On Wed, 16 Dec 2020 at 19:00, Alex Deucher <alexdeucher@xxxxxxxxx> wrote:
>
> On Mon, Dec 14, 2020 at 12:53 PM Ard Biesheuvel <ardb@xxxxxxxxxx> wrote:
> >
> > This reverts commit c38d444e44badc557cf29fdfdfb823604890ccfa.
> >
> > Simply disabling -mgeneral-regs-only left and right is risky, given that
> > the standard AArch64 ABI permits the use of FP/SIMD registers anywhere,
> > and GCC is known to use SIMD registers for spilling, and may invent
> > other uses of the FP/SIMD register file that have nothing to do with the
> > floating point code in question. Note that putting kernel_neon_begin()
> > and kernel_neon_end() around the code that does use FP is not sufficient
> > here, the problem is in all the other code that may be emitted with
> > references to SIMD registers in it.
> >
> > So the only way to do this properly is to put all floating point code in
> > a separate compilation unit, and only compile that unit with
> > -mgeneral-regs-only. But perhaps the use of floating point here is
> > something that should be reconsidered entirely.
> >
> > Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
> > Cc: Will Deacon <will@xxxxxxxxxx>
> > Cc: Dave Martin <dave.martin@xxxxxxx>
> > Cc: Rob Herring <robh@xxxxxxxxxx>
> > Cc: Leo Li <sunpeng.li@xxxxxxx>
> > Cc: Alex Deucher <alexander.deucher@xxxxxxx>
> > Cc: "Christian König" <christian.koenig@xxxxxxx>
> > Cc: David Airlie <airlied@xxxxxxxx>
> > Cc: Daniel Vetter <daniel@xxxxxxxx>
> > Cc: Daniel Kolesa <daniel@xxxxxxxxxxxxx>
> > Cc: amd-gfx@xxxxxxxxxxxxxxxxxxxxx
> > Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
> > Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
>
> Can rebase this on Linus' master branch? There were a number of new
> asics added which copy pasted the ARM64 support.
>
Not sure what you are asking me here. Reverting commit c38d444e44badc5
on top of mainline is not going to fix the other code that was added.
Or are you asking me to go and find the patches (how many?) that added
new ASICs and fix them for arm64?
Note that this code is critically broken, as it may corrupt user
process state arbitrarily. So if new code was added that contains the
same bug, it should be reverted so that the respective authors can fix
it and resubmit.
>
> > ---
> > drivers/gpu/drm/amd/display/Kconfig | 2 +-
> > drivers/gpu/drm/amd/display/dc/calcs/Makefile | 7 --
> > drivers/gpu/drm/amd/display/dc/clk_mgr/Makefile | 7 --
> > drivers/gpu/drm/amd/display/dc/dcn10/Makefile | 7 --
> > drivers/gpu/drm/amd/display/dc/dcn10/dcn10_resource.c | 81 ++++++++------------
> > drivers/gpu/drm/amd/display/dc/dcn20/Makefile | 4 -
> > drivers/gpu/drm/amd/display/dc/dcn21/Makefile | 4 -
> > drivers/gpu/drm/amd/display/dc/dml/Makefile | 13 ----
> > drivers/gpu/drm/amd/display/dc/dsc/Makefile | 5 --
> > drivers/gpu/drm/amd/display/dc/os_types.h | 4 -
> > 10 files changed, 32 insertions(+), 102 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/amd/display/Kconfig b/drivers/gpu/drm/amd/display/Kconfig
> > index 60dfdd432aba..3c410d236c49 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 || (ARM64 && KERNEL_MODE_NEON)) && !(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
> > diff --git a/drivers/gpu/drm/amd/display/dc/calcs/Makefile b/drivers/gpu/drm/amd/display/dc/calcs/Makefile
> > index 64f515d74410..4674aca8f206 100644
> > --- a/drivers/gpu/drm/amd/display/dc/calcs/Makefile
> > +++ b/drivers/gpu/drm/amd/display/dc/calcs/Makefile
> > @@ -33,10 +33,6 @@ ifdef CONFIG_PPC64
> > calcs_ccflags := -mhard-float -maltivec
> > endif
> >
> > -ifdef CONFIG_ARM64
> > -calcs_rcflags := -mgeneral-regs-only
> > -endif
> > -
> > ifdef CONFIG_CC_IS_GCC
> > ifeq ($(call cc-ifversion, -lt, 0701, y), y)
> > IS_OLD_GCC = 1
> > @@ -57,9 +53,6 @@ endif
> > CFLAGS_$(AMDDALPATH)/dc/calcs/dcn_calcs.o := $(calcs_ccflags)
> > CFLAGS_$(AMDDALPATH)/dc/calcs/dcn_calc_auto.o := $(calcs_ccflags)
> > CFLAGS_$(AMDDALPATH)/dc/calcs/dcn_calc_math.o := $(calcs_ccflags) -Wno-tautological-compare
> > -CFLAGS_REMOVE_$(AMDDALPATH)/dc/calcs/dcn_calcs.o := $(calcs_rcflags)
> > -CFLAGS_REMOVE_$(AMDDALPATH)/dc/calcs/dcn_calc_auto.o := $(calcs_rcflags)
> > -CFLAGS_REMOVE_$(AMDDALPATH)/dc/calcs/dcn_calc_math.o := $(calcs_rcflags)
> >
> > BW_CALCS = dce_calcs.o bw_fixed.o custom_float.o
> >
> > diff --git a/drivers/gpu/drm/amd/display/dc/clk_mgr/Makefile b/drivers/gpu/drm/amd/display/dc/clk_mgr/Makefile
> > index 1a495759a034..52b1ce775a1e 100644
> > --- a/drivers/gpu/drm/amd/display/dc/clk_mgr/Makefile
> > +++ b/drivers/gpu/drm/amd/display/dc/clk_mgr/Makefile
> > @@ -104,13 +104,6 @@ ifdef CONFIG_PPC64
> > CFLAGS_$(AMDDALPATH)/dc/clk_mgr/dcn21/rn_clk_mgr.o := $(call cc-option,-mno-gnu-attribute)
> > endif
> >
> > -# prevent build errors:
> > -# ...: '-mgeneral-regs-only' is incompatible with the use of floating-point types
> > -# this file is unused on arm64, just like on ppc64
> > -ifdef CONFIG_ARM64
> > -CFLAGS_REMOVE_$(AMDDALPATH)/dc/clk_mgr/dcn21/rn_clk_mgr.o := -mgeneral-regs-only
> > -endif
> > -
> > AMD_DAL_CLK_MGR_DCN21 = $(addprefix $(AMDDALPATH)/dc/clk_mgr/dcn21/,$(CLK_MGR_DCN21))
> >
> > AMD_DISPLAY_FILES += $(AMD_DAL_CLK_MGR_DCN21)
> > diff --git a/drivers/gpu/drm/amd/display/dc/dcn10/Makefile b/drivers/gpu/drm/amd/display/dc/dcn10/Makefile
> > index 733e6e6e43bd..62ad1a11bff9 100644
> > --- a/drivers/gpu/drm/amd/display/dc/dcn10/Makefile
> > +++ b/drivers/gpu/drm/amd/display/dc/dcn10/Makefile
> > @@ -31,11 +31,4 @@ DCN10 = dcn10_init.o dcn10_resource.o dcn10_ipp.o dcn10_hw_sequencer.o \
> >
> > AMD_DAL_DCN10 = $(addprefix $(AMDDALPATH)/dc/dcn10/,$(DCN10))
> >
> > -# fix:
> > -# ...: '-mgeneral-regs-only' is incompatible with the use of floating-point types
> > -# aarch64 does not support soft-float, so use hard-float and handle this in code
> > -ifdef CONFIG_ARM64
> > -CFLAGS_REMOVE_$(AMDDALPATH)/dc/dcn10/dcn10_resource.o := -mgeneral-regs-only
> > -endif
> > -
> > AMD_DISPLAY_FILES += $(AMD_DAL_DCN10)
> > diff --git a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_resource.c b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_resource.c
> > index a78712caf124..462d3d981ea5 100644
> > --- a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_resource.c
> > +++ b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_resource.c
> > @@ -1339,47 +1339,6 @@ static uint32_t read_pipe_fuses(struct dc_context *ctx)
> > return value;
> > }
> >
> > -/*
> > - * Some architectures don't support soft-float (e.g. aarch64), on those
> > - * this function has to be called with hardfloat enabled, make sure not
> > - * to inline it so whatever fp stuff is done stays inside
> > - */
> > -static noinline void dcn10_resource_construct_fp(
> > - struct dc *dc)
> > -{
> > - if (dc->ctx->dce_version == DCN_VERSION_1_01) {
> > - struct dcn_soc_bounding_box *dcn_soc = dc->dcn_soc;
> > - struct dcn_ip_params *dcn_ip = dc->dcn_ip;
> > - struct display_mode_lib *dml = &dc->dml;
> > -
> > - dml->ip.max_num_dpp = 3;
> > - /* TODO how to handle 23.84? */
> > - dcn_soc->dram_clock_change_latency = 23;
> > - dcn_ip->max_num_dpp = 3;
> > - }
> > - if (ASICREV_IS_RV1_F0(dc->ctx->asic_id.hw_internal_rev)) {
> > - dc->dcn_soc->urgent_latency = 3;
> > - dc->debug.disable_dmcu = true;
> > - dc->dcn_soc->fabric_and_dram_bandwidth_vmax0p9 = 41.60f;
> > - }
> > -
> > -
> > - dc->dcn_soc->number_of_channels = dc->ctx->asic_id.vram_width / ddr4_dram_width;
> > - ASSERT(dc->dcn_soc->number_of_channels < 3);
> > - if (dc->dcn_soc->number_of_channels == 0)/*old sbios bug*/
> > - dc->dcn_soc->number_of_channels = 2;
> > -
> > - if (dc->dcn_soc->number_of_channels == 1) {
> > - dc->dcn_soc->fabric_and_dram_bandwidth_vmax0p9 = 19.2f;
> > - dc->dcn_soc->fabric_and_dram_bandwidth_vnom0p8 = 17.066f;
> > - dc->dcn_soc->fabric_and_dram_bandwidth_vmid0p72 = 14.933f;
> > - dc->dcn_soc->fabric_and_dram_bandwidth_vmin0p65 = 12.8f;
> > - if (ASICREV_IS_RV1_F0(dc->ctx->asic_id.hw_internal_rev)) {
> > - dc->dcn_soc->fabric_and_dram_bandwidth_vmax0p9 = 20.80f;
> > - }
> > - }
> > -}
> > -
> > static bool dcn10_resource_construct(
> > uint8_t num_virtual_links,
> > struct dc *dc,
> > @@ -1531,15 +1490,37 @@ static bool dcn10_resource_construct(
> > memcpy(dc->dcn_ip, &dcn10_ip_defaults, sizeof(dcn10_ip_defaults));
> > memcpy(dc->dcn_soc, &dcn10_soc_defaults, sizeof(dcn10_soc_defaults));
> >
> > -#if defined(CONFIG_ARM64)
> > - /* Aarch64 does not support -msoft-float/-mfloat-abi=soft */
> > - DC_FP_START();
> > - dcn10_resource_construct_fp(dc);
> > - DC_FP_END();
> > -#else
> > - /* Other architectures we build for build this with soft-float */
> > - dcn10_resource_construct_fp(dc);
> > -#endif
> > + if (dc->ctx->dce_version == DCN_VERSION_1_01) {
> > + struct dcn_soc_bounding_box *dcn_soc = dc->dcn_soc;
> > + struct dcn_ip_params *dcn_ip = dc->dcn_ip;
> > + struct display_mode_lib *dml = &dc->dml;
> > +
> > + dml->ip.max_num_dpp = 3;
> > + /* TODO how to handle 23.84? */
> > + dcn_soc->dram_clock_change_latency = 23;
> > + dcn_ip->max_num_dpp = 3;
> > + }
> > + if (ASICREV_IS_RV1_F0(dc->ctx->asic_id.hw_internal_rev)) {
> > + dc->dcn_soc->urgent_latency = 3;
> > + dc->debug.disable_dmcu = true;
> > + dc->dcn_soc->fabric_and_dram_bandwidth_vmax0p9 = 41.60f;
> > + }
> > +
> > +
> > + dc->dcn_soc->number_of_channels = dc->ctx->asic_id.vram_width / ddr4_dram_width;
> > + ASSERT(dc->dcn_soc->number_of_channels < 3);
> > + if (dc->dcn_soc->number_of_channels == 0)/*old sbios bug*/
> > + dc->dcn_soc->number_of_channels = 2;
> > +
> > + if (dc->dcn_soc->number_of_channels == 1) {
> > + dc->dcn_soc->fabric_and_dram_bandwidth_vmax0p9 = 19.2f;
> > + dc->dcn_soc->fabric_and_dram_bandwidth_vnom0p8 = 17.066f;
> > + dc->dcn_soc->fabric_and_dram_bandwidth_vmid0p72 = 14.933f;
> > + dc->dcn_soc->fabric_and_dram_bandwidth_vmin0p65 = 12.8f;
> > + if (ASICREV_IS_RV1_F0(dc->ctx->asic_id.hw_internal_rev)) {
> > + dc->dcn_soc->fabric_and_dram_bandwidth_vmax0p9 = 20.80f;
> > + }
> > + }
> >
> > pool->base.pp_smu = dcn10_pp_smu_create(ctx);
> >
> > diff --git a/drivers/gpu/drm/amd/display/dc/dcn20/Makefile b/drivers/gpu/drm/amd/display/dc/dcn20/Makefile
> > index 624cb1341ef1..5fcaf78334ff 100644
> > --- a/drivers/gpu/drm/amd/display/dc/dcn20/Makefile
> > +++ b/drivers/gpu/drm/amd/display/dc/dcn20/Makefile
> > @@ -17,10 +17,6 @@ ifdef CONFIG_PPC64
> > CFLAGS_$(AMDDALPATH)/dc/dcn20/dcn20_resource.o := -mhard-float -maltivec
> > endif
> >
> > -ifdef CONFIG_ARM64
> > -CFLAGS_REMOVE_$(AMDDALPATH)/dc/dcn20/dcn20_resource.o := -mgeneral-regs-only
> > -endif
> > -
> > ifdef CONFIG_CC_IS_GCC
> > ifeq ($(call cc-ifversion, -lt, 0701, y), y)
> > IS_OLD_GCC = 1
> > diff --git a/drivers/gpu/drm/amd/display/dc/dcn21/Makefile b/drivers/gpu/drm/amd/display/dc/dcn21/Makefile
> > index 51a2f3d4c194..07684d3e375a 100644
> > --- a/drivers/gpu/drm/amd/display/dc/dcn21/Makefile
> > +++ b/drivers/gpu/drm/amd/display/dc/dcn21/Makefile
> > @@ -13,10 +13,6 @@ ifdef CONFIG_PPC64
> > CFLAGS_$(AMDDALPATH)/dc/dcn21/dcn21_resource.o := -mhard-float -maltivec
> > endif
> >
> > -ifdef CONFIG_ARM64
> > -CFLAGS_REMOVE_$(AMDDALPATH)/dc/dcn21/dcn21_resource.o := -mgeneral-regs-only
> > -endif
> > -
> > ifdef CONFIG_CC_IS_GCC
> > ifeq ($(call cc-ifversion, -lt, 0701, y), y)
> > IS_OLD_GCC = 1
> > diff --git a/drivers/gpu/drm/amd/display/dc/dml/Makefile b/drivers/gpu/drm/amd/display/dc/dml/Makefile
> > index dbc7e2abe379..417331438c30 100644
> > --- a/drivers/gpu/drm/amd/display/dc/dml/Makefile
> > +++ b/drivers/gpu/drm/amd/display/dc/dml/Makefile
> > @@ -33,10 +33,6 @@ ifdef CONFIG_PPC64
> > dml_ccflags := -mhard-float -maltivec
> > endif
> >
> > -ifdef CONFIG_ARM64
> > -dml_rcflags := -mgeneral-regs-only
> > -endif
> > -
> > ifdef CONFIG_CC_IS_GCC
> > ifeq ($(call cc-ifversion, -lt, 0701, y), y)
> > IS_OLD_GCC = 1
> > @@ -64,13 +60,6 @@ CFLAGS_$(AMDDALPATH)/dc/dml/dcn20/display_mode_vba_20v2.o := $(dml_ccflags)
> > CFLAGS_$(AMDDALPATH)/dc/dml/dcn20/display_rq_dlg_calc_20v2.o := $(dml_ccflags)
> > CFLAGS_$(AMDDALPATH)/dc/dml/dcn21/display_mode_vba_21.o := $(dml_ccflags)
> > CFLAGS_$(AMDDALPATH)/dc/dml/dcn21/display_rq_dlg_calc_21.o := $(dml_ccflags)
> > -CFLAGS_REMOVE_$(AMDDALPATH)/dc/dml/display_mode_vba.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 := $(dml_rcflags)
> > -CFLAGS_REMOVE_$(AMDDALPATH)/dc/dml/dcn20/display_rq_dlg_calc_20v2.o := $(dml_rcflags)
> > -CFLAGS_REMOVE_$(AMDDALPATH)/dc/dml/dcn21/display_mode_vba_21.o := $(dml_rcflags)
> > -CFLAGS_REMOVE_$(AMDDALPATH)/dc/dml/dcn21/display_rq_dlg_calc_21.o := $(dml_rcflags)
> > endif
> > ifdef CONFIG_DRM_AMD_DC_DCN3_0
> > CFLAGS_$(AMDDALPATH)/dc/dml/dcn30/display_mode_vba_30.o := $(dml_ccflags) -Wframe-larger-than=2048
> > @@ -78,8 +67,6 @@ CFLAGS_$(AMDDALPATH)/dc/dml/dcn30/display_rq_dlg_calc_30.o := $(dml_ccflags)
> > endif
> > CFLAGS_$(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 := $(dml_rcflags)
> > -CFLAGS_REMOVE_$(AMDDALPATH)/dc/dml/display_rq_dlg_helpers.o := $(dml_rcflags)
> >
> > DML = display_mode_lib.o display_rq_dlg_helpers.o dml1_display_rq_dlg_calc.o \
> >
> > diff --git a/drivers/gpu/drm/amd/display/dc/dsc/Makefile b/drivers/gpu/drm/amd/display/dc/dsc/Makefile
> > index f2624a1156e5..ea29cf95d470 100644
> > --- a/drivers/gpu/drm/amd/display/dc/dsc/Makefile
> > +++ b/drivers/gpu/drm/amd/display/dc/dsc/Makefile
> > @@ -10,10 +10,6 @@ ifdef CONFIG_PPC64
> > dsc_ccflags := -mhard-float -maltivec
> > endif
> >
> > -ifdef CONFIG_ARM64
> > -dsc_rcflags := -mgeneral-regs-only
> > -endif
> > -
> > ifdef CONFIG_CC_IS_GCC
> > ifeq ($(call cc-ifversion, -lt, 0701, y), y)
> > IS_OLD_GCC = 1
> > @@ -32,7 +28,6 @@ endif
> > endif
> >
> > CFLAGS_$(AMDDALPATH)/dc/dsc/rc_calc.o := $(dsc_ccflags)
> > -CFLAGS_REMOVE_$(AMDDALPATH)/dc/dsc/rc_calc.o := $(dsc_rcflags)
> >
> > DSC = dc_dsc.o rc_calc.o rc_calc_dpi.o
> >
> > diff --git a/drivers/gpu/drm/amd/display/dc/os_types.h b/drivers/gpu/drm/amd/display/dc/os_types.h
> > index 95cb56929e79..126c2f3a4dd3 100644
> > --- a/drivers/gpu/drm/amd/display/dc/os_types.h
> > +++ b/drivers/gpu/drm/amd/display/dc/os_types.h
> > @@ -55,10 +55,6 @@
> > #include <asm/fpu/api.h>
> > #define DC_FP_START() kernel_fpu_begin()
> > #define DC_FP_END() kernel_fpu_end()
> > -#elif defined(CONFIG_ARM64)
> > -#include <asm/neon.h>
> > -#define DC_FP_START() kernel_neon_begin()
> > -#define DC_FP_END() kernel_neon_end()
> > #elif defined(CONFIG_PPC64)
> > #include <asm/switch_to.h>
> > #include <asm/cputable.h>
> > --
> > 2.20.1
> >
> > _______________________________________________
> > amd-gfx mailing list
> > amd-gfx@xxxxxxxxxxxxxxxxxxxxx
> > https://lists.freedesktop.org/mailman/listinfo/amd-gfx
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