u8 ev3_uart_set_msg_hdr(u8 type, const unsigned long size, u8 cmd)
{
u8 size_code = (find_last_bit(&size, sizeof(unsigned long)) & 0x7) << 3;
return (type & EV3_UART_MSG_TYPE_MASK) | size_code
| (cmd & EV3_UART_MSG_CMD_MASK);
}
/* Checks if a mask spans multiple nodes
*
* @mask : cpumask to check for multiple node span
*/
int xlp_span_multiple_nodes(const struct cpumask *mask)
{
int l, f;
f = cpumask_first(mask);
l = find_last_bit(cpumask_bits(mask), NR_CPUS);
if ((f/NLM_MAX_CPU_PER_NODE) != (l/NLM_MAX_CPU_PER_NODE)) {
printk(KERN_DEBUG "Mask spans from cpu %#x to %#x. Spans across nodes are not supported\n", f, l);
return -EINVAL;
}
return 0;
}
static int __init test_find_last_bit(const void *bitmap, unsigned long len)
{
unsigned long l, cnt = 0;
ktime_t time;
time = ktime_get();
do {
cnt++;
l = find_last_bit(bitmap, len);
if (l >= len)
break;
len = l;
} while (len);
time = ktime_get() - time;
pr_err("find_last_bit: %18llu ns, %6ld iterations\n", time, cnt);
return 0;
}
/*
* nfs4_free_slot - free a slot and efficiently update slot table.
*
* freeing a slot is trivially done by clearing its respective bit
* in the bitmap.
* If the freed slotid equals highest_used_slotid we want to update it
* so that the server would be able to size down the slot table if needed,
* otherwise we know that the highest_used_slotid is still in use.
* When updating highest_used_slotid there may be "holes" in the bitmap
* so we need to scan down from highest_used_slotid to 0 looking for the now
* highest slotid in use.
* If none found, highest_used_slotid is set to NFS4_NO_SLOT.
*
* Must be called while holding tbl->slot_tbl_lock
*/
void nfs4_free_slot(struct nfs4_slot_table *tbl, struct nfs4_slot *slot)
{
u32 slotid = slot->slot_nr;
/* clear used bit in bitmap */
__clear_bit(slotid, tbl->used_slots);
/* update highest_used_slotid when it is freed */
if (slotid == tbl->highest_used_slotid) {
u32 new_max = find_last_bit(tbl->used_slots, slotid);
if (new_max < slotid)
tbl->highest_used_slotid = new_max;
else {
tbl->highest_used_slotid = NFS4_NO_SLOT;
nfs4_slot_tbl_drain_complete(tbl);
}
}
dprintk("%s: slotid %u highest_used_slotid %u\n", __func__,
slotid, tbl->highest_used_slotid);
}
/* An arch may set nr_cpu_ids earlier if needed, so this would be redundant */
static void __init setup_nr_cpu_ids(void)
{
nr_cpu_ids = find_last_bit(cpumask_bits(cpu_possible_mask),NR_CPUS) + 1;
}
static void
host_memory_backend_memory_complete(UserCreatable *uc, Error **errp)
{
HostMemoryBackend *backend = MEMORY_BACKEND(uc);
HostMemoryBackendClass *bc = MEMORY_BACKEND_GET_CLASS(uc);
Error *local_err = NULL;
void *ptr;
uint64_t sz;
if (bc->alloc) {
bc->alloc(backend, &local_err);
if (local_err) {
error_propagate(errp, local_err);
return;
}
ptr = memory_region_get_ram_ptr(&backend->mr);
sz = memory_region_size(&backend->mr);
if (backend->merge) {
qemu_madvise(ptr, sz, QEMU_MADV_MERGEABLE);
}
if (!backend->dump) {
qemu_madvise(ptr, sz, QEMU_MADV_DONTDUMP);
}
#ifdef CONFIG_NUMA
unsigned long lastbit = find_last_bit(backend->host_nodes, MAX_NODES);
/* lastbit == MAX_NODES means maxnode = 0 */
unsigned long maxnode = (lastbit + 1) % (MAX_NODES + 1);
/* ensure policy won't be ignored in case memory is preallocated
* before mbind(). note: MPOL_MF_STRICT is ignored on hugepages so
* this doesn't catch hugepage case. */
unsigned flags = MPOL_MF_STRICT | MPOL_MF_MOVE;
/* check for invalid host-nodes and policies and give more verbose
* error messages than mbind(). */
if (maxnode && backend->policy == MPOL_DEFAULT) {
error_setg(errp, "host-nodes must be empty for policy default,"
" or you should explicitly specify a policy other"
" than default");
return;
} else if (maxnode == 0 && backend->policy != MPOL_DEFAULT) {
error_setg(errp, "host-nodes must be set for policy %s",
HostMemPolicy_lookup[backend->policy]);
return;
}
/* We can have up to MAX_NODES nodes, but we need to pass maxnode+1
* as argument to mbind() due to an old Linux bug (feature?) which
* cuts off the last specified node. This means backend->host_nodes
* must have MAX_NODES+1 bits available.
*/
assert(sizeof(backend->host_nodes) >=
BITS_TO_LONGS(MAX_NODES + 1) * sizeof(unsigned long));
assert(maxnode <= MAX_NODES);
if (mbind(ptr, sz, backend->policy,
maxnode ? backend->host_nodes : NULL, maxnode + 1, flags)) {
error_setg_errno(errp, errno,
"cannot bind memory to host NUMA nodes");
return;
}
#endif
/* Preallocate memory after the NUMA policy has been instantiated.
* This is necessary to guarantee memory is allocated with
* specified NUMA policy in place.
*/
if (backend->prealloc) {
os_mem_prealloc(memory_region_get_fd(&backend->mr), ptr, sz);
}
}
}