[PATCH 02/23] lib: move 64-bit div/mod compiler helpers

From: Jan Beulich <jbeulich@suse.com>
To: "xen-devel@lists.xenproject.org" <xen-devel@lists.xenproject.org>
Cc: "Andrew Cooper" <andrew.cooper3@citrix.com>,
	"George Dunlap" <george.dunlap@citrix.com>,
	"Ian Jackson" <iwj@xenproject.org>,
	"Julien Grall" <julien@xen.org>,
	"Stefano Stabellini" <sstabellini@kernel.org>,
	"Wei Liu" <wl@xen.org>, "Roger Pau Monné" <roger.pau@citrix.com>
Subject: [PATCH 02/23] lib: move 64-bit div/mod compiler helpers
Date: Thu, 1 Apr 2021 12:19:46 +0200	[thread overview]
Message-ID: <0fec827f-bb0b-4ea1-7757-9c27e9138be7@suse.com> (raw)
In-Reply-To: <c53a6802-8bae-1dc6-5ac4-6238e122aaa4@suse.com>

These were built for 32-bit architectures only (the same code could,
with some tweaking, sensibly be used to provide TI-mode helpers on
64-bit arch-es) - retain this property, while still avoiding to have
a CU without any contents at all. For this, Arm's CONFIG_64BIT gets
generalized.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
---
 xen/arch/Kconfig                   |  2 ++
 xen/arch/arm/Kconfig               | 12 +++---------
 xen/arch/x86/Kconfig               |  1 +
 xen/common/Makefile                |  1 -
 xen/lib/Makefile                   |  4 ++++
 xen/{common/lib.c => lib/divmod.c} |  2 --
 6 files changed, 10 insertions(+), 12 deletions(-)
 rename xen/{common/lib.c => lib/divmod.c} (99%)

diff --git a/xen/arch/Kconfig b/xen/arch/Kconfig
index d144d4c8d3ee..f16eb0df43af 100644
--- a/xen/arch/Kconfig
+++ b/xen/arch/Kconfig
@@ -1,3 +1,5 @@
+config 64BIT
+	bool
 
 config NR_CPUS
 	int "Maximum number of CPUs"
diff --git a/xen/arch/arm/Kconfig b/xen/arch/arm/Kconfig
index 330bbf6232d4..ecfa6822e4d3 100644
--- a/xen/arch/arm/Kconfig
+++ b/xen/arch/arm/Kconfig
@@ -1,17 +1,11 @@
-config 64BIT
-	bool
-	default "$(ARCH)" != "arm32"
-	help
-	  Say yes to build a 64-bit Xen
-	  Say no to build a 32-bit Xen
-
 config ARM_32
 	def_bool y
-	depends on !64BIT
+	depends on "$(ARCH)" = "arm32"
 
 config ARM_64
 	def_bool y
-	depends on 64BIT
+	depends on !ARM_32
+	select 64BIT
 	select HAS_FAST_MULTIPLY
 
 config ARM
diff --git a/xen/arch/x86/Kconfig b/xen/arch/x86/Kconfig
index f79e6634db3f..4d6911ffa467 100644
--- a/xen/arch/x86/Kconfig
+++ b/xen/arch/x86/Kconfig
@@ -1,5 +1,6 @@
 config X86_64
 	def_bool y
+	select 64BIT
 
 config X86
 	def_bool y
diff --git a/xen/common/Makefile b/xen/common/Makefile
index 71c1d466bd8f..e2a7e62d14bf 100644
--- a/xen/common/Makefile
+++ b/xen/common/Makefile
@@ -21,7 +21,6 @@ obj-y += kernel.o
 obj-y += keyhandler.o
 obj-$(CONFIG_KEXEC) += kexec.o
 obj-$(CONFIG_KEXEC) += kimage.o
-obj-y += lib.o
 obj-$(CONFIG_LIVEPATCH) += livepatch.o livepatch_elf.o
 obj-$(CONFIG_MEM_ACCESS) += mem_access.o
 obj-y += memory.o
diff --git a/xen/lib/Makefile b/xen/lib/Makefile
index 0b274583ef0b..a5dc1442a422 100644
--- a/xen/lib/Makefile
+++ b/xen/lib/Makefile
@@ -10,3 +10,7 @@ lib-y += rbtree.o
 lib-y += sort.o
 lib-$(CONFIG_X86) += xxhash32.o
 lib-$(CONFIG_X86) += xxhash64.o
+
+lib32-y := divmod.o
+lib32-$(CONFIG_64BIT) :=
+lib-y += $(lib32-y)
diff --git a/xen/common/lib.c b/xen/lib/divmod.c
similarity index 99%
rename from xen/common/lib.c
rename to xen/lib/divmod.c
index 5b8f49153dad..0be6ccc70096 100644
--- a/xen/common/lib.c
+++ b/xen/lib/divmod.c
@@ -40,7 +40,6 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  */
-#if BITS_PER_LONG == 32
 
 /*
  * Depending on the desired operation, we view a `long long' (aka quad_t) in
@@ -391,7 +390,6 @@ s64 __ldivmod_helper(s64 a, s64 b, s64 *r)
     else
         return quot;
 }
-#endif /* BITS_PER_LONG == 32 */
 
 /*
  * Local variables:


