kernel-ark/drivers/infiniband/hw/mthca/mthca_allocator.c
Linus Torvalds 1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00

180 lines
4.7 KiB
C

/*
* 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);
}