[PATCH] reduce diff between x86-64 & i386

This cleans up ioport.c to use BITS_PER_LONG, sizeof, and so on.  This
makes it easier to spot the differences that matter, and thus easier to
find bugs.

arch/i386/kernel/ioport.c

@@ -17,32 +17,32 @@
 #include <linux/thread_info.h>
 
 /* Set EXTENT bits starting at BASE in BITMAP to value TURN_ON. */
-static void set_bitmap(unsigned long *bitmap, short base, short extent, int new_value)
+static void set_bitmap(unsigned long *bitmap, unsigned long base, unsigned long extent, int new_value)
 {
-	int mask;
-	unsigned long *bitmap_base = bitmap + (base >> 5);
-	unsigned short low_index = base & 0x1f;
+	unsigned long mask;
+	unsigned long *bitmap_base = bitmap + (base / BITS_PER_LONG);
+	unsigned long low_index = base & (BITS_PER_LONG-1);
 	int length = low_index + extent;
 
 	if (low_index != 0) {
-		mask = (~0 << low_index);
-		if (length < 32)
-				mask &= ~(~0 << length);
+		mask = (~0UL << low_index);
+		if (length < BITS_PER_LONG)
+				mask &= ~(~0UL << length);
 		if (new_value)
 			*bitmap_base++ |= mask;
 		else
 			*bitmap_base++ &= ~mask;
-		length -= 32;
+		length -= BITS_PER_LONG;
 	}
 
-	mask = (new_value ? ~0 : 0);
-	while (length >= 32) {
+	mask = (new_value ? ~0UL : 0UL);
+	while (length >= BITS_PER_LONG) {
 		*bitmap_base++ = mask;
-		length -= 32;
+		length -= BITS_PER_LONG;
 	}
 
 	if (length > 0) {
-		mask = ~(~0 << length);
+		mask = ~(~0UL << length);
 		if (new_value)
 			*bitmap_base++ |= mask;
 		else
@@ -53,7 +53,7 @@ static void set_bitmap(unsigned long *bitmap, short base, short extent, int new_
 /*
  * this changes the io permissions bitmap in the current task.
  */
-asmlinkage int sys_ioperm(unsigned long from, unsigned long num, int turn_on)
+asmlinkage long sys_ioperm(unsigned long from, unsigned long num, int turn_on)
 {
 	struct thread_struct * t = &current->thread;
 	struct tss_struct * tss;
@@ -111,7 +111,7 @@ asmlinkage int sys_ioperm(unsigned long from, unsigned long num, int turn_on)
  * code.
  */
 
-asmlinkage int sys_iopl(unsigned long unused)
+asmlinkage long sys_iopl(unsigned long unused)
 {
 	volatile struct pt_regs * regs = (struct pt_regs *) &unused;
 	unsigned int level = regs->ebx;
@@ -124,7 +124,7 @@ asmlinkage int sys_iopl(unsigned long unused)
 		if (!capable(CAP_SYS_RAWIO))
 			return -EPERM;
 	}
-	regs->eflags = (regs->eflags & 0xffffcfff) | (level << 12);
+	regs->eflags = (regs->eflags &~ 0x3000UL) | (level << 12);
 	/* Make sure we return the long way (not sysenter) */
 	set_thread_flag(TIF_IRET);
 	return 0;

arch/x86_64/kernel/ioport.c

@@ -21,25 +21,25 @@
 static void set_bitmap(unsigned long *bitmap, short base, short extent, int new_value)
 {
 	unsigned long mask;
-	unsigned long *bitmap_base = bitmap + (base / sizeof(unsigned long));
-	unsigned short low_index = base & 0x3f;
+	unsigned long *bitmap_base = bitmap + (base / BITS_PER_LONG);
+	unsigned long low_index = base & (BITS_PER_LONG-1);
 	int length = low_index + extent;
 
 	if (low_index != 0) {
 		mask = (~0UL << low_index);
-		if (length < 64)
+		if (length < BITS_PER_LONG)
 			mask &= ~(~0UL << length);
 		if (new_value)
 			*bitmap_base++ |= mask;
 		else
 			*bitmap_base++ &= ~mask;
-		length -= 64;
+		length -= BITS_PER_LONG;
 	}
 
 	mask = (new_value ? ~0UL : 0UL);
-	while (length >= 64) {
+	while (length >= BITS_PER_LONG) {
 		*bitmap_base++ = mask;
-		length -= 64;
+		length -= BITS_PER_LONG;
 	}
 
 	if (length > 0) {
@@ -115,7 +115,7 @@ asmlinkage long sys_iopl(unsigned int level, struct pt_regs regs)
 		if (!capable(CAP_SYS_RAWIO))
 			return -EPERM;
 	}
-	regs.eflags = (regs.eflags & 0xffffffffffffcfff) | (level << 12);
+	regs.eflags = (regs.eflags &~ 0x3000UL) | (level << 12);
 	return 0;
 }