qemu: Update bitmap.c/.h

Keeps it up to date with Qemu.

qemu/include/qemu/bitmap.h

@@ -12,11 +12,7 @@
 #ifndef BITMAP_H
 #define BITMAP_H
 
-#include "glib_compat.h"
-#include <string.h>
-#include <stdlib.h>
 
-#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)                                    \
+#define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1)))
-    (                                                                   \
+#define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1)))
-        ((nbits) % BITS_PER_LONG) ?                                     \
-        (1UL<<((nbits) % BITS_PER_LONG))-1 : ~0UL                       \
-        )
 
 #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)

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);
 }
-