Introduce arch/x86/lib/, and make it the home for the somewhat misplaced
x86-specific file that lived in the arch-independent lib/.

Introduce ARCH_LIBS-y as a make variable, to arrange for arch-specific
libraries to (generally) come ahead of generic one(s) when linking. Should
any library be intended to come after the generic one(s), it can be
appended to $(ALL_LIBS-y).

Signed-off-by: Jan Beulich <jbeulich@suse.com>
---
v2: Arrange to link arch-specific lib ahead of generic one.
---
 xen/Makefile                                                  | 4 +++-
 xen/arch/x86/Makefile                                         | 1 +
 xen/arch/x86/arch.mk                                          | 2 ++
 xen/arch/x86/lib/Makefile                                     | 1 +
 .../x86/lib/generic-hweightl.c}                               | 0
 xen/lib/Makefile                                              | 1 -
 6 files changed, 7 insertions(+), 2 deletions(-)
 create mode 100644 xen/arch/x86/lib/Makefile
 rename xen/{lib/x86-generic-hweightl.c => arch/x86/lib/generic-hweightl.c} (100%)

diff --git a/xen/Makefile b/xen/Makefile
index e6cf2874251c..13e336ba5484 100644
--- a/xen/Makefile
+++ b/xen/Makefile
@@ -461,6 +461,7 @@ ALL_OBJS-y                += xsm/built_in.o
 ALL_OBJS-y                += arch/$(SRCARCH)/built_in.o
 ALL_OBJS-$(CONFIG_CRYPTO) += crypto/built_in.o
 
+ARCH_LIBS-y               :=
 ALL_LIBS-y                := lib/lib.a
 
 all-symbols-y :=
@@ -620,7 +621,8 @@ $(TARGET): outputmakefile asm-generic FORCE
 	$(Q)$(MAKE) $(build)=arch/$(SRCARCH) include
 	$(Q)$(MAKE) $(build)=. arch/$(SRCARCH)/include/asm/asm-offsets.h
 	$(Q)$(MAKE) $(build)=. MKRELOC=$(MKRELOC) 'ALL_OBJS=$(ALL_OBJS-y)' \
-	            'ALL_LIBS=$(ALL_LIBS-y)' 'all_symbols=$(all-symbols-y)' $@
+	            'ALL_LIBS=$(ARCH_LIBS-y) $(ALL_LIBS-y)' \
+	            'all_symbols=$(all-symbols-y)' $@
 
 SUBDIRS = xsm arch common crypto drivers lib test
 define all_sources
diff --git a/xen/arch/x86/Makefile b/xen/arch/x86/Makefile
index 300cc67407e9..61e2293a467e 100644
--- a/xen/arch/x86/Makefile
+++ b/xen/arch/x86/Makefile
@@ -5,6 +5,7 @@ obj-y += efi/
 obj-y += genapic/
 obj-$(CONFIG_GUEST) += guest/
 obj-$(CONFIG_HVM) += hvm/
+obj-y += lib/
 obj-y += mm/
 obj-$(CONFIG_XENOPROF) += oprofile/
 obj-$(CONFIG_PV) += pv/
diff --git a/xen/arch/x86/arch.mk b/xen/arch/x86/arch.mk
index 16368a498bb7..0203138a819a 100644
--- a/xen/arch/x86/arch.mk
+++ b/xen/arch/x86/arch.mk
@@ -3,6 +3,8 @@
 
 export XEN_IMG_OFFSET := 0x200000
 
+ARCH_LIBS-y += arch/x86/lib/lib.a
+
 CFLAGS += -DXEN_IMG_OFFSET=$(XEN_IMG_OFFSET)
 
 # Prevent floating-point variables from creeping into Xen.
diff --git a/xen/arch/x86/lib/Makefile b/xen/arch/x86/lib/Makefile
new file mode 100644
index 000000000000..ddf7e19bdc1d
--- /dev/null
+++ b/xen/arch/x86/lib/Makefile
@@ -0,0 +1 @@
+lib-y += generic-hweightl.o
diff --git a/xen/lib/x86-generic-hweightl.c b/xen/arch/x86/lib/generic-hweightl.c
similarity index 100%
rename from xen/lib/x86-generic-hweightl.c
rename to xen/arch/x86/lib/generic-hweightl.c
diff --git a/xen/lib/Makefile b/xen/lib/Makefile
index 954d9216a39c..efca830d924c 100644
--- a/xen/lib/Makefile
+++ b/xen/lib/Makefile
@@ -39,7 +39,6 @@ lib-y += strtol.o
 lib-y += strtoll.o
 lib-y += strtoul.o
 lib-y += strtoull.o
-lib-$(CONFIG_X86) += x86-generic-hweightl.o
 lib-$(CONFIG_X86) += xxhash32.o
 lib-$(CONFIG_X86) += xxhash64.o

On 08/12/2025 12:04 pm, Jan Beulich wrote:
> Introduce arch/x86/lib/, and make it the home for the somewhat misplaced
> x86-specific file that lived in the arch-independent lib/.
>
> Introduce ARCH_LIBS-y as a make variable, to arrange for arch-specific
> libraries to (generally) come ahead of generic one(s) when linking. Should
> any library be intended to come after the generic one(s), it can be
> appended to $(ALL_LIBS-y).
>
> Signed-off-by: Jan Beulich <jbeulich@suse.com>

Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>