mthca_memfree.c

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/*
 * Copyright (c) 2004, 2005 Topspin Communications.  All rights reserved.
 * Copyright (c) 2005 Cisco Systems.  All rights reserved.
 * Copyright (c) 2005 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/mm.h>
#include <linux/scatterlist.h>
#include <linux/sched.h>
#include <linux/slab.h>

#include <asm/page.h>

#include "mthca_memfree.h"
#include "mthca_dev.h"
#include "mthca_cmd.h"

/*
 * We allocate in as big chunks as we can, up to a maximum of 256 KB
 * per chunk.
 */
enum {
    MTHCA_ICM_ALLOC_SIZE   = 1 << 18,
    MTHCA_TABLE_CHUNK_SIZE = 1 << 18
};

struct mthca_user_db_table {
    struct mutex mutex;
    struct {
        u64                uvirt;
        struct scatterlist mem;
        int                refcount;
    }                page[0];
};

static void mthca_free_icm_pages(struct mthca_dev *dev, struct mthca_icm_chunk *chunk)
{
    int i;

    if (chunk->nsg > 0)
        pci_unmap_sg(dev->pdev, chunk->mem, chunk->npages,
                 PCI_DMA_BIDIRECTIONAL);

    for (i = 0; i < chunk->npages; ++i)
        __free_pages(sg_page(&chunk->mem[i]),
                 get_order(chunk->mem[i].length));
}

static void mthca_free_icm_coherent(struct mthca_dev *dev, struct mthca_icm_chunk *chunk)
{
    int i;

    for (i = 0; i < chunk->npages; ++i) {
        dma_free_coherent(&dev->pdev->dev, chunk->mem[i].length,
                  lowmem_page_address(sg_page(&chunk->mem[i])),
                  sg_dma_address(&chunk->mem[i]));
    }
}

void mthca_free_icm(struct mthca_dev *dev, struct mthca_icm *icm, int coherent)
{
    struct mthca_icm_chunk *chunk, *tmp;

    if (!icm)
        return;

    list_for_each_entry_safe(chunk, tmp, &icm->chunk_list, list) {
        if (coherent)
            mthca_free_icm_coherent(dev, chunk);
        else
            mthca_free_icm_pages(dev, chunk);

        kfree(chunk);
    }

    kfree(icm);
}

static int mthca_alloc_icm_pages(struct scatterlist *mem, int order, gfp_t gfp_mask)
{
    struct page *page;

    /*
     * Use __GFP_ZERO because buggy firmware assumes ICM pages are
     * cleared, and subtle failures are seen if they aren't.
     */
    page = alloc_pages(gfp_mask | __GFP_ZERO, order);
    if (!page)
        return -ENOMEM;

    sg_set_page(mem, page, PAGE_SIZE << order, 0);
    return 0;
}

static int mthca_alloc_icm_coherent(struct device *dev, struct scatterlist *mem,
                    int order, gfp_t gfp_mask)
{
    void *buf = dma_alloc_coherent(dev, PAGE_SIZE << order, &sg_dma_address(mem),
                       gfp_mask);
    if (!buf)
        return -ENOMEM;

    sg_set_buf(mem, buf, PAGE_SIZE << order);
    BUG_ON(mem->offset);
    sg_dma_len(mem) = PAGE_SIZE << order;
    return 0;
}

struct mthca_icm *mthca_alloc_icm(struct mthca_dev *dev, int npages,
                  gfp_t gfp_mask, int coherent)
{
    struct mthca_icm *icm;
    struct mthca_icm_chunk *chunk = NULL;
    int cur_order;
    int ret;

    /* We use sg_set_buf for coherent allocs, which assumes low memory */
    BUG_ON(coherent && (gfp_mask & __GFP_HIGHMEM));

    icm = kmalloc(sizeof *icm, gfp_mask & ~(__GFP_HIGHMEM | __GFP_NOWARN));
    if (!icm)
        return icm;

    icm->refcount = 0;
    INIT_LIST_HEAD(&icm->chunk_list);

    cur_order = get_order(MTHCA_ICM_ALLOC_SIZE);

    while (npages > 0) {
        if (!chunk) {
            chunk = kmalloc(sizeof *chunk,
                    gfp_mask & ~(__GFP_HIGHMEM | __GFP_NOWARN));
            if (!chunk)
                goto fail;

            sg_init_table(chunk->mem, MTHCA_ICM_CHUNK_LEN);
            chunk->npages = 0;
            chunk->nsg    = 0;
            list_add_tail(&chunk->list, &icm->chunk_list);
        }

        while (1 << cur_order > npages)
            --cur_order;

        if (coherent)
            ret = mthca_alloc_icm_coherent(&dev->pdev->dev,
                               &chunk->mem[chunk->npages],
                               cur_order, gfp_mask);
        else
            ret = mthca_alloc_icm_pages(&chunk->mem[chunk->npages],
                            cur_order, gfp_mask);

        if (!ret) {
            ++chunk->npages;

            if (coherent)
                ++chunk->nsg;
            else if (chunk->npages == MTHCA_ICM_CHUNK_LEN) {
                chunk->nsg = pci_map_sg(dev->pdev, chunk->mem,
                            chunk->npages,
                            PCI_DMA_BIDIRECTIONAL);

                if (chunk->nsg <= 0)
                    goto fail;
            }

            if (chunk->npages == MTHCA_ICM_CHUNK_LEN)
                chunk = NULL;

            npages -= 1 << cur_order;
        } else {
            --cur_order;
            if (cur_order < 0)
                goto fail;
        }
    }

    if (!coherent && chunk) {
        chunk->nsg = pci_map_sg(dev->pdev, chunk->mem,
                    chunk->npages,
                    PCI_DMA_BIDIRECTIONAL);

        if (chunk->nsg <= 0)
            goto fail;
    }

    return icm;

fail:
    mthca_free_icm(dev, icm, coherent);
    return NULL;
}

int mthca_table_get(struct mthca_dev *dev, struct mthca_icm_table *table, int obj)
{
    int i = (obj & (table->num_obj - 1)) * table->obj_size / MTHCA_TABLE_CHUNK_SIZE;
    int ret = 0;

    mutex_lock(&table->mutex);

    if (table->icm[i]) {
        ++table->icm[i]->refcount;
        goto out;
    }

    table->icm[i] = mthca_alloc_icm(dev, MTHCA_TABLE_CHUNK_SIZE >> PAGE_SHIFT,
                    (table->lowmem ? GFP_KERNEL : GFP_HIGHUSER) |
                    __GFP_NOWARN, table->coherent);
    if (!table->icm[i]) {
        ret = -ENOMEM;
        goto out;
    }

    if (mthca_MAP_ICM(dev, table->icm[i],
              table->virt + i * MTHCA_TABLE_CHUNK_SIZE)) {
        mthca_free_icm(dev, table->icm[i], table->coherent);
        table->icm[i] = NULL;
        ret = -ENOMEM;
        goto out;
    }

    ++table->icm[i]->refcount;

out:
    mutex_unlock(&table->mutex);
    return ret;
}

void mthca_table_put(struct mthca_dev *dev, struct mthca_icm_table *table, int obj)
{
    int i;

    if (!mthca_is_memfree(dev))
        return;

    i = (obj & (table->num_obj - 1)) * table->obj_size / MTHCA_TABLE_CHUNK_SIZE;

    mutex_lock(&table->mutex);

    if (--table->icm[i]->refcount == 0) {
        mthca_UNMAP_ICM(dev, table->virt + i * MTHCA_TABLE_CHUNK_SIZE,
                MTHCA_TABLE_CHUNK_SIZE / MTHCA_ICM_PAGE_SIZE);
        mthca_free_icm(dev, table->icm[i], table->coherent);
        table->icm[i] = NULL;
    }

    mutex_unlock(&table->mutex);
}

void *mthca_table_find(struct mthca_icm_table *table, int obj, dma_addr_t *dma_handle)
{
    int idx, offset, dma_offset, i;
    struct mthca_icm_chunk *chunk;
    struct mthca_icm *icm;
    struct page *page = NULL;

    if (!table->lowmem)
        return NULL;

    mutex_lock(&table->mutex);

    idx = (obj & (table->num_obj - 1)) * table->obj_size;
    icm = table->icm[idx / MTHCA_TABLE_CHUNK_SIZE];
    dma_offset = offset = idx % MTHCA_TABLE_CHUNK_SIZE;

    if (!icm)
        goto out;

    list_for_each_entry(chunk, &icm->chunk_list, list) {
        for (i = 0; i < chunk->npages; ++i) {
            if (dma_handle && dma_offset >= 0) {
                if (sg_dma_len(&chunk->mem[i]) > dma_offset)
                    *dma_handle = sg_dma_address(&chunk->mem[i]) +
                        dma_offset;
                dma_offset -= sg_dma_len(&chunk->mem[i]);
            }
            /* DMA mapping can merge pages but not split them,
             * so if we found the page, dma_handle has already
             * been assigned to. */
            if (chunk->mem[i].length > offset) {
                page = sg_page(&chunk->mem[i]);
                goto out;
            }
            offset -= chunk->mem[i].length;
        }
    }

out:
    mutex_unlock(&table->mutex);
    return page ? lowmem_page_address(page) + offset : NULL;
}

int mthca_table_get_range(struct mthca_dev *dev, struct mthca_icm_table *table,
              int start, int end)
{
    int inc = MTHCA_TABLE_CHUNK_SIZE / table->obj_size;
    int i, err;

    for (i = start; i <= end; i += inc) {
        err = mthca_table_get(dev, table, i);
        if (err)
            goto fail;
    }

    return 0;

fail:
    while (i > start) {
        i -= inc;
        mthca_table_put(dev, table, i);
    }

    return err;
}

void mthca_table_put_range(struct mthca_dev *dev, struct mthca_icm_table *table,
               int start, int end)
{
    int i;

    if (!mthca_is_memfree(dev))
        return;

    for (i = start; i <= end; i += MTHCA_TABLE_CHUNK_SIZE / table->obj_size)
        mthca_table_put(dev, table, i);
}

struct mthca_icm_table *mthca_alloc_icm_table(struct mthca_dev *dev,
                          u64 virt, int obj_size,
                          int nobj, int reserved,
                          int use_lowmem, int use_coherent)
{
    struct mthca_icm_table *table;
    int obj_per_chunk;
    int num_icm;
    unsigned chunk_size;
    int i;

    obj_per_chunk = MTHCA_TABLE_CHUNK_SIZE / obj_size;
    num_icm = DIV_ROUND_UP(nobj, obj_per_chunk);

    table = kmalloc(sizeof *table + num_icm * sizeof *table->icm, GFP_KERNEL);
    if (!table)
        return NULL;

    table->virt     = virt;
    table->num_icm  = num_icm;
    table->num_obj  = nobj;
    table->obj_size = obj_size;
    table->lowmem   = use_lowmem;
    table->coherent = use_coherent;
    mutex_init(&table->mutex);

    for (i = 0; i < num_icm; ++i)
        table->icm[i] = NULL;

    for (i = 0; i * MTHCA_TABLE_CHUNK_SIZE < reserved * obj_size; ++i) {
        chunk_size = MTHCA_TABLE_CHUNK_SIZE;
        if ((i + 1) * MTHCA_TABLE_CHUNK_SIZE > nobj * obj_size)
            chunk_size = nobj * obj_size - i * MTHCA_TABLE_CHUNK_SIZE;

        table->icm[i] = mthca_alloc_icm(dev, chunk_size >> PAGE_SHIFT,
                        (use_lowmem ? GFP_KERNEL : GFP_HIGHUSER) |
                        __GFP_NOWARN, use_coherent);
        if (!table->icm[i])
            goto err;
        if (mthca_MAP_ICM(dev, table->icm[i],
                  virt + i * MTHCA_TABLE_CHUNK_SIZE)) {
            mthca_free_icm(dev, table->icm[i], table->coherent);
            table->icm[i] = NULL;
            goto err;
        }

        /*
         * Add a reference to this ICM chunk so that it never
         * gets freed (since it contains reserved firmware objects).
         */
        ++table->icm[i]->refcount;
    }

    return table;

err:
    for (i = 0; i < num_icm; ++i)
        if (table->icm[i]) {
            mthca_UNMAP_ICM(dev, virt + i * MTHCA_TABLE_CHUNK_SIZE,
                    MTHCA_TABLE_CHUNK_SIZE / MTHCA_ICM_PAGE_SIZE);
            mthca_free_icm(dev, table->icm[i], table->coherent);
        }

    kfree(table);

    return NULL;
}

void mthca_free_icm_table(struct mthca_dev *dev, struct mthca_icm_table *table)
{
    int i;

    for (i = 0; i < table->num_icm; ++i)
        if (table->icm[i]) {
            mthca_UNMAP_ICM(dev,
                    table->virt + i * MTHCA_TABLE_CHUNK_SIZE,
                    MTHCA_TABLE_CHUNK_SIZE / MTHCA_ICM_PAGE_SIZE);
            mthca_free_icm(dev, table->icm[i], table->coherent);
        }

    kfree(table);
}

static u64 mthca_uarc_virt(struct mthca_dev *dev, struct mthca_uar *uar, int page)
{
    return dev->uar_table.uarc_base +
        uar->index * dev->uar_table.uarc_size +
        page * MTHCA_ICM_PAGE_SIZE;
}

int mthca_map_user_db(struct mthca_dev *dev, struct mthca_uar *uar,
              struct mthca_user_db_table *db_tab, int index, u64 uaddr)
{
    struct page *pages[1];
    int ret = 0;
    int i;

    if (!mthca_is_memfree(dev))
        return 0;

    if (index < 0 || index > dev->uar_table.uarc_size / 8)
        return -EINVAL;

    mutex_lock(&db_tab->mutex);

    i = index / MTHCA_DB_REC_PER_PAGE;

    if ((db_tab->page[i].refcount >= MTHCA_DB_REC_PER_PAGE)       ||
        (db_tab->page[i].uvirt && db_tab->page[i].uvirt != uaddr) ||
        (uaddr & 4095)) {
        ret = -EINVAL;
        goto out;
    }

    if (db_tab->page[i].refcount) {
        ++db_tab->page[i].refcount;
        goto out;
    }

    ret = get_user_pages(current, current->mm, uaddr & PAGE_MASK, 1, 1, 0,
                 pages, NULL);
    if (ret < 0)
        goto out;

    sg_set_page(&db_tab->page[i].mem, pages[0], MTHCA_ICM_PAGE_SIZE,
            uaddr & ~PAGE_MASK);

    ret = pci_map_sg(dev->pdev, &db_tab->page[i].mem, 1, PCI_DMA_TODEVICE);
    if (ret < 0) {
        put_page(pages[0]);
        goto out;
    }

    ret = mthca_MAP_ICM_page(dev, sg_dma_address(&db_tab->page[i].mem),
                 mthca_uarc_virt(dev, uar, i));
    if (ret) {
        pci_unmap_sg(dev->pdev, &db_tab->page[i].mem, 1, PCI_DMA_TODEVICE);
        put_page(sg_page(&db_tab->page[i].mem));
        goto out;
    }

    db_tab->page[i].uvirt    = uaddr;
    db_tab->page[i].refcount = 1;

out:
    mutex_unlock(&db_tab->mutex);
    return ret;
}

void mthca_unmap_user_db(struct mthca_dev *dev, struct mthca_uar *uar,
             struct mthca_user_db_table *db_tab, int index)
{
    if (!mthca_is_memfree(dev))
        return;

    /*
     * To make our bookkeeping simpler, we don't unmap DB
     * pages until we clean up the whole db table.
     */

    mutex_lock(&db_tab->mutex);

    --db_tab->page[index / MTHCA_DB_REC_PER_PAGE].refcount;

    mutex_unlock(&db_tab->mutex);
}

struct mthca_user_db_table *mthca_init_user_db_tab(struct mthca_dev *dev)
{
    struct mthca_user_db_table *db_tab;
    int npages;
    int i;

    if (!mthca_is_memfree(dev))
        return NULL;

    npages = dev->uar_table.uarc_size / MTHCA_ICM_PAGE_SIZE;
    db_tab = kmalloc(sizeof *db_tab + npages * sizeof *db_tab->page, GFP_KERNEL);
    if (!db_tab)
        return ERR_PTR(-ENOMEM);

    mutex_init(&db_tab->mutex);
    for (i = 0; i < npages; ++i) {
        db_tab->page[i].refcount = 0;
        db_tab->page[i].uvirt    = 0;
        sg_init_table(&db_tab->page[i].mem, 1);
    }

    return db_tab;
}

void mthca_cleanup_user_db_tab(struct mthca_dev *dev, struct mthca_uar *uar,
                   struct mthca_user_db_table *db_tab)
{
    int i;

    if (!mthca_is_memfree(dev))
        return;

    for (i = 0; i < dev->uar_table.uarc_size / MTHCA_ICM_PAGE_SIZE; ++i) {
        if (db_tab->page[i].uvirt) {
            mthca_UNMAP_ICM(dev, mthca_uarc_virt(dev, uar, i), 1);
            pci_unmap_sg(dev->pdev, &db_tab->page[i].mem, 1, PCI_DMA_TODEVICE);
            put_page(sg_page(&db_tab->page[i].mem));
        }
    }

    kfree(db_tab);
}

int mthca_alloc_db(struct mthca_dev *dev, enum mthca_db_type type,
           u32 qn, __be32 **db)
{
    int group;
    int start, end, dir;
    int i, j;
    struct mthca_db_page *page;
    int ret = 0;

    mutex_lock(&dev->db_tab->mutex);

    switch (type) {
    case MTHCA_DB_TYPE_CQ_ARM:
    case MTHCA_DB_TYPE_SQ:
        group = 0;
        start = 0;
        end   = dev->db_tab->max_group1;
        dir   = 1;
        break;

    case MTHCA_DB_TYPE_CQ_SET_CI:
    case MTHCA_DB_TYPE_RQ:
    case MTHCA_DB_TYPE_SRQ:
        group = 1;
        start = dev->db_tab->npages - 1;
        end   = dev->db_tab->min_group2;
        dir   = -1;
        break;

    default:
        ret = -EINVAL;
        goto out;
    }

    for (i = start; i != end; i += dir)
        if (dev->db_tab->page[i].db_rec &&
            !bitmap_full(dev->db_tab->page[i].used,
                 MTHCA_DB_REC_PER_PAGE)) {
            page = dev->db_tab->page + i;
            goto found;
        }

    for (i = start; i != end; i += dir)
        if (!dev->db_tab->page[i].db_rec) {
            page = dev->db_tab->page + i;
            goto alloc;
        }

    if (dev->db_tab->max_group1 >= dev->db_tab->min_group2 - 1) {
        ret = -ENOMEM;
        goto out;
    }

    if (group == 0)
        ++dev->db_tab->max_group1;
    else
        --dev->db_tab->min_group2;

    page = dev->db_tab->page + end;

alloc:
    page->db_rec = dma_alloc_coherent(&dev->pdev->dev, MTHCA_ICM_PAGE_SIZE,
                      &page->mapping, GFP_KERNEL);
    if (!page->db_rec) {
        ret = -ENOMEM;
        goto out;
    }
    memset(page->db_rec, 0, MTHCA_ICM_PAGE_SIZE);

    ret = mthca_MAP_ICM_page(dev, page->mapping,
                 mthca_uarc_virt(dev, &dev->driver_uar, i));
    if (ret) {
        dma_free_coherent(&dev->pdev->dev, MTHCA_ICM_PAGE_SIZE,
                  page->db_rec, page->mapping);
        goto out;
    }

    bitmap_zero(page->used, MTHCA_DB_REC_PER_PAGE);

found:
    j = find_first_zero_bit(page->used, MTHCA_DB_REC_PER_PAGE);
    set_bit(j, page->used);

    if (group == 1)
        j = MTHCA_DB_REC_PER_PAGE - 1 - j;

    ret = i * MTHCA_DB_REC_PER_PAGE + j;

    page->db_rec[j] = cpu_to_be64((qn << 8) | (type << 5));

    *db = (__be32 *) &page->db_rec[j];

out:
    mutex_unlock(&dev->db_tab->mutex);

    return ret;
}

void mthca_free_db(struct mthca_dev *dev, int type, int db_index)
{
    int i, j;
    struct mthca_db_page *page;

    i = db_index / MTHCA_DB_REC_PER_PAGE;
    j = db_index % MTHCA_DB_REC_PER_PAGE;

    page = dev->db_tab->page + i;

    mutex_lock(&dev->db_tab->mutex);

    page->db_rec[j] = 0;
    if (i >= dev->db_tab->min_group2)
        j = MTHCA_DB_REC_PER_PAGE - 1 - j;
    clear_bit(j, page->used);

    if (bitmap_empty(page->used, MTHCA_DB_REC_PER_PAGE) &&
        i >= dev->db_tab->max_group1 - 1) {
        mthca_UNMAP_ICM(dev, mthca_uarc_virt(dev, &dev->driver_uar, i), 1);

        dma_free_coherent(&dev->pdev->dev, MTHCA_ICM_PAGE_SIZE,
                  page->db_rec, page->mapping);
        page->db_rec = NULL;

        if (i == dev->db_tab->max_group1) {
            --dev->db_tab->max_group1;
            /* XXX may be able to unmap more pages now */
        }
        if (i == dev->db_tab->min_group2)
            ++dev->db_tab->min_group2;
    }

    mutex_unlock(&dev->db_tab->mutex);
}

int mthca_init_db_tab(struct mthca_dev *dev)
{
    int i;

    if (!mthca_is_memfree(dev))
        return 0;

    dev->db_tab = kmalloc(sizeof *dev->db_tab, GFP_KERNEL);
    if (!dev->db_tab)
        return -ENOMEM;

    mutex_init(&dev->db_tab->mutex);

    dev->db_tab->npages     = dev->uar_table.uarc_size / MTHCA_ICM_PAGE_SIZE;
    dev->db_tab->max_group1 = 0;
    dev->db_tab->min_group2 = dev->db_tab->npages - 1;

    dev->db_tab->page = kmalloc(dev->db_tab->npages *
                    sizeof *dev->db_tab->page,
                    GFP_KERNEL);
    if (!dev->db_tab->page) {
        kfree(dev->db_tab);
        return -ENOMEM;
    }

    for (i = 0; i < dev->db_tab->npages; ++i)
        dev->db_tab->page[i].db_rec = NULL;

    return 0;
}

void mthca_cleanup_db_tab(struct mthca_dev *dev)
{
    int i;

    if (!mthca_is_memfree(dev))
        return;

    /*
     * Because we don't always free our UARC pages when they
     * become empty to make mthca_free_db() simpler we need to
     * make a sweep through the doorbell pages and free any
     * leftover pages now.
     */
    for (i = 0; i < dev->db_tab->npages; ++i) {
        if (!dev->db_tab->page[i].db_rec)
            continue;

        if (!bitmap_empty(dev->db_tab->page[i].used, MTHCA_DB_REC_PER_PAGE))
            mthca_warn(dev, "Kernel UARC page %d not empty\n", i);

        mthca_UNMAP_ICM(dev, mthca_uarc_virt(dev, &dev->driver_uar, i), 1);

        dma_free_coherent(&dev->pdev->dev, MTHCA_ICM_PAGE_SIZE,
                  dev->db_tab->page[i].db_rec,
                  dev->db_tab->page[i].mapping);
    }

    kfree(dev->db_tab->page);
    kfree(dev->db_tab);
}