From 8f83e6e6b2727102902cd2e9418b7baebe0fbded Mon Sep 17 00:00:00 2001 From: "ndesaulniers@google.com" Date: Thu, 24 Jan 2019 16:52:59 -0800 Subject: [PATCH] BACKPORT: drm/amd/display: add -msse2 to prevent Clang from emitting libcalls to undefined SW FP routines arch/x86/Makefile disables SSE and SSE2 for the whole kernel. The AMDGPU drivers modified in this patch re-enable SSE but not SSE2. Turn on SSE2 to support emitting double precision floating point instructions rather than calls to non-existent (usually available from gcc_s or compiler_rt) floating point helper routines. Link: https://gcc.gnu.org/onlinedocs/gccint/Soft-float-library-routines.html Link: https://github.com/ClangBuiltLinux/linux/issues/327 Cc: stable@vger.kernel.org # 4.19 Reported-by: S, Shirish Reported-by: Matthias Kaehlcke Suggested-by: James Y Knight Suggested-by: Nathan Chancellor Signed-off-by: Nick Desaulniers Tested-by: Guenter Roeck Tested-by: Matthias Kaehlcke Tested-by: Nathan Chancellor Reviewed-by: Harry Wentland Signed-off-by: Harry Wentland Signed-off-by: Alex Deucher Change-Id: I653676f209c85d1c27c91af1c9347ee59107b04f (cherry picked from commit 10117450735c7a7c0858095fb46a860e7037cb9a) [ added CONFIG_CC_IS_CLANG ] Link: https://bugs.freedesktop.org/show_bug.cgi?id=109487 Signed-off-by: Sami Tolvanen --- drivers/gpu/drm/amd/display/dc/calcs/Makefile | 6 ++++++ drivers/gpu/drm/amd/display/dc/dml/Makefile | 6 ++++++ 2 files changed, 12 insertions(+) diff --git a/drivers/gpu/drm/amd/display/dc/calcs/Makefile b/drivers/gpu/drm/amd/display/dc/calcs/Makefile index 95f332ee3e7e..e4a8b3337f5c 100644 --- a/drivers/gpu/drm/amd/display/dc/calcs/Makefile +++ b/drivers/gpu/drm/amd/display/dc/calcs/Makefile @@ -32,6 +32,12 @@ endif calcs_ccflags := -mhard-float -msse $(cc_stack_align) +# Use -msse2 only with clang: +# https://bugs.freedesktop.org/show_bug.cgi?id=109487 +ifdef CONFIG_CC_IS_CLANG +calcs_cc_flags += -msse2 +endif + CFLAGS_dcn_calcs.o := $(calcs_ccflags) CFLAGS_dcn_calc_auto.o := $(calcs_ccflags) CFLAGS_dcn_calc_math.o := $(calcs_ccflags) -Wno-tautological-compare diff --git a/drivers/gpu/drm/amd/display/dc/dml/Makefile b/drivers/gpu/drm/amd/display/dc/dml/Makefile index d97ca6528f9d..648c80c21680 100644 --- a/drivers/gpu/drm/amd/display/dc/dml/Makefile +++ b/drivers/gpu/drm/amd/display/dc/dml/Makefile @@ -32,6 +32,12 @@ endif dml_ccflags := -mhard-float -msse $(cc_stack_align) +# Use -msse2 only with clang: +# https://bugs.freedesktop.org/show_bug.cgi?id=109487 +ifdef CONFIG_CC_IS_CLANG +dml_ccflags += -msse2 +endif + CFLAGS_display_mode_lib.o := $(dml_ccflags) CFLAGS_display_pipe_clocks.o := $(dml_ccflags) CFLAGS_dml1_display_rq_dlg_calc.o := $(dml_ccflags)