}
EXPORT_SYMBOL(__bitmap_subset);
+#if BITS_PER_LONG == 32
int __bitmap_weight(const unsigned long *bitmap, int bits)
{
int k, w = 0, lim = bits/BITS_PER_LONG;
for (k = 0; k < lim; k++)
- w += hweight_long(bitmap[k]);
+ w += hweight32(bitmap[k]);
if (bits % BITS_PER_LONG)
- w += hweight_long(bitmap[k] & BITMAP_LAST_WORD_MASK(bits));
+ w += hweight32(bitmap[k] & BITMAP_LAST_WORD_MASK(bits));
return w;
}
+#else
+int __bitmap_weight(const unsigned long *bitmap, int bits)
+{
+ int k, w = 0, lim = bits/BITS_PER_LONG;
+
+ for (k = 0; k < lim; k++)
+ w += hweight64(bitmap[k]);
+
+ if (bits % BITS_PER_LONG)
+ w += hweight64(bitmap[k] & BITMAP_LAST_WORD_MASK(bits));
+
+ return w;
+}
+#endif
EXPORT_SYMBOL(__bitmap_weight);
/*
/**
* bitmap_parse - convert an ASCII hex string into a bitmap.
- * @ubuf: pointer to buffer in user space containing string.
- * @ubuflen: buffer size in bytes. If string is smaller than this
+ * @buf: pointer to buffer in user space containing string.
+ * @buflen: buffer size in bytes. If string is smaller than this
* then it must be terminated with a \0.
* @maskp: pointer to bitmap array that will contain result.
* @nmaskbits: size of bitmap, in bits.
*
* Commas group hex digits into chunks. Each chunk defines exactly 32
* bits of the resultant bitmask. No chunk may specify a value larger
- * than 32 bits (%-EOVERFLOW), and if a chunk specifies a smaller value
- * then leading 0-bits are prepended. %-EINVAL is returned for illegal
+ * than 32 bits (-EOVERFLOW), and if a chunk specifies a smaller value
+ * then leading 0-bits are prepended. -EINVAL is returned for illegal
* characters and for grouping errors such as "1,,5", ",44", "," and "".
* Leading and trailing whitespace accepted, but not embedded whitespace.
*/
/**
* bitmap_parselist - convert list format ASCII string to bitmap
- * @bp: read nul-terminated user string from this buffer
- * @maskp: write resulting mask here
+ * @buf: read nul-terminated user string from this buffer
+ * @mask: write resulting mask here
* @nmaskbits: number of bits in mask to be written
*
* Input format is a comma-separated list of decimal numbers and
* decimal numbers, the smallest and largest bit numbers set in
* the range.
*
- * Returns 0 on success, -errno on invalid input strings.
- * Error values:
- * %-EINVAL: second number in range smaller than first
- * %-EINVAL: invalid character in string
- * %-ERANGE: bit number specified too large for mask
+ * Returns 0 on success, -errno on invalid input strings:
+ * -EINVAL: second number in range smaller than first
+ * -EINVAL: invalid character in string
+ * -ERANGE: bit number specified too large for mask
*/
int bitmap_parselist(const char *bp, unsigned long *maskp, int nmaskbits)
{
/**
* bitmap_bitremap - Apply map defined by a pair of bitmaps to a single bit
- * @oldbit: bit position to be mapped
- * @old: defines domain of map
- * @new: defines range of map
- * @bits: number of bits in each of these bitmaps
+ * @oldbit - bit position to be mapped
+ * @old: defines domain of map
+ * @new: defines range of map
+ * @bits: number of bits in each of these bitmaps
*
* Let @old and @new define a mapping of bit positions, such that
* whatever position is held by the n-th set bit in @old is mapped
}
EXPORT_SYMBOL(bitmap_bitremap);
-/*
- * Common code for bitmap_*_region() routines.
- * bitmap: array of unsigned longs corresponding to the bitmap
- * pos: the beginning of the region
- * order: region size (log base 2 of number of bits)
- * reg_op: operation(s) to perform on that region of bitmap
+/**
+ * bitmap_find_free_region - find a contiguous aligned mem region
+ * @bitmap: an array of unsigned longs corresponding to the bitmap
+ * @bits: number of bits in the bitmap
+ * @order: region size to find (size is actually 1<<order)
*
- * Can set, verify and/or release a region of bits in a bitmap,
- * depending on which combination of REG_OP_* flag bits is set.
+ * This is used to allocate a memory region from a bitmap. The idea is
+ * that the region has to be 1<<order sized and 1<<order aligned (this
+ * makes the search algorithm much faster).
*
- * A region of a bitmap is a sequence of bits in the bitmap, of
- * some size '1 << order' (a power of two), aligned to that same
- * '1 << order' power of two.
+ * The region is marked as set bits in the bitmap if a free one is
+ * found.
*
- * Returns 1 if REG_OP_ISFREE succeeds (region is all zero bits).
- * Returns 0 in all other cases and reg_ops.
+ * Returns either beginning of region or negative error
*/
+int bitmap_find_free_region(unsigned long *bitmap, int bits, int order)
+{
+ unsigned long mask;
+ int pages = 1 << order;
+ int i;
-enum {
- REG_OP_ISFREE, /* true if region is all zero bits */
- REG_OP_ALLOC, /* set all bits in region */
- REG_OP_RELEASE, /* clear all bits in region */
-};
+ if(pages > BITS_PER_LONG)
+ return -EINVAL;
-static int __reg_op(unsigned long *bitmap, int pos, int order, int reg_op)
-{
- int nbits_reg; /* number of bits in region */
- int index; /* index first long of region in bitmap */
- int offset; /* bit offset region in bitmap[index] */
- int nlongs_reg; /* num longs spanned by region in bitmap */
- int nbitsinlong; /* num bits of region in each spanned long */
- unsigned long mask; /* bitmask for one long of region */
- int i; /* scans bitmap by longs */
- int ret = 0; /* return value */
-
- /*
- * Either nlongs_reg == 1 (for small orders that fit in one long)
- * or (offset == 0 && mask == ~0UL) (for larger multiword orders.)
- */
- nbits_reg = 1 << order;
- index = pos / BITS_PER_LONG;
- offset = pos - (index * BITS_PER_LONG);
- nlongs_reg = BITS_TO_LONGS(nbits_reg);
- nbitsinlong = min(nbits_reg, BITS_PER_LONG);
-
- /*
- * Can't do "mask = (1UL << nbitsinlong) - 1", as that
- * overflows if nbitsinlong == BITS_PER_LONG.
- */
- mask = (1UL << (nbitsinlong - 1));
+ /* make a mask of the order */
+ mask = (1ul << (pages - 1));
mask += mask - 1;
- mask <<= offset;
- switch (reg_op) {
- case REG_OP_ISFREE:
- for (i = 0; i < nlongs_reg; i++) {
- if (bitmap[index + i] & mask)
- goto done;
+ /* run up the bitmap pages bits at a time */
+ for (i = 0; i < bits; i += pages) {
+ int index = i/BITS_PER_LONG;
+ int offset = i - (index * BITS_PER_LONG);
+ if((bitmap[index] & (mask << offset)) == 0) {
+ /* set region in bimap */
+ bitmap[index] |= (mask << offset);
+ return i;
}
- ret = 1; /* all bits in region free (zero) */
- break;
-
- case REG_OP_ALLOC:
- for (i = 0; i < nlongs_reg; i++)
- bitmap[index + i] |= mask;
- break;
-
- case REG_OP_RELEASE:
- for (i = 0; i < nlongs_reg; i++)
- bitmap[index + i] &= ~mask;
- break;
}
-done:
- return ret;
-}
-
-/**
- * bitmap_find_free_region - find a contiguous aligned mem region
- * @bitmap: array of unsigned longs corresponding to the bitmap
- * @bits: number of bits in the bitmap
- * @order: region size (log base 2 of number of bits) to find
- *
- * Find a region of free (zero) bits in a @bitmap of @bits bits and
- * allocate them (set them to one). Only consider regions of length
- * a power (@order) of two, aligned to that power of two, which
- * makes the search algorithm much faster.
- *
- * Return the bit offset in bitmap of the allocated region,
- * or -errno on failure.
- */
-int bitmap_find_free_region(unsigned long *bitmap, int bits, int order)
-{
- int pos; /* scans bitmap by regions of size order */
-
- for (pos = 0; pos < bits; pos += (1 << order))
- if (__reg_op(bitmap, pos, order, REG_OP_ISFREE))
- break;
- if (pos == bits)
- return -ENOMEM;
- __reg_op(bitmap, pos, order, REG_OP_ALLOC);
- return pos;
+ return -ENOMEM;
}
EXPORT_SYMBOL(bitmap_find_free_region);
/**
- * bitmap_release_region - release allocated bitmap region
- * @bitmap: array of unsigned longs corresponding to the bitmap
- * @pos: beginning of bit region to release
- * @order: region size (log base 2 of number of bits) to release
+ * bitmap_release_region - release allocated bitmap region
+ * @bitmap: a pointer to the bitmap
+ * @pos: the beginning of the region
+ * @order: the order of the bits to release (number is 1<<order)
*
* This is the complement to __bitmap_find_free_region and releases
* the found region (by clearing it in the bitmap).
- *
- * No return value.
*/
void bitmap_release_region(unsigned long *bitmap, int pos, int order)
{
- __reg_op(bitmap, pos, order, REG_OP_RELEASE);
+ int pages = 1 << order;
+ unsigned long mask = (1ul << (pages - 1));
+ int index = pos/BITS_PER_LONG;
+ int offset = pos - (index * BITS_PER_LONG);
+ mask += mask - 1;
+ bitmap[index] &= ~(mask << offset);
}
EXPORT_SYMBOL(bitmap_release_region);
-/**
- * bitmap_allocate_region - allocate bitmap region
- * @bitmap: array of unsigned longs corresponding to the bitmap
- * @pos: beginning of bit region to allocate
- * @order: region size (log base 2 of number of bits) to allocate
- *
- * Allocate (set bits in) a specified region of a bitmap.
- *
- * Return 0 on success, or %-EBUSY if specified region wasn't
- * free (not all bits were zero).
- */
int bitmap_allocate_region(unsigned long *bitmap, int pos, int order)
{
- if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE))
+ int pages = 1 << order;
+ unsigned long mask = (1ul << (pages - 1));
+ int index = pos/BITS_PER_LONG;
+ int offset = pos - (index * BITS_PER_LONG);
+
+ /* We don't do regions of pages > BITS_PER_LONG. The
+ * algorithm would be a simple look for multiple zeros in the
+ * array, but there's no driver today that needs this. If you
+ * trip this BUG(), you get to code it... */
+ BUG_ON(pages > BITS_PER_LONG);
+ mask += mask - 1;
+ if (bitmap[index] & (mask << offset))
return -EBUSY;
- __reg_op(bitmap, pos, order, REG_OP_ALLOC);
+ bitmap[index] |= (mask << offset);
return 0;
}
EXPORT_SYMBOL(bitmap_allocate_region);
git://git.onelab.eu / linux-2.6.git / blobdiff