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);
+}