mthca_allocator.c

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/*
 * Copyright (c) 2004 Topspin Communications.  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/bitmap.h>

#include "mthca_dev.h"

/* Trivial bitmap-based allocator */
u32 mthca_alloc(struct mthca_alloc *alloc)
{
    unsigned long flags;
    u32 obj;

    spin_lock_irqsave(&alloc->lock, flags);

    obj = find_next_zero_bit(alloc->table, alloc->max, alloc->last);
    if (obj >= alloc->max) {
        alloc->top = (alloc->top + alloc->max) & alloc->mask;
        obj = find_first_zero_bit(alloc->table, alloc->max);
    }

    if (obj < alloc->max) {
        set_bit(obj, alloc->table);
        obj |= alloc->top;
    } else
        obj = -1;

    spin_unlock_irqrestore(&alloc->lock, flags);

    return obj;
}

void mthca_free(struct mthca_alloc *alloc, u32 obj)
{
    unsigned long flags;

    obj &= alloc->max - 1;

    spin_lock_irqsave(&alloc->lock, flags);

    clear_bit(obj, alloc->table);
    alloc->last = min(alloc->last, obj);
    alloc->top = (alloc->top + alloc->max) & alloc->mask;

    spin_unlock_irqrestore(&alloc->lock, flags);
}

int mthca_alloc_init(struct mthca_alloc *alloc, u32 num, u32 mask,
             u32 reserved)
{
    int i;

    /* num must be a power of 2 */
    if (num != 1 << (ffs(num) - 1))
        return -EINVAL;

    alloc->last = 0;
    alloc->top  = 0;
    alloc->max  = num;
    alloc->mask = mask;
    spin_lock_init(&alloc->lock);
    alloc->table = kmalloc(BITS_TO_LONGS(num) * sizeof (long),
                   GFP_KERNEL);
    if (!alloc->table)
        return -ENOMEM;

    bitmap_zero(alloc->table, num);
    for (i = 0; i < reserved; ++i)
        set_bit(i, alloc->table);

    return 0;
}

void mthca_alloc_cleanup(struct mthca_alloc *alloc)
{
    kfree(alloc->table);
}

/*
 * Array of pointers with lazy allocation of leaf pages.  Callers of
 * _get, _set and _clear methods must use a lock or otherwise
 * serialize access to the array.
 */

#define MTHCA_ARRAY_MASK (PAGE_SIZE / sizeof (void *) - 1)

void *mthca_array_get(struct mthca_array *array, int index)
{
    int p = (index * sizeof (void *)) >> PAGE_SHIFT;

    if (array->page_list[p].page)
        return array->page_list[p].page[index & MTHCA_ARRAY_MASK];
    else
        return NULL;
}

int mthca_array_set(struct mthca_array *array, int index, void *value)
{
    int p = (index * sizeof (void *)) >> PAGE_SHIFT;

    /* Allocate with GFP_ATOMIC because we'll be called with locks held. */
    if (!array->page_list[p].page)
        array->page_list[p].page = (void **) get_zeroed_page(GFP_ATOMIC);

    if (!array->page_list[p].page)
        return -ENOMEM;

    array->page_list[p].page[index & MTHCA_ARRAY_MASK] = value;
    ++array->page_list[p].used;

    return 0;
}

void mthca_array_clear(struct mthca_array *array, int index)
{
    int p = (index * sizeof (void *)) >> PAGE_SHIFT;

    if (--array->page_list[p].used == 0) {
        free_page((unsigned long) array->page_list[p].page);
        array->page_list[p].page = NULL;
    } else
        array->page_list[p].page[index & MTHCA_ARRAY_MASK] = NULL;

    if (array->page_list[p].used < 0)
        pr_debug("Array %p index %d page %d with ref count %d < 0\n",
             array, index, p, array->page_list[p].used);
}

int mthca_array_init(struct mthca_array *array, int nent)
{
    int npage = (nent * sizeof (void *) + PAGE_SIZE - 1) / PAGE_SIZE;
    int i;

    array->page_list = kmalloc(npage * sizeof *array->page_list, GFP_KERNEL);
    if (!array->page_list)
        return -ENOMEM;

    for (i = 0; i < npage; ++i) {
        array->page_list[i].page = NULL;
        array->page_list[i].used = 0;
    }

    return 0;
}

void mthca_array_cleanup(struct mthca_array *array, int nent)
{
    int i;

    for (i = 0; i < (nent * sizeof (void *) + PAGE_SIZE - 1) / PAGE_SIZE; ++i)
        free_page((unsigned long) array->page_list[i].page);

    kfree(array->page_list);
}

/*
 * 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 mthca_buf_alloc(struct mthca_dev *dev, int size, int max_direct,
            union mthca_buf *buf, int *is_direct, struct mthca_pd *pd,
            int hca_write, struct mthca_mr *mr)
{
    int err = -ENOMEM;
    int npages, shift;
    u64 *dma_list = NULL;
    dma_addr_t t;
    int i;

    if (size <= max_direct) {
        *is_direct = 1;
        npages     = 1;
        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;

        dma_unmap_addr_set(&buf->direct, mapping, t);

        memset(buf->direct.buf, 0, size);

        while (t & ((1 << shift) - 1)) {
            --shift;
            npages *= 2;
        }

        dma_list = kmalloc(npages * sizeof *dma_list, GFP_KERNEL);
        if (!dma_list)
            goto err_free;

        for (i = 0; i < npages; ++i)
            dma_list[i] = t + i * (1 << shift);
    } else {
        *is_direct = 0;
        npages     = (size + PAGE_SIZE - 1) / PAGE_SIZE;
        shift      = PAGE_SHIFT;

        dma_list = kmalloc(npages * sizeof *dma_list, GFP_KERNEL);
        if (!dma_list)
            return -ENOMEM;

        buf->page_list = kmalloc(npages * sizeof *buf->page_list,
                     GFP_KERNEL);
        if (!buf->page_list)
            goto err_out;

        for (i = 0; i < npages; ++i)
            buf->page_list[i].buf = NULL;

        for (i = 0; i < npages; ++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;

            dma_list[i] = t;
            dma_unmap_addr_set(&buf->page_list[i], mapping, t);

            clear_page(buf->page_list[i].buf);
        }
    }

    err = mthca_mr_alloc_phys(dev, pd->pd_num,
                  dma_list, shift, npages,
                  0, size,
                  MTHCA_MPT_FLAG_LOCAL_READ |
                  (hca_write ? MTHCA_MPT_FLAG_LOCAL_WRITE : 0),
                  mr);
    if (err)
        goto err_free;

    kfree(dma_list);

    return 0;

err_free:
    mthca_buf_free(dev, size, buf, *is_direct, NULL);

err_out:
    kfree(dma_list);

    return err;
}

void mthca_buf_free(struct mthca_dev *dev, int size, union mthca_buf *buf,
            int is_direct, struct mthca_mr *mr)
{
    int i;

    if (mr)
        mthca_free_mr(dev, mr);

    if (is_direct)
        dma_free_coherent(&dev->pdev->dev, size, buf->direct.buf,
                  dma_unmap_addr(&buf->direct, mapping));
    else {
        for (i = 0; i < (size + PAGE_SIZE - 1) / PAGE_SIZE; ++i)
            dma_free_coherent(&dev->pdev->dev, PAGE_SIZE,
                      buf->page_list[i].buf,
                      dma_unmap_addr(&buf->page_list[i],
                             mapping));
        kfree(buf->page_list);
    }
}