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![Yury Norov](/assets/img/avatar_default.png)
bitmap_{from,to}_arr64() optimization is overly optimistic on 32-bit LE
architectures when it's wired to bitmap_copy_clear_tail().
bitmap_copy_clear_tail() takes care of unused bits in the bitmap up to
the next word boundary. But on 32-bit machines when copying bits from
bitmap to array of 64-bit words, it's expected that the unused part of
a recipient array must be cleared up to 64-bit boundary, so the last 4
bytes may stay untouched when nbits % 64 <= 32.
While the copying part of the optimization works correct, that clear-tail
trick makes corresponding tests reasonably fail:
test_bitmap: bitmap_to_arr64(nbits == 1): tail is not safely cleared: 0xa5a5a5a500000001 (must be 0x0000000000000001)
Fix it by removing bitmap_{from,to}_arr64() optimization for 32-bit LE
arches.
Reported-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/lkml/20230225184702.GA3587246@roeck-us.net/
Fixes: 0a97953fd2
("lib: add bitmap_{from,to}_arr64")
Signed-off-by: Yury Norov <yury.norov@gmail.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com>
1551 lines
46 KiB
C
1551 lines
46 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* lib/bitmap.c
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* Helper functions for bitmap.h.
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*/
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#include <linux/bitmap.h>
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#include <linux/bitops.h>
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#include <linux/bug.h>
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#include <linux/ctype.h>
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#include <linux/device.h>
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#include <linux/errno.h>
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#include <linux/export.h>
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#include <linux/kernel.h>
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#include <linux/mm.h>
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#include <linux/slab.h>
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#include <linux/string.h>
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#include <linux/thread_info.h>
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#include <linux/uaccess.h>
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#include <asm/page.h>
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#include "kstrtox.h"
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/**
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* DOC: bitmap introduction
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*
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* bitmaps provide an array of bits, implemented using an
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* array of unsigned longs. The number of valid bits in a
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* given bitmap does _not_ need to be an exact multiple of
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* BITS_PER_LONG.
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*
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* The possible unused bits in the last, partially used word
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* of a bitmap are 'don't care'. The implementation makes
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* no particular effort to keep them zero. It ensures that
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* their value will not affect the results of any operation.
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* The bitmap operations that return Boolean (bitmap_empty,
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* for example) or scalar (bitmap_weight, for example) results
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* carefully filter out these unused bits from impacting their
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* results.
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*
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* The byte ordering of bitmaps is more natural on little
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* endian architectures. See the big-endian headers
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* include/asm-ppc64/bitops.h and include/asm-s390/bitops.h
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* for the best explanations of this ordering.
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*/
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bool __bitmap_equal(const unsigned long *bitmap1,
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const unsigned long *bitmap2, unsigned int bits)
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{
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unsigned int k, lim = bits/BITS_PER_LONG;
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for (k = 0; k < lim; ++k)
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if (bitmap1[k] != bitmap2[k])
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return false;
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if (bits % BITS_PER_LONG)
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if ((bitmap1[k] ^ bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
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return false;
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return true;
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}
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EXPORT_SYMBOL(__bitmap_equal);
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bool __bitmap_or_equal(const unsigned long *bitmap1,
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const unsigned long *bitmap2,
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const unsigned long *bitmap3,
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unsigned int bits)
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{
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unsigned int k, lim = bits / BITS_PER_LONG;
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unsigned long tmp;
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for (k = 0; k < lim; ++k) {
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if ((bitmap1[k] | bitmap2[k]) != bitmap3[k])
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return false;
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}
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if (!(bits % BITS_PER_LONG))
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return true;
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tmp = (bitmap1[k] | bitmap2[k]) ^ bitmap3[k];
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return (tmp & BITMAP_LAST_WORD_MASK(bits)) == 0;
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}
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void __bitmap_complement(unsigned long *dst, const unsigned long *src, unsigned int bits)
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{
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unsigned int k, lim = BITS_TO_LONGS(bits);
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for (k = 0; k < lim; ++k)
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dst[k] = ~src[k];
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}
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EXPORT_SYMBOL(__bitmap_complement);
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/**
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* __bitmap_shift_right - logical right shift of the bits in a bitmap
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* @dst : destination bitmap
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* @src : source bitmap
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* @shift : shift by this many bits
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* @nbits : bitmap size, in bits
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*
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* Shifting right (dividing) means moving bits in the MS -> LS bit
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* direction. Zeros are fed into the vacated MS positions and the
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* LS bits shifted off the bottom are lost.
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*/
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void __bitmap_shift_right(unsigned long *dst, const unsigned long *src,
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unsigned shift, unsigned nbits)
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{
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unsigned k, lim = BITS_TO_LONGS(nbits);
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unsigned off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG;
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unsigned long mask = BITMAP_LAST_WORD_MASK(nbits);
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for (k = 0; off + k < lim; ++k) {
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unsigned long upper, lower;
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/*
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* If shift is not word aligned, take lower rem bits of
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* word above and make them the top rem bits of result.
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*/
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if (!rem || off + k + 1 >= lim)
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upper = 0;
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else {
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upper = src[off + k + 1];
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if (off + k + 1 == lim - 1)
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upper &= mask;
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upper <<= (BITS_PER_LONG - rem);
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}
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lower = src[off + k];
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if (off + k == lim - 1)
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lower &= mask;
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lower >>= rem;
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dst[k] = lower | upper;
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}
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if (off)
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memset(&dst[lim - off], 0, off*sizeof(unsigned long));
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}
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EXPORT_SYMBOL(__bitmap_shift_right);
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/**
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* __bitmap_shift_left - logical left shift of the bits in a bitmap
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* @dst : destination bitmap
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* @src : source bitmap
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* @shift : shift by this many bits
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* @nbits : bitmap size, in bits
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*
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* Shifting left (multiplying) means moving bits in the LS -> MS
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* direction. Zeros are fed into the vacated LS bit positions
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* and those MS bits shifted off the top are lost.
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*/
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void __bitmap_shift_left(unsigned long *dst, const unsigned long *src,
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unsigned int shift, unsigned int nbits)
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{
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int k;
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unsigned int lim = BITS_TO_LONGS(nbits);
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unsigned int off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG;
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for (k = lim - off - 1; k >= 0; --k) {
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unsigned long upper, lower;
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/*
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* If shift is not word aligned, take upper rem bits of
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* word below and make them the bottom rem bits of result.
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*/
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if (rem && k > 0)
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lower = src[k - 1] >> (BITS_PER_LONG - rem);
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else
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lower = 0;
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upper = src[k] << rem;
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dst[k + off] = lower | upper;
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}
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if (off)
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memset(dst, 0, off*sizeof(unsigned long));
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}
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EXPORT_SYMBOL(__bitmap_shift_left);
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/**
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* bitmap_cut() - remove bit region from bitmap and right shift remaining bits
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* @dst: destination bitmap, might overlap with src
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* @src: source bitmap
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* @first: start bit of region to be removed
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* @cut: number of bits to remove
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* @nbits: bitmap size, in bits
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*
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* Set the n-th bit of @dst iff the n-th bit of @src is set and
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* n is less than @first, or the m-th bit of @src is set for any
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* m such that @first <= n < nbits, and m = n + @cut.
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*
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* In pictures, example for a big-endian 32-bit architecture:
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*
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* The @src bitmap is::
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*
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* 31 63
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* | |
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* 10000000 11000001 11110010 00010101 10000000 11000001 01110010 00010101
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* | | | |
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* 16 14 0 32
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*
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* if @cut is 3, and @first is 14, bits 14-16 in @src are cut and @dst is::
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*
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* 31 63
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* | |
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* 10110000 00011000 00110010 00010101 00010000 00011000 00101110 01000010
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* | | |
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* 14 (bit 17 0 32
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* from @src)
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*
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* Note that @dst and @src might overlap partially or entirely.
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*
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* This is implemented in the obvious way, with a shift and carry
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* step for each moved bit. Optimisation is left as an exercise
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* for the compiler.
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*/
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void bitmap_cut(unsigned long *dst, const unsigned long *src,
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unsigned int first, unsigned int cut, unsigned int nbits)
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{
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unsigned int len = BITS_TO_LONGS(nbits);
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unsigned long keep = 0, carry;
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int i;
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if (first % BITS_PER_LONG) {
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keep = src[first / BITS_PER_LONG] &
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(~0UL >> (BITS_PER_LONG - first % BITS_PER_LONG));
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}
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memmove(dst, src, len * sizeof(*dst));
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while (cut--) {
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for (i = first / BITS_PER_LONG; i < len; i++) {
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if (i < len - 1)
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carry = dst[i + 1] & 1UL;
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else
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carry = 0;
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dst[i] = (dst[i] >> 1) | (carry << (BITS_PER_LONG - 1));
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}
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}
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dst[first / BITS_PER_LONG] &= ~0UL << (first % BITS_PER_LONG);
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dst[first / BITS_PER_LONG] |= keep;
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}
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EXPORT_SYMBOL(bitmap_cut);
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bool __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
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const unsigned long *bitmap2, unsigned int bits)
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{
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unsigned int k;
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unsigned int lim = bits/BITS_PER_LONG;
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unsigned long result = 0;
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for (k = 0; k < lim; k++)
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result |= (dst[k] = bitmap1[k] & bitmap2[k]);
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if (bits % BITS_PER_LONG)
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result |= (dst[k] = bitmap1[k] & bitmap2[k] &
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BITMAP_LAST_WORD_MASK(bits));
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return result != 0;
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}
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EXPORT_SYMBOL(__bitmap_and);
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void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
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const unsigned long *bitmap2, unsigned int bits)
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{
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unsigned int k;
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unsigned int nr = BITS_TO_LONGS(bits);
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for (k = 0; k < nr; k++)
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dst[k] = bitmap1[k] | bitmap2[k];
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}
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EXPORT_SYMBOL(__bitmap_or);
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void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
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const unsigned long *bitmap2, unsigned int bits)
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{
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unsigned int k;
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unsigned int nr = BITS_TO_LONGS(bits);
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for (k = 0; k < nr; k++)
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dst[k] = bitmap1[k] ^ bitmap2[k];
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}
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EXPORT_SYMBOL(__bitmap_xor);
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bool __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
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const unsigned long *bitmap2, unsigned int bits)
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{
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unsigned int k;
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unsigned int lim = bits/BITS_PER_LONG;
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unsigned long result = 0;
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for (k = 0; k < lim; k++)
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result |= (dst[k] = bitmap1[k] & ~bitmap2[k]);
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if (bits % BITS_PER_LONG)
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result |= (dst[k] = bitmap1[k] & ~bitmap2[k] &
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BITMAP_LAST_WORD_MASK(bits));
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return result != 0;
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}
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EXPORT_SYMBOL(__bitmap_andnot);
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void __bitmap_replace(unsigned long *dst,
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const unsigned long *old, const unsigned long *new,
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const unsigned long *mask, unsigned int nbits)
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{
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unsigned int k;
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unsigned int nr = BITS_TO_LONGS(nbits);
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for (k = 0; k < nr; k++)
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dst[k] = (old[k] & ~mask[k]) | (new[k] & mask[k]);
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}
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EXPORT_SYMBOL(__bitmap_replace);
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bool __bitmap_intersects(const unsigned long *bitmap1,
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const unsigned long *bitmap2, unsigned int bits)
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{
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unsigned int k, lim = bits/BITS_PER_LONG;
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for (k = 0; k < lim; ++k)
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if (bitmap1[k] & bitmap2[k])
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return true;
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if (bits % BITS_PER_LONG)
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if ((bitmap1[k] & bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
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return true;
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return false;
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}
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EXPORT_SYMBOL(__bitmap_intersects);
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bool __bitmap_subset(const unsigned long *bitmap1,
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const unsigned long *bitmap2, unsigned int bits)
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{
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unsigned int k, lim = bits/BITS_PER_LONG;
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for (k = 0; k < lim; ++k)
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if (bitmap1[k] & ~bitmap2[k])
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return false;
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if (bits % BITS_PER_LONG)
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if ((bitmap1[k] & ~bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
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return false;
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return true;
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}
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EXPORT_SYMBOL(__bitmap_subset);
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#define BITMAP_WEIGHT(FETCH, bits) \
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({ \
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unsigned int __bits = (bits), idx, w = 0; \
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\
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for (idx = 0; idx < __bits / BITS_PER_LONG; idx++) \
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w += hweight_long(FETCH); \
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\
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if (__bits % BITS_PER_LONG) \
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w += hweight_long((FETCH) & BITMAP_LAST_WORD_MASK(__bits)); \
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\
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w; \
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})
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unsigned int __bitmap_weight(const unsigned long *bitmap, unsigned int bits)
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{
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return BITMAP_WEIGHT(bitmap[idx], bits);
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}
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EXPORT_SYMBOL(__bitmap_weight);
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unsigned int __bitmap_weight_and(const unsigned long *bitmap1,
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const unsigned long *bitmap2, unsigned int bits)
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{
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return BITMAP_WEIGHT(bitmap1[idx] & bitmap2[idx], bits);
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}
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EXPORT_SYMBOL(__bitmap_weight_and);
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void __bitmap_set(unsigned long *map, unsigned int start, int len)
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{
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unsigned long *p = map + BIT_WORD(start);
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const unsigned int size = start + len;
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int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG);
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unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start);
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while (len - bits_to_set >= 0) {
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*p |= mask_to_set;
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len -= bits_to_set;
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bits_to_set = BITS_PER_LONG;
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mask_to_set = ~0UL;
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p++;
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}
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if (len) {
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mask_to_set &= BITMAP_LAST_WORD_MASK(size);
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*p |= mask_to_set;
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}
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}
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EXPORT_SYMBOL(__bitmap_set);
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void __bitmap_clear(unsigned long *map, unsigned int start, int len)
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{
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unsigned long *p = map + BIT_WORD(start);
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const unsigned int size = start + len;
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int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG);
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unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start);
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while (len - bits_to_clear >= 0) {
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*p &= ~mask_to_clear;
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len -= bits_to_clear;
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bits_to_clear = BITS_PER_LONG;
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mask_to_clear = ~0UL;
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p++;
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}
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if (len) {
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mask_to_clear &= BITMAP_LAST_WORD_MASK(size);
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*p &= ~mask_to_clear;
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}
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}
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EXPORT_SYMBOL(__bitmap_clear);
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/**
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* bitmap_find_next_zero_area_off - find a contiguous aligned zero area
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* @map: The address to base the search on
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* @size: The bitmap size in bits
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* @start: The bitnumber to start searching at
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* @nr: The number of zeroed bits we're looking for
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* @align_mask: Alignment mask for zero area
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* @align_offset: Alignment offset for zero area.
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*
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* The @align_mask should be one less than a power of 2; the effect is that
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* the bit offset of all zero areas this function finds plus @align_offset
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* is multiple of that power of 2.
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*/
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unsigned long bitmap_find_next_zero_area_off(unsigned long *map,
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unsigned long size,
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unsigned long start,
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unsigned int nr,
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unsigned long align_mask,
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unsigned long align_offset)
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{
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unsigned long index, end, i;
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again:
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index = find_next_zero_bit(map, size, start);
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/* Align allocation */
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index = __ALIGN_MASK(index + align_offset, align_mask) - align_offset;
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end = index + nr;
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if (end > size)
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return end;
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i = find_next_bit(map, end, index);
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if (i < end) {
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start = i + 1;
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goto again;
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}
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return index;
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}
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EXPORT_SYMBOL(bitmap_find_next_zero_area_off);
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/*
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* Bitmap printing & parsing functions: first version by Nadia Yvette Chambers,
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* second version by Paul Jackson, third by Joe Korty.
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*/
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/**
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* bitmap_parse_user - convert an ASCII hex string in a user buffer into a bitmap
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*
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* @ubuf: pointer to user buffer containing string.
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* @ulen: buffer size in bytes. If string is smaller than this
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* then it must be terminated with a \0.
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* @maskp: pointer to bitmap array that will contain result.
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* @nmaskbits: size of bitmap, in bits.
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*/
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int bitmap_parse_user(const char __user *ubuf,
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unsigned int ulen, unsigned long *maskp,
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int nmaskbits)
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{
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char *buf;
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int ret;
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buf = memdup_user_nul(ubuf, ulen);
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if (IS_ERR(buf))
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return PTR_ERR(buf);
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ret = bitmap_parse(buf, UINT_MAX, maskp, nmaskbits);
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kfree(buf);
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return ret;
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}
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EXPORT_SYMBOL(bitmap_parse_user);
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/**
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* bitmap_print_to_pagebuf - convert bitmap to list or hex format ASCII string
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* @list: indicates whether the bitmap must be list
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* @buf: page aligned buffer into which string is placed
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* @maskp: pointer to bitmap to convert
|
|
* @nmaskbits: size of bitmap, in bits
|
|
*
|
|
* Output format is a comma-separated list of decimal numbers and
|
|
* ranges if list is specified or hex digits grouped into comma-separated
|
|
* sets of 8 digits/set. Returns the number of characters written to buf.
|
|
*
|
|
* It is assumed that @buf is a pointer into a PAGE_SIZE, page-aligned
|
|
* area and that sufficient storage remains at @buf to accommodate the
|
|
* bitmap_print_to_pagebuf() output. Returns the number of characters
|
|
* actually printed to @buf, excluding terminating '\0'.
|
|
*/
|
|
int bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp,
|
|
int nmaskbits)
|
|
{
|
|
ptrdiff_t len = PAGE_SIZE - offset_in_page(buf);
|
|
|
|
return list ? scnprintf(buf, len, "%*pbl\n", nmaskbits, maskp) :
|
|
scnprintf(buf, len, "%*pb\n", nmaskbits, maskp);
|
|
}
|
|
EXPORT_SYMBOL(bitmap_print_to_pagebuf);
|
|
|
|
/**
|
|
* bitmap_print_to_buf - convert bitmap to list or hex format ASCII string
|
|
* @list: indicates whether the bitmap must be list
|
|
* true: print in decimal list format
|
|
* false: print in hexadecimal bitmask format
|
|
* @buf: buffer into which string is placed
|
|
* @maskp: pointer to bitmap to convert
|
|
* @nmaskbits: size of bitmap, in bits
|
|
* @off: in the string from which we are copying, We copy to @buf
|
|
* @count: the maximum number of bytes to print
|
|
*/
|
|
static int bitmap_print_to_buf(bool list, char *buf, const unsigned long *maskp,
|
|
int nmaskbits, loff_t off, size_t count)
|
|
{
|
|
const char *fmt = list ? "%*pbl\n" : "%*pb\n";
|
|
ssize_t size;
|
|
void *data;
|
|
|
|
data = kasprintf(GFP_KERNEL, fmt, nmaskbits, maskp);
|
|
if (!data)
|
|
return -ENOMEM;
|
|
|
|
size = memory_read_from_buffer(buf, count, &off, data, strlen(data) + 1);
|
|
kfree(data);
|
|
|
|
return size;
|
|
}
|
|
|
|
/**
|
|
* bitmap_print_bitmask_to_buf - convert bitmap to hex bitmask format ASCII string
|
|
* @buf: buffer into which string is placed
|
|
* @maskp: pointer to bitmap to convert
|
|
* @nmaskbits: size of bitmap, in bits
|
|
* @off: in the string from which we are copying, We copy to @buf
|
|
* @count: the maximum number of bytes to print
|
|
*
|
|
* The bitmap_print_to_pagebuf() is used indirectly via its cpumap wrapper
|
|
* cpumap_print_to_pagebuf() or directly by drivers to export hexadecimal
|
|
* bitmask and decimal list to userspace by sysfs ABI.
|
|
* Drivers might be using a normal attribute for this kind of ABIs. A
|
|
* normal attribute typically has show entry as below::
|
|
*
|
|
* static ssize_t example_attribute_show(struct device *dev,
|
|
* struct device_attribute *attr, char *buf)
|
|
* {
|
|
* ...
|
|
* return bitmap_print_to_pagebuf(true, buf, &mask, nr_trig_max);
|
|
* }
|
|
*
|
|
* show entry of attribute has no offset and count parameters and this
|
|
* means the file is limited to one page only.
|
|
* bitmap_print_to_pagebuf() API works terribly well for this kind of
|
|
* normal attribute with buf parameter and without offset, count::
|
|
*
|
|
* bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp,
|
|
* int nmaskbits)
|
|
* {
|
|
* }
|
|
*
|
|
* The problem is once we have a large bitmap, we have a chance to get a
|
|
* bitmask or list more than one page. Especially for list, it could be
|
|
* as complex as 0,3,5,7,9,... We have no simple way to know it exact size.
|
|
* It turns out bin_attribute is a way to break this limit. bin_attribute
|
|
* has show entry as below::
|
|
*
|
|
* static ssize_t
|
|
* example_bin_attribute_show(struct file *filp, struct kobject *kobj,
|
|
* struct bin_attribute *attr, char *buf,
|
|
* loff_t offset, size_t count)
|
|
* {
|
|
* ...
|
|
* }
|
|
*
|
|
* With the new offset and count parameters, this makes sysfs ABI be able
|
|
* to support file size more than one page. For example, offset could be
|
|
* >= 4096.
|
|
* bitmap_print_bitmask_to_buf(), bitmap_print_list_to_buf() wit their
|
|
* cpumap wrapper cpumap_print_bitmask_to_buf(), cpumap_print_list_to_buf()
|
|
* make those drivers be able to support large bitmask and list after they
|
|
* move to use bin_attribute. In result, we have to pass the corresponding
|
|
* parameters such as off, count from bin_attribute show entry to this API.
|
|
*
|
|
* The role of cpumap_print_bitmask_to_buf() and cpumap_print_list_to_buf()
|
|
* is similar with cpumap_print_to_pagebuf(), the difference is that
|
|
* bitmap_print_to_pagebuf() mainly serves sysfs attribute with the assumption
|
|
* the destination buffer is exactly one page and won't be more than one page.
|
|
* cpumap_print_bitmask_to_buf() and cpumap_print_list_to_buf(), on the other
|
|
* hand, mainly serves bin_attribute which doesn't work with exact one page,
|
|
* and it can break the size limit of converted decimal list and hexadecimal
|
|
* bitmask.
|
|
*
|
|
* WARNING!
|
|
*
|
|
* This function is not a replacement for sprintf() or bitmap_print_to_pagebuf().
|
|
* It is intended to workaround sysfs limitations discussed above and should be
|
|
* used carefully in general case for the following reasons:
|
|
*
|
|
* - Time complexity is O(nbits^2/count), comparing to O(nbits) for snprintf().
|
|
* - Memory complexity is O(nbits), comparing to O(1) for snprintf().
|
|
* - @off and @count are NOT offset and number of bits to print.
|
|
* - If printing part of bitmap as list, the resulting string is not a correct
|
|
* list representation of bitmap. Particularly, some bits within or out of
|
|
* related interval may be erroneously set or unset. The format of the string
|
|
* may be broken, so bitmap_parselist-like parser may fail parsing it.
|
|
* - If printing the whole bitmap as list by parts, user must ensure the order
|
|
* of calls of the function such that the offset is incremented linearly.
|
|
* - If printing the whole bitmap as list by parts, user must keep bitmap
|
|
* unchanged between the very first and very last call. Otherwise concatenated
|
|
* result may be incorrect, and format may be broken.
|
|
*
|
|
* Returns the number of characters actually printed to @buf
|
|
*/
|
|
int bitmap_print_bitmask_to_buf(char *buf, const unsigned long *maskp,
|
|
int nmaskbits, loff_t off, size_t count)
|
|
{
|
|
return bitmap_print_to_buf(false, buf, maskp, nmaskbits, off, count);
|
|
}
|
|
EXPORT_SYMBOL(bitmap_print_bitmask_to_buf);
|
|
|
|
/**
|
|
* bitmap_print_list_to_buf - convert bitmap to decimal list format ASCII string
|
|
* @buf: buffer into which string is placed
|
|
* @maskp: pointer to bitmap to convert
|
|
* @nmaskbits: size of bitmap, in bits
|
|
* @off: in the string from which we are copying, We copy to @buf
|
|
* @count: the maximum number of bytes to print
|
|
*
|
|
* Everything is same with the above bitmap_print_bitmask_to_buf() except
|
|
* the print format.
|
|
*/
|
|
int bitmap_print_list_to_buf(char *buf, const unsigned long *maskp,
|
|
int nmaskbits, loff_t off, size_t count)
|
|
{
|
|
return bitmap_print_to_buf(true, buf, maskp, nmaskbits, off, count);
|
|
}
|
|
EXPORT_SYMBOL(bitmap_print_list_to_buf);
|
|
|
|
/*
|
|
* Region 9-38:4/10 describes the following bitmap structure:
|
|
* 0 9 12 18 38 N
|
|
* .........****......****......****..................
|
|
* ^ ^ ^ ^ ^
|
|
* start off group_len end nbits
|
|
*/
|
|
struct region {
|
|
unsigned int start;
|
|
unsigned int off;
|
|
unsigned int group_len;
|
|
unsigned int end;
|
|
unsigned int nbits;
|
|
};
|
|
|
|
static void bitmap_set_region(const struct region *r, unsigned long *bitmap)
|
|
{
|
|
unsigned int start;
|
|
|
|
for (start = r->start; start <= r->end; start += r->group_len)
|
|
bitmap_set(bitmap, start, min(r->end - start + 1, r->off));
|
|
}
|
|
|
|
static int bitmap_check_region(const struct region *r)
|
|
{
|
|
if (r->start > r->end || r->group_len == 0 || r->off > r->group_len)
|
|
return -EINVAL;
|
|
|
|
if (r->end >= r->nbits)
|
|
return -ERANGE;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const char *bitmap_getnum(const char *str, unsigned int *num,
|
|
unsigned int lastbit)
|
|
{
|
|
unsigned long long n;
|
|
unsigned int len;
|
|
|
|
if (str[0] == 'N') {
|
|
*num = lastbit;
|
|
return str + 1;
|
|
}
|
|
|
|
len = _parse_integer(str, 10, &n);
|
|
if (!len)
|
|
return ERR_PTR(-EINVAL);
|
|
if (len & KSTRTOX_OVERFLOW || n != (unsigned int)n)
|
|
return ERR_PTR(-EOVERFLOW);
|
|
|
|
*num = n;
|
|
return str + len;
|
|
}
|
|
|
|
static inline bool end_of_str(char c)
|
|
{
|
|
return c == '\0' || c == '\n';
|
|
}
|
|
|
|
static inline bool __end_of_region(char c)
|
|
{
|
|
return isspace(c) || c == ',';
|
|
}
|
|
|
|
static inline bool end_of_region(char c)
|
|
{
|
|
return __end_of_region(c) || end_of_str(c);
|
|
}
|
|
|
|
/*
|
|
* The format allows commas and whitespaces at the beginning
|
|
* of the region.
|
|
*/
|
|
static const char *bitmap_find_region(const char *str)
|
|
{
|
|
while (__end_of_region(*str))
|
|
str++;
|
|
|
|
return end_of_str(*str) ? NULL : str;
|
|
}
|
|
|
|
static const char *bitmap_find_region_reverse(const char *start, const char *end)
|
|
{
|
|
while (start <= end && __end_of_region(*end))
|
|
end--;
|
|
|
|
return end;
|
|
}
|
|
|
|
static const char *bitmap_parse_region(const char *str, struct region *r)
|
|
{
|
|
unsigned int lastbit = r->nbits - 1;
|
|
|
|
if (!strncasecmp(str, "all", 3)) {
|
|
r->start = 0;
|
|
r->end = lastbit;
|
|
str += 3;
|
|
|
|
goto check_pattern;
|
|
}
|
|
|
|
str = bitmap_getnum(str, &r->start, lastbit);
|
|
if (IS_ERR(str))
|
|
return str;
|
|
|
|
if (end_of_region(*str))
|
|
goto no_end;
|
|
|
|
if (*str != '-')
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
str = bitmap_getnum(str + 1, &r->end, lastbit);
|
|
if (IS_ERR(str))
|
|
return str;
|
|
|
|
check_pattern:
|
|
if (end_of_region(*str))
|
|
goto no_pattern;
|
|
|
|
if (*str != ':')
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
str = bitmap_getnum(str + 1, &r->off, lastbit);
|
|
if (IS_ERR(str))
|
|
return str;
|
|
|
|
if (*str != '/')
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
return bitmap_getnum(str + 1, &r->group_len, lastbit);
|
|
|
|
no_end:
|
|
r->end = r->start;
|
|
no_pattern:
|
|
r->off = r->end + 1;
|
|
r->group_len = r->end + 1;
|
|
|
|
return end_of_str(*str) ? NULL : str;
|
|
}
|
|
|
|
/**
|
|
* bitmap_parselist - convert list format ASCII string to bitmap
|
|
* @buf: read user string from this buffer; must be terminated
|
|
* with a \0 or \n.
|
|
* @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
|
|
* ranges. Consecutively set bits are shown as two hyphen-separated
|
|
* decimal numbers, the smallest and largest bit numbers set in
|
|
* the range.
|
|
* Optionally each range can be postfixed to denote that only parts of it
|
|
* should be set. The range will divided to groups of specific size.
|
|
* From each group will be used only defined amount of bits.
|
|
* Syntax: range:used_size/group_size
|
|
* Example: 0-1023:2/256 ==> 0,1,256,257,512,513,768,769
|
|
* The value 'N' can be used as a dynamically substituted token for the
|
|
* maximum allowed value; i.e (nmaskbits - 1). Keep in mind that it is
|
|
* dynamic, so if system changes cause the bitmap width to change, such
|
|
* as more cores in a CPU list, then any ranges using N will also change.
|
|
*
|
|
* Returns: 0 on success, -errno on invalid input strings. Error values:
|
|
*
|
|
* - ``-EINVAL``: wrong region format
|
|
* - ``-EINVAL``: invalid character in string
|
|
* - ``-ERANGE``: bit number specified too large for mask
|
|
* - ``-EOVERFLOW``: integer overflow in the input parameters
|
|
*/
|
|
int bitmap_parselist(const char *buf, unsigned long *maskp, int nmaskbits)
|
|
{
|
|
struct region r;
|
|
long ret;
|
|
|
|
r.nbits = nmaskbits;
|
|
bitmap_zero(maskp, r.nbits);
|
|
|
|
while (buf) {
|
|
buf = bitmap_find_region(buf);
|
|
if (buf == NULL)
|
|
return 0;
|
|
|
|
buf = bitmap_parse_region(buf, &r);
|
|
if (IS_ERR(buf))
|
|
return PTR_ERR(buf);
|
|
|
|
ret = bitmap_check_region(&r);
|
|
if (ret)
|
|
return ret;
|
|
|
|
bitmap_set_region(&r, maskp);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(bitmap_parselist);
|
|
|
|
|
|
/**
|
|
* bitmap_parselist_user() - convert user buffer's list format ASCII
|
|
* string to bitmap
|
|
*
|
|
* @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_parselist(), providing it with user buffer.
|
|
*/
|
|
int bitmap_parselist_user(const char __user *ubuf,
|
|
unsigned int ulen, unsigned long *maskp,
|
|
int nmaskbits)
|
|
{
|
|
char *buf;
|
|
int ret;
|
|
|
|
buf = memdup_user_nul(ubuf, ulen);
|
|
if (IS_ERR(buf))
|
|
return PTR_ERR(buf);
|
|
|
|
ret = bitmap_parselist(buf, maskp, nmaskbits);
|
|
|
|
kfree(buf);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(bitmap_parselist_user);
|
|
|
|
static const char *bitmap_get_x32_reverse(const char *start,
|
|
const char *end, u32 *num)
|
|
{
|
|
u32 ret = 0;
|
|
int c, i;
|
|
|
|
for (i = 0; i < 32; i += 4) {
|
|
c = hex_to_bin(*end--);
|
|
if (c < 0)
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
ret |= c << i;
|
|
|
|
if (start > end || __end_of_region(*end))
|
|
goto out;
|
|
}
|
|
|
|
if (hex_to_bin(*end--) >= 0)
|
|
return ERR_PTR(-EOVERFLOW);
|
|
out:
|
|
*num = ret;
|
|
return end;
|
|
}
|
|
|
|
/**
|
|
* bitmap_parse - convert an ASCII hex string into a bitmap.
|
|
* @start: pointer to buffer containing string.
|
|
* @buflen: buffer size in bytes. If string is smaller than this
|
|
* then it must be terminated with a \0 or \n. In that case,
|
|
* UINT_MAX may be provided instead of string length.
|
|
* @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
|
|
* characters. Grouping such as "1,,5", ",44", "," or "" is allowed.
|
|
* Leading, embedded and trailing whitespace accepted.
|
|
*/
|
|
int bitmap_parse(const char *start, unsigned int buflen,
|
|
unsigned long *maskp, int nmaskbits)
|
|
{
|
|
const char *end = strnchrnul(start, buflen, '\n') - 1;
|
|
int chunks = BITS_TO_U32(nmaskbits);
|
|
u32 *bitmap = (u32 *)maskp;
|
|
int unset_bit;
|
|
int chunk;
|
|
|
|
for (chunk = 0; ; chunk++) {
|
|
end = bitmap_find_region_reverse(start, end);
|
|
if (start > end)
|
|
break;
|
|
|
|
if (!chunks--)
|
|
return -EOVERFLOW;
|
|
|
|
#if defined(CONFIG_64BIT) && defined(__BIG_ENDIAN)
|
|
end = bitmap_get_x32_reverse(start, end, &bitmap[chunk ^ 1]);
|
|
#else
|
|
end = bitmap_get_x32_reverse(start, end, &bitmap[chunk]);
|
|
#endif
|
|
if (IS_ERR(end))
|
|
return PTR_ERR(end);
|
|
}
|
|
|
|
unset_bit = (BITS_TO_U32(nmaskbits) - chunks) * 32;
|
|
if (unset_bit < nmaskbits) {
|
|
bitmap_clear(maskp, unset_bit, nmaskbits - unset_bit);
|
|
return 0;
|
|
}
|
|
|
|
if (find_next_bit(maskp, unset_bit, nmaskbits) != unset_bit)
|
|
return -EOVERFLOW;
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(bitmap_parse);
|
|
|
|
/**
|
|
* 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 < @nbits)
|
|
* @nbits: number of valid bit positions in @buf
|
|
*
|
|
* Map the bit at position @pos in @buf (of length @nbits) 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 -1. 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, unsigned int pos, unsigned int nbits)
|
|
{
|
|
if (pos >= nbits || !test_bit(pos, buf))
|
|
return -1;
|
|
|
|
return bitmap_weight(buf, 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
|
|
* @nbits: 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,
|
|
unsigned int nbits)
|
|
{
|
|
unsigned int oldbit, w;
|
|
|
|
if (dst == src) /* following doesn't handle inplace remaps */
|
|
return;
|
|
bitmap_zero(dst, nbits);
|
|
|
|
w = bitmap_weight(new, nbits);
|
|
for_each_set_bit(oldbit, src, nbits) {
|
|
int n = bitmap_pos_to_ord(old, oldbit, nbits);
|
|
|
|
if (n < 0 || w == 0)
|
|
set_bit(oldbit, dst); /* identity map */
|
|
else
|
|
set_bit(find_nth_bit(new, nbits, n % w), 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 find_nth_bit(new, bits, n % w);
|
|
}
|
|
EXPORT_SYMBOL(bitmap_bitremap);
|
|
|
|
#ifdef CONFIG_NUMA
|
|
/**
|
|
* 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 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 possibility 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 [#f1]_
|
|
* 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 [#f1]_
|
|
* =============== ============== =================
|
|
*
|
|
* .. [#f1]
|
|
*
|
|
* 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, unsigned int bits)
|
|
{
|
|
unsigned 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 = find_nth_bit(orig, bits, m);
|
|
* 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++;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* bitmap_fold - fold larger bitmap into smaller, modulo specified size
|
|
* @dst: resulting smaller bitmap
|
|
* @orig: original larger bitmap
|
|
* @sz: specified size
|
|
* @nbits: 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,
|
|
unsigned int sz, unsigned int nbits)
|
|
{
|
|
unsigned int oldbit;
|
|
|
|
if (dst == orig) /* following doesn't handle inplace mappings */
|
|
return;
|
|
bitmap_zero(dst, nbits);
|
|
|
|
for_each_set_bit(oldbit, orig, nbits)
|
|
set_bit(oldbit % sz, dst);
|
|
}
|
|
#endif /* CONFIG_NUMA */
|
|
|
|
/*
|
|
* 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, unsigned 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, unsigned int bits, int order)
|
|
{
|
|
unsigned int pos, end; /* scans bitmap by regions of size order */
|
|
|
|
for (pos = 0 ; (end = pos + (1U << 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, unsigned 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, unsigned int pos, int order)
|
|
{
|
|
if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE))
|
|
return -EBUSY;
|
|
return __reg_op(bitmap, pos, order, REG_OP_ALLOC);
|
|
}
|
|
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.
|
|
*/
|
|
#ifdef __BIG_ENDIAN
|
|
void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits)
|
|
{
|
|
unsigned int i;
|
|
|
|
for (i = 0; i < nbits/BITS_PER_LONG; i++) {
|
|
if (BITS_PER_LONG == 64)
|
|
dst[i] = cpu_to_le64(src[i]);
|
|
else
|
|
dst[i] = cpu_to_le32(src[i]);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(bitmap_copy_le);
|
|
#endif
|
|
|
|
unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags)
|
|
{
|
|
return kmalloc_array(BITS_TO_LONGS(nbits), sizeof(unsigned long),
|
|
flags);
|
|
}
|
|
EXPORT_SYMBOL(bitmap_alloc);
|
|
|
|
unsigned long *bitmap_zalloc(unsigned int nbits, gfp_t flags)
|
|
{
|
|
return bitmap_alloc(nbits, flags | __GFP_ZERO);
|
|
}
|
|
EXPORT_SYMBOL(bitmap_zalloc);
|
|
|
|
unsigned long *bitmap_alloc_node(unsigned int nbits, gfp_t flags, int node)
|
|
{
|
|
return kmalloc_array_node(BITS_TO_LONGS(nbits), sizeof(unsigned long),
|
|
flags, node);
|
|
}
|
|
EXPORT_SYMBOL(bitmap_alloc_node);
|
|
|
|
unsigned long *bitmap_zalloc_node(unsigned int nbits, gfp_t flags, int node)
|
|
{
|
|
return bitmap_alloc_node(nbits, flags | __GFP_ZERO, node);
|
|
}
|
|
EXPORT_SYMBOL(bitmap_zalloc_node);
|
|
|
|
void bitmap_free(const unsigned long *bitmap)
|
|
{
|
|
kfree(bitmap);
|
|
}
|
|
EXPORT_SYMBOL(bitmap_free);
|
|
|
|
static void devm_bitmap_free(void *data)
|
|
{
|
|
unsigned long *bitmap = data;
|
|
|
|
bitmap_free(bitmap);
|
|
}
|
|
|
|
unsigned long *devm_bitmap_alloc(struct device *dev,
|
|
unsigned int nbits, gfp_t flags)
|
|
{
|
|
unsigned long *bitmap;
|
|
int ret;
|
|
|
|
bitmap = bitmap_alloc(nbits, flags);
|
|
if (!bitmap)
|
|
return NULL;
|
|
|
|
ret = devm_add_action_or_reset(dev, devm_bitmap_free, bitmap);
|
|
if (ret)
|
|
return NULL;
|
|
|
|
return bitmap;
|
|
}
|
|
EXPORT_SYMBOL_GPL(devm_bitmap_alloc);
|
|
|
|
unsigned long *devm_bitmap_zalloc(struct device *dev,
|
|
unsigned int nbits, gfp_t flags)
|
|
{
|
|
return devm_bitmap_alloc(dev, nbits, flags | __GFP_ZERO);
|
|
}
|
|
EXPORT_SYMBOL_GPL(devm_bitmap_zalloc);
|
|
|
|
#if BITS_PER_LONG == 64
|
|
/**
|
|
* bitmap_from_arr32 - copy the contents of u32 array of bits to bitmap
|
|
* @bitmap: array of unsigned longs, the destination bitmap
|
|
* @buf: array of u32 (in host byte order), the source bitmap
|
|
* @nbits: number of bits in @bitmap
|
|
*/
|
|
void bitmap_from_arr32(unsigned long *bitmap, const u32 *buf, unsigned int nbits)
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{
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|
unsigned int i, halfwords;
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|
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halfwords = DIV_ROUND_UP(nbits, 32);
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for (i = 0; i < halfwords; i++) {
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bitmap[i/2] = (unsigned long) buf[i];
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if (++i < halfwords)
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bitmap[i/2] |= ((unsigned long) buf[i]) << 32;
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|
}
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|
|
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/* Clear tail bits in last word beyond nbits. */
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if (nbits % BITS_PER_LONG)
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|
bitmap[(halfwords - 1) / 2] &= BITMAP_LAST_WORD_MASK(nbits);
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|
}
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EXPORT_SYMBOL(bitmap_from_arr32);
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|
|
|
/**
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|
* bitmap_to_arr32 - copy the contents of bitmap to a u32 array of bits
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|
* @buf: array of u32 (in host byte order), the dest bitmap
|
|
* @bitmap: array of unsigned longs, the source bitmap
|
|
* @nbits: number of bits in @bitmap
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|
*/
|
|
void bitmap_to_arr32(u32 *buf, const unsigned long *bitmap, unsigned int nbits)
|
|
{
|
|
unsigned int i, halfwords;
|
|
|
|
halfwords = DIV_ROUND_UP(nbits, 32);
|
|
for (i = 0; i < halfwords; i++) {
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|
buf[i] = (u32) (bitmap[i/2] & UINT_MAX);
|
|
if (++i < halfwords)
|
|
buf[i] = (u32) (bitmap[i/2] >> 32);
|
|
}
|
|
|
|
/* Clear tail bits in last element of array beyond nbits. */
|
|
if (nbits % BITS_PER_LONG)
|
|
buf[halfwords - 1] &= (u32) (UINT_MAX >> ((-nbits) & 31));
|
|
}
|
|
EXPORT_SYMBOL(bitmap_to_arr32);
|
|
#endif
|
|
|
|
#if BITS_PER_LONG == 32
|
|
/**
|
|
* bitmap_from_arr64 - copy the contents of u64 array of bits to bitmap
|
|
* @bitmap: array of unsigned longs, the destination bitmap
|
|
* @buf: array of u64 (in host byte order), the source bitmap
|
|
* @nbits: number of bits in @bitmap
|
|
*/
|
|
void bitmap_from_arr64(unsigned long *bitmap, const u64 *buf, unsigned int nbits)
|
|
{
|
|
int n;
|
|
|
|
for (n = nbits; n > 0; n -= 64) {
|
|
u64 val = *buf++;
|
|
|
|
*bitmap++ = val;
|
|
if (n > 32)
|
|
*bitmap++ = val >> 32;
|
|
}
|
|
|
|
/*
|
|
* Clear tail bits in the last word beyond nbits.
|
|
*
|
|
* Negative index is OK because here we point to the word next
|
|
* to the last word of the bitmap, except for nbits == 0, which
|
|
* is tested implicitly.
|
|
*/
|
|
if (nbits % BITS_PER_LONG)
|
|
bitmap[-1] &= BITMAP_LAST_WORD_MASK(nbits);
|
|
}
|
|
EXPORT_SYMBOL(bitmap_from_arr64);
|
|
|
|
/**
|
|
* bitmap_to_arr64 - copy the contents of bitmap to a u64 array of bits
|
|
* @buf: array of u64 (in host byte order), the dest bitmap
|
|
* @bitmap: array of unsigned longs, the source bitmap
|
|
* @nbits: number of bits in @bitmap
|
|
*/
|
|
void bitmap_to_arr64(u64 *buf, const unsigned long *bitmap, unsigned int nbits)
|
|
{
|
|
const unsigned long *end = bitmap + BITS_TO_LONGS(nbits);
|
|
|
|
while (bitmap < end) {
|
|
*buf = *bitmap++;
|
|
if (bitmap < end)
|
|
*buf |= (u64)(*bitmap++) << 32;
|
|
buf++;
|
|
}
|
|
|
|
/* Clear tail bits in the last element of array beyond nbits. */
|
|
if (nbits % 64)
|
|
buf[-1] &= GENMASK_ULL((nbits - 1) % 64, 0);
|
|
}
|
|
EXPORT_SYMBOL(bitmap_to_arr64);
|
|
#endif
|