* Modified by George Anzinger to reuse immediately and to use
* find bit instructions. Also removed _irq on spinlocks.
*
- * Small id to pointer translation service.
+ * Small id to pointer translation service.
*
- * It uses a radix tree like structure as a sparse array indexed
+ * It uses a radix tree like structure as a sparse array indexed
* by the id to obtain the pointer. The bitmap makes allocating
- * a new id quick.
+ * a new id quick.
*
* You call it to allocate an id (an int) an associate with that id a
* pointer or what ever, we treat it as a (void *). You can pass this
* id to a user for him to pass back at a later time. You then pass
* that id to this code and it returns your pointer.
- * You can release ids at any time. When all ids are released, most of
+ * You can release ids at any time. When all ids are released, most of
* the memory is returned (we keep IDR_FREE_MAX) in a local pool so we
- * don't need to go to the memory "store" during an id allocate, just
+ * don't need to go to the memory "store" during an id allocate, just
* so you don't need to be too concerned about locking and conflicts
* with the slab allocator.
*/
#include <linux/init.h>
#include <linux/module.h>
#endif
+#include <linux/err.h>
#include <linux/string.h>
#include <linux/idr.h>
static struct idr_layer *alloc_layer(struct idr *idp)
{
struct idr_layer *p;
+ unsigned long flags;
- spin_lock(&idp->lock);
+ spin_lock_irqsave(&idp->lock, flags);
if ((p = idp->id_free)) {
idp->id_free = p->ary[0];
idp->id_free_cnt--;
p->ary[0] = NULL;
}
- spin_unlock(&idp->lock);
+ spin_unlock_irqrestore(&idp->lock, flags);
return(p);
}
+/* only called when idp->lock is held */
+static void __free_layer(struct idr *idp, struct idr_layer *p)
+{
+ p->ary[0] = idp->id_free;
+ idp->id_free = p;
+ idp->id_free_cnt++;
+}
+
static void free_layer(struct idr *idp, struct idr_layer *p)
{
+ unsigned long flags;
+
/*
* Depends on the return element being zeroed.
*/
- spin_lock(&idp->lock);
- p->ary[0] = idp->id_free;
- idp->id_free = p;
- idp->id_free_cnt++;
- spin_unlock(&idp->lock);
+ spin_lock_irqsave(&idp->lock, flags);
+ __free_layer(idp, p);
+ spin_unlock_irqrestore(&idp->lock, flags);
}
/**
* If the system is REALLY out of memory this function returns 0,
* otherwise 1.
*/
-int idr_pre_get(struct idr *idp, unsigned gfp_mask)
+int idr_pre_get(struct idr *idp, gfp_t gfp_mask)
{
while (idp->id_free_cnt < IDR_FREE_MAX) {
struct idr_layer *new;
new = kmem_cache_alloc(idr_layer_cache, gfp_mask);
- if(new == NULL)
+ if (new == NULL)
return (0);
free_layer(idp, new);
}
if (m == IDR_SIZE) {
/* no space available go back to previous layer. */
l++;
- id = (id | ((1 << (IDR_BITS*l))-1)) + 1;
+ id = (id | ((1 << (IDR_BITS * l)) - 1)) + 1;
if (!(p = pa[l])) {
*starting_id = id;
return -2;
{
struct idr_layer *p, *new;
int layers, v, id;
-
+ unsigned long flags;
+
id = starting_id;
build_up:
p = idp->top;
* The allocation failed. If we built part of
* the structure tear it down.
*/
+ spin_lock_irqsave(&idp->lock, flags);
for (new = p; p && p != idp->top; new = p) {
p = p->ary[0];
new->ary[0] = NULL;
new->bitmap = new->count = 0;
- free_layer(idp, new);
+ __free_layer(idp, new);
}
+ spin_unlock_irqrestore(&idp->lock, flags);
return -1;
}
new->ary[0] = p;
int idr_get_new_above(struct idr *idp, void *ptr, int starting_id, int *id)
{
int rv;
+
rv = idr_get_new_above_int(idp, ptr, starting_id);
/*
* This is a cheap hack until the IDR code can be fixed to
int idr_get_new(struct idr *idp, void *ptr, int *id)
{
int rv;
+
rv = idr_get_new_above_int(idp, ptr, 0);
/*
* This is a cheap hack until the IDR code can be fixed to
free_layer(idp, **paa);
**paa-- = NULL;
}
- if ( ! *paa )
+ if (!*paa)
idp->layers = 0;
- } else {
+ } else
idr_remove_warning(id);
- }
}
/**
id &= MAX_ID_MASK;
sub_remove(idp, (idp->layers - 1) * IDR_BITS, id);
- if ( idp->top && idp->top->count == 1 &&
- (idp->layers > 1) &&
- idp->top->ary[0]){ // We can drop a layer
+ if (idp->top && idp->top->count == 1 && (idp->layers > 1) &&
+ idp->top->ary[0]) { // We can drop a layer
p = idp->top->ary[0];
idp->top->bitmap = idp->top->count = 0;
--idp->layers;
}
while (idp->id_free_cnt >= IDR_FREE_MAX) {
-
p = alloc_layer(idp);
kmem_cache_free(idr_layer_cache, p);
return;
}
EXPORT_SYMBOL(idr_find);
-static void idr_cache_ctor(void * idr_layer,
- kmem_cache_t *idr_layer_cache, unsigned long flags)
+/**
+ * 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.
+ *
+ * The caller must serialize vs idr_find(), idr_get_new(), and idr_remove().
+ */
+void *idr_replace(struct idr *idp, void *ptr, int id)
+{
+ int n;
+ struct idr_layer *p, *old_p;
+
+ n = idp->layers * IDR_BITS;
+ p = idp->top;
+
+ id &= MAX_ID_MASK;
+
+ if (id >= (1 << n))
+ return ERR_PTR(-EINVAL);
+
+ n -= IDR_BITS;
+ while ((n > 0) && p) {
+ p = p->ary[(id >> n) & IDR_MASK];
+ n -= IDR_BITS;
+ }
+
+ n = id & IDR_MASK;
+ if (unlikely(p == NULL || !test_bit(n, &p->bitmap)))
+ return ERR_PTR(-ENOENT);
+
+ old_p = p->ary[n];
+ p->ary[n] = ptr;
+
+ return old_p;
+}
+EXPORT_SYMBOL(idr_replace);
+
+static void idr_cache_ctor(void * idr_layer, kmem_cache_t *idr_layer_cache,
+ unsigned long flags)
{
memset(idr_layer, 0, sizeof(struct idr_layer));
}
static int init_id_cache(void)
{
if (!idr_layer_cache)
- idr_layer_cache = kmem_cache_create("idr_layer_cache",
+ idr_layer_cache = kmem_cache_create("idr_layer_cache",
sizeof(struct idr_layer), 0, 0, idr_cache_ctor, NULL);
return 0;
}
git.openpandora.org / pandora-kernel.git / blobdiff