alloc.c

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/*
 * 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/export.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;

    if (obj != -1)
        --bitmap->avail;

    spin_unlock(&bitmap->lock);

    return obj;
}

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

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

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

    spin_lock(&bitmap->lock);

    obj = bitmap_find_next_zero_area(bitmap->table, bitmap->max,
                bitmap->last, cnt, align - 1);
    if (obj >= bitmap->max) {
        bitmap->top = (bitmap->top + bitmap->max + bitmap->reserved_top)
                & bitmap->mask;
        obj = bitmap_find_next_zero_area(bitmap->table, bitmap->max,
                        0, cnt, align - 1);
    }

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

    if (obj != -1)
        bitmap->avail -= cnt;

    spin_unlock(&bitmap->lock);

    return obj;
}

u32 mlx4_bitmap_avail(struct mlx4_bitmap *bitmap)
{
    return bitmap->avail;
}

void mlx4_bitmap_free_range(struct mlx4_bitmap *bitmap, u32 obj, int cnt)
{
    obj &= bitmap->max + bitmap->reserved_top - 1;

    spin_lock(&bitmap->lock);
    bitmap_clear(bitmap->table, obj, cnt);
    bitmap->avail += cnt;
    spin_unlock(&bitmap->lock);
}

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

    bitmap_set(bitmap->table, 0, reserved_bot);

    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->direct.buf  = NULL;
        buf->nbufs       = (size + PAGE_SIZE - 1) / PAGE_SIZE;
        buf->npages      = buf->nbufs;
        buf->page_shift  = PAGE_SHIFT;
        buf->page_list   = kcalloc(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 && buf->direct.buf)
            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);