[snip]
> static inline int find_first_bit(const unsigned long *addr, unsigned size)
> {
[snip]
> + int x = 0;
> + do {
> + if (*addr)
> + return __ffs(*addr) + x;
> + addr++;
> + if (x >= size)
> + break;
> + x += 32;
The 32 looks like it may be problamatic. Is there any i386 64 bit
machines. Or is hard coding 32 OK?
> + } while (1);
> + return x;
> }
>
Just in case, I've updated the patch to use (sizeof(*addr)<<3)
Signed-off-by: Steven Rostedt <[email protected]>
Index: vanilla_kernel/include/asm-i386/bitops.h
===================================================================
--- vanilla_kernel/include/asm-i386/bitops.h (revision 263)
+++ vanilla_kernel/include/asm-i386/bitops.h (working copy)
@@ -311,6 +311,20 @@
int find_next_zero_bit(const unsigned long *addr, int size, int offset);
/**
+ * __ffs - find first bit in word.
+ * @word: The word to search
+ *
+ * Undefined if no bit exists, so code should check against 0 first.
+ */
+static inline unsigned long __ffs(unsigned long word)
+{
+ __asm__("bsfl %1,%0"
+ :"=r" (word)
+ :"rm" (word));
+ return word;
+}
+
+/**
* find_first_bit - find the first set bit in a memory region
* @addr: The address to start the search at
* @size: The maximum size to search
@@ -320,22 +334,16 @@
*/
static inline int find_first_bit(const unsigned long *addr, unsigned size)
{
- int d0, d1;
- int res;
-
- /* This looks at memory. Mark it volatile to tell gcc not to move it around */
- __asm__ __volatile__(
- "xorl %%eax,%%eax\n\t"
- "repe; scasl\n\t"
- "jz 1f\n\t"
- "leal -4(%%edi),%%edi\n\t"
- "bsfl (%%edi),%%eax\n"
- "1:\tsubl %%ebx,%%edi\n\t"
- "shll $3,%%edi\n\t"
- "addl %%edi,%%eax"
- :"=a" (res), "=&c" (d0), "=&D" (d1)
- :"1" ((size + 31) >> 5), "2" (addr), "b" (addr) : "memory");
- return res;
+ int x = 0;
+ do {
+ if (*addr)
+ return __ffs(*addr) + x;
+ addr++;
+ if (x >= size)
+ break;
+ x += (sizeof(*addr)<<3);
+ } while (1);
+ return x;
}
/**
@@ -360,20 +368,6 @@
return word;
}
-/**
- * __ffs - find first bit in word.
- * @word: The word to search
- *
- * Undefined if no bit exists, so code should check against 0 first.
- */
-static inline unsigned long __ffs(unsigned long word)
-{
- __asm__("bsfl %1,%0"
- :"=r" (word)
- :"rm" (word));
- return word;
-}
-
/*
* fls: find last bit set.
*/
-
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