diff mbox series

[v3,08/14] xen/asm-generic: introduce generic div64.h header

Message ID 13bf409f3191d066af9caef417011b6ea039dbd9.1700221559.git.oleksii.kurochko@gmail.com (mailing list archive)
State Superseded
Headers show
Series Introduce generic headers | expand

Commit Message

Oleksii K. Nov. 17, 2023, 12:24 p.m. UTC
All archs have the do_div implementation for BITS_PER_LONG == 64
so do_div64.h is moved to asm-generic.

x86 and PPC were switched to asm-generic version of div64.h.

Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
---
Changes in V3:
 - Drop x86 and PPC's div64.h.
 - Update the commit message.
---
Changes in V2:
	- rename base to divisor
	- add "#if BITS_PER_LONG == 64"
	- fix code style
---
 xen/arch/ppc/include/asm/Makefile |  1 +
 xen/arch/ppc/include/asm/div64.h  | 14 --------------
 xen/arch/x86/include/asm/Makefile |  1 +
 xen/arch/x86/include/asm/div64.h  | 14 --------------
 xen/include/asm-generic/div64.h   | 27 +++++++++++++++++++++++++++
 5 files changed, 29 insertions(+), 28 deletions(-)
 delete mode 100644 xen/arch/ppc/include/asm/div64.h
 delete mode 100644 xen/arch/x86/include/asm/div64.h
 create mode 100644 xen/include/asm-generic/div64.h

Comments

Jan Beulich Nov. 21, 2023, 3:59 p.m. UTC | #1
On 17.11.2023 13:24, Oleksii Kurochko wrote:
> All archs have the do_div implementation for BITS_PER_LONG == 64
> so do_div64.h is moved to asm-generic.
> 
> x86 and PPC were switched to asm-generic version of div64.h.
> 
> Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>

Acked-by: Jan Beulich <jbeulich@suse.com>
Julien Grall Nov. 24, 2023, 11:29 a.m. UTC | #2
Hi,

On 17/11/2023 12:24, Oleksii Kurochko wrote:
> All archs have the do_div implementation for BITS_PER_LONG == 64
> so do_div64.h is moved to asm-generic.

You are saying "all archs" but ...

> 
> x86 and PPC were switched to asm-generic version of div64.h.

... you only switch x86/PPC to div64.h.

I guess this is because for arm we have a different implementation for 
32-bits. The 64-bits version is the same as x86/PPC.

So I wonder if it is possible to include asm-generic/div64.h from 
arch/arm/include/asm/div64.h?

This will avoid duplicating some code.

Cheers,
Oleksii K. Nov. 24, 2023, 12:04 p.m. UTC | #3
Hi Julien,

On Fri, 2023-11-24 at 11:29 +0000, Julien Grall wrote:
> Hi,
> 
> On 17/11/2023 12:24, Oleksii Kurochko wrote:
> > All archs have the do_div implementation for BITS_PER_LONG == 64
> > so do_div64.h is moved to asm-generic.
> 
> You are saying "all archs" but ...
> 
> > 
> > x86 and PPC were switched to asm-generic version of div64.h.
> 
> ... you only switch x86/PPC to div64.h.
You are right. I wasn't precise enough. Also RISC-V uses asm-generic
version of div64.h but for that I have separate patch series.

> 
> I guess this is because for arm we have a different implementation
> for 
> 32-bits. The 64-bits version is the same as x86/PPC.
> 
> So I wonder if it is possible to include asm-generic/div64.h from 
> arch/arm/include/asm/div64.h?
> 
> This will avoid duplicating some code.
Yes, you are right. Arm wasn't switched to asm-generic/div64.h because
of different implementaion for 32-bit.

I think we can include asm-generic/div64.h excplicitly for Arm. I made
a little test and it works so I started full CI and if it won't any
issue with Arm I'll update the patch.


Thanks for the comments.

> Cheers,
>
diff mbox series

Patch

diff --git a/xen/arch/ppc/include/asm/Makefile b/xen/arch/ppc/include/asm/Makefile
index 9b38d2d381..b4fbcc897b 100644
--- a/xen/arch/ppc/include/asm/Makefile
+++ b/xen/arch/ppc/include/asm/Makefile
@@ -1,4 +1,5 @@ 
 # SPDX-License-Identifier: GPL-2.0-only
+generic-y += div64.h
 generic-y += hardirq.h
 generic-y += hypercall.h
 generic-y += iocap.h
diff --git a/xen/arch/ppc/include/asm/div64.h b/xen/arch/ppc/include/asm/div64.h
deleted file mode 100644
index d213e50585..0000000000
--- a/xen/arch/ppc/include/asm/div64.h
+++ /dev/null
@@ -1,14 +0,0 @@ 
-/* SPDX-License-Identifier: GPL-2.0-only */
-#ifndef __ASM_PPC_DIV64_H__
-#define __ASM_PPC_DIV64_H__
-
-#include <xen/types.h>
-
-#define do_div(n, base) ({                       \
-    uint32_t base_ = (base);                     \
-    uint32_t rem_ = (uint64_t)(n) % base_;       \
-    (n) = (uint64_t)(n) / base_;                 \
-    rem_;                                        \
-})
-
-#endif /* __ASM_PPC_DIV64_H__ */
diff --git a/xen/arch/x86/include/asm/Makefile b/xen/arch/x86/include/asm/Makefile
index 874429ed30..daab34ff0a 100644
--- a/xen/arch/x86/include/asm/Makefile
+++ b/xen/arch/x86/include/asm/Makefile
@@ -1,2 +1,3 @@ 
 # SPDX-License-Identifier: GPL-2.0-only
+generic-y += div64.h
 generic-y += percpu.h
diff --git a/xen/arch/x86/include/asm/div64.h b/xen/arch/x86/include/asm/div64.h
deleted file mode 100644
index dd49f64a3b..0000000000
--- a/xen/arch/x86/include/asm/div64.h
+++ /dev/null
@@ -1,14 +0,0 @@ 
-#ifndef __X86_DIV64
-#define __X86_DIV64
-
-#include <xen/types.h>
-
-#define do_div(n,base) ({                       \
-    uint32_t __base = (base);                   \
-    uint32_t __rem;                             \
-    __rem = ((uint64_t)(n)) % __base;           \
-    (n) = ((uint64_t)(n)) / __base;             \
-    __rem;                                      \
-})
-
-#endif
diff --git a/xen/include/asm-generic/div64.h b/xen/include/asm-generic/div64.h
new file mode 100644
index 0000000000..068d8a11ad
--- /dev/null
+++ b/xen/include/asm-generic/div64.h
@@ -0,0 +1,27 @@ 
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef __ASM_GENERIC_DIV64
+#define __ASM_GENERIC_DIV64
+
+#include <xen/types.h>
+
+#if BITS_PER_LONG == 64
+
+#define do_div(n, divisor) ({                   \
+    uint32_t divisor_ = (divisor);              \
+    uint32_t rem_ = (uint64_t)(n) % divisor_;   \
+    (n) = (uint64_t)(n) / divisor_;             \
+    rem_;                                       \
+})
+
+#endif /* BITS_PER_LONG */
+
+#endif
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * indent-tabs-mode: nil
+ * End:
+ */