nouveau_prime.c

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/*
 * Copyright 2011 Red Hat Inc.
 *
 * 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 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
 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) 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: Dave Airlie
 */

#include <linux/dma-buf.h>

#include <drm/drmP.h>

#include "nouveau_drm.h"
#include "nouveau_gem.h"

static struct sg_table *nouveau_gem_map_dma_buf(struct dma_buf_attachment *attachment,
                      enum dma_data_direction dir)
{
    struct nouveau_bo *nvbo = attachment->dmabuf->priv;
    struct drm_device *dev = nvbo->gem->dev;
    int npages = nvbo->bo.num_pages;
    struct sg_table *sg;
    int nents;

    mutex_lock(&dev->struct_mutex);
    sg = drm_prime_pages_to_sg(nvbo->bo.ttm->pages, npages);
    nents = dma_map_sg(attachment->dev, sg->sgl, sg->nents, dir);
    mutex_unlock(&dev->struct_mutex);
    return sg;
}

static void nouveau_gem_unmap_dma_buf(struct dma_buf_attachment *attachment,
                      struct sg_table *sg, enum dma_data_direction dir)
{
    dma_unmap_sg(attachment->dev, sg->sgl, sg->nents, dir);
    sg_free_table(sg);
    kfree(sg);
}

static void nouveau_gem_dmabuf_release(struct dma_buf *dma_buf)
{
    struct nouveau_bo *nvbo = dma_buf->priv;

    if (nvbo->gem->export_dma_buf == dma_buf) {
        nvbo->gem->export_dma_buf = NULL;
        drm_gem_object_unreference_unlocked(nvbo->gem);
    }
}

static void *nouveau_gem_kmap_atomic(struct dma_buf *dma_buf, unsigned long page_num)
{
    return NULL;
}

static void nouveau_gem_kunmap_atomic(struct dma_buf *dma_buf, unsigned long page_num, void *addr)
{

}
static void *nouveau_gem_kmap(struct dma_buf *dma_buf, unsigned long page_num)
{
    return NULL;
}

static void nouveau_gem_kunmap(struct dma_buf *dma_buf, unsigned long page_num, void *addr)
{

}

static int nouveau_gem_prime_mmap(struct dma_buf *dma_buf, struct vm_area_struct *vma)
{
    return -EINVAL;
}

static void *nouveau_gem_prime_vmap(struct dma_buf *dma_buf)
{
    struct nouveau_bo *nvbo = dma_buf->priv;
    struct drm_device *dev = nvbo->gem->dev;
    int ret;

    mutex_lock(&dev->struct_mutex);
    if (nvbo->vmapping_count) {
        nvbo->vmapping_count++;
        goto out_unlock;
    }

    ret = ttm_bo_kmap(&nvbo->bo, 0, nvbo->bo.num_pages,
              &nvbo->dma_buf_vmap);
    if (ret) {
        mutex_unlock(&dev->struct_mutex);
        return ERR_PTR(ret);
    }
    nvbo->vmapping_count = 1;
out_unlock:
    mutex_unlock(&dev->struct_mutex);
    return nvbo->dma_buf_vmap.virtual;
}

static void nouveau_gem_prime_vunmap(struct dma_buf *dma_buf, void *vaddr)
{
    struct nouveau_bo *nvbo = dma_buf->priv;
    struct drm_device *dev = nvbo->gem->dev;

    mutex_lock(&dev->struct_mutex);
    nvbo->vmapping_count--;
    if (nvbo->vmapping_count == 0) {
        ttm_bo_kunmap(&nvbo->dma_buf_vmap);
    }
    mutex_unlock(&dev->struct_mutex);
}

static const struct dma_buf_ops nouveau_dmabuf_ops =  {
    .map_dma_buf = nouveau_gem_map_dma_buf,
    .unmap_dma_buf = nouveau_gem_unmap_dma_buf,
    .release = nouveau_gem_dmabuf_release,
    .kmap = nouveau_gem_kmap,
    .kmap_atomic = nouveau_gem_kmap_atomic,
    .kunmap = nouveau_gem_kunmap,
    .kunmap_atomic = nouveau_gem_kunmap_atomic,
    .mmap = nouveau_gem_prime_mmap,
    .vmap = nouveau_gem_prime_vmap,
    .vunmap = nouveau_gem_prime_vunmap,
};

static int
nouveau_prime_new(struct drm_device *dev,
          size_t size,
          struct sg_table *sg,
          struct nouveau_bo **pnvbo)
{
    struct nouveau_bo *nvbo;
    u32 flags = 0;
    int ret;

    flags = TTM_PL_FLAG_TT;

    ret = nouveau_bo_new(dev, size, 0, flags, 0, 0,
                 sg, pnvbo);
    if (ret)
        return ret;
    nvbo = *pnvbo;

    /* we restrict allowed domains on nv50+ to only the types
     * that were requested at creation time.  not possibly on
     * earlier chips without busting the ABI.
     */
    nvbo->valid_domains = NOUVEAU_GEM_DOMAIN_GART;
    nvbo->gem = drm_gem_object_alloc(dev, nvbo->bo.mem.size);
    if (!nvbo->gem) {
        nouveau_bo_ref(NULL, pnvbo);
        return -ENOMEM;
    }

    nvbo->gem->driver_private = nvbo;
    return 0;
}

struct dma_buf *nouveau_gem_prime_export(struct drm_device *dev,
                struct drm_gem_object *obj, int flags)
{
    struct nouveau_bo *nvbo = nouveau_gem_object(obj);
    int ret = 0;

    /* pin buffer into GTT */
    ret = nouveau_bo_pin(nvbo, TTM_PL_FLAG_TT);
    if (ret)
        return ERR_PTR(-EINVAL);

    return dma_buf_export(nvbo, &nouveau_dmabuf_ops, obj->size, flags);
}

struct drm_gem_object *nouveau_gem_prime_import(struct drm_device *dev,
                struct dma_buf *dma_buf)
{
    struct dma_buf_attachment *attach;
    struct sg_table *sg;
    struct nouveau_bo *nvbo;
    int ret;

    if (dma_buf->ops == &nouveau_dmabuf_ops) {
        nvbo = dma_buf->priv;
        if (nvbo->gem) {
            if (nvbo->gem->dev == dev) {
                drm_gem_object_reference(nvbo->gem);
                return nvbo->gem;
            }
        }
    }
    /* need to attach */
    attach = dma_buf_attach(dma_buf, dev->dev);
    if (IS_ERR(attach))
        return ERR_PTR(PTR_ERR(attach));

    sg = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
    if (IS_ERR(sg)) {
        ret = PTR_ERR(sg);
        goto fail_detach;
    }

    ret = nouveau_prime_new(dev, dma_buf->size, sg, &nvbo);
    if (ret)
        goto fail_unmap;

    nvbo->gem->import_attach = attach;

    return nvbo->gem;

fail_unmap:
    dma_buf_unmap_attachment(attach, sg, DMA_BIDIRECTIONAL);
fail_detach:
    dma_buf_detach(dma_buf, attach);
    return ERR_PTR(ret);
}