/************************************************************************** * * This kernel module is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation; either version 2 of the * License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. * **************************************************************************/ /* * This code provides access to unexported mm kernel features. It is necessary * to use the new DRM memory manager code with kernels that don't support it * directly. * * Authors: Thomas Hellstrom * Linux kernel mm subsystem authors. * (Most code taken from there). */ #include "drmP.h" #ifdef DRM_IDR_COMPAT_FN /* 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_irqsave(&idp->lock, flags); __free_layer(idp, p); spin_unlock_irqrestore(&idp->lock, flags); } /** * idr_for_each - iterate through all stored pointers * @idp: idr handle * @fn: function to be called for each pointer * @data: data passed back to callback function * * Iterate over the pointers registered with the given idr. The * callback function will be called for each pointer currently * registered, passing the id, the pointer and the data pointer passed * to this function. It is not safe to modify the idr tree while in * the callback, so functions such as idr_get_new and idr_remove are * not allowed. * * We check the return of @fn each time. If it returns anything other * than 0, we break out and return that value. * * The caller must serialize idr_find() vs idr_get_new() and idr_remove(). */ int idr_for_each(struct idr *idp, int (*fn)(int id, void *p, void *data), void *data) { int n, id, max, error = 0; struct idr_layer *p; struct idr_layer *pa[MAX_LEVEL]; struct idr_layer **paa = &pa[0]; n = idp->layers * IDR_BITS; p = idp->top; max = 1 << n; id = 0; while (id < max) { while (n > 0 && p) { n -= IDR_BITS; *paa++ = p; p = p->ary[(id >> n) & IDR_MASK]; } if (p) { error = fn(id, (void *)p, data); if (error) break; } id += 1 << n; while (n < fls(id)) { n += IDR_BITS; p = *--paa; } } return error; } EXPORT_SYMBOL(idr_for_each); /** * idr_remove_all - remove all ids from the given idr tree * @idp: idr handle * * idr_destroy() only frees up unused, cached idp_layers, but this * 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 * 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, error = 0; struct idr_layer *p; struct idr_layer *pa[MAX_LEVEL]; struct idr_layer **paa = &pa[0]; n = idp->layers * IDR_BITS; p = idp->top; max = 1 << n; id = 0; while (id < max && !error) { while (n > IDR_BITS && p) { n -= IDR_BITS; *paa++ = p; p = p->ary[(id >> n) & IDR_MASK]; } id += 1 << n; while (n < fls(id)) { if (p) { memset(p, 0, sizeof *p); free_layer(idp, p); } n += IDR_BITS; p = *--paa; } } idp->top = NULL; idp->layers = 0; } EXPORT_SYMBOL(idr_remove_all); #endif /* DRM_IDR_COMPAT_FN */