linux-kernel - [PATCH v4 12/15] drm/amd/display: Only use hard-float, not altivec on powerpc

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Message-ID: <20240329072441.591471-13-samuel.holland@sifive.com>
Date: Fri, 29 Mar 2024 00:18:27 -0700
From: Samuel Holland <samuel.holland@...ive.com>
To: Andrew Morton <akpm@...ux-foundation.org>,
	linux-arm-kernel@...ts.infradead.org,
	x86@...nel.org
Cc: linux-kernel@...r.kernel.org,
	linux-arch@...r.kernel.org,
	linuxppc-dev@...ts.ozlabs.org,
	linux-riscv@...ts.infradead.org,
	Christoph Hellwig <hch@....de>,
	loongarch@...ts.linux.dev,
	amd-gfx@...ts.freedesktop.org,
	Michael Ellerman <mpe@...erman.id.au>,
	Alex Deucher <alexander.deucher@....com>,
	Samuel Holland <samuel.holland@...ive.com>
Subject: [PATCH v4 12/15] drm/amd/display: Only use hard-float, not altivec on powerpc

From: Michael Ellerman <mpe@...erman.id.au>

The compiler flags enable altivec, but that is not required; hard-float
is sufficient for the code to build and function.

Drop altivec from the compiler flags and adjust the enable/disable code
to only enable FPU use.

Signed-off-by: Michael Ellerman <mpe@...erman.id.au>
Acked-by: Alex Deucher <alexander.deucher@....com>
Signed-off-by: Samuel Holland <samuel.holland@...ive.com>
---

(no changes since v2)

Changes in v2:
 - New patch for v2

 drivers/gpu/drm/amd/display/amdgpu_dm/dc_fpu.c | 12 ++----------
 drivers/gpu/drm/amd/display/dc/dml/Makefile    |  2 +-
 drivers/gpu/drm/amd/display/dc/dml2/Makefile   |  2 +-
 3 files changed, 4 insertions(+), 12 deletions(-)

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 4ae4720535a5..0de16796466b 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/dc_fpu.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/dc_fpu.c
@@ -92,11 +92,7 @@ void dc_fpu_begin(const char *function_name, const int line)
 #if defined(CONFIG_X86) || defined(CONFIG_LOONGARCH)
 		kernel_fpu_begin();
 #elif defined(CONFIG_PPC64)
-		if (cpu_has_feature(CPU_FTR_VSX_COMP))
-			enable_kernel_vsx();
-		else if (cpu_has_feature(CPU_FTR_ALTIVEC_COMP))
-			enable_kernel_altivec();
-		else if (!cpu_has_feature(CPU_FTR_FPU_UNAVAILABLE))
+		if (!cpu_has_feature(CPU_FTR_FPU_UNAVAILABLE))
 			enable_kernel_fp();
 #elif defined(CONFIG_ARM64)
 		kernel_neon_begin();
@@ -125,11 +121,7 @@ void dc_fpu_end(const char *function_name, const int line)
 #if defined(CONFIG_X86) || defined(CONFIG_LOONGARCH)
 		kernel_fpu_end();
 #elif defined(CONFIG_PPC64)
-		if (cpu_has_feature(CPU_FTR_VSX_COMP))
-			disable_kernel_vsx();
-		else if (cpu_has_feature(CPU_FTR_ALTIVEC_COMP))
-			disable_kernel_altivec();
-		else if (!cpu_has_feature(CPU_FTR_FPU_UNAVAILABLE))
+		if (!cpu_has_feature(CPU_FTR_FPU_UNAVAILABLE))
 			disable_kernel_fp();
 #elif defined(CONFIG_ARM64)
 		kernel_neon_end();
diff --git a/drivers/gpu/drm/amd/display/dc/dml/Makefile b/drivers/gpu/drm/amd/display/dc/dml/Makefile
index c4a5efd2dda5..59d3972341d2 100644
--- a/drivers/gpu/drm/amd/display/dc/dml/Makefile
+++ b/drivers/gpu/drm/amd/display/dc/dml/Makefile
@@ -31,7 +31,7 @@ dml_ccflags := $(dml_ccflags-y) -msse
 endif
 
 ifdef CONFIG_PPC64
-dml_ccflags := -mhard-float -maltivec
+dml_ccflags := -mhard-float
 endif
 
 ifdef CONFIG_ARM64
diff --git a/drivers/gpu/drm/amd/display/dc/dml2/Makefile b/drivers/gpu/drm/amd/display/dc/dml2/Makefile
index acff3449b8d7..7b51364084b5 100644
--- a/drivers/gpu/drm/amd/display/dc/dml2/Makefile
+++ b/drivers/gpu/drm/amd/display/dc/dml2/Makefile
@@ -30,7 +30,7 @@ dml2_ccflags := $(dml2_ccflags-y) -msse
 endif
 
 ifdef CONFIG_PPC64
-dml2_ccflags := -mhard-float -maltivec
+dml2_ccflags := -mhard-float
 endif
 
 ifdef CONFIG_ARM64
-- 
2.44.0