}
EXPORT_SYMBOL(__bitmap_complement);
-/*
+/**
* __bitmap_shift_right - logical right shift of the bits in a bitmap
- * @dst - destination bitmap
- * @src - source bitmap
- * @nbits - shift by this many bits
- * @bits - bitmap size, in bits
+ * @dst : destination bitmap
+ * @src : source bitmap
+ * @shift : shift by this many bits
+ * @bits : bitmap size, in bits
*
* Shifting right (dividing) means moving bits in the MS -> LS bit
* direction. Zeros are fed into the vacated MS positions and the
EXPORT_SYMBOL(__bitmap_shift_right);
-/*
+/**
* __bitmap_shift_left - logical left shift of the bits in a bitmap
- * @dst - destination bitmap
- * @src - source bitmap
- * @nbits - shift by this many bits
- * @bits - bitmap size, in bits
+ * @dst : destination bitmap
+ * @src : source bitmap
+ * @shift : shift by this many bits
+ * @bits : bitmap size, in bits
*
* Shifting left (multiplying) means moving bits in the LS -> MS
* direction. Zeros are fed into the vacated LS bit positions
}
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 += hweight32(bitmap[k]);
-
- if (bits % BITS_PER_LONG)
- 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]);
+ w += hweight_long(bitmap[k]);
if (bits % BITS_PER_LONG)
- w += hweight64(bitmap[k] & BITMAP_LAST_WORD_MASK(bits));
+ w += hweight_long(bitmap[k] & BITMAP_LAST_WORD_MASK(bits));
return w;
}
-#endif
EXPORT_SYMBOL(__bitmap_weight);
/*
EXPORT_SYMBOL(bitmap_scnprintf);
/**
- * bitmap_parse - convert an ASCII hex string into a bitmap.
- * @buf: pointer to buffer in user space containing string.
+ * __bitmap_parse - convert an ASCII hex string into a bitmap.
+ * @buf: pointer to buffer containing string.
* @buflen: buffer size in bytes. If string is smaller than this
* then it must be terminated with a \0.
+ * @is_user: location of buffer, 0 indicates kernel space
* @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.
*/
-int bitmap_parse(const char __user *ubuf, unsigned int ubuflen,
- unsigned long *maskp, int nmaskbits)
+int __bitmap_parse(const char *buf, unsigned int buflen,
+ int is_user, unsigned long *maskp,
+ int nmaskbits)
{
int c, old_c, totaldigits, ndigits, nchunks, nbits;
u32 chunk;
+ const char __user *ubuf = buf;
bitmap_zero(maskp, nmaskbits);
chunk = ndigits = 0;
/* Get the next chunk of the bitmap */
- while (ubuflen) {
+ while (buflen) {
old_c = c;
- if (get_user(c, ubuf++))
- return -EFAULT;
- ubuflen--;
+ if (is_user) {
+ if (__get_user(c, ubuf++))
+ return -EFAULT;
+ }
+ else
+ c = *buf++;
+ buflen--;
if (isspace(c))
continue;
nbits += (nchunks == 1) ? nbits_to_hold_value(chunk) : CHUNKSZ;
if (nbits > nmaskbits)
return -EOVERFLOW;
- } while (ubuflen && c == ',');
+ } while (buflen && c == ',');
return 0;
}
-EXPORT_SYMBOL(bitmap_parse);
+EXPORT_SYMBOL(__bitmap_parse);
+
+/**
+ * bitmap_parse_user()
+ *
+ * @ubuf: pointer to user buffer containing string.
+ * @ulen: 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.
+ *
+ * Wrapper for __bitmap_parse(), providing it with user buffer.
+ *
+ * We cannot have this as an inline function in bitmap.h because it needs
+ * linux/uaccess.h to get the access_ok() declaration and this causes
+ * cyclic dependencies.
+ */
+int bitmap_parse_user(const char __user *ubuf,
+ unsigned int ulen, unsigned long *maskp,
+ int nmaskbits)
+{
+ if (!access_ok(VERIFY_READ, ubuf, ulen))
+ return -EFAULT;
+ return __bitmap_parse((const char *)ubuf, ulen, 1, maskp, nmaskbits);
+}
+EXPORT_SYMBOL(bitmap_parse_user);
/*
* bscnl_emit(buf, buflen, rbot, rtop, bp)
/* current bit is 'cur', most recently seen range is [rbot, rtop] */
int cur, rbot, rtop;
+ if (buflen == 0)
+ return 0;
+ buf[0] = 0;
+
rbot = cur = find_first_bit(maskp, nmaskbits);
while (cur < nmaskbits) {
rtop = cur;
/**
* bitmap_parselist - convert list format ASCII string to bitmap
- * @buf: read nul-terminated user string from this buffer
- * @mask: write resulting mask here
+ * @bp: read nul-terminated user string from this buffer
+ * @maskp: 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:
- * -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.
+ * Error values:
+ * %-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)
{
}
EXPORT_SYMBOL(bitmap_parselist);
-/*
+/**
* bitmap_pos_to_ord(buf, pos, bits)
* @buf: pointer to a bitmap
* @pos: a bit position in @buf (0 <= @pos < @bits)
/**
* 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);
/**
+ * bitmap_onto - translate one bitmap relative to another
+ * @dst: resulting translated bitmap
+ * @orig: original untranslated bitmap
+ * @relmap: bitmap relative to which translated
+ * @bits: number of bits in each of these bitmaps
+ *
+ * Set the n-th bit of @dst iff there exists some m such that the
+ * n-th bit of @relmap is set, the m-th bit of @orig is set, and
+ * the n-th bit of @relmap is also the m-th _set_ bit of @relmap.
+ * (If you understood the previous sentence the first time your
+ * read it, you're overqualified for your current job.)
+ *
+ * In other words, @orig is mapped onto (surjectively) @dst,
+ * using the the map { <n, m> | the n-th bit of @relmap is the
+ * m-th set bit of @relmap }.
+ *
+ * Any set bits in @orig above bit number W, where W is the
+ * weight of (number of set bits in) @relmap are mapped nowhere.
+ * In particular, if for all bits m set in @orig, m >= W, then
+ * @dst will end up empty. In situations where the possibility
+ * of such an empty result is not desired, one way to avoid it is
+ * to use the bitmap_fold() operator, below, to first fold the
+ * @orig bitmap over itself so that all its set bits x are in the
+ * range 0 <= x < W. The bitmap_fold() operator does this by
+ * setting the bit (m % W) in @dst, for each bit (m) set in @orig.
+ *
+ * Example [1] for bitmap_onto():
+ * Let's say @relmap has bits 30-39 set, and @orig has bits
+ * 1, 3, 5, 7, 9 and 11 set. Then on return from this routine,
+ * @dst will have bits 31, 33, 35, 37 and 39 set.
+ *
+ * When bit 0 is set in @orig, it means turn on the bit in
+ * @dst corresponding to whatever is the first bit (if any)
+ * that is turned on in @relmap. Since bit 0 was off in the
+ * above example, we leave off that bit (bit 30) in @dst.
+ *
+ * When bit 1 is set in @orig (as in the above example), it
+ * means turn on the bit in @dst corresponding to whatever
+ * is the second bit that is turned on in @relmap. The second
+ * bit in @relmap that was turned on in the above example was
+ * bit 31, so we turned on bit 31 in @dst.
+ *
+ * Similarly, we turned on bits 33, 35, 37 and 39 in @dst,
+ * because they were the 4th, 6th, 8th and 10th set bits
+ * set in @relmap, and the 4th, 6th, 8th and 10th bits of
+ * @orig (i.e. bits 3, 5, 7 and 9) were also set.
+ *
+ * When bit 11 is set in @orig, it means turn on the bit in
+ * @dst corresponding to whatever is the twelth bit that is
+ * turned on in @relmap. In the above example, there were
+ * only ten bits turned on in @relmap (30..39), so that bit
+ * 11 was set in @orig had no affect on @dst.
+ *
+ * Example [2] for bitmap_fold() + bitmap_onto():
+ * Let's say @relmap has these ten bits set:
+ * 40 41 42 43 45 48 53 61 74 95
+ * (for the curious, that's 40 plus the first ten terms of the
+ * Fibonacci sequence.)
+ *
+ * Further lets say we use the following code, invoking
+ * bitmap_fold() then bitmap_onto, as suggested above to
+ * avoid the possitility of an empty @dst result:
+ *
+ * unsigned long *tmp; // a temporary bitmap's bits
+ *
+ * bitmap_fold(tmp, orig, bitmap_weight(relmap, bits), bits);
+ * bitmap_onto(dst, tmp, relmap, bits);
+ *
+ * Then this table shows what various values of @dst would be, for
+ * various @orig's. I list the zero-based positions of each set bit.
+ * The tmp column shows the intermediate result, as computed by
+ * using bitmap_fold() to fold the @orig bitmap modulo ten
+ * (the weight of @relmap).
+ *
+ * @orig tmp @dst
+ * 0 0 40
+ * 1 1 41
+ * 9 9 95
+ * 10 0 40 (*)
+ * 1 3 5 7 1 3 5 7 41 43 48 61
+ * 0 1 2 3 4 0 1 2 3 4 40 41 42 43 45
+ * 0 9 18 27 0 9 8 7 40 61 74 95
+ * 0 10 20 30 0 40
+ * 0 11 22 33 0 1 2 3 40 41 42 43
+ * 0 12 24 36 0 2 4 6 40 42 45 53
+ * 78 102 211 1 2 8 41 42 74 (*)
+ *
+ * (*) For these marked lines, if we hadn't first done bitmap_fold()
+ * into tmp, then the @dst result would have been empty.
+ *
+ * If either of @orig or @relmap is empty (no set bits), then @dst
+ * will be returned empty.
+ *
+ * If (as explained above) the only set bits in @orig are in positions
+ * m where m >= W, (where W is the weight of @relmap) then @dst will
+ * once again be returned empty.
+ *
+ * All bits in @dst not set by the above rule are cleared.
+ */
+void bitmap_onto(unsigned long *dst, const unsigned long *orig,
+ const unsigned long *relmap, int bits)
+{
+ int n, m; /* same meaning as in above comment */
+
+ if (dst == orig) /* following doesn't handle inplace mappings */
+ return;
+ bitmap_zero(dst, bits);
+
+ /*
+ * The following code is a more efficient, but less
+ * obvious, equivalent to the loop:
+ * for (m = 0; m < bitmap_weight(relmap, bits); m++) {
+ * n = bitmap_ord_to_pos(orig, m, bits);
+ * if (test_bit(m, orig))
+ * set_bit(n, dst);
+ * }
+ */
+
+ m = 0;
+ for (n = find_first_bit(relmap, bits);
+ n < bits;
+ n = find_next_bit(relmap, bits, n + 1)) {
+ /* m == bitmap_pos_to_ord(relmap, n, bits) */
+ if (test_bit(m, orig))
+ set_bit(n, dst);
+ m++;
+ }
+}
+EXPORT_SYMBOL(bitmap_onto);
+
+/**
+ * bitmap_fold - fold larger bitmap into smaller, modulo specified size
+ * @dst: resulting smaller bitmap
+ * @orig: original larger bitmap
+ * @sz: specified size
+ * @bits: number of bits in each of these bitmaps
+ *
+ * For each bit oldbit in @orig, set bit oldbit mod @sz in @dst.
+ * Clear all other bits in @dst. See further the comment and
+ * Example [2] for bitmap_onto() for why and how to use this.
+ */
+void bitmap_fold(unsigned long *dst, const unsigned long *orig,
+ int sz, int bits)
+{
+ int oldbit;
+
+ if (dst == orig) /* following doesn't handle inplace mappings */
+ return;
+ bitmap_zero(dst, bits);
+
+ for (oldbit = find_first_bit(orig, bits);
+ oldbit < bits;
+ oldbit = find_next_bit(orig, bits, oldbit + 1))
+ set_bit(oldbit % sz, dst);
+}
+EXPORT_SYMBOL(bitmap_fold);
+
+/*
+ * 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
+ *
+ * Can set, verify and/or release a region of bits in a bitmap,
+ * depending on which combination of REG_OP_* flag bits is set.
+ *
+ * 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.
+ *
+ * Returns 1 if REG_OP_ISFREE succeeds (region is all zero bits).
+ * Returns 0 in all other cases and reg_ops.
+ */
+
+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 */
+};
+
+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));
+ 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;
+ }
+ 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: an array of unsigned longs corresponding to the bitmap
+ * @bitmap: 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)
+ * @order: region size (log base 2 of number of bits) to find
*
- * Find a sequence of free (zero) bits in a bitmap and allocate
- * them (set them to one). Only consider sequences of length a
- * power ('order') of two, aligned to that power of two, which
+ * 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 sequence,
+ * 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)
{
- unsigned long mask;
- int nbits = 1 << order;
- int i;
+ int pos, end; /* scans bitmap by regions of size order */
- if (nbits > BITS_PER_LONG)
- return -EINVAL;
-
- /* make a mask of the order */
- mask = (1UL << (nbits - 1));
- mask += mask - 1;
-
- /* run up the bitmap nbits at a time */
- for (i = 0; i < bits; i += nbits) {
- int index = i / BITS_PER_LONG;
- int offset = i - (index * BITS_PER_LONG);
- if ((bitmap[index] & (mask << offset)) == 0) {
- /* set region in bitmap */
- bitmap[index] |= (mask << offset);
- return i;
- }
+ for (pos = 0 ; (end = pos + (1 << order)) <= bits; pos = end) {
+ if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE))
+ continue;
+ __reg_op(bitmap, pos, order, REG_OP_ALLOC);
+ return pos;
}
return -ENOMEM;
}
/**
* 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)
+ * @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
*
- * This is the complement to __bitmap_find_free_region and releases
+ * 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)
{
- int nbits = 1 << order;
- unsigned long mask = (1UL << (nbits - 1));
- int index = pos / BITS_PER_LONG;
- int offset = pos - (index * BITS_PER_LONG);
-
- mask += mask - 1;
- bitmap[index] &= ~(mask << offset);
+ __reg_op(bitmap, pos, order, REG_OP_RELEASE);
}
EXPORT_SYMBOL(bitmap_release_region);
/**
* bitmap_allocate_region - allocate bitmap region
- * @bitmap: a pointer to the bitmap
- * @pos: the beginning of the region
- * @order: the order of the bits to allocate (number is 1<<order)
+ * @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
+ *
+ * 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)
{
- int nbits = 1 << order;
- unsigned long mask = (1UL << (nbits - 1));
- int index = pos / BITS_PER_LONG;
- int offset = pos - (index * BITS_PER_LONG);
-
- /*
- * We don't do regions of nbits > 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(nbits > BITS_PER_LONG);
- mask += mask - 1;
- if (bitmap[index] & (mask << offset))
+ if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE))
return -EBUSY;
- bitmap[index] |= (mask << offset);
+ __reg_op(bitmap, pos, order, REG_OP_ALLOC);
return 0;
}
EXPORT_SYMBOL(bitmap_allocate_region);
+
+/**
+ * bitmap_copy_le - copy a bitmap, putting the bits into little-endian order.
+ * @dst: destination buffer
+ * @src: bitmap to copy
+ * @nbits: number of bits in the bitmap
+ *
+ * Require nbits % BITS_PER_LONG == 0.
+ */
+void bitmap_copy_le(void *dst, const unsigned long *src, int nbits)
+{
+ unsigned long *d = dst;
+ int i;
+
+ for (i = 0; i < nbits/BITS_PER_LONG; i++) {
+ if (BITS_PER_LONG == 64)
+ d[i] = cpu_to_le64(src[i]);
+ else
+ d[i] = cpu_to_le32(src[i]);
+ }
+}
+EXPORT_SYMBOL(bitmap_copy_le);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff