2  * Atomic operations on 64-bit quantities.
9  * See the COPYING file in the top-level directory.
17 /* This provides atomic operations on 64-bit type, using a reader-writer
18  * spinlock on architectures that do not have 64-bit accesses.  Even on
26     uint32_t low, high;
40     return qatomic_read__nocheck(&s->value);  in stat64_get()
45     qatomic_set__nocheck(&s->value, value);  in stat64_set()
50     qatomic_add(&s->value, value);  in stat64_add()
55     uint64_t orig = qatomic_read__nocheck(&s->value);  in stat64_min()
57         orig = qatomic_cmpxchg__nocheck(&s->value, orig, value);  in stat64_min()
63     uint64_t orig = qatomic_read__nocheck(&s->value);  in stat64_max()
65         orig = qatomic_cmpxchg__nocheck(&s->value, orig, value);  in stat64_max()
73 bool stat64_add32_carry(Stat64 *s, uint32_t low, uint32_t high);
78     *s = (Stat64) { .low = value, .high = value >> 32, .lock = 0 };  in stat64_init()
83     uint32_t low, high;  in stat64_add()  local
85     low = (uint32_t) value;  in stat64_add()
86     if (!low) {  in stat64_add()
88             qatomic_add(&s->high, high);  in stat64_add()
94         uint32_t orig = s->low;  in stat64_add()
95         uint32_t result = orig + low;  in stat64_add()
98         if (result < low || high) {  in stat64_add()
100             if (stat64_add32_carry(s, low, high)) {  in stat64_add()
106         /* No carry, try with a 32-bit cmpxchg.  The result is independent of  in stat64_add()
110         old = qatomic_cmpxchg(&s->low, orig, result);  in stat64_add()
119     uint32_t low, high;  in stat64_min()  local
123     low = (uint32_t) value;  in stat64_min()
125         orig_high = qatomic_read(&s->high);  in stat64_min()
131             /* High 32 bits are equal.  Read low after high, otherwise we  in stat64_min()
132              * can get a false positive (e.g. 0x1235,0x0000 changes to  in stat64_min()
137             orig_low = qatomic_read(&s->low);  in stat64_min()
138             if (orig_low <= low) {  in stat64_min()
147             orig_high = qatomic_read(&s->high);  in stat64_min()
159     uint32_t low, high;  in stat64_max()  local
163     low = (uint32_t) value;  in stat64_max()
165         orig_high = qatomic_read(&s->high);  in stat64_max()
171             /* High 32 bits are equal.  Read low after high, otherwise we  in stat64_max()
172              * can get a false positive (e.g. 0x1234,0x8000 changes to  in stat64_max()
177             orig_low = qatomic_read(&s->low);  in stat64_max()
178             if (orig_low >= low) {  in stat64_max()
187             orig_high = qatomic_read(&s->high);  in stat64_max()