[PATCH] drm/i915: remove always-defined CONFIG_AS_MOVNTDQA

[Masahiro Yamada]

CONFIG_AS_MOVNTDQA was introduced by commit 0b1de5d58e19 ("drm/i915:
Use SSE4.1 movntdqa to accelerate reads from WC memory").

We raise the minimal supported binutils version from time to time.
The last bump was commit 1fb12b35e5ff ("kbuild: Raise the minimum
required binutils version to 2.21").

I confirmed the code in $(call as-instr,...) can be assembled by the
binutils 2.21 assembler and also by Clang's integrated assembler.

Remove CONFIG_AS_MOVNTDQA, which is always defined.

Signed-off-by: Masahiro Yamada <masa...@kernel.org>
---

drivers/gpu/drm/i915/Makefile | 3 ---
drivers/gpu/drm/i915/i915_memcpy.c | 5 -----
2 files changed, 8 deletions(-)

diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
index a1f2411aa21b..e559e53fc634 100644
--- a/drivers/gpu/drm/i915/Makefile
+++ b/drivers/gpu/drm/i915/Makefile
@@ -28,9 +28,6 @@ subdir-ccflags-$(CONFIG_DRM_I915_WERROR) += -Werror
CFLAGS_i915_pci.o = $(call cc-disable-warning, override-init)
CFLAGS_display/intel_fbdev.o = $(call cc-disable-warning, override-init)

-subdir-ccflags-y += \
- $(call as-instr,movntdqa (%eax)$(comma)%xmm0,-DCONFIG_AS_MOVNTDQA)
-
subdir-ccflags-y += -I$(srctree)/$(src)

# Please keep these build lists sorted!
diff --git a/drivers/gpu/drm/i915/i915_memcpy.c b/drivers/gpu/drm/i915/i915_memcpy.c
index fdd550405fd3..7b3b83bd5ab8 100644
--- a/drivers/gpu/drm/i915/i915_memcpy.c
+++ b/drivers/gpu/drm/i915/i915_memcpy.c
@@ -35,7 +35,6 @@

static DEFINE_STATIC_KEY_FALSE(has_movntdqa);

-#ifdef CONFIG_AS_MOVNTDQA
static void __memcpy_ntdqa(void *dst, const void *src, unsigned long len)
{
kernel_fpu_begin();
@@ -93,10 +92,6 @@ static void __memcpy_ntdqu(void *dst, const void *src, unsigned long len)

kernel_fpu_end();
}
-#else
-static void __memcpy_ntdqa(void *dst, const void *src, unsigned long len) {}
-static void __memcpy_ntdqu(void *dst, const void *src, unsigned long len) {}
-#endif

/**
* i915_memcpy_from_wc: perform an accelerated *aligned* read from WC
--
2.17.1

[Nick Desaulniers]

On Sun, Mar 22, 2020 at 7:12 PM Masahiro Yamada <masa...@kernel.org> wrote:
>
> CONFIG_AS_MOVNTDQA was introduced by commit 0b1de5d58e19 ("drm/i915:
> Use SSE4.1 movntdqa to accelerate reads from WC memory").
>
> We raise the minimal supported binutils version from time to time.
> The last bump was commit 1fb12b35e5ff ("kbuild: Raise the minimum
> required binutils version to 2.21").

Indeed, I see 2.21 was released in 2010, and I see a commit modifying
existing support for movntdqa in 2008; it looks like these have been
supported for a while. Thanks for this cleanup; the less we have to
invoke tools during make invocation, to lower the overhead of Kbuild.
Reviewed-by: Nick Desaulniers <ndesau...@google.com>

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--
Thanks,
~Nick Desaulniers

[Masahiro Yamada]

Hi i915 maintainers,

On Mon, Mar 23, 2020 at 11:12 AM Masahiro Yamada <masa...@kernel.org> wrote:
>
> CONFIG_AS_MOVNTDQA was introduced by commit 0b1de5d58e19 ("drm/i915:
> Use SSE4.1 movntdqa to accelerate reads from WC memory").
>
> We raise the minimal supported binutils version from time to time.
> The last bump was commit 1fb12b35e5ff ("kbuild: Raise the minimum
> required binutils version to 2.21").
>
> I confirmed the code in $(call as-instr,...) can be assembled by the
> binutils 2.21 assembler and also by Clang's integrated assembler.
>
> Remove CONFIG_AS_MOVNTDQA, which is always defined.
>
> Signed-off-by: Masahiro Yamada <masa...@kernel.org>
> ---

Please discard this.

I decided to fold this (10/16) into the following big series
because I was suggested to do so.

https://lore.kernel.org/patchwork/project/lkml/list/?series=435391





--
Best Regards
Masahiro Yamada