void *
idr_replace(struct idr *idr, void *ptr, int id)
{
struct idr_layer *il;
void *res;
int layer;
int idx;
res = ERR_PTR(-EINVAL);
id &= MAX_ID_MASK;
mtx_lock(&idr->lock);
il = idr->top;
layer = idr->layers - 1;
if (il == NULL || id > idr_max(idr))
goto out;
while (layer && il) {
il = il->ary[idr_pos(id, layer)];
layer--;
}
idx = id & IDR_MASK;
/*
* Replace still returns an error if the item was not allocated.
*/
if (il != NULL && (il->bitmap & (1 << idx)) != 0) {
res = il->ary[idx];
il->ary[idx] = ptr;
}
out:
mtx_unlock(&idr->lock);
return (res);
}
static void
idr_remove_locked(struct idr *idr, int id)
{
struct idr_layer *il;
int layer;
int idx;
id &= MAX_ID_MASK;
il = idr->top;
layer = idr->layers - 1;
if (il == NULL || id > idr_max(idr))
return;
/*
* Walk down the tree to this item setting bitmaps along the way
* as we know at least one item will be free along this path.
*/
while (layer && il) {
idx = idr_pos(id, layer);
il->bitmap |= 1 << idx;
il = il->ary[idx];
layer--;
}
idx = id & IDR_MASK;
/*
* At this point we've set free space bitmaps up the whole tree.
* We could make this non-fatal and unwind but linux dumps a stack
* and a warning so I don't think it's necessary.
*/
if (il == NULL || (il->bitmap & (1 << idx)) != 0)
panic("idr_remove: Item %d not allocated (%p, %p)\n",
id, idr, il);
il->ary[idx] = NULL;
il->bitmap |= 1 << idx;
}
void *
idr_get_next(struct idr *idr, int *nextidp)
{
void *res = NULL;
int id = *nextidp;
mtx_lock(&idr->lock);
for (; id <= idr_max(idr); id++) {
res = idr_find_locked(idr, id);
if (res == NULL)
continue;
*nextidp = id;
break;
}
mtx_unlock(&idr->lock);
return (res);
}
static inline struct idr_layer *
idr_find_layer_locked(struct idr *idr, int id)
{
struct idr_layer *il;
int layer;
id &= MAX_ID_MASK;
il = idr->top;
layer = idr->layers - 1;
if (il == NULL || id > idr_max(idr))
return (NULL);
while (layer && il) {
il = il->ary[idr_pos(id, layer)];
layer--;
}
return (il);
}
static inline void *
idr_find_locked(struct idr *idr, int id)
{
struct idr_layer *il;
void *res;
int layer;
mtx_assert(&idr->lock, MA_OWNED);
id &= MAX_ID_MASK;
res = NULL;
il = idr->top;
layer = idr->layers - 1;
if (il == NULL || id > idr_max(idr))
return (NULL);
while (layer && il) {
il = il->ary[idr_pos(id, layer)];
layer--;
}
if (il != NULL)
res = il->ary[id & IDR_MASK];
return (res);
}
void *
idr_find(struct idr *idr, int id)
{
struct idr_layer *il;
void *res;
int layer;
res = NULL;
id &= MAX_ID_MASK;
mtx_lock(&idr->lock);
il = idr->top;
layer = idr->layers - 1;
if (il == NULL || id > idr_max(idr))
goto out;
while (layer && il) {
il = il->ary[idr_pos(id, layer)];
layer--;
}
if (il != NULL)
res = il->ary[id & IDR_MASK];
out:
mtx_unlock(&idr->lock);
return (res);
}
