2019-11-01 08:14:49

by Masahiro Yamada

[permalink] [raw]
Subject: [PATCH v2 2/3] ARM: decompressor: simplify libfdt builds

Copying source files during the build time may not end up with
as clean code as you expect.

lib/fdt*.c simply wrap scripts/dtc/libfdt/fdt*.c, and it works
nicely. Let's follow that approach for the arm decompressor, too.

Add four wrappers, arch/arm/boot/compressed/fdt*.c and remove the
Makefile messes.

Another nice thing is we no longer need to maintain the separate
libfdt_env.h since we can include <linux/libfdt_env.h>, and the
diff stat also looks nice.

Signed-off-by: Masahiro Yamada <[email protected]>
---

Changes in v2: None

arch/arm/boot/compressed/.gitignore | 9 -------
arch/arm/boot/compressed/Makefile | 33 +++++++------------------
arch/arm/boot/compressed/atags_to_fdt.c | 1 +
arch/arm/boot/compressed/fdt.c | 2 ++
arch/arm/boot/compressed/fdt_ro.c | 2 ++
arch/arm/boot/compressed/fdt_rw.c | 2 ++
arch/arm/boot/compressed/fdt_wip.c | 2 ++
arch/arm/boot/compressed/libfdt_env.h | 22 -----------------
8 files changed, 18 insertions(+), 55 deletions(-)
create mode 100644 arch/arm/boot/compressed/fdt.c
create mode 100644 arch/arm/boot/compressed/fdt_ro.c
create mode 100644 arch/arm/boot/compressed/fdt_rw.c
create mode 100644 arch/arm/boot/compressed/fdt_wip.c
delete mode 100644 arch/arm/boot/compressed/libfdt_env.h

diff --git a/arch/arm/boot/compressed/.gitignore b/arch/arm/boot/compressed/.gitignore
index 86b2f5d28240..2fdb4885846b 100644
--- a/arch/arm/boot/compressed/.gitignore
+++ b/arch/arm/boot/compressed/.gitignore
@@ -6,12 +6,3 @@ hyp-stub.S
piggy_data
vmlinux
vmlinux.lds
-
-# borrowed libfdt files
-fdt.c
-fdt.h
-fdt_ro.c
-fdt_rw.c
-fdt_wip.c
-libfdt.h
-libfdt_internal.h
diff --git a/arch/arm/boot/compressed/Makefile b/arch/arm/boot/compressed/Makefile
index 9219389bbe61..a0d645c66980 100644
--- a/arch/arm/boot/compressed/Makefile
+++ b/arch/arm/boot/compressed/Makefile
@@ -76,29 +76,23 @@ compress-$(CONFIG_KERNEL_LZMA) = lzma
compress-$(CONFIG_KERNEL_XZ) = xzkern
compress-$(CONFIG_KERNEL_LZ4) = lz4

-# Borrowed libfdt files for the ATAG compatibility mode
-
-libfdt := fdt_rw.c fdt_ro.c fdt_wip.c fdt.c
-libfdt_hdrs := fdt.h libfdt.h libfdt_internal.h
-
-libfdt_objs := $(addsuffix .o, $(basename $(libfdt)))
-
-$(addprefix $(obj)/,$(libfdt) $(libfdt_hdrs)): $(obj)/%: $(srctree)/scripts/dtc/libfdt/%
- $(call cmd,shipped)
+ifeq ($(CONFIG_ARM_ATAG_DTB_COMPAT),y)
+libfdt_objs = fdt_rw.o fdt_ro.o fdt_wip.o fdt.o atags_to_fdt.o

-$(addprefix $(obj)/,$(libfdt_objs) atags_to_fdt.o): \
- $(addprefix $(obj)/,$(libfdt_hdrs))
+OBJS += $(libfdt_objs)

-ifeq ($(CONFIG_ARM_ATAG_DTB_COMPAT),y)
-OBJS += $(libfdt_objs) atags_to_fdt.o
+# -fstack-protector-strong triggers protection checks in this code,
+# but it is being used too early to link to meaningful stack_chk logic.
+nossp_flags := $(call cc-option, -fno-stack-protector)
+$(foreach o, $(libfdt_objs), \
+ $(eval CFLAGS_$(o) := -I $(srctree)/scripts/dtc/libfdt) $(nossp_flags))
endif

targets := vmlinux vmlinux.lds piggy_data piggy.o \
lib1funcs.o ashldi3.o bswapsdi2.o \
head.o $(OBJS)

-clean-files += piggy_data lib1funcs.S ashldi3.S bswapsdi2.S \
- $(libfdt) $(libfdt_hdrs) hyp-stub.S
+clean-files += piggy_data lib1funcs.S ashldi3.S bswapsdi2.S hyp-stub.S

KBUILD_CFLAGS += -DDISABLE_BRANCH_PROFILING
KBUILD_CFLAGS += $(DISABLE_ARM_SSP_PER_TASK_PLUGIN)
@@ -108,15 +102,6 @@ ORIG_CFLAGS := $(KBUILD_CFLAGS)
KBUILD_CFLAGS = $(subst -pg, , $(ORIG_CFLAGS))
endif

-# -fstack-protector-strong triggers protection checks in this code,
-# but it is being used too early to link to meaningful stack_chk logic.
-nossp_flags := $(call cc-option, -fno-stack-protector)
-CFLAGS_atags_to_fdt.o := $(nossp_flags)
-CFLAGS_fdt.o := $(nossp_flags)
-CFLAGS_fdt_ro.o := $(nossp_flags)
-CFLAGS_fdt_rw.o := $(nossp_flags)
-CFLAGS_fdt_wip.o := $(nossp_flags)
-
ccflags-y := -fpic $(call cc-option,-mno-single-pic-base,) -fno-builtin -I$(obj)
asflags-y := -DZIMAGE

diff --git a/arch/arm/boot/compressed/atags_to_fdt.c b/arch/arm/boot/compressed/atags_to_fdt.c
index 330cd3c2eae5..53a60ba066a1 100644
--- a/arch/arm/boot/compressed/atags_to_fdt.c
+++ b/arch/arm/boot/compressed/atags_to_fdt.c
@@ -1,4 +1,5 @@
// SPDX-License-Identifier: GPL-2.0
+#include <linux/libfdt_env.h>
#include <asm/setup.h>
#include <libfdt.h>

diff --git a/arch/arm/boot/compressed/fdt.c b/arch/arm/boot/compressed/fdt.c
new file mode 100644
index 000000000000..f8ea7a201ab1
--- /dev/null
+++ b/arch/arm/boot/compressed/fdt.c
@@ -0,0 +1,2 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include "../../../../lib/fdt.c"
diff --git a/arch/arm/boot/compressed/fdt_ro.c b/arch/arm/boot/compressed/fdt_ro.c
new file mode 100644
index 000000000000..93970a4ad5ae
--- /dev/null
+++ b/arch/arm/boot/compressed/fdt_ro.c
@@ -0,0 +1,2 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include "../../../../lib/fdt_ro.c"
diff --git a/arch/arm/boot/compressed/fdt_rw.c b/arch/arm/boot/compressed/fdt_rw.c
new file mode 100644
index 000000000000..f7c6b8b7e01c
--- /dev/null
+++ b/arch/arm/boot/compressed/fdt_rw.c
@@ -0,0 +1,2 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include "../../../../lib/fdt_rw.c"
diff --git a/arch/arm/boot/compressed/fdt_wip.c b/arch/arm/boot/compressed/fdt_wip.c
new file mode 100644
index 000000000000..048d2c7a088d
--- /dev/null
+++ b/arch/arm/boot/compressed/fdt_wip.c
@@ -0,0 +1,2 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include "../../../../lib/fdt_wip.c"
diff --git a/arch/arm/boot/compressed/libfdt_env.h b/arch/arm/boot/compressed/libfdt_env.h
deleted file mode 100644
index b36c0289a308..000000000000
--- a/arch/arm/boot/compressed/libfdt_env.h
+++ /dev/null
@@ -1,22 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _ARM_LIBFDT_ENV_H
-#define _ARM_LIBFDT_ENV_H
-
-#include <linux/types.h>
-#include <linux/string.h>
-#include <asm/byteorder.h>
-
-#define INT_MAX ((int)(~0U>>1))
-
-typedef __be16 fdt16_t;
-typedef __be32 fdt32_t;
-typedef __be64 fdt64_t;
-
-#define fdt16_to_cpu(x) be16_to_cpu(x)
-#define cpu_to_fdt16(x) cpu_to_be16(x)
-#define fdt32_to_cpu(x) be32_to_cpu(x)
-#define cpu_to_fdt32(x) cpu_to_be32(x)
-#define fdt64_to_cpu(x) be64_to_cpu(x)
-#define cpu_to_fdt64(x) cpu_to_be64(x)
-
-#endif
--
2.17.1


2019-11-05 01:05:51

by Rob Herring

[permalink] [raw]
Subject: Re: [PATCH v2 2/3] ARM: decompressor: simplify libfdt builds

On Fri, Nov 1, 2019 at 3:12 AM Masahiro Yamada
<[email protected]> wrote:
>
> Copying source files during the build time may not end up with
> as clean code as you expect.
>
> lib/fdt*.c simply wrap scripts/dtc/libfdt/fdt*.c, and it works
> nicely. Let's follow that approach for the arm decompressor, too.
>
> Add four wrappers, arch/arm/boot/compressed/fdt*.c and remove the
> Makefile messes.
>
> Another nice thing is we no longer need to maintain the separate
> libfdt_env.h since we can include <linux/libfdt_env.h>, and the
> diff stat also looks nice.
>
> Signed-off-by: Masahiro Yamada <[email protected]>
> ---
>
> Changes in v2: None
>
> arch/arm/boot/compressed/.gitignore | 9 -------
> arch/arm/boot/compressed/Makefile | 33 +++++++------------------
> arch/arm/boot/compressed/atags_to_fdt.c | 1 +
> arch/arm/boot/compressed/fdt.c | 2 ++
> arch/arm/boot/compressed/fdt_ro.c | 2 ++
> arch/arm/boot/compressed/fdt_rw.c | 2 ++
> arch/arm/boot/compressed/fdt_wip.c | 2 ++
> arch/arm/boot/compressed/libfdt_env.h | 22 -----------------
> 8 files changed, 18 insertions(+), 55 deletions(-)
> create mode 100644 arch/arm/boot/compressed/fdt.c
> create mode 100644 arch/arm/boot/compressed/fdt_ro.c
> create mode 100644 arch/arm/boot/compressed/fdt_rw.c
> create mode 100644 arch/arm/boot/compressed/fdt_wip.c
> delete mode 100644 arch/arm/boot/compressed/libfdt_env.h

Looks fine to me other than my question on licensing on patch 1.

Who did you want to take the series? I can take it with Russell's ack.

One other side comment below.

> diff --git a/arch/arm/boot/compressed/.gitignore b/arch/arm/boot/compressed/.gitignore
> index 86b2f5d28240..2fdb4885846b 100644
> --- a/arch/arm/boot/compressed/.gitignore
> +++ b/arch/arm/boot/compressed/.gitignore
> @@ -6,12 +6,3 @@ hyp-stub.S
> piggy_data
> vmlinux
> vmlinux.lds
> -
> -# borrowed libfdt files
> -fdt.c
> -fdt.h
> -fdt_ro.c
> -fdt_rw.c
> -fdt_wip.c
> -libfdt.h
> -libfdt_internal.h
> diff --git a/arch/arm/boot/compressed/Makefile b/arch/arm/boot/compressed/Makefile
> index 9219389bbe61..a0d645c66980 100644
> --- a/arch/arm/boot/compressed/Makefile
> +++ b/arch/arm/boot/compressed/Makefile
> @@ -76,29 +76,23 @@ compress-$(CONFIG_KERNEL_LZMA) = lzma
> compress-$(CONFIG_KERNEL_XZ) = xzkern
> compress-$(CONFIG_KERNEL_LZ4) = lz4
>
> -# Borrowed libfdt files for the ATAG compatibility mode
> -
> -libfdt := fdt_rw.c fdt_ro.c fdt_wip.c fdt.c
> -libfdt_hdrs := fdt.h libfdt.h libfdt_internal.h
> -
> -libfdt_objs := $(addsuffix .o, $(basename $(libfdt)))
> -
> -$(addprefix $(obj)/,$(libfdt) $(libfdt_hdrs)): $(obj)/%: $(srctree)/scripts/dtc/libfdt/%
> - $(call cmd,shipped)
> +ifeq ($(CONFIG_ARM_ATAG_DTB_COMPAT),y)
> +libfdt_objs = fdt_rw.o fdt_ro.o fdt_wip.o fdt.o atags_to_fdt.o
>
> -$(addprefix $(obj)/,$(libfdt_objs) atags_to_fdt.o): \
> - $(addprefix $(obj)/,$(libfdt_hdrs))
> +OBJS += $(libfdt_objs)

Seems like this file could benefit from doing 'OBJS-$(CONFIG_*)' style
variables.

> -ifeq ($(CONFIG_ARM_ATAG_DTB_COMPAT),y)
> -OBJS += $(libfdt_objs) atags_to_fdt.o
> +# -fstack-protector-strong triggers protection checks in this code,
> +# but it is being used too early to link to meaningful stack_chk logic.
> +nossp_flags := $(call cc-option, -fno-stack-protector)
> +$(foreach o, $(libfdt_objs), \
> + $(eval CFLAGS_$(o) := -I $(srctree)/scripts/dtc/libfdt) $(nossp_flags))
> endif
>
> targets := vmlinux vmlinux.lds piggy_data piggy.o \
> lib1funcs.o ashldi3.o bswapsdi2.o \
> head.o $(OBJS)
>
> -clean-files += piggy_data lib1funcs.S ashldi3.S bswapsdi2.S \
> - $(libfdt) $(libfdt_hdrs) hyp-stub.S
> +clean-files += piggy_data lib1funcs.S ashldi3.S bswapsdi2.S hyp-stub.S
>
> KBUILD_CFLAGS += -DDISABLE_BRANCH_PROFILING
> KBUILD_CFLAGS += $(DISABLE_ARM_SSP_PER_TASK_PLUGIN)
> @@ -108,15 +102,6 @@ ORIG_CFLAGS := $(KBUILD_CFLAGS)
> KBUILD_CFLAGS = $(subst -pg, , $(ORIG_CFLAGS))
> endif
>
> -# -fstack-protector-strong triggers protection checks in this code,
> -# but it is being used too early to link to meaningful stack_chk logic.
> -nossp_flags := $(call cc-option, -fno-stack-protector)
> -CFLAGS_atags_to_fdt.o := $(nossp_flags)
> -CFLAGS_fdt.o := $(nossp_flags)
> -CFLAGS_fdt_ro.o := $(nossp_flags)
> -CFLAGS_fdt_rw.o := $(nossp_flags)
> -CFLAGS_fdt_wip.o := $(nossp_flags)
> -
> ccflags-y := -fpic $(call cc-option,-mno-single-pic-base,) -fno-builtin -I$(obj)
> asflags-y := -DZIMAGE
>
> diff --git a/arch/arm/boot/compressed/atags_to_fdt.c b/arch/arm/boot/compressed/atags_to_fdt.c
> index 330cd3c2eae5..53a60ba066a1 100644
> --- a/arch/arm/boot/compressed/atags_to_fdt.c
> +++ b/arch/arm/boot/compressed/atags_to_fdt.c
> @@ -1,4 +1,5 @@
> // SPDX-License-Identifier: GPL-2.0
> +#include <linux/libfdt_env.h>
> #include <asm/setup.h>
> #include <libfdt.h>
>
> diff --git a/arch/arm/boot/compressed/fdt.c b/arch/arm/boot/compressed/fdt.c
> new file mode 100644
> index 000000000000..f8ea7a201ab1
> --- /dev/null
> +++ b/arch/arm/boot/compressed/fdt.c
> @@ -0,0 +1,2 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +#include "../../../../lib/fdt.c"
> diff --git a/arch/arm/boot/compressed/fdt_ro.c b/arch/arm/boot/compressed/fdt_ro.c
> new file mode 100644
> index 000000000000..93970a4ad5ae
> --- /dev/null
> +++ b/arch/arm/boot/compressed/fdt_ro.c
> @@ -0,0 +1,2 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +#include "../../../../lib/fdt_ro.c"
> diff --git a/arch/arm/boot/compressed/fdt_rw.c b/arch/arm/boot/compressed/fdt_rw.c
> new file mode 100644
> index 000000000000..f7c6b8b7e01c
> --- /dev/null
> +++ b/arch/arm/boot/compressed/fdt_rw.c
> @@ -0,0 +1,2 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +#include "../../../../lib/fdt_rw.c"
> diff --git a/arch/arm/boot/compressed/fdt_wip.c b/arch/arm/boot/compressed/fdt_wip.c
> new file mode 100644
> index 000000000000..048d2c7a088d
> --- /dev/null
> +++ b/arch/arm/boot/compressed/fdt_wip.c
> @@ -0,0 +1,2 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +#include "../../../../lib/fdt_wip.c"
> diff --git a/arch/arm/boot/compressed/libfdt_env.h b/arch/arm/boot/compressed/libfdt_env.h
> deleted file mode 100644
> index b36c0289a308..000000000000
> --- a/arch/arm/boot/compressed/libfdt_env.h
> +++ /dev/null
> @@ -1,22 +0,0 @@
> -/* SPDX-License-Identifier: GPL-2.0 */
> -#ifndef _ARM_LIBFDT_ENV_H
> -#define _ARM_LIBFDT_ENV_H
> -
> -#include <linux/types.h>
> -#include <linux/string.h>
> -#include <asm/byteorder.h>
> -
> -#define INT_MAX ((int)(~0U>>1))
> -
> -typedef __be16 fdt16_t;
> -typedef __be32 fdt32_t;
> -typedef __be64 fdt64_t;
> -
> -#define fdt16_to_cpu(x) be16_to_cpu(x)
> -#define cpu_to_fdt16(x) cpu_to_be16(x)
> -#define fdt32_to_cpu(x) be32_to_cpu(x)
> -#define cpu_to_fdt32(x) cpu_to_be32(x)
> -#define fdt64_to_cpu(x) be64_to_cpu(x)
> -#define cpu_to_fdt64(x) cpu_to_be64(x)
> -
> -#endif
> --
> 2.17.1
>

2019-11-05 01:59:20

by Masahiro Yamada

[permalink] [raw]
Subject: Re: [PATCH v2 2/3] ARM: decompressor: simplify libfdt builds

On Tue, Nov 5, 2019 at 10:04 AM Rob Herring <[email protected]> wrote:
>
> On Fri, Nov 1, 2019 at 3:12 AM Masahiro Yamada
> <[email protected]> wrote:
> >
> > Copying source files during the build time may not end up with
> > as clean code as you expect.
> >
> > lib/fdt*.c simply wrap scripts/dtc/libfdt/fdt*.c, and it works
> > nicely. Let's follow that approach for the arm decompressor, too.
> >
> > Add four wrappers, arch/arm/boot/compressed/fdt*.c and remove the
> > Makefile messes.
> >
> > Another nice thing is we no longer need to maintain the separate
> > libfdt_env.h since we can include <linux/libfdt_env.h>, and the
> > diff stat also looks nice.
> >
> > Signed-off-by: Masahiro Yamada <[email protected]>
> > ---
> >
> > Changes in v2: None
> >
> > arch/arm/boot/compressed/.gitignore | 9 -------
> > arch/arm/boot/compressed/Makefile | 33 +++++++------------------
> > arch/arm/boot/compressed/atags_to_fdt.c | 1 +
> > arch/arm/boot/compressed/fdt.c | 2 ++
> > arch/arm/boot/compressed/fdt_ro.c | 2 ++
> > arch/arm/boot/compressed/fdt_rw.c | 2 ++
> > arch/arm/boot/compressed/fdt_wip.c | 2 ++
> > arch/arm/boot/compressed/libfdt_env.h | 22 -----------------
> > 8 files changed, 18 insertions(+), 55 deletions(-)
> > create mode 100644 arch/arm/boot/compressed/fdt.c
> > create mode 100644 arch/arm/boot/compressed/fdt_ro.c
> > create mode 100644 arch/arm/boot/compressed/fdt_rw.c
> > create mode 100644 arch/arm/boot/compressed/fdt_wip.c
> > delete mode 100644 arch/arm/boot/compressed/libfdt_env.h
>
> Looks fine to me other than my question on licensing on patch 1.
>
> Who did you want to take the series? I can take it with Russell's ack.

Rob,
I'd like you to take the whole of this patch set
if there is no objection.

Russell,
Is this patch OK with you?



> >
> > -$(addprefix $(obj)/,$(libfdt_objs) atags_to_fdt.o): \
> > - $(addprefix $(obj)/,$(libfdt_hdrs))
> > +OBJS += $(libfdt_objs)
>
> Seems like this file could benefit from doing 'OBJS-$(CONFIG_*)' style
> variables.

I agree, but this kind of refactoring is
not the main interest of this series.

It should be done by a separate patch if it is desired.



> > diff --git a/arch/arm/boot/compressed/fdt.c b/arch/arm/boot/compressed/fdt.c
> > new file mode 100644
> > index 000000000000..f8ea7a201ab1
> > --- /dev/null
> > +++ b/arch/arm/boot/compressed/fdt.c
> > @@ -0,0 +1,2 @@
> > +// SPDX-License-Identifier: GPL-2.0-only
> > +#include "../../../../lib/fdt.c"
> > diff --git a/arch/arm/boot/compressed/fdt_ro.c b/arch/arm/boot/compressed/fdt_ro.c
> > new file mode 100644
> > index 000000000000..93970a4ad5ae
> > --- /dev/null
> > +++ b/arch/arm/boot/compressed/fdt_ro.c
> > @@ -0,0 +1,2 @@
> > +// SPDX-License-Identifier: GPL-2.0-only
> > +#include "../../../../lib/fdt_ro.c"
> > diff --git a/arch/arm/boot/compressed/fdt_rw.c b/arch/arm/boot/compressed/fdt_rw.c
> > new file mode 100644
> > index 000000000000..f7c6b8b7e01c
> > --- /dev/null
> > +++ b/arch/arm/boot/compressed/fdt_rw.c
> > @@ -0,0 +1,2 @@
> > +// SPDX-License-Identifier: GPL-2.0-only
> > +#include "../../../../lib/fdt_rw.c"
> > diff --git a/arch/arm/boot/compressed/fdt_wip.c b/arch/arm/boot/compressed/fdt_wip.c
> > new file mode 100644
> > index 000000000000..048d2c7a088d
> > --- /dev/null
> > +++ b/arch/arm/boot/compressed/fdt_wip.c
> > @@ -0,0 +1,2 @@
> > +// SPDX-License-Identifier: GPL-2.0-only
> > +#include "../../../../lib/fdt_wip.c"


I gave GPL-2.0-only to this,
but it should be the same as lib/fdt*.c,
which is now being discussed in 1/3.



--
Best Regards
Masahiro Yamada