/*
 * Copyright (c) 2006, 2007 Cisco Systems, Inc.  All rights reserved.
 * Copyright (c) 2007, 2008 Mellanox Technologies. 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/mm.h>
#include <linux/bitmap.h>
#include <linux/dma-mapping.h>
#include <linux/vmalloc.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->reserved_top)
                                & bitmap->mask;
                obj = find_first_zero_bit(bitmap->table, bitmap->max);
        }

        if (obj < bitmap->max) {
                set_bit(obj, bitmap->table);
                bitmap->last = (obj + 1);
                if (bitmap->last == bitmap->max)
                        bitmap->last = 0;
                obj |= bitmap->top;
        } else
                obj = -1;

        spin_unlock(&bitmap->lock);

        return obj;
}

void mlx4_bitmap_free(struct mlx4_bitmap *bitmap, u32 obj)
{
        mlx4_bitmap_free_range(bitmap, obj, 1);
}

static unsigned long find_aligned_range(unsigned long *bitmap,
                                        u32 start, u32 nbits,
                                        int len, int align)
{
        unsigned long end, i;

again:
        start = ALIGN(start, align);

        while ((start < nbits) && test_bit(start, bitmap))
                start += align;

        if (start >= nbits)
                return -1;

        end = start+len;
        if (end > nbits)
                return -1;

        for (i = start + 1; i < end; i++) {
                if (test_bit(i, bitmap)) {
                        start = i + 1;
                        goto again;
                }
        }

        return start;
}

u32 mlx4_bitmap_alloc_range(struct mlx4_bitmap *bitmap, int cnt, int align)
{
        u32 obj, i;

        if (likely(cnt == 1 && align == 1))
                return mlx4_bitmap_alloc(bitmap);

        spin_lock(&bitmap->lock);

        obj = find_aligned_range(bitmap->table, bitmap->last,
                                 bitmap->max, cnt, align);
        if (obj >= bitmap->max) {
                bitmap->top = (bitmap->top + bitmap->max + bitmap->reserved_top)
                                & bitmap->mask;
                obj = find_aligned_range(bitmap->table, 0, bitmap->max,
                                         cnt, align);
        }

        if (obj < bitmap->max) {
                for (i = 0; i < cnt; i++)
                        set_bit(obj + i, bitmap->table);
                if (obj == bitmap->last) {
                        bitmap->last = (obj + cnt);
                        if (bitmap->last >= bitmap->max)
                                bitmap->last = 0;
                }
                obj |= bitmap->top;
        } else
                obj = -1;

        spin_unlock(&bitmap->lock);

        return obj;
}

void mlx4_bitmap_free_range(struct mlx4_bitmap *bitmap, u32 obj, int cnt)
{
        u32 i;

        obj &= bitmap->max + bitmap->reserved_top - 1;

        spin_lock(&bitmap->lock);
        for (i = 0; i < cnt; i++)
                clear_bit(obj + i, bitmap->table);
        bitmap->last = min(bitmap->last, obj);
        bitmap->top = (bitmap->top + bitmap->max + bitmap->reserved_top)
                        & bitmap->mask;
        spin_unlock(&bitmap->lock);
}

int mlx4_bitmap_init(struct mlx4_bitmap *bitmap, u32 num, u32 mask,
                     u32 reserved_bot, u32 reserved_top)
{
        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 - reserved_top;
        bitmap->mask = mask;
        bitmap->reserved_top = reserved_top;
        spin_lock_init(&bitmap->lock);
        bitmap->table = kzalloc(BITS_TO_LONGS(bitmap->max) *
                                sizeof (long), GFP_KERNEL);
        if (!bitmap->table)
                return -ENOMEM;

        for (i = 0; i < reserved_bot; ++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->direct.buf   = dma_alloc_coherent(&dev->pdev->dev,
                                                       size, &t, GFP_KERNEL);
                if (!buf->direct.buf)
                        return -ENOMEM;

                buf->direct.map = t;

                while (t & ((1 << buf->page_shift) - 1)) {
                        --buf->page_shift;
                        buf->npages *= 2;
                }

                memset(buf->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->page_list   = kzalloc(buf->nbufs * sizeof *buf->page_list,
                                           GFP_KERNEL);
                if (!buf->page_list)
                        return -ENOMEM;

                for (i = 0; i < buf->nbufs; ++i) {
                        buf->page_list[i].buf =
                                dma_alloc_coherent(&dev->pdev->dev, PAGE_SIZE,
                                                   &t, GFP_KERNEL);
                        if (!buf->page_list[i].buf)
                                goto err_free;

                        buf->page_list[i].map = t;

                        memset(buf->page_list[i].buf, 0, PAGE_SIZE);
                }

                if (BITS_PER_LONG == 64) {
                        struct page **pages;
                        pages = kmalloc(sizeof *pages * buf->nbufs, GFP_KERNEL);
                        if (!pages)
                                goto err_free;
                        for (i = 0; i < buf->nbufs; ++i)
                                pages[i] = virt_to_page(buf->page_list[i].buf);
                        buf->direct.buf = vmap(pages, buf->nbufs, VM_MAP, PAGE_KERNEL);
                        kfree(pages);
                        if (!buf->direct.buf)
                                goto err_free;
                }
        }

        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->direct.buf,
                                  buf->direct.map);
        else {
                if (BITS_PER_LONG == 64)
                        vunmap(buf->direct.buf);

                for (i = 0; i < buf->nbufs; ++i)
                        if (buf->page_list[i].buf)
                                dma_free_coherent(&dev->pdev->dev, PAGE_SIZE,
                                                  buf->page_list[i].buf,
                                                  buf->page_list[i].map);
                kfree(buf->page_list);
        }
}
EXPORT_SYMBOL_GPL(mlx4_buf_free);

static struct mlx4_db_pgdir *mlx4_alloc_db_pgdir(struct device *dma_device)
{
        struct mlx4_db_pgdir *pgdir;

        pgdir = kzalloc(sizeof *pgdir, GFP_KERNEL);
        if (!pgdir)
                return NULL;

        bitmap_fill(pgdir->order1, MLX4_DB_PER_PAGE / 2);
        pgdir->bits[0] = pgdir->order0;
        pgdir->bits[1] = pgdir->order1;
        pgdir->db_page = dma_alloc_coherent(dma_device, PAGE_SIZE,
                                            &pgdir->db_dma, GFP_KERNEL);
        if (!pgdir->db_page) {
                kfree(pgdir);
                return NULL;
        }

        return pgdir;
}

static int mlx4_alloc_db_from_pgdir(struct mlx4_db_pgdir *pgdir,
                                    struct mlx4_db *db, int order)
{
        int o;
        int i;

        for (o = order; o <= 1; ++o) {
                i = find_first_bit(pgdir->bits[o], MLX4_DB_PER_PAGE >> o);
                if (i < MLX4_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_db_alloc(struct mlx4_dev *dev, struct mlx4_db *db, int order)
{
        struct mlx4_priv *priv = mlx4_priv(dev);
        struct mlx4_db_pgdir *pgdir;
        int ret = 0;

        mutex_lock(&priv->pgdir_mutex);

        list_for_each_entry(pgdir, &priv->pgdir_list, list)
                if (!mlx4_alloc_db_from_pgdir(pgdir, db, order))
                        goto out;

        pgdir = mlx4_alloc_db_pgdir(&(dev->pdev->dev));
        if (!pgdir) {
                ret = -ENOMEM;
                goto out;
        }

        list_add(&pgdir->list, &priv->pgdir_list);

        /* This should never fail -- we just allocated an empty page: */
        WARN_ON(mlx4_alloc_db_from_pgdir(pgdir, db, order));

out:
        mutex_unlock(&priv->pgdir_mutex);

        return ret;
}
EXPORT_SYMBOL_GPL(mlx4_db_alloc);

void mlx4_db_free(struct mlx4_dev *dev, struct mlx4_db *db)
{
        struct mlx4_priv *priv = mlx4_priv(dev);
        int o;
        int i;

        mutex_lock(&priv->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_DB_PER_PAGE / 2)) {
                dma_free_coherent(&(dev->pdev->dev), PAGE_SIZE,
                                  db->u.pgdir->db_page, db->u.pgdir->db_dma);
                list_del(&db->u.pgdir->list);
                kfree(db->u.pgdir);
        }

        mutex_unlock(&priv->pgdir_mutex);
}
EXPORT_SYMBOL_GPL(mlx4_db_free);

int mlx4_alloc_hwq_res(struct mlx4_dev *dev, struct mlx4_hwq_resources *wqres,
                       int size, int max_direct)
{
        int err;

        err = mlx4_db_alloc(dev, &wqres->db, 1);
        if (err)
                return err;

        *wqres->db.db = 0;

        err = mlx4_buf_alloc(dev, size, max_direct, &wqres->buf);
        if (err)
                goto err_db;

        err = mlx4_mtt_init(dev, wqres->buf.npages, wqres->buf.page_shift,
                            &wqres->mtt);
        if (err)
                goto err_buf;

        err = mlx4_buf_write_mtt(dev, &wqres->mtt, &wqres->buf);
        if (err)
                goto err_mtt;

        return 0;

err_mtt:
        mlx4_mtt_cleanup(dev, &wqres->mtt);
err_buf:
        mlx4_buf_free(dev, size, &wqres->buf);
err_db:
        mlx4_db_free(dev, &wqres->db);

        return err;
}
EXPORT_SYMBOL_GPL(mlx4_alloc_hwq_res);

void mlx4_free_hwq_res(struct mlx4_dev *dev, struct mlx4_hwq_resources *wqres,
                       int size)
{
        mlx4_mtt_cleanup(dev, &wqres->mtt);
        mlx4_buf_free(dev, size, &wqres->buf);
        mlx4_db_free(dev, &wqres->db);
}
EXPORT_SYMBOL_GPL(mlx4_free_hwq_res);