radeon_mem.c

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/* radeon_mem.c -- Simple GART/fb memory manager for radeon -*- linux-c -*- */
/*
 * Copyright (C) The Weather Channel, Inc.  2002.  All Rights Reserved.
 *
 * The Weather Channel (TM) funded Tungsten Graphics to develop the
 * initial release of the Radeon 8500 driver under the XFree86 license.
 * This notice must be preserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * 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
 * PRECISION INSIGHT AND/OR ITS SUPPLIERS 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.
 *
 * Authors:
 *    Keith Whitwell <[email protected]>
 */

#include <drm/drmP.h>
#include <drm/radeon_drm.h>
#include "radeon_drv.h"

/* Very simple allocator for GART memory, working on a static range
 * already mapped into each client's address space.
 */

static struct mem_block *split_block(struct mem_block *p, int start, int size,
                     struct drm_file *file_priv)
{
    /* Maybe cut off the start of an existing block */
    if (start > p->start) {
        struct mem_block *newblock = kmalloc(sizeof(*newblock),
                             GFP_KERNEL);
        if (!newblock)
            goto out;
        newblock->start = start;
        newblock->size = p->size - (start - p->start);
        newblock->file_priv = NULL;
        newblock->next = p->next;
        newblock->prev = p;
        p->next->prev = newblock;
        p->next = newblock;
        p->size -= newblock->size;
        p = newblock;
    }

    /* Maybe cut off the end of an existing block */
    if (size < p->size) {
        struct mem_block *newblock = kmalloc(sizeof(*newblock),
                             GFP_KERNEL);
        if (!newblock)
            goto out;
        newblock->start = start + size;
        newblock->size = p->size - size;
        newblock->file_priv = NULL;
        newblock->next = p->next;
        newblock->prev = p;
        p->next->prev = newblock;
        p->next = newblock;
        p->size = size;
    }

      out:
    /* Our block is in the middle */
    p->file_priv = file_priv;
    return p;
}

static struct mem_block *alloc_block(struct mem_block *heap, int size,
                     int align2, struct drm_file *file_priv)
{
    struct mem_block *p;
    int mask = (1 << align2) - 1;

    list_for_each(p, heap) {
        int start = (p->start + mask) & ~mask;
        if (p->file_priv == NULL && start + size <= p->start + p->size)
            return split_block(p, start, size, file_priv);
    }

    return NULL;
}

static struct mem_block *find_block(struct mem_block *heap, int start)
{
    struct mem_block *p;

    list_for_each(p, heap)
        if (p->start == start)
        return p;

    return NULL;
}

static void free_block(struct mem_block *p)
{
    p->file_priv = NULL;

    /* Assumes a single contiguous range.  Needs a special file_priv in
     * 'heap' to stop it being subsumed.
     */
    if (p->next->file_priv == NULL) {
        struct mem_block *q = p->next;
        p->size += q->size;
        p->next = q->next;
        p->next->prev = p;
        kfree(q);
    }

    if (p->prev->file_priv == NULL) {
        struct mem_block *q = p->prev;
        q->size += p->size;
        q->next = p->next;
        q->next->prev = q;
        kfree(p);
    }
}

/* Initialize.  How to check for an uninitialized heap?
 */
static int init_heap(struct mem_block **heap, int start, int size)
{
    struct mem_block *blocks = kmalloc(sizeof(*blocks), GFP_KERNEL);

    if (!blocks)
        return -ENOMEM;

    *heap = kzalloc(sizeof(**heap), GFP_KERNEL);
    if (!*heap) {
        kfree(blocks);
        return -ENOMEM;
    }

    blocks->start = start;
    blocks->size = size;
    blocks->file_priv = NULL;
    blocks->next = blocks->prev = *heap;

    (*heap)->file_priv = (struct drm_file *) - 1;
    (*heap)->next = (*heap)->prev = blocks;
    return 0;
}

/* Free all blocks associated with the releasing file.
 */
void radeon_mem_release(struct drm_file *file_priv, struct mem_block *heap)
{
    struct mem_block *p;

    if (!heap || !heap->next)
        return;

    list_for_each(p, heap) {
        if (p->file_priv == file_priv)
            p->file_priv = NULL;
    }

    /* Assumes a single contiguous range.  Needs a special file_priv in
     * 'heap' to stop it being subsumed.
     */
    list_for_each(p, heap) {
        while (p->file_priv == NULL && p->next->file_priv == NULL) {
            struct mem_block *q = p->next;
            p->size += q->size;
            p->next = q->next;
            p->next->prev = p;
            kfree(q);
        }
    }
}

/* Shutdown.
 */
void radeon_mem_takedown(struct mem_block **heap)
{
    struct mem_block *p;

    if (!*heap)
        return;

    for (p = (*heap)->next; p != *heap;) {
        struct mem_block *q = p;
        p = p->next;
        kfree(q);
    }

    kfree(*heap);
    *heap = NULL;
}

/* IOCTL HANDLERS */

static struct mem_block **get_heap(drm_radeon_private_t * dev_priv, int region)
{
    switch (region) {
    case RADEON_MEM_REGION_GART:
        return &dev_priv->gart_heap;
    case RADEON_MEM_REGION_FB:
        return &dev_priv->fb_heap;
    default:
        return NULL;
    }
}

int radeon_mem_alloc(struct drm_device *dev, void *data, struct drm_file *file_priv)
{
    drm_radeon_private_t *dev_priv = dev->dev_private;
    drm_radeon_mem_alloc_t *alloc = data;
    struct mem_block *block, **heap;

    if (!dev_priv) {
        DRM_ERROR("called with no initialization\n");
        return -EINVAL;
    }

    heap = get_heap(dev_priv, alloc->region);
    if (!heap || !*heap)
        return -EFAULT;

    /* Make things easier on ourselves: all allocations at least
     * 4k aligned.
     */
    if (alloc->alignment < 12)
        alloc->alignment = 12;

    block = alloc_block(*heap, alloc->size, alloc->alignment, file_priv);

    if (!block)
        return -ENOMEM;

    if (DRM_COPY_TO_USER(alloc->region_offset, &block->start,
                 sizeof(int))) {
        DRM_ERROR("copy_to_user\n");
        return -EFAULT;
    }

    return 0;
}

int radeon_mem_free(struct drm_device *dev, void *data, struct drm_file *file_priv)
{
    drm_radeon_private_t *dev_priv = dev->dev_private;
    drm_radeon_mem_free_t *memfree = data;
    struct mem_block *block, **heap;

    if (!dev_priv) {
        DRM_ERROR("called with no initialization\n");
        return -EINVAL;
    }

    heap = get_heap(dev_priv, memfree->region);
    if (!heap || !*heap)
        return -EFAULT;

    block = find_block(*heap, memfree->region_offset);
    if (!block)
        return -EFAULT;

    if (block->file_priv != file_priv)
        return -EPERM;

    free_block(block);
    return 0;
}

int radeon_mem_init_heap(struct drm_device *dev, void *data, struct drm_file *file_priv)
{
    drm_radeon_private_t *dev_priv = dev->dev_private;
    drm_radeon_mem_init_heap_t *initheap = data;
    struct mem_block **heap;

    if (!dev_priv) {
        DRM_ERROR("called with no initialization\n");
        return -EINVAL;
    }

    heap = get_heap(dev_priv, initheap->region);
    if (!heap)
        return -EFAULT;

    if (*heap) {
        DRM_ERROR("heap already initialized?");
        return -EFAULT;
    }

    return init_heap(heap, initheap->start, initheap->size);
}