linux/drivers/net/mlx4/alloc.c
Roland Dreier a2cb4a98f2 IB/mlx4: Fix last allocated object tracking in bitmap allocator
Set last allocated object to the object after the one just allocated
before ORing in the extra top bits.  Also handle the case where this
wraps around.

Signed-off-by: Roland Dreier <rolandd@cisco.com>
2007-05-29 16:07:09 -07:00

180 lines
4.7 KiB
C

/*
* Copyright (c) 2006, 2007 Cisco Systems, Inc. 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.
*/
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/bitmap.h>
#include <linux/dma-mapping.h>
#include "mlx4.h"
u32 mlx4_bitmap_alloc(struct mlx4_bitmap *bitmap)
{
u32 obj;
spin_lock(&bitmap->lock);
obj = find_next_zero_bit(bitmap->table, bitmap->max, bitmap->last);
if (obj >= bitmap->max) {
bitmap->top = (bitmap->top + bitmap->max) & bitmap->mask;
obj = find_first_zero_bit(bitmap->table, bitmap->max);
}
if (obj < bitmap->max) {
set_bit(obj, bitmap->table);
bitmap->last = (obj + 1) & (bitmap->max - 1);
obj |= bitmap->top;
} else
obj = -1;
spin_unlock(&bitmap->lock);
return obj;
}
void mlx4_bitmap_free(struct mlx4_bitmap *bitmap, u32 obj)
{
obj &= bitmap->max - 1;
spin_lock(&bitmap->lock);
clear_bit(obj, bitmap->table);
bitmap->last = min(bitmap->last, obj);
bitmap->top = (bitmap->top + bitmap->max) & bitmap->mask;
spin_unlock(&bitmap->lock);
}
int mlx4_bitmap_init(struct mlx4_bitmap *bitmap, u32 num, u32 mask, u32 reserved)
{
int i;
/* num must be a power of 2 */
if (num != roundup_pow_of_two(num))
return -EINVAL;
bitmap->last = 0;
bitmap->top = 0;
bitmap->max = num;
bitmap->mask = mask;
spin_lock_init(&bitmap->lock);
bitmap->table = kzalloc(BITS_TO_LONGS(num) * sizeof (long), GFP_KERNEL);
if (!bitmap->table)
return -ENOMEM;
for (i = 0; i < reserved; ++i)
set_bit(i, bitmap->table);
return 0;
}
void mlx4_bitmap_cleanup(struct mlx4_bitmap *bitmap)
{
kfree(bitmap->table);
}
/*
* Handling for queue buffers -- we allocate a bunch of memory and
* register it in a memory region at HCA virtual address 0. If the
* requested size is > max_direct, we split the allocation into
* multiple pages, so we don't require too much contiguous memory.
*/
int mlx4_buf_alloc(struct mlx4_dev *dev, int size, int max_direct,
struct mlx4_buf *buf)
{
dma_addr_t t;
if (size <= max_direct) {
buf->nbufs = 1;
buf->npages = 1;
buf->page_shift = get_order(size) + PAGE_SHIFT;
buf->u.direct.buf = dma_alloc_coherent(&dev->pdev->dev,
size, &t, GFP_KERNEL);
if (!buf->u.direct.buf)
return -ENOMEM;
buf->u.direct.map = t;
while (t & ((1 << buf->page_shift) - 1)) {
--buf->page_shift;
buf->npages *= 2;
}
memset(buf->u.direct.buf, 0, size);
} else {
int i;
buf->nbufs = (size + PAGE_SIZE - 1) / PAGE_SIZE;
buf->npages = buf->nbufs;
buf->page_shift = PAGE_SHIFT;
buf->u.page_list = kzalloc(buf->nbufs * sizeof *buf->u.page_list,
GFP_KERNEL);
if (!buf->u.page_list)
return -ENOMEM;
for (i = 0; i < buf->nbufs; ++i) {
buf->u.page_list[i].buf =
dma_alloc_coherent(&dev->pdev->dev, PAGE_SIZE,
&t, GFP_KERNEL);
if (!buf->u.page_list[i].buf)
goto err_free;
buf->u.page_list[i].map = t;
memset(buf->u.page_list[i].buf, 0, PAGE_SIZE);
}
}
return 0;
err_free:
mlx4_buf_free(dev, size, buf);
return -ENOMEM;
}
EXPORT_SYMBOL_GPL(mlx4_buf_alloc);
void mlx4_buf_free(struct mlx4_dev *dev, int size, struct mlx4_buf *buf)
{
int i;
if (buf->nbufs == 1)
dma_free_coherent(&dev->pdev->dev, size, buf->u.direct.buf,
buf->u.direct.map);
else {
for (i = 0; i < buf->nbufs; ++i)
dma_free_coherent(&dev->pdev->dev, PAGE_SIZE,
buf->u.page_list[i].buf,
buf->u.page_list[i].map);
kfree(buf->u.page_list);
}
}
EXPORT_SYMBOL_GPL(mlx4_buf_free);