jfs: get rid of homegrown endianness helpers

Get rid of le24 stuff, along with the bitfields use - all that stuff
can be done with standard stuff, in sparse-verifiable manner.  Moreover,
that way (shift-and-mask) often generates better code - gcc optimizer
sucks on bitfields...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
----

fs/jfs/endian24.h

-/*
- *   Copyright (C) International Business Machines Corp., 2001
- *
- *   This program is free software;  you can redistribute it and/or modify
- *   it under the terms of the GNU General Public License as published by
- *   the Free Software Foundation; either version 2 of the License, or
- *   (at your option) any later version.
- *
- *   This program is distributed in the hope that it will be useful,
- *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
- *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
- *   the GNU General Public License for more details.
- *
- *   You should have received a copy of the GNU General Public License
- *   along with this program;  if not, write to the Free Software
- *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- */
-#ifndef _H_ENDIAN24
-#define	_H_ENDIAN24
-
-/*
- *	endian24.h:
- *
- * Endian conversion for 24-byte data
- *
- */
-#define __swab24(x) \
-({ \
-	__u32 __x = (x); \
-	((__u32)( \
-		((__x & (__u32)0x000000ffUL) << 16) | \
-		 (__x & (__u32)0x0000ff00UL)	    | \
-		((__x & (__u32)0x00ff0000UL) >> 16) )); \
-})
-
-#if (defined(__KERNEL__) && defined(__LITTLE_ENDIAN)) || (defined(__BYTE_ORDER) && (__BYTE_ORDER == __LITTLE_ENDIAN))
-	#define __cpu_to_le24(x) ((__u32)(x))
-	#define __le24_to_cpu(x) ((__u32)(x))
-#else
-	#define __cpu_to_le24(x) __swab24(x)
-	#define __le24_to_cpu(x) __swab24(x)
-#endif
-
-#ifdef __KERNEL__
-	#define cpu_to_le24 __cpu_to_le24
-	#define le24_to_cpu __le24_to_cpu
-#endif
-
-#endif				/* !_H_ENDIAN24 */

fs/jfs/jfs_dtree.c

@@ -1040,8 +1040,8 @@ static int dtSplitUp(tid_t tid,
 		pxdlist.maxnpxd = 1;
 		pxdlist.npxd = 0;
 		pxd = &pxdlist.pxd[0];
-		PXDaddress(pxd, nxaddr)
-		    PXDlength(pxd, xlen + n);
+		PXDaddress(pxd, nxaddr);
+		PXDlength(pxd, xlen + n);
 		split->pxdlist = &pxdlist;
 		if ((rc = dtExtendPage(tid, ip, split, btstack))) {
 			nxaddr = addressPXD(pxd);

fs/jfs/jfs_types.h

@@ -30,8 +30,6 @@
 #include <linux/types.h>
 #include <linux/nls.h>
 
-#include "endian24.h"
-
 /*
  * transaction and lock id's
  *
@@ -59,26 +57,42 @@ struct timestruc_t {
 
 /*
  *	physical xd (pxd)
+ *
+ *	The leftmost 24 bits of len_addr are the extent length.
+ *	The rightmost 8 bits of len_addr are the most signficant bits of
+ *	the extent address
  */
 typedef struct {
-	unsigned len:24;
-	unsigned addr1:8;
+	__le32 len_addr;
 	__le32 addr2;
 } pxd_t;
 
 /* xd_t field construction */
 
-#define	PXDlength(pxd, length32)	((pxd)->len = __cpu_to_le24(length32))
-#define	PXDaddress(pxd, address64)\
-{\
-	(pxd)->addr1 = ((s64)address64) >> 32;\
-	(pxd)->addr2 = __cpu_to_le32((address64) & 0xffffffff);\
+static inline void PXDlength(pxd_t *pxd, __u32 len)
+{
+	pxd->len_addr = (pxd->len_addr & cpu_to_le32(~0xffffff)) |
+			cpu_to_le32(len & 0xffffff);
+}
+
+static inline void PXDaddress(pxd_t *pxd, __u64 addr)
+{
+	pxd->len_addr = (pxd->len_addr & cpu_to_le32(0xffffff)) |
+			cpu_to_le32((addr >> 32)<<24);
+	pxd->addr2 = cpu_to_le32(addr & 0xffffffff);
 }
 
 /* xd_t field extraction */
-#define	lengthPXD(pxd)	__le24_to_cpu((pxd)->len)
-#define	addressPXD(pxd)\
-	( ((s64)((pxd)->addr1)) << 32 | __le32_to_cpu((pxd)->addr2))
+static inline __u32 lengthPXD(pxd_t *pxd)
+{
+	return le32_to_cpu((pxd)->len_addr) & 0xffffff;
+}
+
+static inline __u64 addressPXD(pxd_t *pxd)
+{
+	__u64 n = le32_to_cpu(pxd->len_addr) & ~0xffffff;
+	return (n << 8) + le32_to_cpu(pxd->addr2);
+}
 
 #define MAXTREEHEIGHT 8
 /* pxd list */
@@ -93,12 +107,10 @@ struct pxdlist {
  *	data extent descriptor (dxd)
  */
 typedef struct {
-	unsigned flag:8;	/* 1: flags */
-	unsigned rsrvd:24;
+	__u8 flag;	/* 1: flags */
+	__u8 rsrvd[3];
 	__le32 size;		/* 4: size in byte */
-	unsigned len:24;	/* 3: length in unit of fsblksize */
-	unsigned addr1:8;	/* 1: address in unit of fsblksize */
-	__le32 addr2;		/* 4: address in unit of fsblksize */
+	pxd_t loc;		/* 8: address and length in unit of fsblksize */
 } dxd_t;			/* - 16 - */
 
 /* dxd_t flags */
@@ -109,12 +121,11 @@ typedef struct {
 #define DXD_CORRUPT	0x08	/* Inconsistency detected */
 
 /* dxd_t field construction
- *	Conveniently, the PXD macros work for DXD
  */
-#define	DXDlength	PXDlength
-#define	DXDaddress	PXDaddress
-#define	lengthDXD	lengthPXD
-#define	addressDXD	addressPXD
+#define	DXDlength(dxd, len)	PXDlength(&(dxd)->loc, len)
+#define	DXDaddress(dxd, addr)	PXDaddress(&(dxd)->loc, addr)
+#define	lengthDXD(dxd)	lengthPXD(&(dxd)->loc)
+#define	addressDXD(dxd)	addressPXD(&(dxd)->loc)
 #define DXDsize(dxd, size32) ((dxd)->size = cpu_to_le32(size32))
 #define sizeDXD(dxd)	le32_to_cpu((dxd)->size)
 

fs/jfs/jfs_xtree.h

@@ -29,13 +29,11 @@
  *	extent allocation descriptor (xad)
  */
 typedef struct xad {
-	unsigned flag:8;	/* 1: flag */
-	unsigned rsvrd:16;	/* 2: reserved */
-	unsigned off1:8;	/* 1: offset in unit of fsblksize */
-	__le32 off2;		/* 4: offset in unit of fsblksize */
-	unsigned len:24;	/* 3: length in unit of fsblksize */
-	unsigned addr1:8;	/* 1: address in unit of fsblksize */
-	__le32 addr2;		/* 4: address in unit of fsblksize */
+	__u8 flag;	/* 1: flag */
+	__u8 rsvrd[2];	/* 2: reserved */
+	__u8 off1;	/* 1: offset in unit of fsblksize */
+	__le32 off2;	/* 4: offset in unit of fsblksize */
+	pxd_t loc;	/* 8: length and address in unit of fsblksize */
 } xad_t;			/* (16) */
 
 #define MAXXLEN		((1 << 24) - 1)
@@ -49,19 +47,14 @@ typedef struct xad {
 	(xad)->off1 = ((u64)offset64) >> 32;\
 	(xad)->off2 = __cpu_to_le32((offset64) & 0xffffffff);\
 }
-#define XADaddress(xad, address64)\
-{\
-	(xad)->addr1 = ((u64)address64) >> 32;\
-	(xad)->addr2 = __cpu_to_le32((address64) & 0xffffffff);\
-}
-#define XADlength(xad, length32)	(xad)->len = __cpu_to_le24(length32)
+#define XADaddress(xad, address64) PXDaddress(&(xad)->loc, address64)
+#define XADlength(xad, length32) PXDlength(&(xad)->loc, length32)
 
 /* xad_t field extraction */
 #define offsetXAD(xad)\
 	( ((s64)((xad)->off1)) << 32 | __le32_to_cpu((xad)->off2))
-#define addressXAD(xad)\
-	( ((s64)((xad)->addr1)) << 32 | __le32_to_cpu((xad)->addr2))
-#define lengthXAD(xad)	__le24_to_cpu((xad)->len)
+#define addressXAD(xad) addressPXD(&(xad)->loc)
+#define lengthXAD(xad) lengthPXD(&(xad)->loc)
 
 /* xad list */
 struct xadlist {