diff options
Diffstat (limited to 'drivers/infiniband/hw/mlx4/doorbell.c')
| -rw-r--r-- | drivers/infiniband/hw/mlx4/doorbell.c | 216 |
1 files changed, 216 insertions, 0 deletions
diff --git a/drivers/infiniband/hw/mlx4/doorbell.c b/drivers/infiniband/hw/mlx4/doorbell.c new file mode 100644 index 000000000000..1c36087aef14 --- /dev/null +++ b/drivers/infiniband/hw/mlx4/doorbell.c @@ -0,0 +1,216 @@ +/* + * 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); +} |