summaryrefslogtreecommitdiff
path: root/drivers/infiniband/hw/mlx4/doorbell.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/infiniband/hw/mlx4/doorbell.c')
-rw-r--r--drivers/infiniband/hw/mlx4/doorbell.c216
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);
+}