drm/amd/display: move FPU associated DSC code to DML folder

[Why & How]
As part of the FPU isolation work documented in
https://patchwork.freedesktop.org/series/93042/, isolate code that uses
FPU in

drm/amd/display: move FPU associated DSC code to DML folder

[Why & How]
As part of the FPU isolation work documented in
https://patchwork.freedesktop.org/series/93042/, isolate code that uses
FPU in DSC to DML, where all FPU code should locate.

This change does not refactor any functions but move code around.

Cc: Christian König <christian.koenig@amd.com>
Cc: Hersen Wu <hersenxs.wu@amd.com>
Cc: Anson Jacob <Anson.Jacob@amd.com>
Cc: Harry Wentland <harry.wentland@amd.com>
Reviewed-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Acked-by: Agustin Gutierrez <agustin.gutierrez@amd.com>
Tested-by: Anson Jacob <Anson.Jacob@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

show more ...

drm/amd/display: move FPU associated DSC code to DML folder

[ Upstream commit d738db6883df3e3c513f9e777c842262693f951b ]

[Why & How]
As part of the FPU isolation work documented in
https://patchwor

drm/amd/display: move FPU associated DSC code to DML folder

[ Upstream commit d738db6883df3e3c513f9e777c842262693f951b ]

[Why & How]
As part of the FPU isolation work documented in
https://patchwork.freedesktop.org/series/93042/, isolate code that uses
FPU in DSC to DML, where all FPU code should locate.

This change does not refactor any functions but move code around.

Cc: Christian König <christian.koenig@amd.com>
Cc: Hersen Wu <hersenxs.wu@amd.com>
Cc: Anson Jacob <Anson.Jacob@amd.com>
Cc: Harry Wentland <harry.wentland@amd.com>
Reviewed-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Acked-by: Agustin Gutierrez <agustin.gutierrez@amd.com>
Tested-by: Anson Jacob <Anson.Jacob@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

show more ...

drm/amdgpu/display: drop DCN support for aarch64

From Ard:

"Simply disabling -mgeneral-regs-only left and right is risky, given that
the standard AArch64 ABI permits the use of FP/SIMD registers an

drm/amdgpu/display: drop DCN support for aarch64

From Ard:

"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."

Disable support until the code can be properly refactored to support this
properly on aarch64.

Acked-by: Will Deacon <will@kernel.org>
Reported-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

show more ...

drm/amdgpu/display: drop DCN support for aarch64

From Ard:

"Simply disabling -mgeneral-regs-only left and right is risky, given that
the standard AArch64 ABI permits the use of FP/SIMD registers an

drm/amdgpu/display: drop DCN support for aarch64

From Ard:

"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."

Disable support until the code can be properly refactored to support this
properly on aarch64.

Acked-by: Will Deacon <will@kernel.org>
Reported-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

show more ...

drm/amdgpu/display: drop DCN support for aarch64

commit c241ed2f0ea549c18cff62a3708b43846b84dae3 upstream.

From Ard:

"Simply disabling -mgeneral-regs-only left and right is risky, given that
the s

drm/amdgpu/display: drop DCN support for aarch64

commit c241ed2f0ea549c18cff62a3708b43846b84dae3 upstream.

From Ard:

"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."

Disable support until the code can be properly refactored to support this
properly on aarch64.

Acked-by: Will Deacon <will@kernel.org>
Reported-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[ardb: backport to v5.10 by reverting c38d444e44badc55 instead]
Acked-by: Alex Deucher <alexander.deucher@amd.com> # v5.10 backport
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

drm/amd/display: add DCN support for aarch64

This adds ARM64 support into the DCN. This mainly enables support
for Navi graphics cards. The dcn10 changes haven't been tested,
since I don't have the

drm/amd/display: add DCN support for aarch64

This adds ARM64 support into the DCN. This mainly enables support
for Navi graphics cards. The dcn10 changes haven't been tested,
since I don't have the relevant hardware available, but there
is no way to conditionally disable them, so I've done them anyway.

Signed-off-by: Daniel Kolesa <daniel@octaforge.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

show more ...

drm/amd/display: Rework dsc to isolate FPU operations

When we want to use float point operation on Linux
we need to use within special kernel protection
(`kernel_fpu_{begin,end}()`.), otherwise the

drm/amd/display: Rework dsc to isolate FPU operations

When we want to use float point operation on Linux
we need to use within special kernel protection
(`kernel_fpu_{begin,end}()`.), otherwise the kernel
can clobber userspace FPU register state. For detecting
these issues we use a tool named objtool (with -Ffa
flags) to highlight the FPU problems, all warnings can
be summed up as follows:

./tools/objtool/objtool check -Ffa
drivers/gpu/drm/amd/display/dc/dml/dml_common_defs.o

[..] dc/dsc/rc_calc.o: warning: objtool: get_qp_set()+0x2f8:
FPU instruction outside of kernel_fpu_{begin,end}()
[..] dc/dsc/rc_calc.o: warning: objtool: dsc_roundf()+0x5:
FPU instruction outside of kernel_fpu_{begin,end}()
[..] dc/dsc/rc_calc.o: warning: objtool: dsc_ceil()+0x5:
FPU instruction outside of kernel_fpu_{begin,end}()
[..] dc/dsc/rc_calc.o: warning: objtool: get_ofs_set()+0x3eb:
FPU instruction outside of kernel_fpu_{begin,end}()
[..] dc/dsc/rc_calc.o: warning: objtool: calc_rc_params()+0x3c:
FPU instruction outside of kernel_fpu_{begin,end}()
[..] dc/dsc/dc_dsc.o: warning: objtool:
get_dsc_bandwidth_range.isra.0()+0x8d:
FPU instruction outside of kernel_fpu_{begin,end}()
[..] dc/dsc/dc_dsc.o: warning: objtool: setup_dsc_config()+0x2ef:
FPU instruction outside of kernel_fpu_{begin,end}()
[..] dc/dsc/rc_calc_dpi.o: warning: objtool:copy_pps_fields()+0xbb:
FPU instruction outside of kernel_fpu_{begin,end}()
[..] dc/dsc/rc_calc_dpi.o: warning: objtool:
dscc_compute_dsc_parameters()+0x7b:
FPU instruction outside of kernel_fpu_{begin,end}()

This commit fixes the above issues by rework DSC as described:

1. Isolate all FPU operations in a single file;
2. Use FPU flags only in the file that handles FPU operations;
3. Isolate all functions that require float point operation in static
functions;
4. Add a mid-layer function that does not use any float point operation,
and that could be safely invoked in other parts of the code.
5. Keep float point operation under DC_FP_{START/END} macro.

CC: Christian König <christian.koenig@amd.com>
CC: Alexander Deucher <Alexander.Deucher@amd.com>
CC: Peter Zijlstra <peterz@infradead.org>
CC: Tony Cheng <tony.cheng@amd.com>
CC: Harry Wentland <hwentlan@amd.com>
Signed-off-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Reviewed-by: Mikita Lipski <Mikita.Lipski@amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

show more ...

drm/amd/display: Rework dsc to isolate FPU operations

When we want to use float point operation on Linux
we need to use within special kernel protection
(`kernel_fpu_{begin,end}()`.), otherwise the

drm/amd/display: Rework dsc to isolate FPU operations

When we want to use float point operation on Linux
we need to use within special kernel protection
(`kernel_fpu_{begin,end}()`.), otherwise the kernel
can clobber userspace FPU register state. For detecting
these issues we use a tool named objtool (with -Ffa
flags) to highlight the FPU problems, all warnings can
be summed up as follows:

./tools/objtool/objtool check -Ffa
drivers/gpu/drm/amd/display/dc/dml/dml_common_defs.o

[..] dc/dsc/rc_calc.o: warning: objtool: get_qp_set()+0x2f8:
FPU instruction outside of kernel_fpu_{begin,end}()
[..] dc/dsc/rc_calc.o: warning: objtool: dsc_roundf()+0x5:
FPU instruction outside of kernel_fpu_{begin,end}()
[..] dc/dsc/rc_calc.o: warning: objtool: dsc_ceil()+0x5:
FPU instruction outside of kernel_fpu_{begin,end}()
[..] dc/dsc/rc_calc.o: warning: objtool: get_ofs_set()+0x3eb:
FPU instruction outside of kernel_fpu_{begin,end}()
[..] dc/dsc/rc_calc.o: warning: objtool: calc_rc_params()+0x3c:
FPU instruction outside of kernel_fpu_{begin,end}()
[..] dc/dsc/dc_dsc.o: warning: objtool:
get_dsc_bandwidth_range.isra.0()+0x8d:
FPU instruction outside of kernel_fpu_{begin,end}()
[..] dc/dsc/dc_dsc.o: warning: objtool: setup_dsc_config()+0x2ef:
FPU instruction outside of kernel_fpu_{begin,end}()
[..] dc/dsc/rc_calc_dpi.o: warning: objtool:copy_pps_fields()+0xbb:
FPU instruction outside of kernel_fpu_{begin,end}()
[..] dc/dsc/rc_calc_dpi.o: warning: objtool:
dscc_compute_dsc_parameters()+0x7b:
FPU instruction outside of kernel_fpu_{begin,end}()

This commit fixes the above issues by rework DSC as described:

1. Isolate all FPU operations in a single file;
2. Use FPU flags only in the file that handles FPU operations;
3. Isolate all functions that require float point operation in static
functions;
4. Add a mid-layer function that does not use any float point operation,
and that could be safely invoked in other parts of the code.
5. Keep float point operation under DC_FP_{START/END} macro.

CC: Christian König <christian.koenig@amd.com>
CC: Alexander Deucher <Alexander.Deucher@amd.com>
CC: Peter Zijlstra <peterz@infradead.org>
CC: Tony Cheng <tony.cheng@amd.com>
CC: Harry Wentland <hwentlan@amd.com>
Signed-off-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Reviewed-by: Mikita Lipski <Mikita.Lipski@amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

show more ...

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 curr

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>

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drm/amdgpu: fix license on Kconfig and Makefiles

amdgpu is MIT licensed.

Fixes: ec8f24b7faaf3d ("treewide: Add SPDX license identifier - Makefile/Kconfig")
Reviewed-by: Christian König <christian.k

drm/amdgpu: fix license on Kconfig and Makefiles

amdgpu is MIT licensed.

Fixes: ec8f24b7faaf3d ("treewide: Add SPDX license identifier - Makefile/Kconfig")
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

show more ...

drm/amdgpu: fix license on Kconfig and Makefiles

amdgpu is MIT licensed.

Fixes: ec8f24b7faaf3d ("treewide: Add SPDX license identifier - Makefile/Kconfig")
Reviewed-by: Christian König <christian.k

drm/amdgpu: fix license on Kconfig and Makefiles

amdgpu is MIT licensed.

Fixes: ec8f24b7faaf3d ("treewide: Add SPDX license identifier - Makefile/Kconfig")
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

show more ...

drm/amdgpu: enable -msse2 for GCC 7.1+ users

A final attempt at enabling sse2 for GCC users.

Orininally attempted in:
commit 10117450735c ("drm/amd/display: add -msse2 to prevent Clang from emittin

drm/amdgpu: enable -msse2 for GCC 7.1+ users

A final attempt at enabling sse2 for GCC users.

Orininally attempted in:
commit 10117450735c ("drm/amd/display: add -msse2 to prevent Clang from emitting libcalls to undefined SW FP routines")

Reverted due to "reported instability" in:
commit 193392ed9f69 ("Revert "drm/amd/display: add -msse2 to prevent Clang from emitting libcalls to undefined SW FP routines"")

Re-added just for Clang in:
commit 0f0727d971f6 ("drm/amd/display: readd -msse2 to prevent Clang from emitting libcalls to undefined SW FP routines")

The original report didn't have enough information to know if the GPF
was due to misalignment, but I suspect that it was. (The missing
information was the disassembly of the function at the bottom of the
trace, to see if the instruction pointer pointed to an instruction with
16B alignment memory operand requirements. The stack trace does show
the stack was only 8B but not 16B aligned though, which makes this a
strong possibility).

Now that the stack misalignment issue has been fixed for users of GCC
7.1+, reattempt adding -msse2. This matches Clang.

It will likely never be safe to enable this for pre-GCC 7.1 AND use a
16B aligned stack in these translation units.

This is only a functional change for GCC 7.1+ users, and should be boot
tested.

Link: https://bugs.freedesktop.org/show_bug.cgi?id=109487
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

show more ...

drm/amdgpu: fix stack alignment ABI mismatch for GCC 7.1+

GCC earlier than 7.1 errors when compiling code that makes use of
`double`s and sets a stack alignment outside of the range of [2^4-2^12]:

drm/amdgpu: fix stack alignment ABI mismatch for GCC 7.1+

GCC earlier than 7.1 errors when compiling code that makes use of
`double`s and sets a stack alignment outside of the range of [2^4-2^12]:

$ cat foo.c
double foo(double x, double y) {
return x + y;
}
$ gcc-4.9 -mpreferred-stack-boundary=3 foo.c
error: -mpreferred-stack-boundary=3 is not between 4 and 12

This is likely why the AMDGPU driver was ever compiled with a different
stack alignment (and thus different ABI) than the rest of the x86
kernel. The kernel uses 8B stack alignment, while the driver was using
16B stack alignment in a few places.

Since GCC 7.1+ doesn't error, fix the ABI mismatch for users of newer
versions of GCC.

There was discussion about whether to mark the driver broken or not for
users of GCC earlier than 7.1, but since the driver currently is
working, don't explicitly break the driver for them here.

Relying on differing stack alignment is unspecified behavior, and
brittle, and may break in the future.

This patch is no functional change for GCC users earlier than 7.1. It's
been compile tested on GCC 4.9 and 8.3 to check the correct flags. It
should be boot tested when built with GCC 7.1+.

-mincoming-stack-boundary= or -mstackrealign may help keep this code
building for pre-GCC 7.1 users.

The version check for GCC is broken into two conditionals, both because
cc-ifversion is currently GCC specific, and it simplifies a subsequent
patch.

Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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drm/amdgpu: fix stack alignment ABI mismatch for Clang

The x86 kernel is compiled with an 8B stack alignment via
`-mpreferred-stack-boundary=3` for GCC since 3.6-rc1 via
commit d9b0cde91c60 ("x86-64

drm/amdgpu: fix stack alignment ABI mismatch for Clang

The x86 kernel is compiled with an 8B stack alignment via
`-mpreferred-stack-boundary=3` for GCC since 3.6-rc1 via
commit d9b0cde91c60 ("x86-64, gcc: Use -mpreferred-stack-boundary=3 if supported")
or `-mstack-alignment=8` for Clang. Parts of the AMDGPU driver are
compiled with 16B stack alignment.

Generally, the stack alignment is part of the ABI. Linking together two
different translation units with differing stack alignment is dangerous,
particularly when the translation unit with the smaller stack alignment
makes calls into the translation unit with the larger stack alignment.
While 8B aligned stacks are sometimes also 16B aligned, they are not
always.

Multiple users have reported General Protection Faults (GPF) when using
the AMDGPU driver compiled with Clang. Clang is placing objects in stack
slots assuming the stack is 16B aligned, and selecting instructions that
require 16B aligned memory operands.

At runtime, syscall handlers with 8B aligned stack call into code that
assumes 16B stack alignment. When the stack is a multiple of 8B but not
16B, these instructions result in a GPF.

Remove the code that added compatibility between the differing compiler
flags, as it will result in runtime GPFs when built with Clang. Cleanups
for GCC will be sent in later patches in the series.

Link: https://github.com/ClangBuiltLinux/linux/issues/735
Debugged-by: Yuxuan Shui <yshuiv7@gmail.com>
Reported-by: Shirish S <shirish.s@amd.com>
Reported-by: Yuxuan Shui <yshuiv7@gmail.com>
Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

show more ...

kbuild: change *FLAGS_<basetarget>.o to take the path relative to $(obj)

Kbuild provides per-file compiler flag addition/removal:

CFLAGS_<basetarget>.o
CFLAGS_REMOVE_<basetarget>.o
AFLAGS_<ba

kbuild: change *FLAGS_<basetarget>.o to take the path relative to $(obj)

Kbuild provides per-file compiler flag addition/removal:

CFLAGS_<basetarget>.o
CFLAGS_REMOVE_<basetarget>.o
AFLAGS_<basetarget>.o
AFLAGS_REMOVE_<basetarget>.o
CPPFLAGS_<basetarget>.lds
HOSTCFLAGS_<basetarget>.o
HOSTCXXFLAGS_<basetarget>.o

The <basetarget> is the filename of the target with its directory and
suffix stripped.

This syntax comes into a trouble when two files with the same basename
appear in one Makefile, for example:

obj-y += foo.o
obj-y += dir/foo.o
CFLAGS_foo.o := <some-flags>

Here, the <some-flags> applies to both foo.o and dir/foo.o

The real world problem is:

scripts/kconfig/util.c
scripts/kconfig/lxdialog/util.c

Both files are compiled into scripts/kconfig/mconf, but only the
latter should be given with the ncurses flags.

It is more sensible to use the relative path to the Makefile, like this:

obj-y += foo.o
CFLAGS_foo.o := <some-flags>
obj-y += dir/foo.o
CFLAGS_dir/foo.o := <other-flags>

At first, I attempted to replace $(basetarget) with $*. The $* variable
is replaced with the stem ('%') part in a pattern rule. This works with
most of cases, but does not for explicit rules.

For example, arch/ia64/lib/Makefile reuses rule_as_o_S in its own
explicit rules, so $* will be empty, resulting in ignoring the per-file
AFLAGS.

I introduced a new variable, target-stem, which can be used also from
explicit rules.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Marc Zyngier <maz@kernel.org>

show more ...

drm/amd/display: readd -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 p

drm/amd/display: readd -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 for Clang.

This was originally landed in:
commit 10117450735c ("drm/amd/display: add -msse2 to prevent Clang from emitting libcalls to undefined SW FP routines")
but reverted in:
commit 193392ed9f69 ("Revert "drm/amd/display: add -msse2 to prevent Clang from emitting libcalls to undefined SW FP routines"")
due to bugreports from GCC builds. Add guards to only do so for Clang.

Link: https://bugs.freedesktop.org/show_bug.cgi?id=109487
Link: https://github.com/ClangBuiltLinux/linux/issues/327

Suggested-by: Sedat Dilek <sedat.dilek@gmail.com>
Suggested-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

show more ...

drm/amd/display: Support clang option for stack alignment

As previously fixed for dml in commit 4769278e5c7f ("amdgpu/dc/dml:
Support clang option for stack alignment") and calcs in commit
cc32ad8f5

drm/amd/display: Support clang option for stack alignment

As previously fixed for dml in commit 4769278e5c7f ("amdgpu/dc/dml:
Support clang option for stack alignment") and calcs in commit
cc32ad8f559c ("amdgpu/dc/calcs: Support clang option for stack
alignment"), dcn20 uses an option that is not available with clang:

clang: error: unknown argument: '-mpreferred-stack-boundary=4'
scripts/Makefile.build:281: recipe for target 'drivers/gpu/drm/amd/amdgpu/../display/dc/dcn20/dcn20_resource.o' failed

Use the same trick that we have in the other two files.

Fixes: 7ed4e6352c16 ("drm/amd/display: Add DCN2 HW Sequencer and Resource")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

show more ...

drm/amd/display: Add DSC support for Navi (v2)

Add support for DCN2 DSC (Display Stream Compression)

HW Blocks:

+--------++------+ +----------+
| HUBBUB || HUBP | <-- | MMHUBBUB |
+----

drm/amd/display: Add DSC support for Navi (v2)

Add support for DCN2 DSC (Display Stream Compression)

HW Blocks:

+--------++------+ +----------+
| HUBBUB || HUBP | <-- | MMHUBBUB |
+--------++------+ +----------+
| ^
v |
+--------+ +--------+
| DPP | | DWB |
+--------+ +--------+
|
v ^
+--------+ |
| MPC | |
+--------+ |
| |
v |
+-------+ +-------+ |
| OPP | <--> | DSC | |
+-------+ +-------+ |
| |
v |
+--------+ /
| OPTC | --------------
+--------+
|
v
+--------+ +--------+
| DIO | | DCCG |
+--------+ +--------+

v2: rebase (Alex)

Signed-off-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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drm/amd/display: Rework dsc to isolate FPU operations

When we want to use float point operation on Linux
we need to use within special kernel protection
(`kernel_fpu_{begin,end}()`.)

drm/amd/display: Rework dsc to isolate FPU operations

When we want to use float point operation on Linux
we need to use within special kernel protection
(`kernel_fpu_{begin,end}()`.), otherwise the kernel
can clobber userspace FPU register state. For detecting
these issues we use a tool named objtool (with -Ffa
flags) to highlight the FPU problems, all warnings can
be summed up as follows:

./tools/objtool/objtool check -Ffa
drivers/gpu/drm/amd/display/dc/dml/dml_common_defs.o

[..] dc/dsc/rc_calc.o: warning: objtool: get_qp_set()+0x2f8:
FPU instruction outside of kernel_fpu_{begin,end}()
[..] dc/dsc/rc_calc.o: warning: objtool: dsc_roundf()+0x5:
FPU instruction outside of kernel_fpu_{begin,end}()
[..] dc/dsc/rc_calc.o: warning: objtool: dsc_ceil()+0x5:
FPU instruction outside of kernel_fpu_{begin,end}()
[..] dc/dsc/rc_calc.o: warning: objtool: get_ofs_set()+0x3eb:
FPU instruction outside of kernel_fpu_{begin,end}()
[..] dc/dsc/rc_calc.o: warning: objtool: calc_rc_params()+0x3c:
FPU instruction outside of kernel_fpu_{begin,end}()
[..] dc/dsc/dc_dsc.o: warning: objtool:
get_dsc_bandwidth_range.isra.0()+0x8d:
FPU instruction outside of kernel_fpu_{begin,end}()
[..] dc/dsc/dc_dsc.o: warning: objtool: setup_dsc_config()+0x2ef:
FPU instruction outside of kernel_fpu_{begin,end}()
[..] dc/dsc/rc_calc_dpi.o: warning: objtool:copy_pps_fields()+0xbb:
FPU instruction outside of kernel_fpu_{begin,end}()
[..] dc/dsc/rc_calc_dpi.o: warning: objtool:
dscc_compute_dsc_parameters()+0x7b:
FPU instruction outside of kernel_fpu_{begin,end}()

This commit fixes the above issues by rework DSC as described:

1. Isolate all FPU operations in a single file;
2. Use FPU flags only in the file that handles FPU operations;
3. Isolate all functions that require float point operation in static
functions;
4. Add a mid-layer function that does not use any float point operation,
and that could be safely invoked in other parts of the code.
5. Keep float point operation under DC_FP_{START/END} macro.

CC: Christian König <christian.koenig@amd.com>
CC: Alexander Deucher <Alexander.Deucher@amd.com>
CC: Peter Zijlstra <peterz@infradead.org>
CC: Tony Cheng <tony.cheng@amd.com>
CC: Harry Wentland <hwentlan@amd.com>
Signed-off-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Reviewed-by: Mikita Lipski <Mikita.Lipski@amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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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.

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>

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drm/amdgpu: fix license on Kconfig and Makefiles

amdgpu is MIT licensed.

Fixes: ec8f24b7faaf3d ("treewide: Add SPDX license identifier - Makefile/Kconfig")
Reviewed-by: Christia

drm/amdgpu: fix license on Kconfig and Makefiles

amdgpu is MIT licensed.

Fixes: ec8f24b7faaf3d ("treewide: Add SPDX license identifier - Makefile/Kconfig")
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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drm/amdgpu: enable -msse2 for GCC 7.1+ users

A final attempt at enabling sse2 for GCC users.

Orininally attempted in:
commit 10117450735c ("drm/amd/display: add -msse2 to preven

drm/amdgpu: enable -msse2 for GCC 7.1+ users

A final attempt at enabling sse2 for GCC users.

Orininally attempted in:
commit 10117450735c ("drm/amd/display: add -msse2 to prevent Clang from emitting libcalls to undefined SW FP routines")

Reverted due to "reported instability" in:
commit 193392ed9f69 ("Revert "drm/amd/display: add -msse2 to prevent Clang from emitting libcalls to undefined SW FP routines"")

Re-added just for Clang in:
commit 0f0727d971f6 ("drm/amd/display: readd -msse2 to prevent Clang from emitting libcalls to undefined SW FP routines")

The original report didn't have enough information to know if the GPF
was due to misalignment, but I suspect that it was. (The missing
information was the disassembly of the function at the bottom of the
trace, to see if the instruction pointer pointed to an instruction with
16B alignment memory operand requirements. The stack trace does show
the stack was only 8B but not 16B aligned though, which makes this a
strong possibility).

Now that the stack misalignment issue has been fixed for users of GCC
7.1+, reattempt adding -msse2. This matches Clang.

It will likely never be safe to enable this for pre-GCC 7.1 AND use a
16B aligned stack in these translation units.

This is only a functional change for GCC 7.1+ users, and should be boot
tested.

Link: https://bugs.freedesktop.org/show_bug.cgi?id=109487
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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drm/amdgpu: fix stack alignment ABI mismatch for GCC 7.1+

GCC earlier than 7.1 errors when compiling code that makes use of
`double`s and sets a stack alignment outside of the range of [

drm/amdgpu: fix stack alignment ABI mismatch for GCC 7.1+

GCC earlier than 7.1 errors when compiling code that makes use of
`double`s and sets a stack alignment outside of the range of [2^4-2^12]:

$ cat foo.c
double foo(double x, double y) {
return x + y;
}
$ gcc-4.9 -mpreferred-stack-boundary=3 foo.c
error: -mpreferred-stack-boundary=3 is not between 4 and 12

This is likely why the AMDGPU driver was ever compiled with a different
stack alignment (and thus different ABI) than the rest of the x86
kernel. The kernel uses 8B stack alignment, while the driver was using
16B stack alignment in a few places.

Since GCC 7.1+ doesn't error, fix the ABI mismatch for users of newer
versions of GCC.

There was discussion about whether to mark the driver broken or not for
users of GCC earlier than 7.1, but since the driver currently is
working, don't explicitly break the driver for them here.

Relying on differing stack alignment is unspecified behavior, and
brittle, and may break in the future.

This patch is no functional change for GCC users earlier than 7.1. It's
been compile tested on GCC 4.9 and 8.3 to check the correct flags. It
should be boot tested when built with GCC 7.1+.

-mincoming-stack-boundary= or -mstackrealign may help keep this code
building for pre-GCC 7.1 users.

The version check for GCC is broken into two conditionals, both because
cc-ifversion is currently GCC specific, and it simplifies a subsequent
patch.

Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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drm/amdgpu: fix stack alignment ABI mismatch for Clang

The x86 kernel is compiled with an 8B stack alignment via
`-mpreferred-stack-boundary=3` for GCC since 3.6-rc1 via
commit d9b0c

drm/amdgpu: fix stack alignment ABI mismatch for Clang

The x86 kernel is compiled with an 8B stack alignment via
`-mpreferred-stack-boundary=3` for GCC since 3.6-rc1 via
commit d9b0cde91c60 ("x86-64, gcc: Use -mpreferred-stack-boundary=3 if supported")
or `-mstack-alignment=8` for Clang. Parts of the AMDGPU driver are
compiled with 16B stack alignment.

Generally, the stack alignment is part of the ABI. Linking together two
different translation units with differing stack alignment is dangerous,
particularly when the translation unit with the smaller stack alignment
makes calls into the translation unit with the larger stack alignment.
While 8B aligned stacks are sometimes also 16B aligned, they are not
always.

Multiple users have reported General Protection Faults (GPF) when using
the AMDGPU driver compiled with Clang. Clang is placing objects in stack
slots assuming the stack is 16B aligned, and selecting instructions that
require 16B aligned memory operands.

At runtime, syscall handlers with 8B aligned stack call into code that
assumes 16B stack alignment. When the stack is a multiple of 8B but not
16B, these instructions result in a GPF.

Remove the code that added compatibility between the differing compiler
flags, as it will result in runtime GPFs when built with Clang. Cleanups
for GCC will be sent in later patches in the series.

Link: https://github.com/ClangBuiltLinux/linux/issues/735
Debugged-by: Yuxuan Shui <yshuiv7@gmail.com>
Reported-by: Shirish S <shirish.s@amd.com>
Reported-by: Yuxuan Shui <yshuiv7@gmail.com>
Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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Merge tag 'kbuild-v5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

- add modpost warn exported symbols marked

Merge tag 'kbuild-v5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

- add modpost warn exported symbols marked as 'static' because 'static'
and EXPORT_SYMBOL is an odd combination

- break the build early if gold linker is used

- optimize the Bison rule to produce .c and .h files by a single
pattern rule

- handle PREEMPT_RT in the module vermagic and UTS_VERSION

- warn CONFIG options leaked to the user-space except existing ones

- make single targets work properly

- rebuild modules when module linker scripts are updated

- split the module final link stage into scripts/Makefile.modfinal

- fix the missed error code in merge_config.sh

- improve the error message displayed on the attempt of the O= build in
unclean source tree

- remove 'clean-dirs' syntax

- disable -Wimplicit-fallthrough warning for Clang

- add CONFIG_CC_OPTIMIZE_FOR_SIZE_O3 for ARC

- remove ARCH_{CPP,A,C}FLAGS variables

- add $(BASH) to run bash scripts

- change *CFLAGS_<basetarget>.o to take the relative path to $(obj)
instead of the basename

- stop suppressing Clang's -Wunused-function warnings when W=1

- fix linux/export.h to avoid genksyms calculating CRC of trimmed
exported symbols

- misc cleanups

* tag 'kbuild-v5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (63 commits)
genksyms: convert to SPDX License Identifier for lex.l and parse.y
modpost: use __section in the output to *.mod.c
modpost: use MODULE_INFO() for __module_depends
export.h, genksyms: do not make genksyms calculate CRC of trimmed symbols
export.h: remove defined(__KERNEL__), which is no longer needed
kbuild: allow Clang to find unused static inline functions for W=1 build
kbuild: rename KBUILD_ENABLE_EXTRA_GCC_CHECKS to KBUILD_EXTRA_WARN
kbuild: refactor scripts/Makefile.extrawarn
merge_config.sh: ignore unwanted grep errors
kbuild: change *FLAGS_<basetarget>.o to take the path relative to $(obj)
modpost: add NOFAIL to strndup
modpost: add guid_t type definition
kbuild: add $(BASH) to run scripts with bash-extension
kbuild: remove ARCH_{CPP,A,C}FLAGS
kbuild,arc: add CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3 for ARC
kbuild: Do not enable -Wimplicit-fallthrough for clang for now
kbuild: clean up subdir-ymn calculation in Makefile.clean
kbuild: remove unneeded '+' marker from cmd_clean
kbuild: remove clean-dirs syntax
kbuild: check clean srctree even earlier
...

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