diff --git a/qemu/include/qemu/bitmap.h b/qemu/include/qemu/bitmap.h index 378ed3f9..5c313346 100644 --- a/qemu/include/qemu/bitmap.h +++ b/qemu/include/qemu/bitmap.h @@ -12,11 +12,7 @@ #ifndef BITMAP_H #define BITMAP_H -#include "glib_compat.h" -#include -#include -#include "qemu/osdep.h" #include "qemu/bitops.h" /* @@ -26,10 +22,23 @@ * Note that nbits should be always a compile time evaluable constant. * Otherwise many inlines will generate horrible code. * + * bitmap_zero(dst, nbits) *dst = 0UL + * bitmap_fill(dst, nbits) *dst = ~0UL + * bitmap_copy(dst, src, nbits) *dst = *src + * bitmap_and(dst, src1, src2, nbits) *dst = *src1 & *src2 + * bitmap_or(dst, src1, src2, nbits) *dst = *src1 | *src2 + * bitmap_xor(dst, src1, src2, nbits) *dst = *src1 ^ *src2 + * bitmap_andnot(dst, src1, src2, nbits) *dst = *src1 & ~(*src2) + * bitmap_complement(dst, src, nbits) *dst = ~(*src) + * bitmap_equal(src1, src2, nbits) Are *src1 and *src2 equal? + * bitmap_intersects(src1, src2, nbits) Do *src1 and *src2 overlap? + * bitmap_empty(src, nbits) Are all bits zero in *src? + * bitmap_full(src, nbits) Are all bits set in *src? * bitmap_set(dst, pos, nbits) Set specified bit area * bitmap_set_atomic(dst, pos, nbits) Set specified bit area with atomic ops * bitmap_clear(dst, pos, nbits) Clear specified bit area * bitmap_test_and_clear_atomic(dst, pos, nbits) Test and clear area + * bitmap_find_next_zero_area(buf, len, pos, n, mask) Find bit free area * bitmap_to_le(dst, src, nbits) Convert bitmap to little endian * bitmap_from_le(dst, src, nbits) Convert bitmap from little endian */ @@ -39,13 +48,19 @@ * * set_bit(bit, addr) *addr |= bit * clear_bit(bit, addr) *addr &= ~bit + * change_bit(bit, addr) *addr ^= bit + * test_bit(bit, addr) Is bit set in *addr? + * test_and_set_bit(bit, addr) Set bit and return old value + * test_and_clear_bit(bit, addr) Clear bit and return old value + * test_and_change_bit(bit, addr) Change bit and return old value + * find_first_zero_bit(addr, nbits) Position first zero bit in *addr + * find_first_bit(addr, nbits) Position first set bit in *addr + * find_next_zero_bit(addr, nbits, bit) Position next zero bit in *addr >= bit + * find_next_bit(addr, nbits, bit) Position next set bit in *addr >= bit */ -#define BITMAP_LAST_WORD_MASK(nbits) \ - ( \ - ((nbits) % BITS_PER_LONG) ? \ - (1UL<<((nbits) % BITS_PER_LONG))-1 : ~0UL \ - ) +#define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1))) +#define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1))) #define DECLARE_BITMAP(name,bits) \ unsigned long name[BITS_TO_LONGS(bits)] @@ -53,6 +68,22 @@ #define small_nbits(nbits) \ ((nbits) <= BITS_PER_LONG) +int slow_bitmap_empty(const unsigned long *bitmap, long bits); +int slow_bitmap_full(const unsigned long *bitmap, long bits); +int slow_bitmap_equal(const unsigned long *bitmap1, + const unsigned long *bitmap2, long bits); +void slow_bitmap_complement(unsigned long *dst, const unsigned long *src, + long bits); +int slow_bitmap_and(unsigned long *dst, const unsigned long *bitmap1, + const unsigned long *bitmap2, long bits); +void slow_bitmap_or(unsigned long *dst, const unsigned long *bitmap1, + const unsigned long *bitmap2, long bits); +void slow_bitmap_xor(unsigned long *dst, const unsigned long *bitmap1, + const unsigned long *bitmap2, long bits); +int slow_bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, + const unsigned long *bitmap2, long bits); +int slow_bitmap_intersects(const unsigned long *bitmap1, + const unsigned long *bitmap2, long bits); long slow_bitmap_count_one(const unsigned long *bitmap, long nbits); static inline unsigned long *bitmap_try_new(long nbits) @@ -70,8 +101,130 @@ static inline unsigned long *bitmap_new(long nbits) return ptr; } +static inline void bitmap_zero(unsigned long *dst, long nbits) +{ + if (small_nbits(nbits)) { + *dst = 0UL; + } else { + long len = BITS_TO_LONGS(nbits) * sizeof(unsigned long); + memset(dst, 0, len); + } +} + +static inline void bitmap_fill(unsigned long *dst, long nbits) +{ + size_t nlongs = BITS_TO_LONGS(nbits); + if (!small_nbits(nbits)) { + long len = (nlongs - 1) * sizeof(unsigned long); + memset(dst, 0xff, len); + } + dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits); +} + +static inline void bitmap_copy(unsigned long *dst, const unsigned long *src, + long nbits) +{ + if (small_nbits(nbits)) { + *dst = *src; + } else { + long len = BITS_TO_LONGS(nbits) * sizeof(unsigned long); + memcpy(dst, src, len); + } +} + +static inline int bitmap_and(unsigned long *dst, const unsigned long *src1, + const unsigned long *src2, long nbits) +{ + if (small_nbits(nbits)) { + return (*dst = *src1 & *src2) != 0; + } + return slow_bitmap_and(dst, src1, src2, nbits); +} + +static inline void bitmap_or(unsigned long *dst, const unsigned long *src1, + const unsigned long *src2, long nbits) +{ + if (small_nbits(nbits)) { + *dst = *src1 | *src2; + } else { + slow_bitmap_or(dst, src1, src2, nbits); + } +} + +static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1, + const unsigned long *src2, long nbits) +{ + if (small_nbits(nbits)) { + *dst = *src1 ^ *src2; + } else { + slow_bitmap_xor(dst, src1, src2, nbits); + } +} + +static inline int bitmap_andnot(unsigned long *dst, const unsigned long *src1, + const unsigned long *src2, long nbits) +{ + if (small_nbits(nbits)) { + return (*dst = *src1 & ~(*src2)) != 0; + } + return slow_bitmap_andnot(dst, src1, src2, nbits); +} + +static inline void bitmap_complement(unsigned long *dst, + const unsigned long *src, + long nbits) +{ + if (small_nbits(nbits)) { + *dst = ~(*src) & BITMAP_LAST_WORD_MASK(nbits); + } else { + slow_bitmap_complement(dst, src, nbits); + } +} + +static inline int bitmap_equal(const unsigned long *src1, + const unsigned long *src2, long nbits) +{ + if (small_nbits(nbits)) { + return ! ((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits)); + } else { + return slow_bitmap_equal(src1, src2, nbits); + } +} + +static inline int bitmap_empty(const unsigned long *src, long nbits) +{ + if (small_nbits(nbits)) { + return ! (*src & BITMAP_LAST_WORD_MASK(nbits)); + } else { + return slow_bitmap_empty(src, nbits); + } +} + +static inline int bitmap_full(const unsigned long *src, long nbits) +{ + if (small_nbits(nbits)) { + return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits)); + } else { + return slow_bitmap_full(src, nbits); + } +} + +static inline int bitmap_intersects(const unsigned long *src1, + const unsigned long *src2, long nbits) +{ + if (small_nbits(nbits)) { + return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0; + } else { + return slow_bitmap_intersects(src1, src2, nbits); + } +} + static inline long bitmap_count_one(const unsigned long *bitmap, long nbits) { + if (unlikely(!nbits)) { + return 0; + } + if (small_nbits(nbits)) { return ctpopl(*bitmap & BITMAP_LAST_WORD_MASK(nbits)); } else { @@ -79,12 +232,30 @@ static inline long bitmap_count_one(const unsigned long *bitmap, long nbits) } } +static inline long bitmap_count_one_with_offset(const unsigned long *bitmap, + long offset, long nbits) +{ + long aligned_offset = QEMU_ALIGN_DOWN(offset, BITS_PER_LONG); + long redundant_bits = offset - aligned_offset; + long bits_to_count = nbits + redundant_bits; + const unsigned long *bitmap_start = bitmap + + aligned_offset / BITS_PER_LONG; + + return bitmap_count_one(bitmap_start, bits_to_count) - + bitmap_count_one(bitmap_start, redundant_bits); +} + void bitmap_set(unsigned long *map, long i, long len); void bitmap_set_atomic(unsigned long *map, long i, long len); void bitmap_clear(unsigned long *map, long start, long nr); bool bitmap_test_and_clear_atomic(unsigned long *map, long start, long nr); void bitmap_copy_and_clear_atomic(unsigned long *dst, unsigned long *src, long nr); +unsigned long bitmap_find_next_zero_area(unsigned long *map, + unsigned long size, + unsigned long start, + unsigned long nr, + unsigned long align_mask); static inline unsigned long *bitmap_zero_extend(unsigned long *old, long old_nbits, long new_nbits) diff --git a/qemu/util/bitmap.c b/qemu/util/bitmap.c index 765b3f14..cb618c65 100644 --- a/qemu/util/bitmap.c +++ b/qemu/util/bitmap.c @@ -14,7 +14,148 @@ #include "qemu/bitmap.h" #include "qemu/atomic.h" -#define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) % BITS_PER_LONG)) +/* + * bitmaps provide an array of bits, implemented using 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. + */ + +int slow_bitmap_empty(const unsigned long *bitmap, long bits) +{ + long 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; +} + +int slow_bitmap_full(const unsigned long *bitmap, long bits) +{ + long 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; +} + +int slow_bitmap_equal(const unsigned long *bitmap1, + const unsigned long *bitmap2, long bits) +{ + long 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; +} + +void slow_bitmap_complement(unsigned long *dst, const unsigned long *src, + long bits) +{ + long 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); + } +} + +int slow_bitmap_and(unsigned long *dst, const unsigned long *bitmap1, + const unsigned long *bitmap2, long bits) +{ + long k; + long 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; +} + +void slow_bitmap_or(unsigned long *dst, const unsigned long *bitmap1, + const unsigned long *bitmap2, long bits) +{ + long k; + long nr = BITS_TO_LONGS(bits); + + for (k = 0; k < nr; k++) { + dst[k] = bitmap1[k] | bitmap2[k]; + } +} + +void slow_bitmap_xor(unsigned long *dst, const unsigned long *bitmap1, + const unsigned long *bitmap2, long bits) +{ + long k; + long nr = BITS_TO_LONGS(bits); + + for (k = 0; k < nr; k++) { + dst[k] = bitmap1[k] ^ bitmap2[k]; + } +} + +int slow_bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, + const unsigned long *bitmap2, long bits) +{ + long k; + long 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; +} void bitmap_set(unsigned long *map, long start, long nr) { @@ -23,6 +164,8 @@ void bitmap_set(unsigned long *map, long start, long nr) int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG); unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start); + assert(start >= 0 && nr >= 0); + while (nr - bits_to_set >= 0) { *p |= mask_to_set; nr -= bits_to_set; @@ -43,6 +186,8 @@ void bitmap_set_atomic(unsigned long *map, long start, long nr) int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG); unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start); + assert(start >= 0 && nr >= 0); + /* First word */ if (nr - bits_to_set > 0) { atomic_or(p, mask_to_set); @@ -80,6 +225,8 @@ void bitmap_clear(unsigned long *map, long start, long nr) int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG); unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start); + assert(start >= 0 && nr >= 0); + while (nr - bits_to_clear >= 0) { *p &= ~mask_to_clear; nr -= bits_to_clear; @@ -102,6 +249,8 @@ bool bitmap_test_and_clear_atomic(unsigned long *map, long start, long nr) unsigned long dirty = 0; unsigned long old_bits; + assert(start >= 0 && nr >= 0); + /* First word */ if (nr - bits_to_clear > 0) { old_bits = atomic_fetch_and(p, ~mask_to_clear); @@ -149,6 +298,64 @@ void bitmap_copy_and_clear_atomic(unsigned long *dst, unsigned long *src, } } +#define ALIGN_MASK(x,mask) (((x)+(mask))&~(mask)) + +/** + * 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 long 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; +} + +int slow_bitmap_intersects(const unsigned long *bitmap1, + const unsigned long *bitmap2, long bits) +{ + long 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; +} + long slow_bitmap_count_one(const unsigned long *bitmap, long nbits) { long k, lim = nbits / BITS_PER_LONG, result = 0; @@ -195,4 +402,3 @@ void bitmap_to_le(unsigned long *dst, const unsigned long *src, { bitmap_to_from_le(dst, src, nbits); } -