X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2Fidr.c;h=16d2143fea4847e5c367e56d87db654599109713;hb=be3ca7fecb1a9903c6253f49aec0af2a0f3a04e4;hp=d4df21debc4ddb77948206f6091fb27c569e9909;hpb=2d300fece23a4ae638b43ce9a7ac1e566ac6c843;p=linux-2.6-omap-h63xx.git diff --git a/lib/idr.c b/lib/idr.c index d4df21debc4..16d2143fea4 100644 --- a/lib/idr.c +++ b/lib/idr.c @@ -6,20 +6,20 @@ * 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. */ @@ -29,6 +29,7 @@ #include #include #endif +#include #include #include @@ -37,27 +38,36 @@ static kmem_cache_t *idr_layer_cache; 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); } /** @@ -72,12 +82,12 @@ static void free_layer(struct idr *idp, struct idr_layer *p) * 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); } @@ -107,7 +117,7 @@ static int sub_alloc(struct idr *idp, void *ptr, int *starting_id) 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; @@ -161,7 +171,8 @@ static int idr_get_new_above_int(struct idr *idp, void *ptr, int starting_id) { struct idr_layer *p, *new; int layers, v, id; - + unsigned long flags; + id = starting_id; build_up: p = idp->top; @@ -184,12 +195,14 @@ build_up: * 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; @@ -225,6 +238,7 @@ build_up: 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 @@ -259,6 +273,7 @@ EXPORT_SYMBOL(idr_get_new_above); 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 @@ -306,11 +321,10 @@ static void sub_remove(struct idr *idp, int shift, int id) free_layer(idp, **paa); **paa-- = NULL; } - if ( ! *paa ) + if (!*paa) idp->layers = 0; - } else { + } else idr_remove_warning(id); - } } /** @@ -326,9 +340,8 @@ void idr_remove(struct idr *idp, int 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; @@ -337,7 +350,6 @@ void idr_remove(struct idr *idp, int id) --idp->layers; } while (idp->id_free_cnt >= IDR_FREE_MAX) { - p = alloc_layer(idp); kmem_cache_free(idr_layer_cache, p); return; @@ -391,8 +403,50 @@ void *idr_find(struct idr *idp, int id) } 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)); } @@ -400,7 +454,7 @@ static void idr_cache_ctor(void * 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; }