diff mbox series

[v6,1/2] xen: asm-generic support

Message ID cf5f446915bd5c8980beda22718efff32678e16b.1694078544.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State Superseded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. 7, 2023, 9:32 a.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/Makefile

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

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

As the base Makefile.asm-generic from Linux kernel was taken.
( 06c2afb862f9da8 "Linux 6.5-rc1" ).

Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
---
Changes in V6:
 - introduce $(asm-generic) macro in Kbuild.include.
 - move "asm-generic" after the rule "__distclean".
---
Changes in V5:
 - Update the commit message
 - Update SPDX license in Makefile.
 - Remove code related to UML
 - Include $(src)/Makefile instead of $(kbuild-file) 
 - Update comment message in Makefile.asm-generic
 - Update .gitignore
 - Update path to generated headers in CFLAGS.
 - Use the latest version of Linux's Makefile.asm-generic
---
Changes in V4:
 - introduce asm-generic support
 - update commit message
---
Changes in V3:
 - Rename stubs dir to asm-generic
---
Changes in V2:
 - Nothing changed.
---
 .gitignore                       |  1 +
 xen/Makefile                     |  9 +++++-
 xen/scripts/Kbuild.include       |  6 ++++
 xen/scripts/Makefile.asm-generic | 53 ++++++++++++++++++++++++++++++++
 4 files changed, 68 insertions(+), 1 deletion(-)
 create mode 100644 xen/scripts/Makefile.asm-generic

Comments

Anthony PERARD Sept. 7, 2023, 10:08 a.m. UTC | #1 
On Thu, Sep 07, 2023 at 12:32:56PM +0300, Oleksii Kurochko wrote:
> diff --git a/xen/scripts/Makefile.asm-generic b/xen/scripts/Makefile.asm-generic
> new file mode 100644
> index 0000000000..92a3a741c5
> --- /dev/null
> +++ b/xen/scripts/Makefile.asm-generic
> @@ -0,0 +1,53 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +# include/asm-generic contains a lot of files that are used
> +# verbatim by several architectures.
> +#
> +# This Makefile reads the file arch/$(SRCARCH)/include/asm/Makefile
> +# and for each file listed in this file with generic-y creates
> +# a small wrapper file in arch/$(SRCARCH)/include/generated/asm.
> +
> +PHONY := all
> +all:
> +
> +src := $(subst /generated,,$(obj))
> +
> +include $(srctree)/scripts/Kbuild.include
> +-include $(src)/Makefile
> +
> +redundant := $(filter $(mandatory-y) $(generated-y), $(generic-y))
> +redundant += $(foreach f, $(generic-y), $(if $(wildcard $(srctree)/$(src)/$(f)),$(f)))
> +redundant := $(sort $(redundant))
> +$(if $(redundant),\
> +	$(warning redundant generic-y found in $(src)/Kbuild: $(redundant)))

This warning would need to say "$(src)/Makefile" now instead of Kbuild.

Beside this, patch looks fine to me:
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>

Thanks,
Jan Beulich Sept. 7, 2023, 10:48 a.m. UTC | #2 
On 07.09.2023 11:32, Oleksii Kurochko wrote:
> --- /dev/null
> +++ b/xen/scripts/Makefile.asm-generic
> @@ -0,0 +1,53 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +# include/asm-generic contains a lot of files that are used
> +# verbatim by several architectures.
> +#
> +# This Makefile reads the file arch/$(SRCARCH)/include/asm/Makefile
> +# and for each file listed in this file with generic-y creates
> +# a small wrapper file in arch/$(SRCARCH)/include/generated/asm.
> +
> +PHONY := all
> +all:
> +
> +src := $(subst /generated,,$(obj))
> +
> +include $(srctree)/scripts/Kbuild.include
> +-include $(src)/Makefile

With the definition of src above, is this correct for out-of-tree builds?
You want to reference the Makefile in the source tree, ...

> +redundant := $(filter $(mandatory-y) $(generated-y), $(generic-y))
> +redundant += $(foreach f, $(generic-y), $(if $(wildcard $(srctree)/$(src)/$(f)),$(f)))

... much like $(srctree) is used here (and similarly again further down).

Jan
Oleksii Kurochko Sept. 7, 2023, 1 p.m. UTC | #3 
On Thu, 2023-09-07 at 11:08 +0100, Anthony PERARD wrote:
> On Thu, Sep 07, 2023 at 12:32:56PM +0300, Oleksii Kurochko wrote:
> > diff --git a/xen/scripts/Makefile.asm-generic
> > b/xen/scripts/Makefile.asm-generic
> > new file mode 100644
> > index 0000000000..92a3a741c5
> > --- /dev/null
> > +++ b/xen/scripts/Makefile.asm-generic
> > @@ -0,0 +1,53 @@
> > +# SPDX-License-Identifier: GPL-2.0-only
> > +# include/asm-generic contains a lot of files that are used
> > +# verbatim by several architectures.
> > +#
> > +# This Makefile reads the file
> > arch/$(SRCARCH)/include/asm/Makefile
> > +# and for each file listed in this file with generic-y creates
> > +# a small wrapper file in arch/$(SRCARCH)/include/generated/asm.
> > +
> > +PHONY := all
> > +all:
> > +
> > +src := $(subst /generated,,$(obj))
> > +
> > +include $(srctree)/scripts/Kbuild.include
> > +-include $(src)/Makefile
> > +
> > +redundant := $(filter $(mandatory-y) $(generated-y), $(generic-y))
> > +redundant += $(foreach f, $(generic-y), $(if $(wildcard
> > $(srctree)/$(src)/$(f)),$(f)))
> > +redundant := $(sort $(redundant))
> > +$(if $(redundant),\
> > +       $(warning redundant generic-y found in $(src)/Kbuild:
> > $(redundant)))
> 
> This warning would need to say "$(src)/Makefile" now instead of
> Kbuild.
Thanks. Missed that.

> 
> Beside this, patch looks fine to me:
> Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
> 
> Thanks,
> 

~ Oleksii
Oleksii Kurochko Sept. 7, 2023, 1:45 p.m. UTC | #4 
On Thu, 2023-09-07 at 12:48 +0200, Jan Beulich wrote:
> On 07.09.2023 11:32, Oleksii Kurochko wrote:
> > --- /dev/null
> > +++ b/xen/scripts/Makefile.asm-generic
> > @@ -0,0 +1,53 @@
> > +# SPDX-License-Identifier: GPL-2.0-only
> > +# include/asm-generic contains a lot of files that are used
> > +# verbatim by several architectures.
> > +#
> > +# This Makefile reads the file
> > arch/$(SRCARCH)/include/asm/Makefile
> > +# and for each file listed in this file with generic-y creates
> > +# a small wrapper file in arch/$(SRCARCH)/include/generated/asm.
> > +
> > +PHONY := all
> > +all:
> > +
> > +src := $(subst /generated,,$(obj))
> > +
> > +include $(srctree)/scripts/Kbuild.include
> > +-include $(src)/Makefile
> 
> With the definition of src above, is this correct for out-of-tree
> builds?
Logically you are right and I think it would be better to use
$(srctree)/$src but it works for out-of-tree builds too.

$ CONTAINER_NO_PULL=1 CONTAINER=riscv64
./automation/scripts/containerize make O=xen-build V=2
XEN_TARGET_ARCH=riscv64 -C xen build

$ ls -la xen/xen-build/arch/riscv/include/generated/asm/vm_event.h
-rw-r--r--. 1 ok ok 34 вер  7 16:27 xen/xen-
build/arch/riscv/include/generated/asm/vm_event.h

> You want to reference the Makefile in the source tree, ...
> 
> > +redundant := $(filter $(mandatory-y) $(generated-y), $(generic-y))
> > +redundant += $(foreach f, $(generic-y), $(if $(wildcard
> > $(srctree)/$(src)/$(f)),$(f)))
> 
> ... much like $(srctree) is used here (and similarly again further
> down).
> 
~ Oleksii
Jan Beulich Sept. 7, 2023, 1:56 p.m. UTC | #5 
On 07.09.2023 15:45, Oleksii wrote:
> On Thu, 2023-09-07 at 12:48 +0200, Jan Beulich wrote:
>> On 07.09.2023 11:32, Oleksii Kurochko wrote:
>>> --- /dev/null
>>> +++ b/xen/scripts/Makefile.asm-generic
>>> @@ -0,0 +1,53 @@
>>> +# SPDX-License-Identifier: GPL-2.0-only
>>> +# include/asm-generic contains a lot of files that are used
>>> +# verbatim by several architectures.
>>> +#
>>> +# This Makefile reads the file
>>> arch/$(SRCARCH)/include/asm/Makefile
>>> +# and for each file listed in this file with generic-y creates
>>> +# a small wrapper file in arch/$(SRCARCH)/include/generated/asm.
>>> +
>>> +PHONY := all
>>> +all:
>>> +
>>> +src := $(subst /generated,,$(obj))
>>> +
>>> +include $(srctree)/scripts/Kbuild.include
>>> +-include $(src)/Makefile
>>
>> With the definition of src above, is this correct for out-of-tree
>> builds?
> Logically you are right and I think it would be better to use
> $(srctree)/$src but it works for out-of-tree builds too.
> 
> $ CONTAINER_NO_PULL=1 CONTAINER=riscv64
> ./automation/scripts/containerize make O=xen-build V=2
> XEN_TARGET_ARCH=riscv64 -C xen build
> 
> $ ls -la xen/xen-build/arch/riscv/include/generated/asm/vm_event.h
> -rw-r--r--. 1 ok ok 34 вер  7 16:27 xen/xen-
> build/arch/riscv/include/generated/asm/vm_event.h

Oh, right, aiui because of VPATH being set to $(srctree), and therefore
in the absence of a Makefile in $(objtree)/$(src)/ it'll go look for
one in $(srctree)/$(src)/. Never mind then:
Acked-by: Jan Beulich <jbeulich@suse.com>

Jan
Oleksii Kurochko Sept. 7, 2023, 2:13 p.m. UTC | #6 
On Thu, 2023-09-07 at 15:56 +0200, Jan Beulich wrote:
> On 07.09.2023 15:45, Oleksii wrote:
> > On Thu, 2023-09-07 at 12:48 +0200, Jan Beulich wrote:
> > > On 07.09.2023 11:32, Oleksii Kurochko wrote:
> > > > --- /dev/null
> > > > +++ b/xen/scripts/Makefile.asm-generic
> > > > @@ -0,0 +1,53 @@
> > > > +# SPDX-License-Identifier: GPL-2.0-only
> > > > +# include/asm-generic contains a lot of files that are used
> > > > +# verbatim by several architectures.
> > > > +#
> > > > +# This Makefile reads the file
> > > > arch/$(SRCARCH)/include/asm/Makefile
> > > > +# and for each file listed in this file with generic-y creates
> > > > +# a small wrapper file in
> > > > arch/$(SRCARCH)/include/generated/asm.
> > > > +
> > > > +PHONY := all
> > > > +all:
> > > > +
> > > > +src := $(subst /generated,,$(obj))
> > > > +
> > > > +include $(srctree)/scripts/Kbuild.include
> > > > +-include $(src)/Makefile
> > > 
> > > With the definition of src above, is this correct for out-of-tree
> > > builds?
> > Logically you are right and I think it would be better to use
> > $(srctree)/$src but it works for out-of-tree builds too.
> > 
> > $ CONTAINER_NO_PULL=1 CONTAINER=riscv64
> > ./automation/scripts/containerize make O=xen-build V=2
> > XEN_TARGET_ARCH=riscv64 -C xen build
> > 
> > $ ls -la xen/xen-build/arch/riscv/include/generated/asm/vm_event.h
> > -rw-r--r--. 1 ok ok 34 вер  7 16:27 xen/xen-
> > build/arch/riscv/include/generated/asm/vm_event.h
> 
> Oh, right, aiui because of VPATH being set to $(srctree), and
> therefore
> in the absence of a Makefile in $(objtree)/$(src)/ it'll go look for
> one in $(srctree)/$(src)/. Never mind then:
> Acked-by: Jan Beulich <jbeulich@suse.com>
> 
Thanks for explanation.


~ Oleksii
diff mbox series

Patch

diff --git a/.gitignore b/.gitignore
index 50273adb8d..287166f8fc 100644
--- a/.gitignore
+++ b/.gitignore
@@ -267,6 +267,7 @@  xen/arch/*/efi/efi.h
 xen/arch/*/efi/pe.c
 xen/arch/*/efi/runtime.c
 xen/arch/*/include/asm/asm-offsets.h
+xen/arch/*/include/generated
 xen/build-dir-cppcheck/
 xen/common/config_data.S
 xen/common/config.gz
diff --git a/xen/Makefile b/xen/Makefile
index f57e5a596c..2dc5e3526d 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/$(SRCARCH)/include
+CFLAGS += -I$(objtree)/arch/$(SRCARCH)/include/generated
 
 # Note that link order matters!
 ALL_OBJS-y                := common/built_in.o
@@ -580,16 +581,22 @@  _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 $(objtree)/arch/*/include/generated
 
 .PHONY: _distclean
 _distclean: clean
 	rm -f tags TAGS cscope.files cscope.in.out cscope.out cscope.po.out GTAGS GPATH GRTAGS GSYMS .config source
 
+# Support for using generic headers in asm-generic
+PHONY += asm-generic
+asm-generic:
+	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/asm
+
 $(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
diff --git a/xen/scripts/Kbuild.include b/xen/scripts/Kbuild.include
index 785a32c32e..c2bd8498e1 100644
--- a/xen/scripts/Kbuild.include
+++ b/xen/scripts/Kbuild.include
@@ -91,6 +91,12 @@  cc-ifversion = $(shell [ $(CONFIG_GCC_VERSION)0 $(1) $(2)000 ] && echo $(3) || e
 
 clang-ifversion = $(shell [ $(CONFIG_CLANG_VERSION)0 $(1) $(2)000 ] && echo $(3) || echo $(4))
 
+###
+# Shorthand for $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.asm-generic obj
+# Usage:
+# $(Q)$(MAKE) $(asm-generic)=dir
+asm-generic := -f $(srctree)/scripts/Makefile.asm-generic obj
+
 ###
 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj=
 # Usage:
diff --git a/xen/scripts/Makefile.asm-generic b/xen/scripts/Makefile.asm-generic
new file mode 100644
index 0000000000..92a3a741c5
--- /dev/null
+++ b/xen/scripts/Makefile.asm-generic
@@ -0,0 +1,53 @@ 
+# SPDX-License-Identifier: GPL-2.0-only
+# include/asm-generic contains a lot of files that are used
+# verbatim by several architectures.
+#
+# This Makefile reads the file arch/$(SRCARCH)/include/asm/Makefile
+# and for each file listed in this file with generic-y creates
+# a small wrapper file in arch/$(SRCARCH)/include/generated/asm.
+
+PHONY := all
+all:
+
+src := $(subst /generated,,$(obj))
+
+include $(srctree)/scripts/Kbuild.include
+-include $(src)/Makefile
+
+redundant := $(filter $(mandatory-y) $(generated-y), $(generic-y))
+redundant += $(foreach f, $(generic-y), $(if $(wildcard $(srctree)/$(src)/$(f)),$(f)))
+redundant := $(sort $(redundant))
+$(if $(redundant),\
+	$(warning redundant generic-y found in $(src)/Kbuild: $(redundant)))
+
+# If arch does not implement mandatory headers, fallback to asm-generic ones.
+mandatory-y := $(filter-out $(generated-y), $(mandatory-y))
+generic-y   += $(foreach f, $(mandatory-y), $(if $(wildcard $(srctree)/$(src)/$(f)),,$(f)))
+
+generic-y   := $(addprefix $(obj)/, $(generic-y))
+generated-y := $(addprefix $(obj)/, $(generated-y))
+
+# Remove stale wrappers when the corresponding files are removed from generic-y
+old-headers := $(wildcard $(obj)/*.h)
+unwanted    := $(filter-out $(generic-y) $(generated-y),$(old-headers))
+
+quiet_cmd_wrap = WRAP    $@
+      cmd_wrap = echo "\#include <asm-generic/$*.h>" > $@
+
+quiet_cmd_remove = REMOVE  $(unwanted)
+      cmd_remove = rm -f $(unwanted)
+
+all: $(generic-y)
+	$(if $(unwanted),$(call cmd,remove))
+	@:
+
+$(obj)/%.h:
+	$(call cmd,wrap)
+
+# Create output directory. Skip it if at least one old header exists
+# since we know the output directory already exists.
+ifeq ($(old-headers),)
+$(shell mkdir -p $(obj))
+endif
+
+.PHONY: $(PHONY)