/drivers/ddk/linux/bitmap.c |
---|
0,0 → 1,848 |
/* |
* lib/bitmap.c |
* Helper functions for bitmap.h. |
* |
* Tlhis source code is licensed under the GNU General Public License, |
* Version 2. See the file COPYING for more details. |
*/ |
#include <syscall.h> |
#include <linux/export.h> |
//#include <linux/thread_info.h> |
#include <linux/ctype.h> |
#include <linux/errno.h> |
#include <linux/bitmap.h> |
#include <linux/bitops.h> |
#include <linux/bug.h> |
//#include <asm/uaccess.h> |
/* |
* bitmaps provide an array of bits, implemented using an an |
* array of unsigned longs. The number of valid bits in a |
* given bitmap does _not_ need to be an exact multiple of |
* BITS_PER_LONG. |
* |
* The possible unused bits in the last, partially used word |
* of a bitmap are 'don't care'. The implementation makes |
* no particular effort to keep them zero. It ensures that |
* their value will not affect the results of any operation. |
* The bitmap operations that return Boolean (bitmap_empty, |
* for example) or scalar (bitmap_weight, for example) results |
* carefully filter out these unused bits from impacting their |
* results. |
* |
* These operations actually hold to a slightly stronger rule: |
* if you don't input any bitmaps to these ops that have some |
* unused bits set, then they won't output any set unused bits |
* in output bitmaps. |
* |
* The byte ordering of bitmaps is more natural on little |
* endian architectures. See the big-endian headers |
* include/asm-ppc64/bitops.h and include/asm-s390/bitops.h |
* for the best explanations of this ordering. |
*/ |
int __bitmap_empty(const unsigned long *bitmap, int bits) |
{ |
int k, lim = bits/BITS_PER_LONG; |
for (k = 0; k < lim; ++k) |
if (bitmap[k]) |
return 0; |
if (bits % BITS_PER_LONG) |
if (bitmap[k] & BITMAP_LAST_WORD_MASK(bits)) |
return 0; |
return 1; |
} |
EXPORT_SYMBOL(__bitmap_empty); |
int __bitmap_full(const unsigned long *bitmap, int bits) |
{ |
int k, lim = bits/BITS_PER_LONG; |
for (k = 0; k < lim; ++k) |
if (~bitmap[k]) |
return 0; |
if (bits % BITS_PER_LONG) |
if (~bitmap[k] & BITMAP_LAST_WORD_MASK(bits)) |
return 0; |
return 1; |
} |
EXPORT_SYMBOL(__bitmap_full); |
int __bitmap_equal(const unsigned long *bitmap1, |
const unsigned long *bitmap2, int bits) |
{ |
int k, lim = bits/BITS_PER_LONG; |
for (k = 0; k < lim; ++k) |
if (bitmap1[k] != bitmap2[k]) |
return 0; |
if (bits % BITS_PER_LONG) |
if ((bitmap1[k] ^ bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) |
return 0; |
return 1; |
} |
EXPORT_SYMBOL(__bitmap_equal); |
void __bitmap_complement(unsigned long *dst, const unsigned long *src, int bits) |
{ |
int k, lim = bits/BITS_PER_LONG; |
for (k = 0; k < lim; ++k) |
dst[k] = ~src[k]; |
if (bits % BITS_PER_LONG) |
dst[k] = ~src[k] & BITMAP_LAST_WORD_MASK(bits); |
} |
EXPORT_SYMBOL(__bitmap_complement); |
/** |
* __bitmap_shift_right - logical right shift of the bits in a bitmap |
* @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 |
* LS bits shifted off the bottom are lost. |
*/ |
void __bitmap_shift_right(unsigned long *dst, |
const unsigned long *src, int shift, int bits) |
{ |
int k, lim = BITS_TO_LONGS(bits), left = bits % BITS_PER_LONG; |
int off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG; |
unsigned long mask = (1UL << left) - 1; |
for (k = 0; off + k < lim; ++k) { |
unsigned long upper, lower; |
/* |
* If shift is not word aligned, take lower rem bits of |
* word above and make them the top rem bits of result. |
*/ |
if (!rem || off + k + 1 >= lim) |
upper = 0; |
else { |
upper = src[off + k + 1]; |
if (off + k + 1 == lim - 1 && left) |
upper &= mask; |
} |
lower = src[off + k]; |
if (left && off + k == lim - 1) |
lower &= mask; |
dst[k] = upper << (BITS_PER_LONG - rem) | lower >> rem; |
if (left && k == lim - 1) |
dst[k] &= mask; |
} |
if (off) |
memset(&dst[lim - off], 0, off*sizeof(unsigned long)); |
} |
EXPORT_SYMBOL(__bitmap_shift_right); |
/** |
* __bitmap_shift_left - logical left shift of the bits in a bitmap |
* @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 |
* and those MS bits shifted off the top are lost. |
*/ |
void __bitmap_shift_left(unsigned long *dst, |
const unsigned long *src, int shift, int bits) |
{ |
int k, lim = BITS_TO_LONGS(bits), left = bits % BITS_PER_LONG; |
int off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG; |
for (k = lim - off - 1; k >= 0; --k) { |
unsigned long upper, lower; |
/* |
* If shift is not word aligned, take upper rem bits of |
* word below and make them the bottom rem bits of result. |
*/ |
if (rem && k > 0) |
lower = src[k - 1]; |
else |
lower = 0; |
upper = src[k]; |
if (left && k == lim - 1) |
upper &= (1UL << left) - 1; |
dst[k + off] = lower >> (BITS_PER_LONG - rem) | upper << rem; |
if (left && k + off == lim - 1) |
dst[k + off] &= (1UL << left) - 1; |
} |
if (off) |
memset(dst, 0, off*sizeof(unsigned long)); |
} |
EXPORT_SYMBOL(__bitmap_shift_left); |
int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1, |
const unsigned long *bitmap2, int bits) |
{ |
int k; |
int nr = BITS_TO_LONGS(bits); |
unsigned long result = 0; |
for (k = 0; k < nr; k++) |
result |= (dst[k] = bitmap1[k] & bitmap2[k]); |
return result != 0; |
} |
EXPORT_SYMBOL(__bitmap_and); |
void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1, |
const unsigned long *bitmap2, int bits) |
{ |
int k; |
int nr = BITS_TO_LONGS(bits); |
for (k = 0; k < nr; k++) |
dst[k] = bitmap1[k] | bitmap2[k]; |
} |
EXPORT_SYMBOL(__bitmap_or); |
void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1, |
const unsigned long *bitmap2, int bits) |
{ |
int k; |
int nr = BITS_TO_LONGS(bits); |
for (k = 0; k < nr; k++) |
dst[k] = bitmap1[k] ^ bitmap2[k]; |
} |
EXPORT_SYMBOL(__bitmap_xor); |
int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, |
const unsigned long *bitmap2, int bits) |
{ |
int k; |
int nr = BITS_TO_LONGS(bits); |
unsigned long result = 0; |
for (k = 0; k < nr; k++) |
result |= (dst[k] = bitmap1[k] & ~bitmap2[k]); |
return result != 0; |
} |
EXPORT_SYMBOL(__bitmap_andnot); |
int __bitmap_intersects(const unsigned long *bitmap1, |
const unsigned long *bitmap2, int bits) |
{ |
int k, lim = bits/BITS_PER_LONG; |
for (k = 0; k < lim; ++k) |
if (bitmap1[k] & bitmap2[k]) |
return 1; |
if (bits % BITS_PER_LONG) |
if ((bitmap1[k] & bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) |
return 1; |
return 0; |
} |
EXPORT_SYMBOL(__bitmap_intersects); |
int __bitmap_subset(const unsigned long *bitmap1, |
const unsigned long *bitmap2, int bits) |
{ |
int k, lim = bits/BITS_PER_LONG; |
for (k = 0; k < lim; ++k) |
if (bitmap1[k] & ~bitmap2[k]) |
return 0; |
if (bits % BITS_PER_LONG) |
if ((bitmap1[k] & ~bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) |
return 0; |
return 1; |
} |
EXPORT_SYMBOL(__bitmap_subset); |
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]); |
if (bits % BITS_PER_LONG) |
w += hweight_long(bitmap[k] & BITMAP_LAST_WORD_MASK(bits)); |
return w; |
} |
EXPORT_SYMBOL(__bitmap_weight); |
void bitmap_set(unsigned long *map, int start, int nr) |
{ |
unsigned long *p = map + BIT_WORD(start); |
const int size = start + nr; |
int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG); |
unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start); |
while (nr - bits_to_set >= 0) { |
*p |= mask_to_set; |
nr -= bits_to_set; |
bits_to_set = BITS_PER_LONG; |
mask_to_set = ~0UL; |
p++; |
} |
if (nr) { |
mask_to_set &= BITMAP_LAST_WORD_MASK(size); |
*p |= mask_to_set; |
} |
} |
EXPORT_SYMBOL(bitmap_set); |
void bitmap_clear(unsigned long *map, int start, int nr) |
{ |
unsigned long *p = map + BIT_WORD(start); |
const int size = start + nr; |
int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG); |
unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start); |
while (nr - bits_to_clear >= 0) { |
*p &= ~mask_to_clear; |
nr -= bits_to_clear; |
bits_to_clear = BITS_PER_LONG; |
mask_to_clear = ~0UL; |
p++; |
} |
if (nr) { |
mask_to_clear &= BITMAP_LAST_WORD_MASK(size); |
*p &= ~mask_to_clear; |
} |
} |
EXPORT_SYMBOL(bitmap_clear); |
/* |
* bitmap_find_next_zero_area - find a contiguous aligned zero area |
* @map: The address to base the search on |
* @size: The bitmap size in bits |
* @start: The bitnumber to start searching at |
* @nr: The number of zeroed bits we're looking for |
* @align_mask: Alignment mask for zero area |
* |
* The @align_mask should be one less than a power of 2; the effect is that |
* the bit offset of all zero areas this function finds is multiples of that |
* power of 2. A @align_mask of 0 means no alignment is required. |
*/ |
unsigned long bitmap_find_next_zero_area(unsigned long *map, |
unsigned long size, |
unsigned long start, |
unsigned int nr, |
unsigned long align_mask) |
{ |
unsigned long index, end, i; |
again: |
index = find_next_zero_bit(map, size, start); |
/* Align allocation */ |
index = __ALIGN_MASK(index, align_mask); |
end = index + nr; |
if (end > size) |
return end; |
i = find_next_bit(map, end, index); |
if (i < end) { |
start = i + 1; |
goto again; |
} |
return index; |
} |
EXPORT_SYMBOL(bitmap_find_next_zero_area); |
/* |
* Bitmap printing & parsing functions: first version by Nadia Yvette Chambers, |
* second version by Paul Jackson, third by Joe Korty. |
*/ |
#define CHUNKSZ 32 |
#define nbits_to_hold_value(val) fls(val) |
#define BASEDEC 10 /* fancier cpuset lists input in decimal */ |
/** |
* bitmap_pos_to_ord - find ordinal of set bit at given position in bitmap |
* @buf: pointer to a bitmap |
* @pos: a bit position in @buf (0 <= @pos < @bits) |
* @bits: number of valid bit positions in @buf |
* |
* Map the bit at position @pos in @buf (of length @bits) to the |
* ordinal of which set bit it is. If it is not set or if @pos |
* is not a valid bit position, map to -1. |
* |
* If for example, just bits 4 through 7 are set in @buf, then @pos |
* values 4 through 7 will get mapped to 0 through 3, respectively, |
* and other @pos values will get mapped to 0. When @pos value 7 |
* gets mapped to (returns) @ord value 3 in this example, that means |
* that bit 7 is the 3rd (starting with 0th) set bit in @buf. |
* |
* The bit positions 0 through @bits are valid positions in @buf. |
*/ |
static int bitmap_pos_to_ord(const unsigned long *buf, int pos, int bits) |
{ |
int i, ord; |
if (pos < 0 || pos >= bits || !test_bit(pos, buf)) |
return -1; |
i = find_first_bit(buf, bits); |
ord = 0; |
while (i < pos) { |
i = find_next_bit(buf, bits, i + 1); |
ord++; |
} |
BUG_ON(i != pos); |
return ord; |
} |
/** |
* bitmap_ord_to_pos - find position of n-th set bit in bitmap |
* @buf: pointer to bitmap |
* @ord: ordinal bit position (n-th set bit, n >= 0) |
* @bits: number of valid bit positions in @buf |
* |
* Map the ordinal offset of bit @ord in @buf to its position in @buf. |
* Value of @ord should be in range 0 <= @ord < weight(buf), else |
* results are undefined. |
* |
* If for example, just bits 4 through 7 are set in @buf, then @ord |
* values 0 through 3 will get mapped to 4 through 7, respectively, |
* and all other @ord values return undefined values. When @ord value 3 |
* gets mapped to (returns) @pos value 7 in this example, that means |
* that the 3rd set bit (starting with 0th) is at position 7 in @buf. |
* |
* The bit positions 0 through @bits are valid positions in @buf. |
*/ |
int bitmap_ord_to_pos(const unsigned long *buf, int ord, int bits) |
{ |
int pos = 0; |
if (ord >= 0 && ord < bits) { |
int i; |
for (i = find_first_bit(buf, bits); |
i < bits && ord > 0; |
i = find_next_bit(buf, bits, i + 1)) |
ord--; |
if (i < bits && ord == 0) |
pos = i; |
} |
return pos; |
} |
/** |
* bitmap_remap - Apply map defined by a pair of bitmaps to another bitmap |
* @dst: remapped result |
* @src: subset to be remapped |
* @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 |
* to the n-th set bit in @new. In the more general case, allowing |
* for the possibility that the weight 'w' of @new is less than the |
* weight of @old, map the position of the n-th set bit in @old to |
* the position of the m-th set bit in @new, where m == n % w. |
* |
* If either of the @old and @new bitmaps are empty, or if @src and |
* @dst point to the same location, then this routine copies @src |
* to @dst. |
* |
* The positions of unset bits in @old are mapped to themselves |
* (the identify map). |
* |
* Apply the above specified mapping to @src, placing the result in |
* @dst, clearing any bits previously set in @dst. |
* |
* For example, lets say that @old has bits 4 through 7 set, and |
* @new has bits 12 through 15 set. This defines the mapping of bit |
* position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other |
* bit positions unchanged. So if say @src comes into this routine |
* with bits 1, 5 and 7 set, then @dst should leave with bits 1, |
* 13 and 15 set. |
*/ |
void bitmap_remap(unsigned long *dst, const unsigned long *src, |
const unsigned long *old, const unsigned long *new, |
int bits) |
{ |
int oldbit, w; |
if (dst == src) /* following doesn't handle inplace remaps */ |
return; |
bitmap_zero(dst, bits); |
w = bitmap_weight(new, bits); |
for_each_set_bit(oldbit, src, bits) { |
int n = bitmap_pos_to_ord(old, oldbit, bits); |
if (n < 0 || w == 0) |
set_bit(oldbit, dst); /* identity map */ |
else |
set_bit(bitmap_ord_to_pos(new, n % w, bits), dst); |
} |
} |
EXPORT_SYMBOL(bitmap_remap); |
/** |
* 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 |
* |
* 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 |
* to the n-th set bit in @new. In the more general case, allowing |
* for the possibility that the weight 'w' of @new is less than the |
* weight of @old, map the position of the n-th set bit in @old to |
* the position of the m-th set bit in @new, where m == n % w. |
* |
* The positions of unset bits in @old are mapped to themselves |
* (the identify map). |
* |
* Apply the above specified mapping to bit position @oldbit, returning |
* the new bit position. |
* |
* For example, lets say that @old has bits 4 through 7 set, and |
* @new has bits 12 through 15 set. This defines the mapping of bit |
* position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other |
* bit positions unchanged. So if say @oldbit is 5, then this routine |
* returns 13. |
*/ |
int bitmap_bitremap(int oldbit, const unsigned long *old, |
const unsigned long *new, int bits) |
{ |
int w = bitmap_weight(new, bits); |
int n = bitmap_pos_to_ord(old, oldbit, bits); |
if (n < 0 || w == 0) |
return oldbit; |
else |
return bitmap_ord_to_pos(new, n % w, bits); |
} |
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 twelfth 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_each_set_bit(n, relmap, bits) { |
/* 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_each_set_bit(oldbit, orig, bits) |
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: 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, end; /* scans bitmap by regions of size order */ |
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; |
} |
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 |
* |
* 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); |
} |
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)) |
return -EBUSY; |
__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); |
/drivers/ddk/linux/idr.c |
---|
20,7 → 20,7 |
* that id to this code and it returns your pointer. |
* You can release ids at any time. When all ids are released, most of |
* the memory is returned (we keep IDR_FREE_MAX) in a local pool so we |
* the memory is returned (we keep MAX_IDR_FREE) in a local pool so we |
* don't need to go to the memory "store" during an id allocate, just |
* so you don't need to be too concerned about locking and conflicts |
* with the slab allocator. |
27,96 → 27,99 |
*/ |
#include <linux/kernel.h> |
#include <linux/export.h> |
#include <linux/string.h> |
#include <linux/bitops.h> |
#include <linux/idr.h> |
//#include <stdlib.h> |
unsigned long find_first_bit(const unsigned long *addr, unsigned long size) |
{ |
const unsigned long *p = addr; |
unsigned long result = 0; |
unsigned long tmp; |
unsigned long find_next_zero_bit(const unsigned long *addr, unsigned long size, |
unsigned long offset); |
while (size & ~(BITS_PER_LONG-1)) { |
if ((tmp = *(p++))) |
goto found; |
result += BITS_PER_LONG; |
size -= BITS_PER_LONG; |
} |
if (!size) |
return result; |
tmp = (*p) & (~0UL >> (BITS_PER_LONG - size)); |
if (tmp == 0UL) /* Are any bits set? */ |
return result + size; /* Nope. */ |
found: |
return result + __ffs(tmp); |
} |
#define MAX_IDR_SHIFT (sizeof(int) * 8 - 1) |
#define MAX_IDR_BIT (1U << MAX_IDR_SHIFT) |
int find_next_bit(const unsigned long *addr, int size, int offset) |
/* Leave the possibility of an incomplete final layer */ |
#define MAX_IDR_LEVEL ((MAX_IDR_SHIFT + IDR_BITS - 1) / IDR_BITS) |
/* Number of id_layer structs to leave in free list */ |
#define MAX_IDR_FREE (MAX_IDR_LEVEL * 2) |
static struct idr_layer *idr_preload_head; |
static int idr_preload_cnt; |
/* the maximum ID which can be allocated given idr->layers */ |
static int idr_max(int layers) |
{ |
const unsigned long *p = addr + (offset >> 5); |
int set = 0, bit = offset & 31, res; |
int bits = min_t(int, layers * IDR_BITS, MAX_IDR_SHIFT); |
if (bit) |
{ |
/* |
* Look for nonzero in the first 32 bits: |
*/ |
__asm__("bsfl %1,%0\n\t" |
"jne 1f\n\t" |
"movl $32, %0\n" |
"1:" |
: "=r" (set) |
: "r" (*p >> bit)); |
if (set < (32 - bit)) |
return set + offset; |
set = 32 - bit; |
p++; |
return (1 << bits) - 1; |
} |
/* |
* No set bit yet, search remaining full words for a bit |
* Prefix mask for an idr_layer at @layer. For layer 0, the prefix mask is |
* all bits except for the lower IDR_BITS. For layer 1, 2 * IDR_BITS, and |
* so on. |
*/ |
res = find_first_bit (p, size - 32 * (p - addr)); |
return (offset + set + res); |
static int idr_layer_prefix_mask(int layer) |
{ |
return ~idr_max(layer + 1); |
} |
#define ACCESS_ONCE(x) (*(volatile typeof(x) *)&(x)) |
#define rcu_dereference(p) ({ \ |
typeof(p) _________p1 = ACCESS_ONCE(p); \ |
(_________p1); \ |
}) |
#define rcu_assign_pointer(p, v) \ |
({ \ |
if (!__builtin_constant_p(v) || \ |
((v) != NULL)) \ |
(p) = (v); \ |
}) |
//static struct kmem_cache *idr_layer_cache; |
static struct idr_layer *get_from_free_list(struct idr *idp) |
{ |
struct idr_layer *p; |
unsigned long flags; |
// spin_lock_irqsave(&idp->lock, flags); |
spin_lock_irqsave(&idp->lock, flags); |
if ((p = idp->id_free)) { |
idp->id_free = p->ary[0]; |
idp->id_free_cnt--; |
p->ary[0] = NULL; |
} |
// spin_unlock_irqrestore(&idp->lock, flags); |
spin_unlock_irqrestore(&idp->lock, flags); |
return(p); |
} |
/** |
* idr_layer_alloc - allocate a new idr_layer |
* @gfp_mask: allocation mask |
* @layer_idr: optional idr to allocate from |
* |
* If @layer_idr is %NULL, directly allocate one using @gfp_mask or fetch |
* one from the per-cpu preload buffer. If @layer_idr is not %NULL, fetch |
* an idr_layer from @idr->id_free. |
* |
* @layer_idr is to maintain backward compatibility with the old alloc |
* interface - idr_pre_get() and idr_get_new*() - and will be removed |
* together with per-pool preload buffer. |
*/ |
static struct idr_layer *idr_layer_alloc(gfp_t gfp_mask, struct idr *layer_idr) |
{ |
struct idr_layer *new; |
/* this is the old path, bypass to get_from_free_list() */ |
if (layer_idr) |
return get_from_free_list(layer_idr); |
/* try to allocate directly from kmem_cache */ |
new = kzalloc(sizeof(struct idr_layer), gfp_mask); |
if (new) |
return new; |
new = idr_preload_head; |
if (new) { |
idr_preload_head = new->ary[0]; |
idr_preload_cnt--; |
new->ary[0] = NULL; |
} |
preempt_enable(); |
return new; |
} |
static void idr_layer_rcu_free(struct rcu_head *head) |
{ |
struct idr_layer *layer; |
125,9 → 128,11 |
kfree(layer); |
} |
static inline void free_layer(struct idr_layer *p) |
static inline void free_layer(struct idr *idr, struct idr_layer *p) |
{ |
kfree(p); |
if (idr->hint && idr->hint == p) |
RCU_INIT_POINTER(idr->hint, NULL); |
idr_layer_rcu_free(&p->rcu_head); |
} |
/* only called when idp->lock is held */ |
145,9 → 150,9 |
/* |
* Depends on the return element being zeroed. |
*/ |
// spin_lock_irqsave(&idp->lock, flags); |
spin_lock_irqsave(&idp->lock, flags); |
__move_to_free_list(idp, p); |
// spin_unlock_irqrestore(&idp->lock, flags); |
spin_unlock_irqrestore(&idp->lock, flags); |
} |
static void idr_mark_full(struct idr_layer **pa, int id) |
155,7 → 160,7 |
struct idr_layer *p = pa[0]; |
int l = 0; |
__set_bit(id & IDR_MASK, &p->bitmap); |
__set_bit(id & IDR_MASK, p->bitmap); |
/* |
* If this layer is full mark the bit in the layer above to |
* show that this part of the radix tree is full. This may |
162,11 → 167,11 |
* complete the layer above and require walking up the radix |
* tree. |
*/ |
while (p->bitmap == IDR_FULL) { |
while (bitmap_full(p->bitmap, IDR_SIZE)) { |
if (!(p = pa[++l])) |
break; |
id = id >> IDR_BITS; |
__set_bit((id & IDR_MASK), &p->bitmap); |
__set_bit((id & IDR_MASK), p->bitmap); |
} |
} |
185,7 → 190,7 |
*/ |
int idr_pre_get(struct idr *idp, gfp_t gfp_mask) |
{ |
while (idp->id_free_cnt < IDR_FREE_MAX) { |
while (idp->id_free_cnt < MAX_IDR_FREE) { |
struct idr_layer *new; |
new = kzalloc(sizeof(struct idr_layer), gfp_mask); |
if (new == NULL) |
194,13 → 199,31 |
} |
return 1; |
} |
EXPORT_SYMBOL(idr_pre_get); |
static int sub_alloc(struct idr *idp, int *starting_id, struct idr_layer **pa) |
/** |
* sub_alloc - try to allocate an id without growing the tree depth |
* @idp: idr handle |
* @starting_id: id to start search at |
* @id: pointer to the allocated handle |
* @pa: idr_layer[MAX_IDR_LEVEL] used as backtrack buffer |
* @gfp_mask: allocation mask for idr_layer_alloc() |
* @layer_idr: optional idr passed to idr_layer_alloc() |
* |
* Allocate an id in range [@starting_id, INT_MAX] from @idp without |
* growing its depth. Returns |
* |
* the allocated id >= 0 if successful, |
* -EAGAIN if the tree needs to grow for allocation to succeed, |
* -ENOSPC if the id space is exhausted, |
* -ENOMEM if more idr_layers need to be allocated. |
*/ |
static int sub_alloc(struct idr *idp, int *starting_id, struct idr_layer **pa, |
gfp_t gfp_mask, struct idr *layer_idr) |
{ |
int n, m, sh; |
struct idr_layer *p, *new; |
int l, id, oid; |
unsigned long bm; |
id = *starting_id; |
restart: |
212,8 → 235,7 |
* We run around this while until we reach the leaf node... |
*/ |
n = (id >> (IDR_BITS*l)) & IDR_MASK; |
bm = ~p->bitmap; |
m = find_next_bit(&bm, IDR_SIZE, n); |
m = find_next_zero_bit(p->bitmap, IDR_SIZE, n); |
if (m == IDR_SIZE) { |
/* no space available go back to previous layer. */ |
l++; |
221,10 → 243,12 |
id = (id | ((1 << (IDR_BITS * l)) - 1)) + 1; |
/* if already at the top layer, we need to grow */ |
if (!(p = pa[l])) { |
if (id >= 1 << (idp->layers * IDR_BITS)) { |
*starting_id = id; |
return IDR_NEED_TO_GROW; |
return -EAGAIN; |
} |
p = pa[l]; |
BUG_ON(!p); |
/* If we need to go up one layer, continue the |
* loop; otherwise, restart from the top. |
239,8 → 263,8 |
sh = IDR_BITS*l; |
id = ((id >> sh) ^ n ^ m) << sh; |
} |
if ((id >= MAX_ID_BIT) || (id < 0)) |
return IDR_NOMORE_SPACE; |
if ((id >= MAX_IDR_BIT) || (id < 0)) |
return -ENOSPC; |
if (l == 0) |
break; |
/* |
247,10 → 271,11 |
* Create the layer below if it is missing. |
*/ |
if (!p->ary[m]) { |
new = get_from_free_list(idp); |
new = idr_layer_alloc(gfp_mask, layer_idr); |
if (!new) |
return -1; |
return -ENOMEM; |
new->layer = l-1; |
new->prefix = id & idr_layer_prefix_mask(new->layer); |
rcu_assign_pointer(p->ary[m], new); |
p->count++; |
} |
263,7 → 288,8 |
} |
static int idr_get_empty_slot(struct idr *idp, int starting_id, |
struct idr_layer **pa) |
struct idr_layer **pa, gfp_t gfp_mask, |
struct idr *layer_idr) |
{ |
struct idr_layer *p, *new; |
int layers, v, id; |
274,8 → 300,8 |
p = idp->top; |
layers = idp->layers; |
if (unlikely(!p)) { |
if (!(p = get_from_free_list(idp))) |
return -1; |
if (!(p = idr_layer_alloc(gfp_mask, layer_idr))) |
return -ENOMEM; |
p->layer = 0; |
layers = 1; |
} |
283,7 → 309,7 |
* Add a new layer to the top of the tree if the requested |
* id is larger than the currently allocated space. |
*/ |
while ((layers < (MAX_LEVEL - 1)) && (id >= (1 << (layers*IDR_BITS)))) { |
while (id > idr_max(layers)) { |
layers++; |
if (!p->count) { |
/* special case: if the tree is currently empty, |
291,58 → 317,56 |
* upwards. |
*/ |
p->layer++; |
WARN_ON_ONCE(p->prefix); |
continue; |
} |
if (!(new = get_from_free_list(idp))) { |
if (!(new = idr_layer_alloc(gfp_mask, layer_idr))) { |
/* |
* The allocation failed. If we built part of |
* the structure tear it down. |
*/ |
// spin_lock_irqsave(&idp->lock, flags); |
spin_lock_irqsave(&idp->lock, flags); |
for (new = p; p && p != idp->top; new = p) { |
p = p->ary[0]; |
new->ary[0] = NULL; |
new->bitmap = new->count = 0; |
new->count = 0; |
bitmap_clear(new->bitmap, 0, IDR_SIZE); |
__move_to_free_list(idp, new); |
} |
// spin_unlock_irqrestore(&idp->lock, flags); |
return -1; |
spin_unlock_irqrestore(&idp->lock, flags); |
return -ENOMEM; |
} |
new->ary[0] = p; |
new->count = 1; |
new->layer = layers-1; |
if (p->bitmap == IDR_FULL) |
__set_bit(0, &new->bitmap); |
new->prefix = id & idr_layer_prefix_mask(new->layer); |
if (bitmap_full(p->bitmap, IDR_SIZE)) |
__set_bit(0, new->bitmap); |
p = new; |
} |
rcu_assign_pointer(idp->top, p); |
idp->layers = layers; |
v = sub_alloc(idp, &id, pa); |
if (v == IDR_NEED_TO_GROW) |
v = sub_alloc(idp, &id, pa, gfp_mask, layer_idr); |
if (v == -EAGAIN) |
goto build_up; |
return(v); |
} |
static int idr_get_new_above_int(struct idr *idp, void *ptr, int starting_id) |
/* |
* @id and @pa are from a successful allocation from idr_get_empty_slot(). |
* Install the user pointer @ptr and mark the slot full. |
*/ |
static void idr_fill_slot(struct idr *idr, void *ptr, int id, |
struct idr_layer **pa) |
{ |
struct idr_layer *pa[MAX_LEVEL]; |
int id; |
/* update hint used for lookup, cleared from free_layer() */ |
rcu_assign_pointer(idr->hint, pa[0]); |
id = idr_get_empty_slot(idp, starting_id, pa); |
if (id >= 0) { |
/* |
* Successfully found an empty slot. Install the user |
* pointer and mark the slot full. |
*/ |
rcu_assign_pointer(pa[0]->ary[id & IDR_MASK], |
(struct idr_layer *)ptr); |
rcu_assign_pointer(pa[0]->ary[id & IDR_MASK], (struct idr_layer *)ptr); |
pa[0]->count++; |
idr_mark_full(pa, id); |
} |
return id; |
} |
/** |
* idr_get_new_above - allocate new idr entry above or equal to a start id |
* @idp: idr handle |
363,51 → 387,113 |
*/ |
int idr_get_new_above(struct idr *idp, void *ptr, int starting_id, int *id) |
{ |
struct idr_layer *pa[MAX_IDR_LEVEL + 1]; |
int rv; |
rv = idr_get_new_above_int(idp, ptr, starting_id); |
/* |
* This is a cheap hack until the IDR code can be fixed to |
* return proper error values. |
*/ |
rv = idr_get_empty_slot(idp, starting_id, pa, 0, idp); |
if (rv < 0) |
{ |
dbgprintf("fail\n"); |
return _idr_rc_to_errno(rv); |
}; |
return rv == -ENOMEM ? -EAGAIN : rv; |
idr_fill_slot(idp, ptr, rv, pa); |
*id = rv; |
return 0; |
} |
EXPORT_SYMBOL(idr_get_new_above); |
/** |
* idr_get_new - allocate new idr entry |
* @idp: idr handle |
* @ptr: pointer you want associated with the id |
* @id: pointer to the allocated handle |
* idr_preload - preload for idr_alloc() |
* @gfp_mask: allocation mask to use for preloading |
* |
* If allocation from IDR's private freelist fails, idr_get_new_above() will |
* return %-EAGAIN. The caller should retry the idr_pre_get() call to refill |
* IDR's preallocation and then retry the idr_get_new_above() call. |
* Preload per-cpu layer buffer for idr_alloc(). Can only be used from |
* process context and each idr_preload() invocation should be matched with |
* idr_preload_end(). Note that preemption is disabled while preloaded. |
* |
* If the idr is full idr_get_new_above() will return %-ENOSPC. |
* The first idr_alloc() in the preloaded section can be treated as if it |
* were invoked with @gfp_mask used for preloading. This allows using more |
* permissive allocation masks for idrs protected by spinlocks. |
* |
* @id returns a value in the range %0 ... %0x7fffffff |
* For example, if idr_alloc() below fails, the failure can be treated as |
* if idr_alloc() were called with GFP_KERNEL rather than GFP_NOWAIT. |
* |
* idr_preload(GFP_KERNEL); |
* spin_lock(lock); |
* |
* id = idr_alloc(idr, ptr, start, end, GFP_NOWAIT); |
* |
* spin_unlock(lock); |
* idr_preload_end(); |
* if (id < 0) |
* error; |
*/ |
int idr_get_new(struct idr *idp, void *ptr, int *id) |
void idr_preload(gfp_t gfp_mask) |
{ |
int rv; |
rv = idr_get_new_above_int(idp, ptr, 0); |
/* |
* This is a cheap hack until the IDR code can be fixed to |
* return proper error values. |
* idr_alloc() is likely to succeed w/o full idr_layer buffer and |
* return value from idr_alloc() needs to be checked for failure |
* anyway. Silently give up if allocation fails. The caller can |
* treat failures from idr_alloc() as if idr_alloc() were called |
* with @gfp_mask which should be enough. |
*/ |
if (rv < 0) |
return _idr_rc_to_errno(rv); |
*id = rv; |
return 0; |
while (idr_preload_cnt < MAX_IDR_FREE) { |
struct idr_layer *new; |
new = kzalloc(sizeof(struct idr_layer), gfp_mask); |
if (!new) |
break; |
/* link the new one to per-cpu preload list */ |
new->ary[0] = idr_preload_head; |
idr_preload_head = new; |
idr_preload_cnt++; |
} |
} |
EXPORT_SYMBOL(idr_preload); |
/** |
* idr_alloc - allocate new idr entry |
* @idr: the (initialized) idr |
* @ptr: pointer to be associated with the new id |
* @start: the minimum id (inclusive) |
* @end: the maximum id (exclusive, <= 0 for max) |
* @gfp_mask: memory allocation flags |
* |
* Allocate an id in [start, end) and associate it with @ptr. If no ID is |
* available in the specified range, returns -ENOSPC. On memory allocation |
* failure, returns -ENOMEM. |
* |
* Note that @end is treated as max when <= 0. This is to always allow |
* using @start + N as @end as long as N is inside integer range. |
* |
* The user is responsible for exclusively synchronizing all operations |
* which may modify @idr. However, read-only accesses such as idr_find() |
* or iteration can be performed under RCU read lock provided the user |
* destroys @ptr in RCU-safe way after removal from idr. |
*/ |
int idr_alloc(struct idr *idr, void *ptr, int start, int end, gfp_t gfp_mask) |
{ |
int max = end > 0 ? end - 1 : INT_MAX; /* inclusive upper limit */ |
struct idr_layer *pa[MAX_IDR_LEVEL + 1]; |
int id; |
/* sanity checks */ |
if (WARN_ON_ONCE(start < 0)) |
return -EINVAL; |
if (unlikely(max < start)) |
return -ENOSPC; |
/* allocate id */ |
id = idr_get_empty_slot(idr, start, pa, gfp_mask, NULL); |
if (unlikely(id < 0)) |
return id; |
if (unlikely(id > max)) |
return -ENOSPC; |
idr_fill_slot(idr, ptr, id, pa); |
return id; |
} |
EXPORT_SYMBOL_GPL(idr_alloc); |
static void idr_remove_warning(int id) |
{ |
printk(KERN_WARNING |
418,7 → 504,7 |
static void sub_remove(struct idr *idp, int shift, int id) |
{ |
struct idr_layer *p = idp->top; |
struct idr_layer **pa[MAX_LEVEL]; |
struct idr_layer **pa[MAX_IDR_LEVEL + 1]; |
struct idr_layer ***paa = &pa[0]; |
struct idr_layer *to_free; |
int n; |
428,19 → 514,19 |
while ((shift > 0) && p) { |
n = (id >> shift) & IDR_MASK; |
__clear_bit(n, &p->bitmap); |
__clear_bit(n, p->bitmap); |
*++paa = &p->ary[n]; |
p = p->ary[n]; |
shift -= IDR_BITS; |
} |
n = id & IDR_MASK; |
if (likely(p != NULL && test_bit(n, &p->bitmap))){ |
__clear_bit(n, &p->bitmap); |
if (likely(p != NULL && test_bit(n, p->bitmap))) { |
__clear_bit(n, p->bitmap); |
rcu_assign_pointer(p->ary[n], NULL); |
to_free = NULL; |
while(*paa && ! --((**paa)->count)){ |
if (to_free) |
free_layer(to_free); |
free_layer(idp, to_free); |
to_free = **paa; |
**paa-- = NULL; |
} |
447,7 → 533,7 |
if (!*paa) |
idp->layers = 0; |
if (to_free) |
free_layer(to_free); |
free_layer(idp, to_free); |
} else |
idr_remove_warning(id); |
} |
462,8 → 548,9 |
struct idr_layer *p; |
struct idr_layer *to_free; |
/* Mask off upper bits we don't use for the search. */ |
id &= MAX_ID_MASK; |
/* see comment in idr_find_slowpath() */ |
if (WARN_ON_ONCE(id < 0)) |
return; |
sub_remove(idp, (idp->layers - 1) * IDR_BITS, id); |
if (idp->top && idp->top->count == 1 && (idp->layers > 1) && |
478,10 → 565,11 |
p = idp->top->ary[0]; |
rcu_assign_pointer(idp->top, p); |
--idp->layers; |
to_free->bitmap = to_free->count = 0; |
free_layer(to_free); |
to_free->count = 0; |
bitmap_clear(to_free->bitmap, 0, IDR_SIZE); |
free_layer(idp, to_free); |
} |
while (idp->id_free_cnt >= IDR_FREE_MAX) { |
while (idp->id_free_cnt >= MAX_IDR_FREE) { |
p = get_from_free_list(idp); |
/* |
* Note: we don't call the rcu callback here, since the only |
492,36 → 580,23 |
} |
return; |
} |
EXPORT_SYMBOL(idr_remove); |
/** |
* idr_remove_all - remove all ids from the given idr tree |
* @idp: idr handle |
* |
* idr_destroy() only frees up unused, cached idp_layers, but this |
* function will remove all id mappings and leave all idp_layers |
* unused. |
* |
* A typical clean-up sequence for objects stored in an idr tree will |
* use idr_for_each() to free all objects, if necessay, then |
* idr_remove_all() to remove all ids, and idr_destroy() to free |
* up the cached idr_layers. |
*/ |
void idr_remove_all(struct idr *idp) |
void __idr_remove_all(struct idr *idp) |
{ |
int n, id, max; |
int bt_mask; |
struct idr_layer *p; |
struct idr_layer *pa[MAX_LEVEL]; |
struct idr_layer *pa[MAX_IDR_LEVEL + 1]; |
struct idr_layer **paa = &pa[0]; |
n = idp->layers * IDR_BITS; |
p = idp->top; |
rcu_assign_pointer(idp->top, NULL); |
max = 1 << n; |
max = idr_max(idp->layers); |
id = 0; |
while (id < max) { |
while (id >= 0 && id <= max) { |
while (n > IDR_BITS && p) { |
n -= IDR_BITS; |
*paa++ = p; |
533,7 → 608,7 |
/* Get the highest bit that the above add changed from 0->1. */ |
while (n < fls(id ^ bt_mask)) { |
if (p) |
free_layer(p); |
free_layer(idp, p); |
n += IDR_BITS; |
p = *--paa; |
} |
540,46 → 615,54 |
} |
idp->layers = 0; |
} |
EXPORT_SYMBOL(__idr_remove_all); |
/** |
* idr_destroy - release all cached layers within an idr tree |
* @idp: idr handle |
* |
* Free all id mappings and all idp_layers. After this function, @idp is |
* completely unused and can be freed / recycled. The caller is |
* responsible for ensuring that no one else accesses @idp during or after |
* idr_destroy(). |
* |
* A typical clean-up sequence for objects stored in an idr tree will use |
* idr_for_each() to free all objects, if necessay, then idr_destroy() to |
* free up the id mappings and cached idr_layers. |
*/ |
void idr_destroy(struct idr *idp) |
{ |
__idr_remove_all(idp); |
while (idp->id_free_cnt) { |
struct idr_layer *p = get_from_free_list(idp); |
kfree(p); |
} |
} |
EXPORT_SYMBOL(idr_destroy); |
/** |
* idr_find - return pointer for given id |
* @idp: idr handle |
* @id: lookup key |
* |
* Return the pointer given the id it has been registered with. A %NULL |
* return indicates that @id is not valid or you passed %NULL in |
* idr_get_new(). |
* |
* This function can be called under rcu_read_lock(), given that the leaf |
* pointers lifetimes are correctly managed. |
*/ |
void *idr_find(struct idr *idp, int id) |
void *idr_find_slowpath(struct idr *idp, int id) |
{ |
int n; |
struct idr_layer *p; |
p = rcu_dereference(idp->top); |
/* |
* If @id is negative, idr_find() used to ignore the sign bit and |
* performed lookup with the rest of bits, which is weird and can |
* lead to very obscure bugs. We're now returning NULL for all |
* negative IDs but just in case somebody was depending on the sign |
* bit being ignored, let's trigger WARN_ON_ONCE() so that they can |
* be detected and fixed. WARN_ON_ONCE() can later be removed. |
*/ |
if (WARN_ON_ONCE(id < 0)) |
return NULL; |
p = rcu_dereference_raw(idp->top); |
if (!p) |
return NULL; |
n = (p->layer+1) * IDR_BITS; |
/* Mask off upper bits we don't use for the search. */ |
id &= MAX_ID_MASK; |
if (id >= (1 << n)) |
if (id > idr_max(p->layer + 1)) |
return NULL; |
BUG_ON(n == 0); |
586,10 → 669,11 |
while (n > 0 && p) { |
n -= IDR_BITS; |
BUG_ON(n != p->layer*IDR_BITS); |
p = rcu_dereference(p->ary[(id >> n) & IDR_MASK]); |
p = rcu_dereference_raw(p->ary[(id >> n) & IDR_MASK]); |
} |
return((void *)p); |
} |
EXPORT_SYMBOL(idr_find_slowpath); |
#if 0 |
/** |
615,19 → 699,19 |
{ |
int n, id, max, error = 0; |
struct idr_layer *p; |
struct idr_layer *pa[MAX_LEVEL]; |
struct idr_layer *pa[MAX_IDR_LEVEL + 1]; |
struct idr_layer **paa = &pa[0]; |
n = idp->layers * IDR_BITS; |
p = rcu_dereference(idp->top); |
max = 1 << n; |
p = rcu_dereference_raw(idp->top); |
max = idr_max(idp->layers); |
id = 0; |
while (id < max) { |
while (id >= 0 && id <= max) { |
while (n > 0 && p) { |
n -= IDR_BITS; |
*paa++ = p; |
p = rcu_dereference(p->ary[(id >> n) & IDR_MASK]); |
p = rcu_dereference_raw(p->ary[(id >> n) & IDR_MASK]); |
} |
if (p) { |
655,27 → 739,29 |
* Returns pointer to registered object with id, which is next number to |
* given id. After being looked up, *@nextidp will be updated for the next |
* iteration. |
* |
* This function can be called under rcu_read_lock(), given that the leaf |
* pointers lifetimes are correctly managed. |
*/ |
void *idr_get_next(struct idr *idp, int *nextidp) |
{ |
struct idr_layer *p, *pa[MAX_LEVEL]; |
struct idr_layer *p, *pa[MAX_IDR_LEVEL + 1]; |
struct idr_layer **paa = &pa[0]; |
int id = *nextidp; |
int n, max; |
/* find first ent */ |
n = idp->layers * IDR_BITS; |
max = 1 << n; |
p = rcu_dereference(idp->top); |
p = rcu_dereference_raw(idp->top); |
if (!p) |
return NULL; |
n = (p->layer + 1) * IDR_BITS; |
max = idr_max(p->layer + 1); |
while (id < max) { |
while (id >= 0 && id <= max) { |
while (n > 0 && p) { |
n -= IDR_BITS; |
*paa++ = p; |
p = rcu_dereference(p->ary[(id >> n) & IDR_MASK]); |
p = rcu_dereference_raw(p->ary[(id >> n) & IDR_MASK]); |
} |
if (p) { |
683,7 → 769,14 |
return p; |
} |
id += 1 << n; |
/* |
* Proceed to the next layer at the current level. Unlike |
* idr_for_each(), @id isn't guaranteed to be aligned to |
* layer boundary at this point and adding 1 << n may |
* incorrectly skip IDs. Make sure we jump to the |
* beginning of the next layer using round_up(). |
*/ |
id = round_up(id + 1, 1 << n); |
while (n < fls(id)) { |
n += IDR_BITS; |
p = *--paa; |
691,9 → 784,9 |
} |
return NULL; |
} |
EXPORT_SYMBOL(idr_get_next); |
/** |
* idr_replace - replace pointer for given id |
* @idp: idr handle |
711,6 → 804,10 |
int n; |
struct idr_layer *p, *old_p; |
/* see comment in idr_find_slowpath() */ |
if (WARN_ON_ONCE(id < 0)) |
return ERR_PTR(-EINVAL); |
p = idp->top; |
if (!p) |
return ERR_PTR(-EINVAL); |
717,8 → 814,6 |
n = (p->layer+1) * IDR_BITS; |
id &= MAX_ID_MASK; |
if (id >= (1 << n)) |
return ERR_PTR(-EINVAL); |
729,7 → 824,7 |
} |
n = id & IDR_MASK; |
if (unlikely(p == NULL || !test_bit(n, &p->bitmap))) |
if (unlikely(p == NULL || !test_bit(n, p->bitmap))) |
return ERR_PTR(-ENOENT); |
old_p = p->ary[n]; |
759,12 → 854,14 |
void idr_init(struct idr *idp) |
{ |
memset(idp, 0, sizeof(struct idr)); |
// spin_lock_init(&idp->lock); |
spin_lock_init(&idp->lock); |
} |
EXPORT_SYMBOL(idr_init); |
#if 0 |
/* |
/** |
* DOC: IDA description |
* IDA - IDR based ID allocator |
* |
* This is id allocator without id -> pointer translation. Memory |
813,7 → 910,7 |
if (!ida->free_bitmap) { |
struct ida_bitmap *bitmap; |
bitmap = kzalloc(sizeof(struct ida_bitmap), gfp_mask); |
bitmap = kmalloc(sizeof(struct ida_bitmap), gfp_mask); |
if (!bitmap) |
return 0; |
841,7 → 938,7 |
*/ |
int ida_get_new_above(struct ida *ida, int starting_id, int *p_id) |
{ |
struct idr_layer *pa[MAX_LEVEL]; |
struct idr_layer *pa[MAX_IDR_LEVEL + 1]; |
struct ida_bitmap *bitmap; |
unsigned long flags; |
int idr_id = starting_id / IDA_BITMAP_BITS; |
850,11 → 947,11 |
restart: |
/* get vacant slot */ |
t = idr_get_empty_slot(&ida->idr, idr_id, pa); |
t = idr_get_empty_slot(&ida->idr, idr_id, pa, 0, &ida->idr); |
if (t < 0) |
return _idr_rc_to_errno(t); |
return t == -ENOMEM ? -EAGAIN : t; |
if (t * IDA_BITMAP_BITS >= MAX_ID_BIT) |
if (t * IDA_BITMAP_BITS >= MAX_IDR_BIT) |
return -ENOSPC; |
if (t != idr_id) |
888,7 → 985,7 |
} |
id = idr_id * IDA_BITMAP_BITS + t; |
if (id >= MAX_ID_BIT) |
if (id >= MAX_IDR_BIT) |
return -ENOSPC; |
__set_bit(t, bitmap->bitmap); |
913,25 → 1010,6 |
EXPORT_SYMBOL(ida_get_new_above); |
/** |
* ida_get_new - allocate new ID |
* @ida: idr handle |
* @p_id: pointer to the allocated handle |
* |
* Allocate new ID. It should be called with any required locks. |
* |
* If memory is required, it will return %-EAGAIN, you should unlock |
* and go back to the idr_pre_get() call. If the idr is full, it will |
* return %-ENOSPC. |
* |
* @p_id returns a value in the range %0 ... %0x7fffffff. |
*/ |
int ida_get_new(struct ida *ida, int *p_id) |
{ |
return ida_get_new_above(ida, 0, p_id); |
} |
EXPORT_SYMBOL(ida_get_new); |
/** |
* ida_remove - remove the given ID |
* @ida: ida handle |
* @id: ID to free |
948,7 → 1026,7 |
/* clear full bits while looking up the leaf idr_layer */ |
while ((shift > 0) && p) { |
n = (idr_id >> shift) & IDR_MASK; |
__clear_bit(n, &p->bitmap); |
__clear_bit(n, p->bitmap); |
p = p->ary[n]; |
shift -= IDR_BITS; |
} |
957,7 → 1035,7 |
goto err; |
n = idr_id & IDR_MASK; |
__clear_bit(n, &p->bitmap); |
__clear_bit(n, p->bitmap); |
bitmap = (void *)p->ary[n]; |
if (!test_bit(offset, bitmap->bitmap)) |
966,7 → 1044,7 |
/* update bitmap and remove it if empty */ |
__clear_bit(offset, bitmap->bitmap); |
if (--bitmap->nr_busy == 0) { |
__set_bit(n, &p->bitmap); /* to please idr_remove() */ |
__set_bit(n, p->bitmap); /* to please idr_remove() */ |
idr_remove(&ida->idr, idr_id); |
free_bitmap(ida, bitmap); |
} |
1007,3 → 1085,114 |
#endif |
unsigned long find_first_bit(const unsigned long *addr, unsigned long size) |
{ |
const unsigned long *p = addr; |
unsigned long result = 0; |
unsigned long tmp; |
while (size & ~(BITS_PER_LONG-1)) { |
if ((tmp = *(p++))) |
goto found; |
result += BITS_PER_LONG; |
size -= BITS_PER_LONG; |
} |
if (!size) |
return result; |
tmp = (*p) & (~0UL >> (BITS_PER_LONG - size)); |
if (tmp == 0UL) /* Are any bits set? */ |
return result + size; /* Nope. */ |
found: |
return result + __ffs(tmp); |
} |
unsigned long find_next_bit(const unsigned long *addr, unsigned long size, |
unsigned long offset) |
{ |
const unsigned long *p = addr + BITOP_WORD(offset); |
unsigned long result = offset & ~(BITS_PER_LONG-1); |
unsigned long tmp; |
if (offset >= size) |
return size; |
size -= result; |
offset %= BITS_PER_LONG; |
if (offset) { |
tmp = *(p++); |
tmp &= (~0UL << offset); |
if (size < BITS_PER_LONG) |
goto found_first; |
if (tmp) |
goto found_middle; |
size -= BITS_PER_LONG; |
result += BITS_PER_LONG; |
} |
while (size & ~(BITS_PER_LONG-1)) { |
if ((tmp = *(p++))) |
goto found_middle; |
result += BITS_PER_LONG; |
size -= BITS_PER_LONG; |
} |
if (!size) |
return result; |
tmp = *p; |
found_first: |
tmp &= (~0UL >> (BITS_PER_LONG - size)); |
if (tmp == 0UL) /* Are any bits set? */ |
return result + size; /* Nope. */ |
found_middle: |
return result + __ffs(tmp); |
} |
unsigned long find_next_zero_bit(const unsigned long *addr, unsigned long size, |
unsigned long offset) |
{ |
const unsigned long *p = addr + BITOP_WORD(offset); |
unsigned long result = offset & ~(BITS_PER_LONG-1); |
unsigned long tmp; |
if (offset >= size) |
return size; |
size -= result; |
offset %= BITS_PER_LONG; |
if (offset) { |
tmp = *(p++); |
tmp |= ~0UL >> (BITS_PER_LONG - offset); |
if (size < BITS_PER_LONG) |
goto found_first; |
if (~tmp) |
goto found_middle; |
size -= BITS_PER_LONG; |
result += BITS_PER_LONG; |
} |
while (size & ~(BITS_PER_LONG-1)) { |
if (~(tmp = *(p++))) |
goto found_middle; |
result += BITS_PER_LONG; |
size -= BITS_PER_LONG; |
} |
if (!size) |
return result; |
tmp = *p; |
found_first: |
tmp |= ~0UL << size; |
if (tmp == ~0UL) /* Are any bits zero? */ |
return result + size; /* Nope. */ |
found_middle: |
return result + ffz(tmp); |
} |
unsigned int hweight32(unsigned int w) |
{ |
unsigned int res = w - ((w >> 1) & 0x55555555); |
res = (res & 0x33333333) + ((res >> 2) & 0x33333333); |
res = (res + (res >> 4)) & 0x0F0F0F0F; |
res = res + (res >> 8); |
return (res + (res >> 16)) & 0x000000FF; |
} |