diff mbox series

[v4,1/2] xen: asm-generic support

Message ID 96b2a4ff48578b7b105581529d2aa6bebd8ad622.1693583721.git.oleksii.kurochko@gmail.com (mailing list archive)
State Superseded
Headers show
Series introduce stub directory to storing empty/stub headers | expand

Commit Message

Oleksii Kurochko Sept. 1, 2023, 4:02 p.m. UTC
Some headers are shared between individual architectures or are empty.
To avoid duplication of these headers, asm-generic is introduced.

With the following patch, an architecture uses generic headers
mentioned in the file arch/$(ARCH)/include/asm/Kbuild.

To use a generic header is needed to add to
arch/$(ARCH)/include/asm/Kbuild :
        generic-y += <name-of-header-file.h>

For each mentioned header in arch/$(ARCH)/include/asm/Kbuild,
kbuild will generate the necessary wrapper in
arch/$(ARCH)/include/generated/asm.

Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
---
Changes in V4:
 - introduce asm-generic support
 - update commit message
---
Changes in V3:
 - Rename stubs dir to asm-generic
---
Changes in V2:
 - Nothing changed.
---
 xen/Makefile                      | 10 +++++++++-
 xen/arch/arm/include/asm/Kbuild   |  1 +
 xen/arch/ppc/include/asm/Kbuild   |  1 +
 xen/arch/riscv/include/asm/Kbuild |  1 +
 xen/arch/x86/include/asm/Kbuild   |  1 +
 xen/scripts/Makefile.asm-generic  | 23 +++++++++++++++++++++++
 6 files changed, 36 insertions(+), 1 deletion(-)
 create mode 100644 xen/arch/arm/include/asm/Kbuild
 create mode 100644 xen/arch/ppc/include/asm/Kbuild
 create mode 100644 xen/arch/riscv/include/asm/Kbuild
 create mode 100644 xen/arch/x86/include/asm/Kbuild
 create mode 100644 xen/scripts/Makefile.asm-generic

Comments

Bertrand Marquis Sept. 4, 2023, 1:39 p.m. UTC | #1
Hi Oleksii,

> On 1 Sep 2023, at 18:02, Oleksii Kurochko <oleksii.kurochko@gmail.com> wrote:
> 
> Some headers are shared between individual architectures or are empty.
> To avoid duplication of these headers, asm-generic is introduced.
> 
> With the following patch, an architecture uses generic headers
> mentioned in the file arch/$(ARCH)/include/asm/Kbuild.

Kbuild refers to "Kernel build" I guess.
I am ok to keep that name to keep things simpler when compared to
Linux scripts but it would be good to mention that in the commit
message for future reference. 

> 
> To use a generic header is needed to add to
> arch/$(ARCH)/include/asm/Kbuild :
>        generic-y += <name-of-header-file.h>
> 
> For each mentioned header in arch/$(ARCH)/include/asm/Kbuild,
> kbuild will generate the necessary wrapper in
> arch/$(ARCH)/include/generated/asm.
> 
> Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
> ---
> Changes in V4:
> - introduce asm-generic support
> - update commit message
> ---
> Changes in V3:
> - Rename stubs dir to asm-generic
> ---
> Changes in V2:
> - Nothing changed.
> ---
> xen/Makefile                      | 10 +++++++++-
> xen/arch/arm/include/asm/Kbuild   |  1 +
> xen/arch/ppc/include/asm/Kbuild   |  1 +
> xen/arch/riscv/include/asm/Kbuild |  1 +
> xen/arch/x86/include/asm/Kbuild   |  1 +
> xen/scripts/Makefile.asm-generic  | 23 +++++++++++++++++++++++
> 6 files changed, 36 insertions(+), 1 deletion(-)
> create mode 100644 xen/arch/arm/include/asm/Kbuild
> create mode 100644 xen/arch/ppc/include/asm/Kbuild
> create mode 100644 xen/arch/riscv/include/asm/Kbuild
> create mode 100644 xen/arch/x86/include/asm/Kbuild
> create mode 100644 xen/scripts/Makefile.asm-generic
> 
> diff --git a/xen/Makefile b/xen/Makefile
> index f57e5a596c..698d6ddeb8 100644
> --- a/xen/Makefile
> +++ b/xen/Makefile
> @@ -438,6 +438,7 @@ ifdef building_out_of_srctree
> endif
> CFLAGS += -I$(srctree)/include
> CFLAGS += -I$(srctree)/arch/$(SRCARCH)/include
> +CFLAGS += -I$(srctree)/arch/$(SRCARCH)/include/generated

Why are we generating files in the source tree ? 
Shouldn't we keep it unmodified ?

> 
> # Note that link order matters!
> ALL_OBJS-y                := common/built_in.o
> @@ -580,6 +581,7 @@ _clean:
> rm -f $(TARGET).efi $(TARGET).efi.map $(TARGET).efi.elf $(TARGET).efi.stripped
> rm -f asm-offsets.s arch/*/include/asm/asm-offsets.h
> rm -f .banner .allconfig.tmp include/xen/compile.h
> + rm -rf arch/*/include/generated
> 

You must use the same as for CFLAGS here so $(srctree) would be needed.
(or something else depending on the fix for previous comment)

> .PHONY: _distclean
> _distclean: clean
> @@ -589,7 +591,7 @@ $(TARGET).gz: $(TARGET)
> gzip -n -f -9 < $< > $@.new
> mv $@.new $@
> 
> -$(TARGET): outputmakefile FORCE
> +$(TARGET): outputmakefile asm-generic FORCE
> $(Q)$(MAKE) $(build)=tools
> $(Q)$(MAKE) $(build)=. include/xen/compile.h
> $(Q)$(MAKE) $(build)=include all
> @@ -667,6 +669,12 @@ endif # need-sub-make
> PHONY += FORCE
> FORCE:
> 
> +# Support for using generic headers in asm-generic
> +PHONY += asm-generic
> +asm-generic:
> + $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.asm-generic \
> +            obj=arch/$(SRCARCH)/include/generated/asm
> +
> # Declare the contents of the PHONY variable as phony.  We keep that
> # information in a variable so we can use it in if_changed and friends.
> .PHONY: $(PHONY)
> diff --git a/xen/arch/arm/include/asm/Kbuild b/xen/arch/arm/include/asm/Kbuild
> new file mode 100644
> index 0000000000..a4e40e534e
> --- /dev/null
> +++ b/xen/arch/arm/include/asm/Kbuild
> @@ -0,0 +1 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> diff --git a/xen/arch/ppc/include/asm/Kbuild b/xen/arch/ppc/include/asm/Kbuild
> new file mode 100644
> index 0000000000..a4e40e534e
> --- /dev/null
> +++ b/xen/arch/ppc/include/asm/Kbuild
> @@ -0,0 +1 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> diff --git a/xen/arch/riscv/include/asm/Kbuild b/xen/arch/riscv/include/asm/Kbuild
> new file mode 100644
> index 0000000000..a4e40e534e
> --- /dev/null
> +++ b/xen/arch/riscv/include/asm/Kbuild
> @@ -0,0 +1 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> diff --git a/xen/arch/x86/include/asm/Kbuild b/xen/arch/x86/include/asm/Kbuild
> new file mode 100644
> index 0000000000..a4e40e534e
> --- /dev/null
> +++ b/xen/arch/x86/include/asm/Kbuild
> @@ -0,0 +1 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> diff --git a/xen/scripts/Makefile.asm-generic b/xen/scripts/Makefile.asm-generic
> new file mode 100644
> index 0000000000..0aac3f50b8
> --- /dev/null
> +++ b/xen/scripts/Makefile.asm-generic
> @@ -0,0 +1,23 @@
> +# SPDX-License-Identifier: GPL-2.0
> +# include/asm-generic contains a lot of files that are used
> +# verbatim by several architectures.
> +#
> +# This Makefile reads the file arch/$(SRCARCH)/include/asm/Kbuild
> +# and for each file listed in this file with generic-y creates
> +# a small wrapper file in $(obj) (arch/$(SRCARCH)/include/generated/asm)
> +
> +kbuild-file := $(srctree)/arch/$(SRCARCH)/include/asm/Kbuild
> +include $(kbuild-file)
> +
> +include scripts/Kbuild.include
> +
> +# Create output directory if not already present
> +_dummy := $(shell [ -d $(obj) ] || mkdir -p $(obj))
> +
> +quiet_cmd_wrap = WRAP    $@
> +cmd_wrap = echo "\#include <asm-generic/$*.h>" >$@
> +
> +all: $(patsubst %, $(obj)/%, $(generic-y))
> +
> +$(obj)/%.h:
> + $(call cmd,wrap)

In fact i think your files are not generated in the srctree so this
will break if you use out of tree compilation.

Cheers
Bertrand

> -- 
> 2.41.0
>
Oleksii Kurochko Sept. 5, 2023, 1:37 p.m. UTC | #2
Hi Bertrand,

On Mon, 2023-09-04 at 13:39 +0000, Bertrand Marquis wrote:
> Hi Oleksii,
> 
> > On 1 Sep 2023, at 18:02, Oleksii Kurochko
> > <oleksii.kurochko@gmail.com> wrote:
> > 
> > Some headers are shared between individual architectures or are
> > empty.
> > To avoid duplication of these headers, asm-generic is introduced.
> > 
> > With the following patch, an architecture uses generic headers
> > mentioned in the file arch/$(ARCH)/include/asm/Kbuild.
> 
> Kbuild refers to "Kernel build" I guess.
> I am ok to keep that name to keep things simpler when compared to
> Linux scripts but it would be good to mention that in the commit
> message for future reference.
Sure. I'll add that Kbuild refers to "Kernel build"
> 
> > 
> > To use a generic header is needed to add to
> > arch/$(ARCH)/include/asm/Kbuild :
> >        generic-y += <name-of-header-file.h>
> > 
> > For each mentioned header in arch/$(ARCH)/include/asm/Kbuild,
> > kbuild will generate the necessary wrapper in
> > arch/$(ARCH)/include/generated/asm.
> > 
> > Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
> > ---
> > Changes in V4:
> > - introduce asm-generic support
> > - update commit message
> > ---
> > Changes in V3:
> > - Rename stubs dir to asm-generic
> > ---
> > Changes in V2:
> > - Nothing changed.
> > ---
> > xen/Makefile                      | 10 +++++++++-
> > xen/arch/arm/include/asm/Kbuild   |  1 +
> > xen/arch/ppc/include/asm/Kbuild   |  1 +
> > xen/arch/riscv/include/asm/Kbuild |  1 +
> > xen/arch/x86/include/asm/Kbuild   |  1 +
> > xen/scripts/Makefile.asm-generic  | 23 +++++++++++++++++++++++
> > 6 files changed, 36 insertions(+), 1 deletion(-)
> > create mode 100644 xen/arch/arm/include/asm/Kbuild
> > create mode 100644 xen/arch/ppc/include/asm/Kbuild
> > create mode 100644 xen/arch/riscv/include/asm/Kbuild
> > create mode 100644 xen/arch/x86/include/asm/Kbuild
> > create mode 100644 xen/scripts/Makefile.asm-generic
> > 
> > diff --git a/xen/Makefile b/xen/Makefile
> > index f57e5a596c..698d6ddeb8 100644
> > --- a/xen/Makefile
> > +++ b/xen/Makefile
> > @@ -438,6 +438,7 @@ ifdef building_out_of_srctree
> > endif
> > CFLAGS += -I$(srctree)/include
> > CFLAGS += -I$(srctree)/arch/$(SRCARCH)/include
> > +CFLAGS += -I$(srctree)/arch/$(SRCARCH)/include/generated
> 
> Why are we generating files in the source tree ? 
> Shouldn't we keep it unmodified ?
I think you are right.
I got myself confused because I do not use out-of-tree compilation so
for me it looked like $(srctree).

It would be better to use $(objtree) instead.
> 
> > 
> > # Note that link order matters!
> > ALL_OBJS-y                := common/built_in.o
> > @@ -580,6 +581,7 @@ _clean:
> > rm -f $(TARGET).efi $(TARGET).efi.map $(TARGET).efi.elf
> > $(TARGET).efi.stripped
> > rm -f asm-offsets.s arch/*/include/asm/asm-offsets.h
> > rm -f .banner .allconfig.tmp include/xen/compile.h
> > + rm -rf arch/*/include/generated
> > 
> 
> You must use the same as for CFLAGS here so $(srctree) would be
> needed.
> (or something else depending on the fix for previous comment)
Thanks. I'll change to the value mentioned in CFLAGS.

> 
> > .PHONY: _distclean
> > _distclean: clean
> > @@ -589,7 +591,7 @@ $(TARGET).gz: $(TARGET)
> > gzip -n -f -9 < $< > $@.new
> > mv $@.new $@
> > 
> > -$(TARGET): outputmakefile FORCE
> > +$(TARGET): outputmakefile asm-generic FORCE
> > $(Q)$(MAKE) $(build)=tools
> > $(Q)$(MAKE) $(build)=. include/xen/compile.h
> > $(Q)$(MAKE) $(build)=include all
> > @@ -667,6 +669,12 @@ endif # need-sub-make
> > PHONY += FORCE
> > FORCE:
> > 
> > +# Support for using generic headers in asm-generic
> > +PHONY += asm-generic
> > +asm-generic:
> > + $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.asm-generic \
> > +            obj=arch/$(SRCARCH)/include/generated/asm
> > +
> > # Declare the contents of the PHONY variable as phony.  We keep
> > that
> > # information in a variable so we can use it in if_changed and
> > friends.
> > .PHONY: $(PHONY)
> > diff --git a/xen/arch/arm/include/asm/Kbuild
> > b/xen/arch/arm/include/asm/Kbuild
> > new file mode 100644
> > index 0000000000..a4e40e534e
> > --- /dev/null
> > +++ b/xen/arch/arm/include/asm/Kbuild
> > @@ -0,0 +1 @@
> > +# SPDX-License-Identifier: GPL-2.0-only
> > diff --git a/xen/arch/ppc/include/asm/Kbuild
> > b/xen/arch/ppc/include/asm/Kbuild
> > new file mode 100644
> > index 0000000000..a4e40e534e
> > --- /dev/null
> > +++ b/xen/arch/ppc/include/asm/Kbuild
> > @@ -0,0 +1 @@
> > +# SPDX-License-Identifier: GPL-2.0-only
> > diff --git a/xen/arch/riscv/include/asm/Kbuild
> > b/xen/arch/riscv/include/asm/Kbuild
> > new file mode 100644
> > index 0000000000..a4e40e534e
> > --- /dev/null
> > +++ b/xen/arch/riscv/include/asm/Kbuild
> > @@ -0,0 +1 @@
> > +# SPDX-License-Identifier: GPL-2.0-only
> > diff --git a/xen/arch/x86/include/asm/Kbuild
> > b/xen/arch/x86/include/asm/Kbuild
> > new file mode 100644
> > index 0000000000..a4e40e534e
> > --- /dev/null
> > +++ b/xen/arch/x86/include/asm/Kbuild
> > @@ -0,0 +1 @@
> > +# SPDX-License-Identifier: GPL-2.0-only
> > diff --git a/xen/scripts/Makefile.asm-generic
> > b/xen/scripts/Makefile.asm-generic
> > new file mode 100644
> > index 0000000000..0aac3f50b8
> > --- /dev/null
> > +++ b/xen/scripts/Makefile.asm-generic
> > @@ -0,0 +1,23 @@
> > +# SPDX-License-Identifier: GPL-2.0
> > +# include/asm-generic contains a lot of files that are used
> > +# verbatim by several architectures.
> > +#
> > +# This Makefile reads the file arch/$(SRCARCH)/include/asm/Kbuild
> > +# and for each file listed in this file with generic-y creates
> > +# a small wrapper file in $(obj)
> > (arch/$(SRCARCH)/include/generated/asm)
> > +
> > +kbuild-file := $(srctree)/arch/$(SRCARCH)/include/asm/Kbuild
> > +include $(kbuild-file)
> > +
> > +include scripts/Kbuild.include
> > +
> > +# Create output directory if not already present
> > +_dummy := $(shell [ -d $(obj) ] || mkdir -p $(obj))
> > +
> > +quiet_cmd_wrap = WRAP    $@
> > +cmd_wrap = echo "\#include <asm-generic/$*.h>" >$@
> > +
> > +all: $(patsubst %, $(obj)/%, $(generic-y))
> > +
> > +$(obj)/%.h:
> > + $(call cmd,wrap)
> 
> In fact i think your files are not generated in the srctree so this
> will break if you use out of tree compilation.
Why not? They will be generated in $obj which equal to
obj=arch/$(SRCARCH)/include/generated/asm ( in my case ).

Anyway I think that obj should be equal to what is mentioned in CFLAGS.

~ Oleksii
Bertrand Marquis Sept. 5, 2023, 2:10 p.m. UTC | #3
Hi Oleksii,

> On 5 Sep 2023, at 15:37, Oleksii <oleksii.kurochko@gmail.com> wrote:
> 
> Hi Bertrand,
> 
> On Mon, 2023-09-04 at 13:39 +0000, Bertrand Marquis wrote:
>> Hi Oleksii,
>> 
>>> On 1 Sep 2023, at 18:02, Oleksii Kurochko
>>> <oleksii.kurochko@gmail.com> wrote:
>>> 
>>> Some headers are shared between individual architectures or are
>>> empty.
>>> To avoid duplication of these headers, asm-generic is introduced.
>>> 
>>> With the following patch, an architecture uses generic headers
>>> mentioned in the file arch/$(ARCH)/include/asm/Kbuild.
>> 
>> Kbuild refers to "Kernel build" I guess.
>> I am ok to keep that name to keep things simpler when compared to
>> Linux scripts but it would be good to mention that in the commit
>> message for future reference.
> Sure. I'll add that Kbuild refers to "Kernel build"
>> 
>>> 
>>> To use a generic header is needed to add to
>>> arch/$(ARCH)/include/asm/Kbuild :
>>>        generic-y += <name-of-header-file.h>
>>> 
>>> For each mentioned header in arch/$(ARCH)/include/asm/Kbuild,
>>> kbuild will generate the necessary wrapper in
>>> arch/$(ARCH)/include/generated/asm.
>>> 
>>> Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
>>> ---
>>> Changes in V4:
>>> - introduce asm-generic support
>>> - update commit message
>>> ---
>>> Changes in V3:
>>> - Rename stubs dir to asm-generic
>>> ---
>>> Changes in V2:
>>> - Nothing changed.
>>> ---
>>> xen/Makefile                      | 10 +++++++++-
>>> xen/arch/arm/include/asm/Kbuild   |  1 +
>>> xen/arch/ppc/include/asm/Kbuild   |  1 +
>>> xen/arch/riscv/include/asm/Kbuild |  1 +
>>> xen/arch/x86/include/asm/Kbuild   |  1 +
>>> xen/scripts/Makefile.asm-generic  | 23 +++++++++++++++++++++++
>>> 6 files changed, 36 insertions(+), 1 deletion(-)
>>> create mode 100644 xen/arch/arm/include/asm/Kbuild
>>> create mode 100644 xen/arch/ppc/include/asm/Kbuild
>>> create mode 100644 xen/arch/riscv/include/asm/Kbuild
>>> create mode 100644 xen/arch/x86/include/asm/Kbuild
>>> create mode 100644 xen/scripts/Makefile.asm-generic
>>> 
>>> diff --git a/xen/Makefile b/xen/Makefile
>>> index f57e5a596c..698d6ddeb8 100644
>>> --- a/xen/Makefile
>>> +++ b/xen/Makefile
>>> @@ -438,6 +438,7 @@ ifdef building_out_of_srctree
>>> endif
>>> CFLAGS += -I$(srctree)/include
>>> CFLAGS += -I$(srctree)/arch/$(SRCARCH)/include
>>> +CFLAGS += -I$(srctree)/arch/$(SRCARCH)/include/generated
>> 
>> Why are we generating files in the source tree ? 
>> Shouldn't we keep it unmodified ?
> I think you are right.
> I got myself confused because I do not use out-of-tree compilation so
> for me it looked like $(srctree).
> 
> It would be better to use $(objtree) instead.

Ack

>> 
>>> 
>>> # Note that link order matters!
>>> ALL_OBJS-y                := common/built_in.o
>>> @@ -580,6 +581,7 @@ _clean:
>>> rm -f $(TARGET).efi $(TARGET).efi.map $(TARGET).efi.elf
>>> $(TARGET).efi.stripped
>>> rm -f asm-offsets.s arch/*/include/asm/asm-offsets.h
>>> rm -f .banner .allconfig.tmp include/xen/compile.h
>>> + rm -rf arch/*/include/generated
>>> 
>> 
>> You must use the same as for CFLAGS here so $(srctree) would be
>> needed.
>> (or something else depending on the fix for previous comment)
> Thanks. I'll change to the value mentioned in CFLAGS.
> 
>> 
>>> .PHONY: _distclean
>>> _distclean: clean
>>> @@ -589,7 +591,7 @@ $(TARGET).gz: $(TARGET)
>>> gzip -n -f -9 < $< > $@.new
>>> mv $@.new $@
>>> 
>>> -$(TARGET): outputmakefile FORCE
>>> +$(TARGET): outputmakefile asm-generic FORCE
>>> $(Q)$(MAKE) $(build)=tools
>>> $(Q)$(MAKE) $(build)=. include/xen/compile.h
>>> $(Q)$(MAKE) $(build)=include all
>>> @@ -667,6 +669,12 @@ endif # need-sub-make
>>> PHONY += FORCE
>>> FORCE:
>>> 
>>> +# Support for using generic headers in asm-generic
>>> +PHONY += asm-generic
>>> +asm-generic:
>>> + $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.asm-generic \
>>> +            obj=arch/$(SRCARCH)/include/generated/asm
>>> +
>>> # Declare the contents of the PHONY variable as phony.  We keep
>>> that
>>> # information in a variable so we can use it in if_changed and
>>> friends.
>>> .PHONY: $(PHONY)
>>> diff --git a/xen/arch/arm/include/asm/Kbuild
>>> b/xen/arch/arm/include/asm/Kbuild
>>> new file mode 100644
>>> index 0000000000..a4e40e534e
>>> --- /dev/null
>>> +++ b/xen/arch/arm/include/asm/Kbuild
>>> @@ -0,0 +1 @@
>>> +# SPDX-License-Identifier: GPL-2.0-only
>>> diff --git a/xen/arch/ppc/include/asm/Kbuild
>>> b/xen/arch/ppc/include/asm/Kbuild
>>> new file mode 100644
>>> index 0000000000..a4e40e534e
>>> --- /dev/null
>>> +++ b/xen/arch/ppc/include/asm/Kbuild
>>> @@ -0,0 +1 @@
>>> +# SPDX-License-Identifier: GPL-2.0-only
>>> diff --git a/xen/arch/riscv/include/asm/Kbuild
>>> b/xen/arch/riscv/include/asm/Kbuild
>>> new file mode 100644
>>> index 0000000000..a4e40e534e
>>> --- /dev/null
>>> +++ b/xen/arch/riscv/include/asm/Kbuild
>>> @@ -0,0 +1 @@
>>> +# SPDX-License-Identifier: GPL-2.0-only
>>> diff --git a/xen/arch/x86/include/asm/Kbuild
>>> b/xen/arch/x86/include/asm/Kbuild
>>> new file mode 100644
>>> index 0000000000..a4e40e534e
>>> --- /dev/null
>>> +++ b/xen/arch/x86/include/asm/Kbuild
>>> @@ -0,0 +1 @@
>>> +# SPDX-License-Identifier: GPL-2.0-only
>>> diff --git a/xen/scripts/Makefile.asm-generic
>>> b/xen/scripts/Makefile.asm-generic
>>> new file mode 100644
>>> index 0000000000..0aac3f50b8
>>> --- /dev/null
>>> +++ b/xen/scripts/Makefile.asm-generic
>>> @@ -0,0 +1,23 @@
>>> +# SPDX-License-Identifier: GPL-2.0
>>> +# include/asm-generic contains a lot of files that are used
>>> +# verbatim by several architectures.
>>> +#
>>> +# This Makefile reads the file arch/$(SRCARCH)/include/asm/Kbuild
>>> +# and for each file listed in this file with generic-y creates
>>> +# a small wrapper file in $(obj)
>>> (arch/$(SRCARCH)/include/generated/asm)
>>> +
>>> +kbuild-file := $(srctree)/arch/$(SRCARCH)/include/asm/Kbuild
>>> +include $(kbuild-file)
>>> +
>>> +include scripts/Kbuild.include
>>> +
>>> +# Create output directory if not already present
>>> +_dummy := $(shell [ -d $(obj) ] || mkdir -p $(obj))
>>> +
>>> +quiet_cmd_wrap = WRAP    $@
>>> +cmd_wrap = echo "\#include <asm-generic/$*.h>" >$@
>>> +
>>> +all: $(patsubst %, $(obj)/%, $(generic-y))
>>> +
>>> +$(obj)/%.h:
>>> + $(call cmd,wrap)
>> 
>> In fact i think your files are not generated in the srctree so this
>> will break if you use out of tree compilation.
> Why not? They will be generated in $obj which equal to
> obj=arch/$(SRCARCH)/include/generated/asm ( in my case ).

Right they are generated in the build tree but if it is not the same
as srctree it will not work due to CFLAGS.

> 
> Anyway I think that obj should be equal to what is mentioned in CFLAGS.

We generate other files like asm-offsets.h and it could in fact be that
both srctree and build tree are already in include path.

There is in makefile a rule already removing asm-offsets.h which is generated
and this one does not use a prefix so we should follow this standard in fact.

So we should not use any prefix (srctree or obj) i think.

@anthony: any suggestion here ?

Bertrand

> 
> ~ Oleksii
Oleksii Kurochko Sept. 6, 2023, 10:36 a.m. UTC | #4
On Tue, 2023-09-05 at 14:10 +0000, Bertrand Marquis wrote:
> Hi Oleksii,
> 
> > On 5 Sep 2023, at 15:37, Oleksii <oleksii.kurochko@gmail.com>
> > wrote:
> > 
> > Hi Bertrand,
> > 
> > On Mon, 2023-09-04 at 13:39 +0000, Bertrand Marquis wrote:
> > > Hi Oleksii,
> > > 
> > > > On 1 Sep 2023, at 18:02, Oleksii Kurochko
> > > > <oleksii.kurochko@gmail.com> wrote:
> > > > 
> > > > Some headers are shared between individual architectures or are
> > > > empty.
> > > > To avoid duplication of these headers, asm-generic is
> > > > introduced.
> > > > 
> > > > With the following patch, an architecture uses generic headers
> > > > mentioned in the file arch/$(ARCH)/include/asm/Kbuild.
> > > 
> > > Kbuild refers to "Kernel build" I guess.
> > > I am ok to keep that name to keep things simpler when compared to
> > > Linux scripts but it would be good to mention that in the commit
> > > message for future reference.
> > Sure. I'll add that Kbuild refers to "Kernel build"
> > > 
> > > > 
> > > > To use a generic header is needed to add to
> > > > arch/$(ARCH)/include/asm/Kbuild :
> > > >        generic-y += <name-of-header-file.h>
> > > > 
> > > > For each mentioned header in arch/$(ARCH)/include/asm/Kbuild,
> > > > kbuild will generate the necessary wrapper in
> > > > arch/$(ARCH)/include/generated/asm.
> > > > 
> > > > Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
> > > > ---
> > > > Changes in V4:
> > > > - introduce asm-generic support
> > > > - update commit message
> > > > ---
> > > > Changes in V3:
> > > > - Rename stubs dir to asm-generic
> > > > ---
> > > > Changes in V2:
> > > > - Nothing changed.
> > > > ---
> > > > xen/Makefile                      | 10 +++++++++-
> > > > xen/arch/arm/include/asm/Kbuild   |  1 +
> > > > xen/arch/ppc/include/asm/Kbuild   |  1 +
> > > > xen/arch/riscv/include/asm/Kbuild |  1 +
> > > > xen/arch/x86/include/asm/Kbuild   |  1 +
> > > > xen/scripts/Makefile.asm-generic  | 23 +++++++++++++++++++++++
> > > > 6 files changed, 36 insertions(+), 1 deletion(-)
> > > > create mode 100644 xen/arch/arm/include/asm/Kbuild
> > > > create mode 100644 xen/arch/ppc/include/asm/Kbuild
> > > > create mode 100644 xen/arch/riscv/include/asm/Kbuild
> > > > create mode 100644 xen/arch/x86/include/asm/Kbuild
> > > > create mode 100644 xen/scripts/Makefile.asm-generic
> > > > 
> > > > diff --git a/xen/Makefile b/xen/Makefile
> > > > index f57e5a596c..698d6ddeb8 100644
> > > > --- a/xen/Makefile
> > > > +++ b/xen/Makefile
> > > > @@ -438,6 +438,7 @@ ifdef building_out_of_srctree
> > > > endif
> > > > CFLAGS += -I$(srctree)/include
> > > > CFLAGS += -I$(srctree)/arch/$(SRCARCH)/include
> > > > +CFLAGS += -I$(srctree)/arch/$(SRCARCH)/include/generated
> > > 
> > > Why are we generating files in the source tree ? 
> > > Shouldn't we keep it unmodified ?
> > I think you are right.
> > I got myself confused because I do not use out-of-tree compilation
> > so
> > for me it looked like $(srctree).
> > 
> > It would be better to use $(objtree) instead.
> 
> Ack
> 
> > > 
> > > > 
> > > > # Note that link order matters!
> > > > ALL_OBJS-y                := common/built_in.o
> > > > @@ -580,6 +581,7 @@ _clean:
> > > > rm -f $(TARGET).efi $(TARGET).efi.map $(TARGET).efi.elf
> > > > $(TARGET).efi.stripped
> > > > rm -f asm-offsets.s arch/*/include/asm/asm-offsets.h
> > > > rm -f .banner .allconfig.tmp include/xen/compile.h
> > > > + rm -rf arch/*/include/generated
> > > > 
> > > 
> > > You must use the same as for CFLAGS here so $(srctree) would be
> > > needed.
> > > (or something else depending on the fix for previous comment)
> > Thanks. I'll change to the value mentioned in CFLAGS.
> > 
> > > 
> > > > .PHONY: _distclean
> > > > _distclean: clean
> > > > @@ -589,7 +591,7 @@ $(TARGET).gz: $(TARGET)
> > > > gzip -n -f -9 < $< > $@.new
> > > > mv $@.new $@
> > > > 
> > > > -$(TARGET): outputmakefile FORCE
> > > > +$(TARGET): outputmakefile asm-generic FORCE
> > > > $(Q)$(MAKE) $(build)=tools
> > > > $(Q)$(MAKE) $(build)=. include/xen/compile.h
> > > > $(Q)$(MAKE) $(build)=include all
> > > > @@ -667,6 +669,12 @@ endif # need-sub-make
> > > > PHONY += FORCE
> > > > FORCE:
> > > > 
> > > > +# Support for using generic headers in asm-generic
> > > > +PHONY += asm-generic
> > > > +asm-generic:
> > > > + $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.asm-generic \
> > > > +            obj=arch/$(SRCARCH)/include/generated/asm
> > > > +
> > > > # Declare the contents of the PHONY variable as phony.  We keep
> > > > that
> > > > # information in a variable so we can use it in if_changed and
> > > > friends.
> > > > .PHONY: $(PHONY)
> > > > diff --git a/xen/arch/arm/include/asm/Kbuild
> > > > b/xen/arch/arm/include/asm/Kbuild
> > > > new file mode 100644
> > > > index 0000000000..a4e40e534e
> > > > --- /dev/null
> > > > +++ b/xen/arch/arm/include/asm/Kbuild
> > > > @@ -0,0 +1 @@
> > > > +# SPDX-License-Identifier: GPL-2.0-only
> > > > diff --git a/xen/arch/ppc/include/asm/Kbuild
> > > > b/xen/arch/ppc/include/asm/Kbuild
> > > > new file mode 100644
> > > > index 0000000000..a4e40e534e
> > > > --- /dev/null
> > > > +++ b/xen/arch/ppc/include/asm/Kbuild
> > > > @@ -0,0 +1 @@
> > > > +# SPDX-License-Identifier: GPL-2.0-only
> > > > diff --git a/xen/arch/riscv/include/asm/Kbuild
> > > > b/xen/arch/riscv/include/asm/Kbuild
> > > > new file mode 100644
> > > > index 0000000000..a4e40e534e
> > > > --- /dev/null
> > > > +++ b/xen/arch/riscv/include/asm/Kbuild
> > > > @@ -0,0 +1 @@
> > > > +# SPDX-License-Identifier: GPL-2.0-only
> > > > diff --git a/xen/arch/x86/include/asm/Kbuild
> > > > b/xen/arch/x86/include/asm/Kbuild
> > > > new file mode 100644
> > > > index 0000000000..a4e40e534e
> > > > --- /dev/null
> > > > +++ b/xen/arch/x86/include/asm/Kbuild
> > > > @@ -0,0 +1 @@
> > > > +# SPDX-License-Identifier: GPL-2.0-only
> > > > diff --git a/xen/scripts/Makefile.asm-generic
> > > > b/xen/scripts/Makefile.asm-generic
> > > > new file mode 100644
> > > > index 0000000000..0aac3f50b8
> > > > --- /dev/null
> > > > +++ b/xen/scripts/Makefile.asm-generic
> > > > @@ -0,0 +1,23 @@
> > > > +# SPDX-License-Identifier: GPL-2.0
> > > > +# include/asm-generic contains a lot of files that are used
> > > > +# verbatim by several architectures.
> > > > +#
> > > > +# This Makefile reads the file
> > > > arch/$(SRCARCH)/include/asm/Kbuild
> > > > +# and for each file listed in this file with generic-y creates
> > > > +# a small wrapper file in $(obj)
> > > > (arch/$(SRCARCH)/include/generated/asm)
> > > > +
> > > > +kbuild-file := $(srctree)/arch/$(SRCARCH)/include/asm/Kbuild
> > > > +include $(kbuild-file)
> > > > +
> > > > +include scripts/Kbuild.include
> > > > +
> > > > +# Create output directory if not already present
> > > > +_dummy := $(shell [ -d $(obj) ] || mkdir -p $(obj))
> > > > +
> > > > +quiet_cmd_wrap = WRAP    $@
> > > > +cmd_wrap = echo "\#include <asm-generic/$*.h>" >$@
> > > > +
> > > > +all: $(patsubst %, $(obj)/%, $(generic-y))
> > > > +
> > > > +$(obj)/%.h:
> > > > + $(call cmd,wrap)
> > > 
> > > In fact i think your files are not generated in the srctree so
> > > this
> > > will break if you use out of tree compilation.
> > Why not? They will be generated in $obj which equal to
> > obj=arch/$(SRCARCH)/include/generated/asm ( in my case ).
> 
> Right they are generated in the build tree but if it is not the same
> as srctree it will not work due to CFLAGS.
> 
> > 
> > Anyway I think that obj should be equal to what is mentioned in
> > CFLAGS.
> 
> We generate other files like asm-offsets.h and it could in fact be
> that
> both srctree and build tree are already in include path.
> 
> There is in makefile a rule already removing asm-offsets.h which is
> generated
> and this one does not use a prefix so we should follow this standard
> in fact.
> 
> So we should not use any prefix (srctree or obj) i think.
I think you are right. Lets avoid usage of srctree/obj.


~ Oleksii
Oleksii Kurochko Sept. 6, 2023, 11:37 a.m. UTC | #5
Hello Bertrand

On Mon, 2023-09-04 at 13:39 +0000, Bertrand Marquis wrote:
> > diff --git a/xen/scripts/Makefile.asm-generic
> > b/xen/scripts/Makefile.asm-generic
> > new file mode 100644
> > index 0000000000..0aac3f50b8
> > --- /dev/null
> > +++ b/xen/scripts/Makefile.asm-generic
> > @@ -0,0 +1,23 @@
> > +# SPDX-License-Identifier: GPL-2.0
> > +# include/asm-generic contains a lot of files that are used
> > +# verbatim by several architectures.
> > +#
> > +# This Makefile reads the file arch/$(SRCARCH)/include/asm/Kbuild
> > +# and for each file listed in this file with generic-y creates
> > +# a small wrapper file in $(obj)
> > (arch/$(SRCARCH)/include/generated/asm)
> > +
> > +kbuild-file := $(srctree)/arch/$(SRCARCH)/include/asm/Kbuild
> > +include $(kbuild-file)
> > +
> > +include scripts/Kbuild.include
> > +
> > +# Create output directory if not already present
> > +_dummy := $(shell [ -d $(obj) ] || mkdir -p $(obj))
> > +
> > +quiet_cmd_wrap = WRAP    $@
> > +cmd_wrap = echo "\#include <asm-generic/$*.h>" >$@
> > +
> > +all: $(patsubst %, $(obj)/%, $(generic-y))
> > +
> > +$(obj)/%.h:
> > + $(call cmd,wrap)
> 
> In fact i think your files are not generated in the srctree so this
> will break if you use out of tree compilation.
I checked that and in both cases it generated in correct place.

First case:
$ CONTAINER_NO_PULL=1 CONTAINER=riscv64
./automation/scripts/containerize make XEN_TARGET_ARCH=riscv64 -C xen
build

$ ls -la xen/arch/riscv/include/generated/asm/vm_event.h 
-rw-r--r--. 1 ok ok 34 вер  6 14:32
xen/arch/riscv/include/generated/asm/vm_event.h

Second case: ( out-of-tree )
$ CONTAINER_NO_PULL=1 CONTAINER=riscv64
./automation/scripts/containerize make O=xen_build
XEN_TARGET_ARCH=riscv64 -C xen build V=1

$ ls -la xen/xen_build/arch/riscv/include/generated/asm/vm_event.h 
-rw-r--r--. 1 ok ok 34 вер  6 14:34
xen/xen_build/arch/riscv/include/generated/asm/vm_event.h

Could you please clarify if there's somithing I might have overlooked?

~ Oleksii
Jan Beulich Sept. 6, 2023, 12:16 p.m. UTC | #6
On 01.09.2023 18:02, Oleksii Kurochko wrote:
> --- /dev/null
> +++ b/xen/scripts/Makefile.asm-generic
> @@ -0,0 +1,23 @@
> +# SPDX-License-Identifier: GPL-2.0

While this is what the Linux file presently says, you still want to add
"-only", which is merely the newer name for the same thing.

> +# include/asm-generic contains a lot of files that are used
> +# verbatim by several architectures.
> +#
> +# This Makefile reads the file arch/$(SRCARCH)/include/asm/Kbuild
> +# and for each file listed in this file with generic-y creates
> +# a small wrapper file in $(obj) (arch/$(SRCARCH)/include/generated/asm)
> +
> +kbuild-file := $(srctree)/arch/$(SRCARCH)/include/asm/Kbuild
> +include $(kbuild-file)
> +
> +include scripts/Kbuild.include
> +
> +# Create output directory if not already present
> +_dummy := $(shell [ -d $(obj) ] || mkdir -p $(obj))
> +
> +quiet_cmd_wrap = WRAP    $@
> +cmd_wrap = echo "\#include <asm-generic/$*.h>" >$@
> +
> +all: $(patsubst %, $(obj)/%, $(generic-y))
> +
> +$(obj)/%.h:
> +	$(call cmd,wrap)

You've removed quite a bit of functionality, comparing with the Linux
original. May I ask why that is? What they have all makes sense to me,
and looks to be useful down the road.

Jan
Oleksii Kurochko Sept. 6, 2023, 12:28 p.m. UTC | #7
On Wed, 2023-09-06 at 14:16 +0200, Jan Beulich wrote:
> On 01.09.2023 18:02, Oleksii Kurochko wrote:
> > --- /dev/null
> > +++ b/xen/scripts/Makefile.asm-generic
> > @@ -0,0 +1,23 @@
> > +# SPDX-License-Identifier: GPL-2.0
> 
> While this is what the Linux file presently says, you still want to
> add
> "-only", which is merely the newer name for the same thing.
> 
> > +# include/asm-generic contains a lot of files that are used
> > +# verbatim by several architectures.
> > +#
> > +# This Makefile reads the file arch/$(SRCARCH)/include/asm/Kbuild
> > +# and for each file listed in this file with generic-y creates
> > +# a small wrapper file in $(obj)
> > (arch/$(SRCARCH)/include/generated/asm)
> > +
> > +kbuild-file := $(srctree)/arch/$(SRCARCH)/include/asm/Kbuild
> > +include $(kbuild-file)
> > +
> > +include scripts/Kbuild.include
> > +
> > +# Create output directory if not already present
> > +_dummy := $(shell [ -d $(obj) ] || mkdir -p $(obj))
> > +
> > +quiet_cmd_wrap = WRAP    $@
> > +cmd_wrap = echo "\#include <asm-generic/$*.h>" >$@
> > +
> > +all: $(patsubst %, $(obj)/%, $(generic-y))
> > +
> > +$(obj)/%.h:
> > +       $(call cmd,wrap)
> 
> You've removed quite a bit of functionality, comparing with the Linux
> original. May I ask why that is? What they have all makes sense to
> me,
> and looks to be useful down the road.
I decided to take only minimum needed now but if you think it would be
better to use the latest Linux's Makefile.asm-generic then I will
update it in the next patch version.

~ Oleksii
Jan Beulich Sept. 6, 2023, 12:40 p.m. UTC | #8
On 06.09.2023 14:28, Oleksii wrote:
> On Wed, 2023-09-06 at 14:16 +0200, Jan Beulich wrote:
>> On 01.09.2023 18:02, Oleksii Kurochko wrote:
>>> --- /dev/null
>>> +++ b/xen/scripts/Makefile.asm-generic
>>> @@ -0,0 +1,23 @@
>>> +# SPDX-License-Identifier: GPL-2.0
>>
>> While this is what the Linux file presently says, you still want to
>> add
>> "-only", which is merely the newer name for the same thing.
>>
>>> +# include/asm-generic contains a lot of files that are used
>>> +# verbatim by several architectures.
>>> +#
>>> +# This Makefile reads the file arch/$(SRCARCH)/include/asm/Kbuild
>>> +# and for each file listed in this file with generic-y creates
>>> +# a small wrapper file in $(obj)
>>> (arch/$(SRCARCH)/include/generated/asm)
>>> +
>>> +kbuild-file := $(srctree)/arch/$(SRCARCH)/include/asm/Kbuild
>>> +include $(kbuild-file)
>>> +
>>> +include scripts/Kbuild.include
>>> +
>>> +# Create output directory if not already present
>>> +_dummy := $(shell [ -d $(obj) ] || mkdir -p $(obj))
>>> +
>>> +quiet_cmd_wrap = WRAP    $@
>>> +cmd_wrap = echo "\#include <asm-generic/$*.h>" >$@
>>> +
>>> +all: $(patsubst %, $(obj)/%, $(generic-y))
>>> +
>>> +$(obj)/%.h:
>>> +       $(call cmd,wrap)
>>
>> You've removed quite a bit of functionality, comparing with the Linux
>> original. May I ask why that is? What they have all makes sense to
>> me,
>> and looks to be useful down the road.
> I decided to take only minimum needed now but if you think it would be
> better to use the latest Linux's Makefile.asm-generic then I will
> update it in the next patch version.

Unless there are things getting in the way, I indeed think it would be
better to take the whole thing largely verbatim (a few edits are
unavoidable afaict).

Jan
Bertrand Marquis Sept. 6, 2023, 1:03 p.m. UTC | #9
Hi Oleksii,

> On 6 Sep 2023, at 13:37, Oleksii <oleksii.kurochko@gmail.com> wrote:
> 
> Hello Bertrand
> 
> On Mon, 2023-09-04 at 13:39 +0000, Bertrand Marquis wrote:
>>> diff --git a/xen/scripts/Makefile.asm-generic
>>> b/xen/scripts/Makefile.asm-generic
>>> new file mode 100644
>>> index 0000000000..0aac3f50b8
>>> --- /dev/null
>>> +++ b/xen/scripts/Makefile.asm-generic
>>> @@ -0,0 +1,23 @@
>>> +# SPDX-License-Identifier: GPL-2.0
>>> +# include/asm-generic contains a lot of files that are used
>>> +# verbatim by several architectures.
>>> +#
>>> +# This Makefile reads the file arch/$(SRCARCH)/include/asm/Kbuild
>>> +# and for each file listed in this file with generic-y creates
>>> +# a small wrapper file in $(obj)
>>> (arch/$(SRCARCH)/include/generated/asm)
>>> +
>>> +kbuild-file := $(srctree)/arch/$(SRCARCH)/include/asm/Kbuild
>>> +include $(kbuild-file)
>>> +
>>> +include scripts/Kbuild.include
>>> +
>>> +# Create output directory if not already present
>>> +_dummy := $(shell [ -d $(obj) ] || mkdir -p $(obj))
>>> +
>>> +quiet_cmd_wrap = WRAP    $@
>>> +cmd_wrap = echo "\#include <asm-generic/$*.h>" >$@
>>> +
>>> +all: $(patsubst %, $(obj)/%, $(generic-y))
>>> +
>>> +$(obj)/%.h:
>>> + $(call cmd,wrap)
>> 
>> In fact i think your files are not generated in the srctree so this
>> will break if you use out of tree compilation.
> I checked that and in both cases it generated in correct place.
> 
> First case:
> $ CONTAINER_NO_PULL=1 CONTAINER=riscv64
> ./automation/scripts/containerize make XEN_TARGET_ARCH=riscv64 -C xen
> build
> 
> $ ls -la xen/arch/riscv/include/generated/asm/vm_event.h 
> -rw-r--r--. 1 ok ok 34 вер  6 14:32
> xen/arch/riscv/include/generated/asm/vm_event.h
> 
> Second case: ( out-of-tree )
> $ CONTAINER_NO_PULL=1 CONTAINER=riscv64
> ./automation/scripts/containerize make O=xen_build
> XEN_TARGET_ARCH=riscv64 -C xen build V=1
> 
> $ ls -la xen/xen_build/arch/riscv/include/generated/asm/vm_event.h 
> -rw-r--r--. 1 ok ok 34 вер  6 14:34
> xen/xen_build/arch/riscv/include/generated/asm/vm_event.h
> 
> Could you please clarify if there's somithing I might have overlooked?

No I do not think you did.

So obj is empty I would guess.
Anyway you just need to make sure that CFLAGS is coherent with what you generate.
So if you generate in $(obj) you need to make sure you use the same in CFLAGS i would say.

@anthony: any advice here ?

Cheers
Bertrand



> 
> ~ Oleksii
> 
> 
>
Anthony PERARD Sept. 6, 2023, 3:06 p.m. UTC | #10
On Wed, Sep 06, 2023 at 02:40:29PM +0200, Jan Beulich wrote:
> On 06.09.2023 14:28, Oleksii wrote:
> > On Wed, 2023-09-06 at 14:16 +0200, Jan Beulich wrote:
> >> You've removed quite a bit of functionality, comparing with the Linux
> >> original. May I ask why that is? What they have all makes sense to
> >> me,
> >> and looks to be useful down the road.
> > I decided to take only minimum needed now but if you think it would be
> > better to use the latest Linux's Makefile.asm-generic then I will
> > update it in the next patch version.
> 
> Unless there are things getting in the way, I indeed think it would be
> better to take the whole thing largely verbatim (a few edits are
> unavoidable afaict).

Yes, I think it would be useful as well to take most of the file from
Linux. At least, this would include the "$(unwanted)" variable, which is
used to remove old wrapper when an header is removed from "generic-y".
But instead of the "-include $(kbuild-file)", could you include
"$(src)/Makefile" instead like we do in "Rules.mk"? We don't have
$(kbuild-file) macro anyway, and I don't see the point in using files
name "Kbuild" when "Makefile" works and is enough.

Thanks,
Oleksii Kurochko Sept. 6, 2023, 3:24 p.m. UTC | #11
On Wed, 2023-09-06 at 16:06 +0100, Anthony PERARD wrote:
> On Wed, Sep 06, 2023 at 02:40:29PM +0200, Jan Beulich wrote:
> > On 06.09.2023 14:28, Oleksii wrote:
> > > On Wed, 2023-09-06 at 14:16 +0200, Jan Beulich wrote:
> > > > You've removed quite a bit of functionality, comparing with the
> > > > Linux
> > > > original. May I ask why that is? What they have all makes sense
> > > > to
> > > > me,
> > > > and looks to be useful down the road.
> > > I decided to take only minimum needed now but if you think it
> > > would be
> > > better to use the latest Linux's Makefile.asm-generic then I will
> > > update it in the next patch version.
> > 
> > Unless there are things getting in the way, I indeed think it would
> > be
> > better to take the whole thing largely verbatim (a few edits are
> > unavoidable afaict).
> 
> Yes, I think it would be useful as well to take most of the file from
> Linux. At least, this would include the "$(unwanted)" variable, which
> is
> used to remove old wrapper when an header is removed from "generic-
> y".
> But instead of the "-include $(kbuild-file)", could you include
> "$(src)/Makefile" instead like we do in "Rules.mk"? We don't have
> $(kbuild-file) macro anyway, and I don't see the point in using files
> name "Kbuild" when "Makefile" works and is enough.
> 
Thank you for your feedback.

I'll take into account your suggestions in the next patch version.

~ Oleksii
Anthony PERARD Sept. 6, 2023, 3:37 p.m. UTC | #12
On Wed, Sep 06, 2023 at 01:03:32PM +0000, Bertrand Marquis wrote:
> > On 6 Sep 2023, at 13:37, Oleksii <oleksii.kurochko@gmail.com> wrote:
> > On Mon, 2023-09-04 at 13:39 +0000, Bertrand Marquis wrote:
> >>> diff --git a/xen/scripts/Makefile.asm-generic
> >>> b/xen/scripts/Makefile.asm-generic
> >>> new file mode 100644
> >>> index 0000000000..0aac3f50b8
> >>> --- /dev/null
> >>> +++ b/xen/scripts/Makefile.asm-generic
> >>> +
> >>> +$(obj)/%.h:
> >>> + $(call cmd,wrap)
> >> 
> >> In fact i think your files are not generated in the srctree so this
> >> will break if you use out of tree compilation.
> > I checked that and in both cases it generated in correct place.
> > 
> > First case:
> > $ CONTAINER_NO_PULL=1 CONTAINER=riscv64
> > ./automation/scripts/containerize make XEN_TARGET_ARCH=riscv64 -C xen
> > build
> > 
> > $ ls -la xen/arch/riscv/include/generated/asm/vm_event.h 
> > -rw-r--r--. 1 ok ok 34 вер  6 14:32
> > xen/arch/riscv/include/generated/asm/vm_event.h
> > 
> > Second case: ( out-of-tree )
> > $ CONTAINER_NO_PULL=1 CONTAINER=riscv64
> > ./automation/scripts/containerize make O=xen_build
> > XEN_TARGET_ARCH=riscv64 -C xen build V=1
> > 
> > $ ls -la xen/xen_build/arch/riscv/include/generated/asm/vm_event.h 
> > -rw-r--r--. 1 ok ok 34 вер  6 14:34
> > xen/xen_build/arch/riscv/include/generated/asm/vm_event.h
> > 
> > Could you please clarify if there's somithing I might have overlooked?
> 
> No I do not think you did.
> 
> So obj is empty I would guess.
> Anyway you just need to make sure that CFLAGS is coherent with what you generate.
> So if you generate in $(obj) you need to make sure you use the same in CFLAGS i would say.
> 
> @anthony: any advice here ?

The use of $(obj) looks fine here. $(obj) is temporary and set for a
single subdirectory. $(obj) is set by whatever is calling
"Makefile.asm-generic", or "Rules.mk" is other cases.

In this patch, you can see $(obj) been set in "xen/Makefile":
    $(MAKE) -f $(srctree)/scripts/Makefile.asm-generic obj=arch/$(SRCARCH)/include/generated/asm

Another thing to know, `make` runs from the build directory, so in
Oleksii second case, `make` is running in "xen/xen_build", so $(obj) point
to a directory within the build directory.

For the CFLAGS, we can use $(objtree) (even if it is just "."), which
always point to the top directory of the build tree.

I hope that clarifies things.

Cheers,
Anthony PERARD Sept. 6, 2023, 3:57 p.m. UTC | #13
On Fri, Sep 01, 2023 at 07:02:14PM +0300, Oleksii Kurochko wrote:
> diff --git a/xen/Makefile b/xen/Makefile
> index f57e5a596c..698d6ddeb8 100644
> --- a/xen/Makefile
> +++ b/xen/Makefile
> @@ -667,6 +669,12 @@ endif # need-sub-make
>  PHONY += FORCE
>  FORCE:
>  
> +# Support for using generic headers in asm-generic
> +PHONY += asm-generic
> +asm-generic:
> +	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.asm-generic \
> +	            obj=arch/$(SRCARCH)/include/generated/asm

Could you introduce a $(asm-generic) macro in Kbuild.include like we
already have for $(build) and $(clean)? As I think it would be nicer to
have
	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/asm
in the main makefile.

Also, could you move the rule "asm-generic" within the "!config-build"
part of the Makefile? Somewhere around the rule for $(TARGET), maybe
just after the rule "_distclean".

Cheers,
Oleksii Kurochko Sept. 6, 2023, 7:46 p.m. UTC | #14
On Wed, 2023-09-06 at 16:57 +0100, Anthony PERARD wrote:
> On Fri, Sep 01, 2023 at 07:02:14PM +0300, Oleksii Kurochko wrote:
> > diff --git a/xen/Makefile b/xen/Makefile
> > index f57e5a596c..698d6ddeb8 100644
> > --- a/xen/Makefile
> > +++ b/xen/Makefile
> > @@ -667,6 +669,12 @@ endif # need-sub-make
> >  PHONY += FORCE
> >  FORCE:
> >  
> > +# Support for using generic headers in asm-generic
> > +PHONY += asm-generic
> > +asm-generic:
> > +       $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.asm-generic \
> > +                   obj=arch/$(SRCARCH)/include/generated/asm
> 
> Could you introduce a $(asm-generic) macro in Kbuild.include like we
> already have for $(build) and $(clean)? As I think it would be nicer
> to
> have
>         $(Q)$(MAKE) $(asm-
> generic)=arch/$(SRCARCH)/include/generated/asm
> in the main makefile.
> 
> Also, could you move the rule "asm-generic" within the "!config-
> build"
> part of the Makefile? Somewhere around the rule for $(TARGET), maybe
> just after the rule "_distclean".
> 
I pushed a new patch version tomorrow. I'll rework it based on your
comments here.

~ Oleksii
diff mbox series

Patch

diff --git a/xen/Makefile b/xen/Makefile
index f57e5a596c..698d6ddeb8 100644
--- a/xen/Makefile
+++ b/xen/Makefile
@@ -438,6 +438,7 @@  ifdef building_out_of_srctree
 endif
 CFLAGS += -I$(srctree)/include
 CFLAGS += -I$(srctree)/arch/$(SRCARCH)/include
+CFLAGS += -I$(srctree)/arch/$(SRCARCH)/include/generated
 
 # Note that link order matters!
 ALL_OBJS-y                := common/built_in.o
@@ -580,6 +581,7 @@  _clean:
 	rm -f $(TARGET).efi $(TARGET).efi.map $(TARGET).efi.elf $(TARGET).efi.stripped
 	rm -f asm-offsets.s arch/*/include/asm/asm-offsets.h
 	rm -f .banner .allconfig.tmp include/xen/compile.h
+	rm -rf arch/*/include/generated
 
 .PHONY: _distclean
 _distclean: clean
@@ -589,7 +591,7 @@  $(TARGET).gz: $(TARGET)
 	gzip -n -f -9 < $< > $@.new
 	mv $@.new $@
 
-$(TARGET): outputmakefile FORCE
+$(TARGET): outputmakefile asm-generic FORCE
 	$(Q)$(MAKE) $(build)=tools
 	$(Q)$(MAKE) $(build)=. include/xen/compile.h
 	$(Q)$(MAKE) $(build)=include all
@@ -667,6 +669,12 @@  endif # need-sub-make
 PHONY += FORCE
 FORCE:
 
+# Support for using generic headers in asm-generic
+PHONY += asm-generic
+asm-generic:
+	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.asm-generic \
+	            obj=arch/$(SRCARCH)/include/generated/asm
+
 # Declare the contents of the PHONY variable as phony.  We keep that
 # information in a variable so we can use it in if_changed and friends.
 .PHONY: $(PHONY)
diff --git a/xen/arch/arm/include/asm/Kbuild b/xen/arch/arm/include/asm/Kbuild
new file mode 100644
index 0000000000..a4e40e534e
--- /dev/null
+++ b/xen/arch/arm/include/asm/Kbuild
@@ -0,0 +1 @@ 
+# SPDX-License-Identifier: GPL-2.0-only
diff --git a/xen/arch/ppc/include/asm/Kbuild b/xen/arch/ppc/include/asm/Kbuild
new file mode 100644
index 0000000000..a4e40e534e
--- /dev/null
+++ b/xen/arch/ppc/include/asm/Kbuild
@@ -0,0 +1 @@ 
+# SPDX-License-Identifier: GPL-2.0-only
diff --git a/xen/arch/riscv/include/asm/Kbuild b/xen/arch/riscv/include/asm/Kbuild
new file mode 100644
index 0000000000..a4e40e534e
--- /dev/null
+++ b/xen/arch/riscv/include/asm/Kbuild
@@ -0,0 +1 @@ 
+# SPDX-License-Identifier: GPL-2.0-only
diff --git a/xen/arch/x86/include/asm/Kbuild b/xen/arch/x86/include/asm/Kbuild
new file mode 100644
index 0000000000..a4e40e534e
--- /dev/null
+++ b/xen/arch/x86/include/asm/Kbuild
@@ -0,0 +1 @@ 
+# SPDX-License-Identifier: GPL-2.0-only
diff --git a/xen/scripts/Makefile.asm-generic b/xen/scripts/Makefile.asm-generic
new file mode 100644
index 0000000000..0aac3f50b8
--- /dev/null
+++ b/xen/scripts/Makefile.asm-generic
@@ -0,0 +1,23 @@ 
+# SPDX-License-Identifier: GPL-2.0
+# include/asm-generic contains a lot of files that are used
+# verbatim by several architectures.
+#
+# This Makefile reads the file arch/$(SRCARCH)/include/asm/Kbuild
+# and for each file listed in this file with generic-y creates
+# a small wrapper file in $(obj) (arch/$(SRCARCH)/include/generated/asm)
+
+kbuild-file := $(srctree)/arch/$(SRCARCH)/include/asm/Kbuild
+include $(kbuild-file)
+
+include scripts/Kbuild.include
+
+# Create output directory if not already present
+_dummy := $(shell [ -d $(obj) ] || mkdir -p $(obj))
+
+quiet_cmd_wrap = WRAP    $@
+cmd_wrap = echo "\#include <asm-generic/$*.h>" >$@
+
+all: $(patsubst %, $(obj)/%, $(generic-y))
+
+$(obj)/%.h:
+	$(call cmd,wrap)