--- /dev/null
+/*
+ * Copyright (c) 2004 Topspin Communications. All rights reserved.
+ *
+ * This software is available to you under a choice of one of two
+ * licenses. You may choose to be licensed under the terms of the GNU
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the
+ * OpenIB.org BSD license below:
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ * - Redistributions of source code must retain the above
+ * copyright notice, this list of conditions and the following
+ * disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following
+ * disclaimer in the documentation and/or other materials
+ * provided with the distribution.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ * $Id: mthca_allocator.c 1349 2004-12-16 21:09:43Z roland $
+ */
+
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/bitmap.h>
+
+#include "mthca_dev.h"
+
+/* Trivial bitmap-based allocator */
+u32 mthca_alloc(struct mthca_alloc *alloc)
+{
+ u32 obj;
+
+ spin_lock(&alloc->lock);
+ obj = find_next_zero_bit(alloc->table, alloc->max, alloc->last);
+ if (obj >= alloc->max) {
+ alloc->top = (alloc->top + alloc->max) & alloc->mask;
+ obj = find_first_zero_bit(alloc->table, alloc->max);
+ }
+
+ if (obj < alloc->max) {
+ set_bit(obj, alloc->table);
+ obj |= alloc->top;
+ } else
+ obj = -1;
+
+ spin_unlock(&alloc->lock);
+
+ return obj;
+}
+
+void mthca_free(struct mthca_alloc *alloc, u32 obj)
+{
+ obj &= alloc->max - 1;
+ spin_lock(&alloc->lock);
+ clear_bit(obj, alloc->table);
+ alloc->last = min(alloc->last, obj);
+ alloc->top = (alloc->top + alloc->max) & alloc->mask;
+ spin_unlock(&alloc->lock);
+}
+
+int mthca_alloc_init(struct mthca_alloc *alloc, u32 num, u32 mask,
+ u32 reserved)
+{
+ int i;
+
+ /* num must be a power of 2 */
+ if (num != 1 << (ffs(num) - 1))
+ return -EINVAL;
+
+ alloc->last = 0;
+ alloc->top = 0;
+ alloc->max = num;
+ alloc->mask = mask;
+ spin_lock_init(&alloc->lock);
+ alloc->table = kmalloc(BITS_TO_LONGS(num) * sizeof (long),
+ GFP_KERNEL);
+ if (!alloc->table)
+ return -ENOMEM;
+
+ bitmap_zero(alloc->table, num);
+ for (i = 0; i < reserved; ++i)
+ set_bit(i, alloc->table);
+
+ return 0;
+}
+
+void mthca_alloc_cleanup(struct mthca_alloc *alloc)
+{
+ kfree(alloc->table);
+}
+
+/*
+ * Array of pointers with lazy allocation of leaf pages. Callers of
+ * _get, _set and _clear methods must use a lock or otherwise
+ * serialize access to the array.
+ */
+
+void *mthca_array_get(struct mthca_array *array, int index)
+{
+ int p = (index * sizeof (void *)) >> PAGE_SHIFT;
+
+ if (array->page_list[p].page) {
+ int i = index & (PAGE_SIZE / sizeof (void *) - 1);
+ return array->page_list[p].page[i];
+ } else
+ return NULL;
+}
+
+int mthca_array_set(struct mthca_array *array, int index, void *value)
+{
+ int p = (index * sizeof (void *)) >> PAGE_SHIFT;
+
+ /* Allocate with GFP_ATOMIC because we'll be called with locks held. */
+ if (!array->page_list[p].page)
+ array->page_list[p].page = (void **) get_zeroed_page(GFP_ATOMIC);
+
+ if (!array->page_list[p].page)
+ return -ENOMEM;
+
+ array->page_list[p].page[index & (PAGE_SIZE / sizeof (void *) - 1)] =
+ value;
+ ++array->page_list[p].used;
+
+ return 0;
+}
+
+void mthca_array_clear(struct mthca_array *array, int index)
+{
+ int p = (index * sizeof (void *)) >> PAGE_SHIFT;
+
+ if (--array->page_list[p].used == 0) {
+ free_page((unsigned long) array->page_list[p].page);
+ array->page_list[p].page = NULL;
+ }
+
+ if (array->page_list[p].used < 0)
+ pr_debug("Array %p index %d page %d with ref count %d < 0\n",
+ array, index, p, array->page_list[p].used);
+}
+
+int mthca_array_init(struct mthca_array *array, int nent)
+{
+ int npage = (nent * sizeof (void *) + PAGE_SIZE - 1) / PAGE_SIZE;
+ int i;
+
+ array->page_list = kmalloc(npage * sizeof *array->page_list, GFP_KERNEL);
+ if (!array->page_list)
+ return -ENOMEM;
+
+ for (i = 0; i < npage; ++i) {
+ array->page_list[i].page = NULL;
+ array->page_list[i].used = 0;
+ }
+
+ return 0;
+}
+
+void mthca_array_cleanup(struct mthca_array *array, int nent)
+{
+ int i;
+
+ for (i = 0; i < (nent * sizeof (void *) + PAGE_SIZE - 1) / PAGE_SIZE; ++i)
+ free_page((unsigned long) array->page_list[i].page);
+
+ kfree(array->page_list);
+}
git://git.onelab.eu / linux-2.6.git / blobdiff