/*
* Copyright (c) 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/slab.h>
#include "mlx4_ib.h"
struct mlx4_ib_db_pgdir {
struct list_head list;
DECLARE_BITMAP(order0, MLX4_IB_DB_PER_PAGE);
DECLARE_BITMAP(order1, MLX4_IB_DB_PER_PAGE / 2);
unsigned long *bits[2];
__be32 *db_page;
dma_addr_t db_dma;
};
static struct mlx4_ib_db_pgdir *mlx4_ib_alloc_db_pgdir(struct mlx4_ib_dev *dev)
{
struct mlx4_ib_db_pgdir *pgdir;
pgdir = kzalloc(sizeof *pgdir, GFP_KERNEL);
if (!pgdir)
return NULL;
bitmap_fill(pgdir->order1, MLX4_IB_DB_PER_PAGE / 2);
pgdir->bits[0] = pgdir->order0;
pgdir->bits[1] = pgdir->order1;
pgdir->db_page = dma_alloc_coherent(dev->ib_dev.dma_device,
PAGE_SIZE, &pgdir->db_dma,
GFP_KERNEL);
if (!pgdir->db_page) {
kfree(pgdir);
return NULL;
}
return pgdir;
}
static int mlx4_ib_alloc_db_from_pgdir(struct mlx4_ib_db_pgdir *pgdir,
struct mlx4_ib_db *db, int order)
{
int o;
int i;
for (o = order; o <= 1; ++o) {
i = find_first_bit(pgdir->bits[o], MLX4_IB_DB_PER_PAGE >> o);
if (i < MLX4_IB_DB_PER_PAGE >> o)
goto found;
}
return -ENOMEM;
found:
clear_bit(i, pgdir->bits[o]);
i <<= o;
if (o > order)
set_bit(i ^ 1, pgdir->bits[order]);
db->u.pgdir = pgdir;
db->index = i;
db->db = pgdir->db_page + db->index;
db->dma = pgdir->db_dma + db->index * 4;
db->order = order;
return 0;
}
int mlx4_ib_db_alloc(struct mlx4_ib_dev *dev, struct mlx4_ib_db *db, int order)
{
struct mlx4_ib_db_pgdir *pgdir;
int ret = 0;
mutex_lock(&dev->pgdir_mutex);
list_for_each_entry(pgdir, &dev->pgdir_list, list)
if (!mlx4_ib_alloc_db_from_pgdir(pgdir, db, order))
goto out;
pgdir = mlx4_ib_alloc_db_pgdir(dev);
if (!pgdir) {
ret = -ENOMEM;
goto out;
}
list_add(&pgdir->list, &dev->pgdir_list);
/* This should never fail -- we just allocated an empty page: */
WARN_ON(mlx4_ib_alloc_db_from_pgdir(pgdir, db, order));
out:
mutex_unlock(&dev->pgdir_mutex);
return ret;
}
void mlx4_ib_db_free(struct mlx4_ib_dev *dev, struct mlx4_ib_db *db)
{
int o;
int i;
mutex_lock(&dev->pgdir_mutex);
o = db->order;
i = db->index;
if (db->order == 0 && test_bit(i ^ 1, db->u.pgdir->order0)) {
clear_bit(i ^ 1, db->u.pgdir->order0);
++o;
}
i >>= o;
set_bit(i, db->u.pgdir->bits[o]);
if (bitmap_full(db->u.pgdir->order1, MLX4_IB_DB_PER_PAGE / 2)) {
dma_free_coherent(dev->ib_dev.dma_device, PAGE_SIZE,
db->u.pgdir->db_page, db->u.pgdir->db_dma);
list_del(&db->u.pgdir->list);
kfree(db->u.pgdir);
}
mutex_unlock(&dev->pgdir_mutex);
}
struct mlx4_ib_user_db_page {
struct list_head list;
struct ib_umem *umem;
unsigned long user_virt;
int refcnt;
};
int mlx4_ib_db_map_user(struct mlx4_ib_ucontext *context, unsigned long virt,
struct mlx4_ib_db *db)
{
struct mlx4_ib_user_db_page *page;
struct ib_umem_chunk *chunk;
int err = 0;
mutex_lock(&context->db_page_mutex);
list_for_each_entry(page, &context->db_page_list, list)
if (page->user_virt == (virt & PAGE_MASK))
goto found;
page = kmalloc(sizeof *page, GFP_KERNEL);
if (!page) {
err = -ENOMEM;
goto out;
}
page->user_virt = (virt & PAGE_MASK);
page->refcnt = 0;
page->umem = ib_umem_get(&context->ibucontext, virt & PAGE_MASK,
PAGE_SIZE, 0);
if (IS_ERR(page->umem)) {
err = PTR_ERR(page->umem);
kfree(page);
goto out;
}
list_add(&page->list, &context->db_page_list);
found:
chunk = list_entry(page->umem->chunk_list.next, struct ib_umem_chunk, list);
db->dma = sg_dma_address(chunk->page_list) + (virt & ~PAGE_MASK);
db->u.user_page = page;
++page->refcnt;
out:
mutex_unlock(&context->db_page_mutex);
return err;
}
void mlx4_ib_db_unmap_user(struct mlx4_ib_ucontext *context, struct mlx4_ib_db *db)
{
mutex_lock(&context->db_page_mutex);
if (!--db->u.user_page->refcnt) {
list_del(&db->u.user_page->list);
ib_umem_release(db->u.user_page->umem);
kfree(db->u.user_page);
}
mutex_unlock(&context->db_page_mutex);
}
