/,$(DCN21))
 

drivers/gpu/drm/amd/display/dc/dml/Makefile

 #
 # Copyright 2017 Advanced Micro Devices, Inc.
+# Copyright 2019 Raptor Engineering, LLC
 #
 # Permission is hereby granted, free of charge, to any person obtaining a
 # copy of this software and associated documentation files (the "Software"),
@@ -24,7 +25,13 @@
 # It provides the general basic services required by other DAL
 # subcomponents.
 
+ifdef CONFIG_X86
 dml_ccflags := -mhard-float -msse
+endif
+
+ifdef CONFIG_PPC64
+dml_ccflags := -mhard-float -maltivec
+endif
 
 ifdef CONFIG_CC_IS_GCC
 ifeq ($(call cc-ifversion, -lt, 0701, y), y)
@@ -32,6 +39,7 @@ IS_OLD_GCC = 1
 endif
 endif
 
+ifdef CONFIG_X86
 ifdef IS_OLD_GCC
 # Stack alignment mismatch, proceed with caution.
 # GCC < 7.1 cannot compile code using `double` and -mpreferred-stack-boundary=3
@@ -40,6 +48,7 @@ dml_ccflags += -mpreferred-stack-boundary=4
 else
 dml_ccflags += -msse2
 endif
+endif
 
 CFLAGS_$(AMDDALPATH)/dc/dml/display_mode_lib.o := $(dml_ccflags)
 

drivers/gpu/drm/amd/display/dc/dsc/Makefile

@@ -2,7 +2,13 @@
 #
 # Makefile for the 'dsc' sub-component of DAL.
 
+ifdef CONFIG_X86
 dsc_ccflags := -mhard-float -msse
+endif
+
+ifdef CONFIG_PPC64
+dsc_ccflags := -mhard-float -maltivec
+endif
 
 ifdef CONFIG_CC_IS_GCC
 ifeq ($(call cc-ifversion, -lt, 0701, y), y)
@@ -10,6 +16,7 @@ IS_OLD_GCC = 1
 endif
 endif
 
+ifdef CONFIG_X86
 ifdef IS_OLD_GCC
 # Stack alignment mismatch, proceed with caution.
 # GCC < 7.1 cannot compile code using `double` and -mpreferred-stack-boundary=3
@@ -18,6 +25,7 @@ dsc_ccflags += -mpreferred-stack-boundary=4
 else
 dsc_ccflags += -msse2
 endif
+endif
 
 CFLAGS_$(AMDDALPATH)/dc/dsc/rc_calc.o := $(dsc_ccflags)
 CFLAGS_$(AMDDALPATH)/dc/dsc/rc_calc_dpi.o := $(dsc_ccflags)

drivers/gpu/drm/amd/display/dc/os_types.h

@@ -51,9 +51,38 @@
 #define dm_error(fmt, ...) DRM_ERROR(fmt, ##__VA_ARGS__)
 
 #if defined(CONFIG_DRM_AMD_DC_DCN)
+#if defined(CONFIG_X86)
 #include <asm/fpu/api.h>
 #define DC_FP_START() kernel_fpu_begin()
 #define DC_FP_END() kernel_fpu_end()
+#elif defined(CONFIG_PPC64)
+#include <asm/switch_to.h>
+#include <asm/cputable.h>
+#define DC_FP_START() { \
+	if (cpu_has_feature(CPU_FTR_VSX_COMP)) { \
+		preempt_disable(); \
+		enable_kernel_vsx(); \
+	} else if (cpu_has_feature(CPU_FTR_ALTIVEC_COMP)) { \
+		preempt_disable(); \
+		enable_kernel_altivec(); \
+	} else if (!cpu_has_feature(CPU_FTR_FPU_UNAVAILABLE)) { \
+		preempt_disable(); \
+		enable_kernel_fp(); \
+	} \
+}
+#define DC_FP_END() { \
+	if (cpu_has_feature(CPU_FTR_VSX_COMP)) { \
+		disable_kernel_vsx(); \
+		preempt_enable(); \
+	} else if (cpu_has_feature(CPU_FTR_ALTIVEC_COMP)) { \
+		disable_kernel_altivec(); \
+		preempt_enable(); \
+	} else if (!cpu_has_feature(CPU_FTR_FPU_UNAVAILABLE)) { \
+		disable_kernel_fp(); \
+		preempt_enable(); \
+	} \
+}
+#endif
 #endif
 
 /*