}
/**
- * idr_pre_get - reserver resources for idr allocation
+ * idr_pre_get - reserve resources for idr allocation
* @idp: idr handle
* @gfp_mask: memory allocation flags
*
- * This function should be called prior to locking and calling the
- * idr_get_new* functions. It preallocates enough memory to satisfy
- * the worst possible allocation.
+ * This function should be called prior to calling the idr_get_new* functions.
+ * It preallocates enough memory to satisfy the worst possible allocation. The
+ * caller should pass in GFP_KERNEL if possible. This of course requires that
+ * no spinning locks be held.
*
- * If the system is REALLY out of memory this function returns 0,
- * otherwise 1.
+ * If the system is REALLY out of memory this function returns %0,
+ * otherwise %1.
*/
int idr_pre_get(struct idr *idp, gfp_t gfp_mask)
{
id = (id | ((1 << (IDR_BITS * l)) - 1)) + 1;
/* if already at the top layer, we need to grow */
- if (!(p = pa[l])) {
+ if (id >= 1 << (idp->layers * IDR_BITS)) {
*starting_id = id;
return IDR_NEED_TO_GROW;
}
+ p = pa[l];
+ BUG_ON(!p);
/* If we need to go up one layer, continue the
* loop; otherwise, restart from the top.
/**
* idr_get_new_above - allocate new idr entry above or equal to a start id
* @idp: idr handle
- * @ptr: pointer you want associated with the ide
- * @start_id: id to start search at
+ * @ptr: pointer you want associated with the id
+ * @starting_id: id to start search at
* @id: pointer to the allocated handle
*
* This is the allocate id function. It should be called with any
* required locks.
*
- * If memory is required, it will return -EAGAIN, you should unlock
- * and go back to the idr_pre_get() call. If the idr is full, it will
- * return -ENOSPC.
+ * If allocation from IDR's private freelist fails, idr_get_new_above() will
+ * return %-EAGAIN. The caller should retry the idr_pre_get() call to refill
+ * IDR's preallocation and then retry the idr_get_new_above() call.
*
- * @id returns a value in the range @starting_id ... 0x7fffffff
+ * If the idr is full idr_get_new_above() will return %-ENOSPC.
+ *
+ * @id returns a value in the range @starting_id ... %0x7fffffff
*/
int idr_get_new_above(struct idr *idp, void *ptr, int starting_id, int *id)
{
/**
* idr_get_new - allocate new idr entry
* @idp: idr handle
- * @ptr: pointer you want associated with the ide
+ * @ptr: pointer you want associated with the id
* @id: pointer to the allocated handle
*
- * This is the allocate id function. It should be called with any
- * required locks.
+ * If allocation from IDR's private freelist fails, idr_get_new_above() will
+ * return %-EAGAIN. The caller should retry the idr_pre_get() call to refill
+ * IDR's preallocation and then retry the idr_get_new_above() call.
*
- * If memory is required, it will return -EAGAIN, you should unlock
- * and go back to the idr_pre_get() call. If the idr is full, it will
- * return -ENOSPC.
+ * If the idr is full idr_get_new_above() will return %-ENOSPC.
*
- * @id returns a value in the range 0 ... 0x7fffffff
+ * @id returns a value in the range %0 ... %0x7fffffff
*/
int idr_get_new(struct idr *idp, void *ptr, int *id)
{
}
/**
- * idr_remove - remove the given id and free it's slot
+ * idr_remove - remove the given id and free its slot
* @idp: idr handle
* @id: unique key
*/
* function will remove all id mappings and leave all idp_layers
* unused.
*
- * A typical clean-up sequence for objects stored in an idr tree, will
+ * A typical clean-up sequence for objects stored in an idr tree will
* use idr_for_each() to free all objects, if necessay, then
* idr_remove_all() to remove all ids, and idr_destroy() to free
* up the cached idr_layers.
void idr_remove_all(struct idr *idp)
{
int n, id, max;
+ int bt_mask;
struct idr_layer *p;
struct idr_layer *pa[MAX_LEVEL];
struct idr_layer **paa = &pa[0];
p = p->ary[(id >> n) & IDR_MASK];
}
+ bt_mask = id;
id += 1 << n;
- while (n < fls(id)) {
+ /* Get the highest bit that the above add changed from 0->1. */
+ while (n < fls(id ^ bt_mask)) {
if (p)
free_layer(p);
n += IDR_BITS;
/**
* idr_destroy - release all cached layers within an idr tree
- * idp: idr handle
+ * @idp: idr handle
*/
void idr_destroy(struct idr *idp)
{
int n;
struct idr_layer *p;
- p = rcu_dereference(idp->top);
+ p = rcu_dereference_raw(idp->top);
if (!p)
return NULL;
n = (p->layer+1) * IDR_BITS;
while (n > 0 && p) {
n -= IDR_BITS;
BUG_ON(n != p->layer*IDR_BITS);
- p = rcu_dereference(p->ary[(id >> n) & IDR_MASK]);
+ p = rcu_dereference_raw(p->ary[(id >> n) & IDR_MASK]);
}
return((void *)p);
}
* not allowed.
*
* We check the return of @fn each time. If it returns anything other
- * than 0, we break out and return that value.
+ * than %0, we break out and return that value.
*
* The caller must serialize idr_for_each() vs idr_get_new() and idr_remove().
*/
struct idr_layer **paa = &pa[0];
n = idp->layers * IDR_BITS;
- p = rcu_dereference(idp->top);
+ p = rcu_dereference_raw(idp->top);
max = 1 << n;
id = 0;
while (n > 0 && p) {
n -= IDR_BITS;
*paa++ = p;
- p = rcu_dereference(p->ary[(id >> n) & IDR_MASK]);
+ p = rcu_dereference_raw(p->ary[(id >> n) & IDR_MASK]);
}
if (p) {
EXPORT_SYMBOL(idr_for_each);
/**
+ * idr_get_next - lookup next object of id to given id.
+ * @idp: idr handle
+ * @nextidp: pointer to lookup key
+ *
+ * Returns pointer to registered object with id, which is next number to
+ * given id. After being looked up, *@nextidp will be updated for the next
+ * iteration.
+ */
+
+void *idr_get_next(struct idr *idp, int *nextidp)
+{
+ struct idr_layer *p, *pa[MAX_LEVEL];
+ struct idr_layer **paa = &pa[0];
+ int id = *nextidp;
+ int n, max;
+
+ /* find first ent */
+ n = idp->layers * IDR_BITS;
+ max = 1 << n;
+ p = rcu_dereference_raw(idp->top);
+ if (!p)
+ return NULL;
+
+ while (id < max) {
+ while (n > 0 && p) {
+ n -= IDR_BITS;
+ *paa++ = p;
+ p = rcu_dereference_raw(p->ary[(id >> n) & IDR_MASK]);
+ }
+
+ if (p) {
+ *nextidp = id;
+ return p;
+ }
+
+ id += 1 << n;
+ while (n < fls(id)) {
+ n += IDR_BITS;
+ p = *--paa;
+ }
+ }
+ return NULL;
+}
+EXPORT_SYMBOL(idr_get_next);
+
+
+/**
* idr_replace - replace pointer for given id
* @idp: idr handle
* @ptr: pointer you want associated with the id
* @id: lookup key
*
* Replace the pointer registered with an id and return the old value.
- * A -ENOENT return indicates that @id was not found.
- * A -EINVAL return indicates that @id was not within valid constraints.
+ * A %-ENOENT return indicates that @id was not found.
+ * A %-EINVAL return indicates that @id was not within valid constraints.
*
* The caller must serialize with writers.
*/
EXPORT_SYMBOL(idr_init);
-/*
+/**
+ * DOC: IDA description
* IDA - IDR based ID allocator
*
- * this is id allocator without id -> pointer translation. Memory
+ * This is id allocator without id -> pointer translation. Memory
* usage is much lower than full blown idr because each id only
* occupies a bit. ida uses a custom leaf node which contains
* IDA_BITMAP_BITS slots.
* following function. It preallocates enough memory to satisfy the
* worst possible allocation.
*
- * If the system is REALLY out of memory this function returns 0,
- * otherwise 1.
+ * If the system is REALLY out of memory this function returns %0,
+ * otherwise %1.
*/
int ida_pre_get(struct ida *ida, gfp_t gfp_mask)
{
/**
* ida_get_new_above - allocate new ID above or equal to a start id
* @ida: ida handle
- * @staring_id: id to start search at
+ * @starting_id: id to start search at
* @p_id: pointer to the allocated handle
*
* Allocate new ID above or equal to @ida. It should be called with
* any required locks.
*
- * If memory is required, it will return -EAGAIN, you should unlock
+ * If memory is required, it will return %-EAGAIN, you should unlock
* and go back to the ida_pre_get() call. If the ida is full, it will
- * return -ENOSPC.
+ * return %-ENOSPC.
*
- * @p_id returns a value in the range @starting_id ... 0x7fffffff.
+ * @p_id returns a value in the range @starting_id ... %0x7fffffff.
*/
int ida_get_new_above(struct ida *ida, int starting_id, int *p_id)
{
*
* Allocate new ID. It should be called with any required locks.
*
- * If memory is required, it will return -EAGAIN, you should unlock
+ * If memory is required, it will return %-EAGAIN, you should unlock
* and go back to the idr_pre_get() call. If the idr is full, it will
- * return -ENOSPC.
+ * return %-ENOSPC.
*
- * @id returns a value in the range 0 ... 0x7fffffff.
+ * @id returns a value in the range %0 ... %0x7fffffff.
*/
int ida_get_new(struct ida *ida, int *p_id)
{
/**
* ida_destroy - release all cached layers within an ida tree
- * ida: ida handle
+ * @ida: ida handle
*/
void ida_destroy(struct ida *ida)
{
projects / linux-flexiantxendom0-natty.git / blobdiff