radeon_prime.c

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/*
 * Copyright 2012 Advanced Micro Devices, 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.
 *
 * based on nouveau_prime.c
 *
 * Authors: Alex Deucher
 */
#include <drm/drmP.h>

#include "radeon.h"
#include <drm/radeon_drm.h>

#include <linux/dma-buf.h>

static struct sg_table *radeon_gem_map_dma_buf(struct dma_buf_attachment *attachment,
                           enum dma_data_direction dir)
{
    struct radeon_bo *bo = attachment->dmabuf->priv;
    struct drm_device *dev = bo->rdev->ddev;
    int npages = bo->tbo.num_pages;
    struct sg_table *sg;
    int nents;

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

static void radeon_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 radeon_gem_dmabuf_release(struct dma_buf *dma_buf)
{
    struct radeon_bo *bo = dma_buf->priv;

    if (bo->gem_base.export_dma_buf == dma_buf) {
        DRM_ERROR("unreference dmabuf %p\n", &bo->gem_base);
        bo->gem_base.export_dma_buf = NULL;
        drm_gem_object_unreference_unlocked(&bo->gem_base);
    }
}

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

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

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

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

}

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

static void *radeon_gem_prime_vmap(struct dma_buf *dma_buf)
{
    struct radeon_bo *bo = dma_buf->priv;
    struct drm_device *dev = bo->rdev->ddev;
    int ret;

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

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

static void radeon_gem_prime_vunmap(struct dma_buf *dma_buf, void *vaddr)
{
    struct radeon_bo *bo = dma_buf->priv;
    struct drm_device *dev = bo->rdev->ddev;

    mutex_lock(&dev->struct_mutex);
    bo->vmapping_count--;
    if (bo->vmapping_count == 0) {
        ttm_bo_kunmap(&bo->dma_buf_vmap);
    }
    mutex_unlock(&dev->struct_mutex);
}
const static struct dma_buf_ops radeon_dmabuf_ops =  {
    .map_dma_buf = radeon_gem_map_dma_buf,
    .unmap_dma_buf = radeon_gem_unmap_dma_buf,
    .release = radeon_gem_dmabuf_release,
    .kmap = radeon_gem_kmap,
    .kmap_atomic = radeon_gem_kmap_atomic,
    .kunmap = radeon_gem_kunmap,
    .kunmap_atomic = radeon_gem_kunmap_atomic,
    .mmap = radeon_gem_prime_mmap,
    .vmap = radeon_gem_prime_vmap,
    .vunmap = radeon_gem_prime_vunmap,
};

static int radeon_prime_create(struct drm_device *dev,
                   size_t size,
                   struct sg_table *sg,
                   struct radeon_bo **pbo)
{
    struct radeon_device *rdev = dev->dev_private;
    struct radeon_bo *bo;
    int ret;

    ret = radeon_bo_create(rdev, size, PAGE_SIZE, false,
                   RADEON_GEM_DOMAIN_GTT, sg, pbo);
    if (ret)
        return ret;
    bo = *pbo;
    bo->gem_base.driver_private = bo;

    mutex_lock(&rdev->gem.mutex);
    list_add_tail(&bo->list, &rdev->gem.objects);
    mutex_unlock(&rdev->gem.mutex);

    return 0;
}

struct dma_buf *radeon_gem_prime_export(struct drm_device *dev,
                    struct drm_gem_object *obj,
                    int flags)
{
    struct radeon_bo *bo = gem_to_radeon_bo(obj);
    int ret = 0;

    ret = radeon_bo_reserve(bo, false);
    if (unlikely(ret != 0))
        return ERR_PTR(ret);

    /* pin buffer into GTT */
    ret = radeon_bo_pin(bo, RADEON_GEM_DOMAIN_GTT, NULL);
    if (ret) {
        radeon_bo_unreserve(bo);
        return ERR_PTR(ret);
    }
    radeon_bo_unreserve(bo);
    return dma_buf_export(bo, &radeon_dmabuf_ops, obj->size, flags);
}

struct drm_gem_object *radeon_gem_prime_import(struct drm_device *dev,
                           struct dma_buf *dma_buf)
{
    struct dma_buf_attachment *attach;
    struct sg_table *sg;
    struct radeon_bo *bo;
    int ret;

    if (dma_buf->ops == &radeon_dmabuf_ops) {
        bo = dma_buf->priv;
        if (bo->gem_base.dev == dev) {
            drm_gem_object_reference(&bo->gem_base);
            return &bo->gem_base;
        }
    }

    /* need to attach */
    attach = dma_buf_attach(dma_buf, dev->dev);
    if (IS_ERR(attach))
        return ERR_CAST(attach);

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

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

    bo->gem_base.import_attach = attach;

    return &bo->gem_base;

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