diff mbox series

[v5,04/16] xen/lib: Switch to xen/byteorder.h

Message ID 20250328134427.874848-5-andrew.cooper3@citrix.com (mailing list archive)
State New
Headers show
Series xen: Centralise byteswap infrastructure | expand

Commit Message

Andrew Cooper March 28, 2025, 1:44 p.m. UTC 
From: Lin Liu <lin.liu@citrix.com>

In divmod.c, additionally swap xen/lib.h for xen/macros.h as only ABS() is
needed.

In find-next-bit.c, ext2 has nothing to do with this logic.  Despite the
comments, it was a local modification when the logic was imported from Linux,
because Xen didn't have a suitable helper.

The new infrsatructure does have a suitable primitive, so use it.

No functional change.

Signed-off-by: Lin Liu <lin.liu@citrix.com>
---
CC: Anthony PERARD <anthony.perard@vates.tech>
CC: Michal Orzel <michal.orzel@amd.com>
CC: Jan Beulich <jbeulich@suse.com>
CC: Julien Grall <julien@xen.org>
CC: Roger Pau Monné <roger.pau@citrix.com>
CC: Stefano Stabellini <sstabellini@kernel.org>
CC: Volodymyr Babchuk <Volodymyr_Babchuk@epam.com>
CC: Bertrand Marquis <bertrand.marquis@arm.com>
CC: Shawn Anastasio <sanastasio@raptorengineering.com>
CC: Oleksii Kurochko <oleksii.kurochko@gmail.com>
CC: Daniel P. Smith <dpsmith@apertussolutions.com>
CC: Lin Liu <lin.liu@citrix.com>

The find-next-bit.c changes, being inside __BIG_ENDIAN aren't even compiled in
any build of Xen.  I manually checked that they compiled.

v5:
 * Rebase
 * Include a fixto divmod.c
 * Explain why even Linux has never had anything by the name ext2_swab()
---
 xen/lib/divmod.c        |  5 ++---
 xen/lib/find-next-bit.c | 39 +++++++--------------------------------
 2 files changed, 9 insertions(+), 35 deletions(-)

Comments

Jan Beulich March 31, 2025, 8:44 a.m. UTC | #1 
On 28.03.2025 14:44, Andrew Cooper wrote:
> From: Lin Liu <lin.liu@citrix.com>
> 
> In divmod.c, additionally swap xen/lib.h for xen/macros.h as only ABS() is
> needed.
> 
> In find-next-bit.c, ext2 has nothing to do with this logic.

While I agree here, ...

>  Despite the
> comments, it was a local modification when the logic was imported from Linux,
> because Xen didn't have a suitable helper.

... I certainly can see functions of these names in Linux 2.6.16. Just in the
PA-RISC bitops.h, though. Yet this may be an indication that yet earlier on
this was a wider thing there.

> The new infrsatructure does have a suitable primitive, so use it.
> 
> No functional change.
> 
> Signed-off-by: Lin Liu <lin.liu@citrix.com>

Missing your own S-o-b?

Reviewed-by: Jan Beulich <jbeulich@suse.com>

Jan
diff mbox series

Patch

diff --git a/xen/lib/divmod.c b/xen/lib/divmod.c
index 0377d62130ae..b5b111dacecc 100644
--- a/xen/lib/divmod.c
+++ b/xen/lib/divmod.c
@@ -1,6 +1,5 @@ 
-#include <xen/lib.h>
-#include <xen/types.h>
-#include <asm/byteorder.h>
+#include <xen/byteorder.h>
+#include <xen/macros.h>
 
 /*
  * A couple of 64 bit operations ported from FreeBSD.
diff --git a/xen/lib/find-next-bit.c b/xen/lib/find-next-bit.c
index 761b02739841..9b8d7814f20c 100644
--- a/xen/lib/find-next-bit.c
+++ b/xen/lib/find-next-bit.c
@@ -9,8 +9,7 @@ 
  * 2 of the License, or (at your option) any later version.
  */
 #include <xen/bitops.h>
-
-#include <asm/byteorder.h>
+#include <xen/byteorder.h>
 
 #define __ffs(x) (ffsl(x) - 1)
 #define ffz(x) __ffs(~(x))
@@ -164,30 +163,6 @@  EXPORT_SYMBOL(find_first_zero_bit);
 
 #ifdef __BIG_ENDIAN
 
-/* include/linux/byteorder does not support "unsigned long" type */
-static inline unsigned long ext2_swabp(const unsigned long * x)
-{
-#if BITS_PER_LONG == 64
-	return (unsigned long) __swab64p((u64 *) x);
-#elif BITS_PER_LONG == 32
-	return (unsigned long) __swab32p((u32 *) x);
-#else
-#error BITS_PER_LONG not defined
-#endif
-}
-
-/* include/linux/byteorder doesn't support "unsigned long" type */
-static inline unsigned long ext2_swab(const unsigned long y)
-{
-#if BITS_PER_LONG == 64
-	return (unsigned long) __swab64((u64) y);
-#elif BITS_PER_LONG == 32
-	return (unsigned long) __swab32((u32) y);
-#else
-#error BITS_PER_LONG not defined
-#endif
-}
-
 #ifndef find_next_zero_bit_le
 unsigned long find_next_zero_bit_le(const void *addr, unsigned
 		long size, unsigned long offset)
@@ -202,7 +177,7 @@  unsigned long find_next_zero_bit_le(const void *addr, unsigned
 	size -= result;
 	offset &= (BITS_PER_LONG - 1UL);
 	if (offset) {
-		tmp = ext2_swabp(p++);
+		tmp = bswapl(*p++);
 		tmp |= (~0UL >> (BITS_PER_LONG - offset));
 		if (size < BITS_PER_LONG)
 			goto found_first;
@@ -220,7 +195,7 @@  unsigned long find_next_zero_bit_le(const void *addr, unsigned
 	}
 	if (!size)
 		return result;
-	tmp = ext2_swabp(p);
+	tmp = bswapl(*p);
 found_first:
 	tmp |= ~0UL << size;
 	if (tmp == ~0UL)	/* Are any bits zero? */
@@ -229,7 +204,7 @@  unsigned long find_next_zero_bit_le(const void *addr, unsigned
 	return result + ffz(tmp);
 
 found_middle_swap:
-	return result + ffz(ext2_swab(tmp));
+	return result + ffz(bswapl(tmp));
 }
 EXPORT_SYMBOL(find_next_zero_bit_le);
 #endif
@@ -248,7 +223,7 @@  unsigned long find_next_bit_le(const void *addr, unsigned
 	size -= result;
 	offset &= (BITS_PER_LONG - 1UL);
 	if (offset) {
-		tmp = ext2_swabp(p++);
+		tmp = bswapl(*p++);
 		tmp &= (~0UL << offset);
 		if (size < BITS_PER_LONG)
 			goto found_first;
@@ -267,7 +242,7 @@  unsigned long find_next_bit_le(const void *addr, unsigned
 	}
 	if (!size)
 		return result;
-	tmp = ext2_swabp(p);
+	tmp = bswapl(*p);
 found_first:
 	tmp &= (~0UL >> (BITS_PER_LONG - size));
 	if (tmp == 0UL)		/* Are any bits set? */
@@ -276,7 +251,7 @@  unsigned long find_next_bit_le(const void *addr, unsigned
 	return result + __ffs(tmp);
 
 found_middle_swap:
-	return result + __ffs(ext2_swab(tmp));
+	return result + __ffs(bswapl(tmp));
 }
 EXPORT_SYMBOL(find_next_bit_le);
 #endif