exynos_drm_gem.c

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/* exynos_drm_gem.c
 *
 * Copyright (c) 2011 Samsung Electronics Co., Ltd.
 * Author: Inki Dae <[email protected]>
 *
 * 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
 * VA LINUX SYSTEMS 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.
 */

#include <drm/drmP.h>

#include <linux/shmem_fs.h>
#include <drm/exynos_drm.h>

#include "exynos_drm_drv.h"
#include "exynos_drm_gem.h"
#include "exynos_drm_buf.h"

static unsigned int convert_to_vm_err_msg(int msg)
{
    unsigned int out_msg;

    switch (msg) {
    case 0:
    case -ERESTARTSYS:
    case -EINTR:
        out_msg = VM_FAULT_NOPAGE;
        break;

    case -ENOMEM:
        out_msg = VM_FAULT_OOM;
        break;

    default:
        out_msg = VM_FAULT_SIGBUS;
        break;
    }

    return out_msg;
}

static int check_gem_flags(unsigned int flags)
{
    if (flags & ~(EXYNOS_BO_MASK)) {
        DRM_ERROR("invalid flags.\n");
        return -EINVAL;
    }

    return 0;
}

static void update_vm_cache_attr(struct exynos_drm_gem_obj *obj,
                    struct vm_area_struct *vma)
{
    DRM_DEBUG_KMS("flags = 0x%x\n", obj->flags);

    /* non-cachable as default. */
    if (obj->flags & EXYNOS_BO_CACHABLE)
        vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
    else if (obj->flags & EXYNOS_BO_WC)
        vma->vm_page_prot =
            pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
    else
        vma->vm_page_prot =
            pgprot_noncached(vm_get_page_prot(vma->vm_flags));
}

static unsigned long roundup_gem_size(unsigned long size, unsigned int flags)
{
    if (!IS_NONCONTIG_BUFFER(flags)) {
        if (size >= SZ_1M)
            return roundup(size, SECTION_SIZE);
        else if (size >= SZ_64K)
            return roundup(size, SZ_64K);
        else
            goto out;
    }
out:
    return roundup(size, PAGE_SIZE);
}

struct page **exynos_gem_get_pages(struct drm_gem_object *obj,
                        gfp_t gfpmask)
{
    struct page *p, **pages;
    int i, npages;

    npages = obj->size >> PAGE_SHIFT;

    pages = drm_malloc_ab(npages, sizeof(struct page *));
    if (pages == NULL)
        return ERR_PTR(-ENOMEM);

    for (i = 0; i < npages; i++) {
        p = alloc_page(gfpmask);
        if (IS_ERR(p))
            goto fail;
        pages[i] = p;
    }

    return pages;

fail:
    while (--i)
        __free_page(pages[i]);

    drm_free_large(pages);
    return ERR_CAST(p);
}

static void exynos_gem_put_pages(struct drm_gem_object *obj,
                    struct page **pages)
{
    int npages;

    npages = obj->size >> PAGE_SHIFT;

    while (--npages >= 0)
        __free_page(pages[npages]);

    drm_free_large(pages);
}

static int exynos_drm_gem_map_pages(struct drm_gem_object *obj,
                    struct vm_area_struct *vma,
                    unsigned long f_vaddr,
                    pgoff_t page_offset)
{
    struct exynos_drm_gem_obj *exynos_gem_obj = to_exynos_gem_obj(obj);
    struct exynos_drm_gem_buf *buf = exynos_gem_obj->buffer;
    unsigned long pfn;

    if (exynos_gem_obj->flags & EXYNOS_BO_NONCONTIG) {
        if (!buf->pages)
            return -EINTR;

        pfn = page_to_pfn(buf->pages[page_offset++]);
    } else
        pfn = (buf->dma_addr >> PAGE_SHIFT) + page_offset;

    return vm_insert_mixed(vma, f_vaddr, pfn);
}

static int exynos_drm_gem_get_pages(struct drm_gem_object *obj)
{
    struct exynos_drm_gem_obj *exynos_gem_obj = to_exynos_gem_obj(obj);
    struct exynos_drm_gem_buf *buf = exynos_gem_obj->buffer;
    struct scatterlist *sgl;
    struct page **pages;
    unsigned int npages, i = 0;
    int ret;

    if (buf->pages) {
        DRM_DEBUG_KMS("already allocated.\n");
        return -EINVAL;
    }

    pages = exynos_gem_get_pages(obj, GFP_HIGHUSER_MOVABLE);
    if (IS_ERR(pages)) {
        DRM_ERROR("failed to get pages.\n");
        return PTR_ERR(pages);
    }

    npages = obj->size >> PAGE_SHIFT;
    buf->page_size = PAGE_SIZE;

    buf->sgt = kzalloc(sizeof(struct sg_table), GFP_KERNEL);
    if (!buf->sgt) {
        DRM_ERROR("failed to allocate sg table.\n");
        ret = -ENOMEM;
        goto err;
    }

    ret = sg_alloc_table(buf->sgt, npages, GFP_KERNEL);
    if (ret < 0) {
        DRM_ERROR("failed to initialize sg table.\n");
        ret = -EFAULT;
        goto err1;
    }

    sgl = buf->sgt->sgl;

    /* set all pages to sg list. */
    while (i < npages) {
        sg_set_page(sgl, pages[i], PAGE_SIZE, 0);
        sg_dma_address(sgl) = page_to_phys(pages[i]);
        i++;
        sgl = sg_next(sgl);
    }

    /* add some codes for UNCACHED type here. TODO */

    buf->pages = pages;
    return ret;
err1:
    kfree(buf->sgt);
    buf->sgt = NULL;
err:
    exynos_gem_put_pages(obj, pages);
    return ret;

}

static void exynos_drm_gem_put_pages(struct drm_gem_object *obj)
{
    struct exynos_drm_gem_obj *exynos_gem_obj = to_exynos_gem_obj(obj);
    struct exynos_drm_gem_buf *buf = exynos_gem_obj->buffer;

    /*
     * if buffer typs is EXYNOS_BO_NONCONTIG then release all pages
     * allocated at gem fault handler.
     */
    sg_free_table(buf->sgt);
    kfree(buf->sgt);
    buf->sgt = NULL;

    exynos_gem_put_pages(obj, buf->pages);
    buf->pages = NULL;

    /* add some codes for UNCACHED type here. TODO */
}

static int exynos_drm_gem_handle_create(struct drm_gem_object *obj,
                    struct drm_file *file_priv,
                    unsigned int *handle)
{
    int ret;

    /*
     * allocate a id of idr table where the obj is registered
     * and handle has the id what user can see.
     */
    ret = drm_gem_handle_create(file_priv, obj, handle);
    if (ret)
        return ret;

    DRM_DEBUG_KMS("gem handle = 0x%x\n", *handle);

    /* drop reference from allocate - handle holds it now. */
    drm_gem_object_unreference_unlocked(obj);

    return 0;
}

void exynos_drm_gem_destroy(struct exynos_drm_gem_obj *exynos_gem_obj)
{
    struct drm_gem_object *obj;
    struct exynos_drm_gem_buf *buf;

    DRM_DEBUG_KMS("%s\n", __FILE__);

    obj = &exynos_gem_obj->base;
    buf = exynos_gem_obj->buffer;

    DRM_DEBUG_KMS("handle count = %d\n", atomic_read(&obj->handle_count));

    if (!buf->pages)
        return;

    /*
     * do not release memory region from exporter.
     *
     * the region will be released by exporter
     * once dmabuf's refcount becomes 0.
     */
    if (obj->import_attach)
        goto out;

    if (exynos_gem_obj->flags & EXYNOS_BO_NONCONTIG)
        exynos_drm_gem_put_pages(obj);
    else
        exynos_drm_free_buf(obj->dev, exynos_gem_obj->flags, buf);

out:
    exynos_drm_fini_buf(obj->dev, buf);
    exynos_gem_obj->buffer = NULL;

    if (obj->map_list.map)
        drm_gem_free_mmap_offset(obj);

    /* release file pointer to gem object. */
    drm_gem_object_release(obj);

    kfree(exynos_gem_obj);
    exynos_gem_obj = NULL;
}

struct exynos_drm_gem_obj *exynos_drm_gem_init(struct drm_device *dev,
                              unsigned long size)
{
    struct exynos_drm_gem_obj *exynos_gem_obj;
    struct drm_gem_object *obj;
    int ret;

    exynos_gem_obj = kzalloc(sizeof(*exynos_gem_obj), GFP_KERNEL);
    if (!exynos_gem_obj) {
        DRM_ERROR("failed to allocate exynos gem object\n");
        return NULL;
    }

    exynos_gem_obj->size = size;
    obj = &exynos_gem_obj->base;

    ret = drm_gem_object_init(dev, obj, size);
    if (ret < 0) {
        DRM_ERROR("failed to initialize gem object\n");
        kfree(exynos_gem_obj);
        return NULL;
    }

    DRM_DEBUG_KMS("created file object = 0x%x\n", (unsigned int)obj->filp);

    return exynos_gem_obj;
}

struct exynos_drm_gem_obj *exynos_drm_gem_create(struct drm_device *dev,
                        unsigned int flags,
                        unsigned long size)
{
    struct exynos_drm_gem_obj *exynos_gem_obj;
    struct exynos_drm_gem_buf *buf;
    int ret;

    if (!size) {
        DRM_ERROR("invalid size.\n");
        return ERR_PTR(-EINVAL);
    }

    size = roundup_gem_size(size, flags);
    DRM_DEBUG_KMS("%s\n", __FILE__);

    ret = check_gem_flags(flags);
    if (ret)
        return ERR_PTR(ret);

    buf = exynos_drm_init_buf(dev, size);
    if (!buf)
        return ERR_PTR(-ENOMEM);

    exynos_gem_obj = exynos_drm_gem_init(dev, size);
    if (!exynos_gem_obj) {
        ret = -ENOMEM;
        goto err_fini_buf;
    }

    exynos_gem_obj->buffer = buf;

    /* set memory type and cache attribute from user side. */
    exynos_gem_obj->flags = flags;

    /*
     * allocate all pages as desired size if user wants to allocate
     * physically non-continuous memory.
     */
    if (flags & EXYNOS_BO_NONCONTIG) {
        ret = exynos_drm_gem_get_pages(&exynos_gem_obj->base);
        if (ret < 0) {
            drm_gem_object_release(&exynos_gem_obj->base);
            goto err_fini_buf;
        }
    } else {
        ret = exynos_drm_alloc_buf(dev, buf, flags);
        if (ret < 0) {
            drm_gem_object_release(&exynos_gem_obj->base);
            goto err_fini_buf;
        }
    }

    return exynos_gem_obj;

err_fini_buf:
    exynos_drm_fini_buf(dev, buf);
    return ERR_PTR(ret);
}

int exynos_drm_gem_create_ioctl(struct drm_device *dev, void *data,
                struct drm_file *file_priv)
{
    struct drm_exynos_gem_create *args = data;
    struct exynos_drm_gem_obj *exynos_gem_obj;
    int ret;

    DRM_DEBUG_KMS("%s\n", __FILE__);

    exynos_gem_obj = exynos_drm_gem_create(dev, args->flags, args->size);
    if (IS_ERR(exynos_gem_obj))
        return PTR_ERR(exynos_gem_obj);

    ret = exynos_drm_gem_handle_create(&exynos_gem_obj->base, file_priv,
            &args->handle);
    if (ret) {
        exynos_drm_gem_destroy(exynos_gem_obj);
        return ret;
    }

    return 0;
}

void *exynos_drm_gem_get_dma_addr(struct drm_device *dev,
                    unsigned int gem_handle,
                    struct drm_file *file_priv)
{
    struct exynos_drm_gem_obj *exynos_gem_obj;
    struct drm_gem_object *obj;

    obj = drm_gem_object_lookup(dev, file_priv, gem_handle);
    if (!obj) {
        DRM_ERROR("failed to lookup gem object.\n");
        return ERR_PTR(-EINVAL);
    }

    exynos_gem_obj = to_exynos_gem_obj(obj);

    if (exynos_gem_obj->flags & EXYNOS_BO_NONCONTIG) {
        DRM_DEBUG_KMS("not support NONCONTIG type.\n");
        drm_gem_object_unreference_unlocked(obj);

        /* TODO */
        return ERR_PTR(-EINVAL);
    }

    return &exynos_gem_obj->buffer->dma_addr;
}

void exynos_drm_gem_put_dma_addr(struct drm_device *dev,
                    unsigned int gem_handle,
                    struct drm_file *file_priv)
{
    struct exynos_drm_gem_obj *exynos_gem_obj;
    struct drm_gem_object *obj;

    obj = drm_gem_object_lookup(dev, file_priv, gem_handle);
    if (!obj) {
        DRM_ERROR("failed to lookup gem object.\n");
        return;
    }

    exynos_gem_obj = to_exynos_gem_obj(obj);

    if (exynos_gem_obj->flags & EXYNOS_BO_NONCONTIG) {
        DRM_DEBUG_KMS("not support NONCONTIG type.\n");
        drm_gem_object_unreference_unlocked(obj);

        /* TODO */
        return;
    }

    drm_gem_object_unreference_unlocked(obj);

    /*
     * decrease obj->refcount one more time because we has already
     * increased it at exynos_drm_gem_get_dma_addr().
     */
    drm_gem_object_unreference_unlocked(obj);
}

int exynos_drm_gem_map_offset_ioctl(struct drm_device *dev, void *data,
                    struct drm_file *file_priv)
{
    struct drm_exynos_gem_map_off *args = data;

    DRM_DEBUG_KMS("%s\n", __FILE__);

    DRM_DEBUG_KMS("handle = 0x%x, offset = 0x%lx\n",
            args->handle, (unsigned long)args->offset);

    if (!(dev->driver->driver_features & DRIVER_GEM)) {
        DRM_ERROR("does not support GEM.\n");
        return -ENODEV;
    }

    return exynos_drm_gem_dumb_map_offset(file_priv, dev, args->handle,
            &args->offset);
}

static int exynos_drm_gem_mmap_buffer(struct file *filp,
                      struct vm_area_struct *vma)
{
    struct drm_gem_object *obj = filp->private_data;
    struct exynos_drm_gem_obj *exynos_gem_obj = to_exynos_gem_obj(obj);
    struct exynos_drm_gem_buf *buffer;
    unsigned long pfn, vm_size, usize, uaddr = vma->vm_start;
    int ret;

    DRM_DEBUG_KMS("%s\n", __FILE__);

    vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP;

    update_vm_cache_attr(exynos_gem_obj, vma);

    vm_size = usize = vma->vm_end - vma->vm_start;

    /*
     * a buffer contains information to physically continuous memory
     * allocated by user request or at framebuffer creation.
     */
    buffer = exynos_gem_obj->buffer;

    /* check if user-requested size is valid. */
    if (vm_size > buffer->size)
        return -EINVAL;

    if (exynos_gem_obj->flags & EXYNOS_BO_NONCONTIG) {
        int i = 0;

        if (!buffer->pages)
            return -EINVAL;

        vma->vm_flags |= VM_MIXEDMAP;

        do {
            ret = vm_insert_page(vma, uaddr, buffer->pages[i++]);
            if (ret) {
                DRM_ERROR("failed to remap user space.\n");
                return ret;
            }

            uaddr += PAGE_SIZE;
            usize -= PAGE_SIZE;
        } while (usize > 0);
    } else {
        /*
         * get page frame number to physical memory to be mapped
         * to user space.
         */
        pfn = ((unsigned long)exynos_gem_obj->buffer->dma_addr) >>
                                PAGE_SHIFT;

        DRM_DEBUG_KMS("pfn = 0x%lx\n", pfn);

        if (remap_pfn_range(vma, vma->vm_start, pfn, vm_size,
                    vma->vm_page_prot)) {
            DRM_ERROR("failed to remap pfn range.\n");
            return -EAGAIN;
        }
    }

    return 0;
}

static const struct file_operations exynos_drm_gem_fops = {
    .mmap = exynos_drm_gem_mmap_buffer,
};

int exynos_drm_gem_mmap_ioctl(struct drm_device *dev, void *data,
                  struct drm_file *file_priv)
{
    struct drm_exynos_gem_mmap *args = data;
    struct drm_gem_object *obj;
    unsigned int addr;

    DRM_DEBUG_KMS("%s\n", __FILE__);

    if (!(dev->driver->driver_features & DRIVER_GEM)) {
        DRM_ERROR("does not support GEM.\n");
        return -ENODEV;
    }

    obj = drm_gem_object_lookup(dev, file_priv, args->handle);
    if (!obj) {
        DRM_ERROR("failed to lookup gem object.\n");
        return -EINVAL;
    }

    obj->filp->f_op = &exynos_drm_gem_fops;
    obj->filp->private_data = obj;

    addr = vm_mmap(obj->filp, 0, args->size,
            PROT_READ | PROT_WRITE, MAP_SHARED, 0);

    drm_gem_object_unreference_unlocked(obj);

    if (IS_ERR((void *)addr))
        return PTR_ERR((void *)addr);

    args->mapped = addr;

    DRM_DEBUG_KMS("mapped = 0x%lx\n", (unsigned long)args->mapped);

    return 0;
}

int exynos_drm_gem_get_ioctl(struct drm_device *dev, void *data,
                      struct drm_file *file_priv)
{   struct exynos_drm_gem_obj *exynos_gem_obj;
    struct drm_exynos_gem_info *args = data;
    struct drm_gem_object *obj;

    mutex_lock(&dev->struct_mutex);

    obj = drm_gem_object_lookup(dev, file_priv, args->handle);
    if (!obj) {
        DRM_ERROR("failed to lookup gem object.\n");
        mutex_unlock(&dev->struct_mutex);
        return -EINVAL;
    }

    exynos_gem_obj = to_exynos_gem_obj(obj);

    args->flags = exynos_gem_obj->flags;
    args->size = exynos_gem_obj->size;

    drm_gem_object_unreference(obj);
    mutex_unlock(&dev->struct_mutex);

    return 0;
}

int exynos_drm_gem_init_object(struct drm_gem_object *obj)
{
    DRM_DEBUG_KMS("%s\n", __FILE__);

    return 0;
}

void exynos_drm_gem_free_object(struct drm_gem_object *obj)
{
    struct exynos_drm_gem_obj *exynos_gem_obj;
    struct exynos_drm_gem_buf *buf;

    DRM_DEBUG_KMS("%s\n", __FILE__);

    exynos_gem_obj = to_exynos_gem_obj(obj);
    buf = exynos_gem_obj->buffer;

    if (obj->import_attach)
        drm_prime_gem_destroy(obj, buf->sgt);

    exynos_drm_gem_destroy(to_exynos_gem_obj(obj));
}

int exynos_drm_gem_dumb_create(struct drm_file *file_priv,
                   struct drm_device *dev,
                   struct drm_mode_create_dumb *args)
{
    struct exynos_drm_gem_obj *exynos_gem_obj;
    int ret;

    DRM_DEBUG_KMS("%s\n", __FILE__);

    /*
     * alocate memory to be used for framebuffer.
     * - this callback would be called by user application
     *  with DRM_IOCTL_MODE_CREATE_DUMB command.
     */

    args->pitch = args->width * ((args->bpp + 7) / 8);
    args->size = args->pitch * args->height;

    exynos_gem_obj = exynos_drm_gem_create(dev, args->flags, args->size);
    if (IS_ERR(exynos_gem_obj))
        return PTR_ERR(exynos_gem_obj);

    ret = exynos_drm_gem_handle_create(&exynos_gem_obj->base, file_priv,
            &args->handle);
    if (ret) {
        exynos_drm_gem_destroy(exynos_gem_obj);
        return ret;
    }

    return 0;
}

int exynos_drm_gem_dumb_map_offset(struct drm_file *file_priv,
                   struct drm_device *dev, uint32_t handle,
                   uint64_t *offset)
{
    struct drm_gem_object *obj;
    int ret = 0;

    DRM_DEBUG_KMS("%s\n", __FILE__);

    mutex_lock(&dev->struct_mutex);

    /*
     * get offset of memory allocated for drm framebuffer.
     * - this callback would be called by user application
     *  with DRM_IOCTL_MODE_MAP_DUMB command.
     */

    obj = drm_gem_object_lookup(dev, file_priv, handle);
    if (!obj) {
        DRM_ERROR("failed to lookup gem object.\n");
        ret = -EINVAL;
        goto unlock;
    }

    if (!obj->map_list.map) {
        ret = drm_gem_create_mmap_offset(obj);
        if (ret)
            goto out;
    }

    *offset = (u64)obj->map_list.hash.key << PAGE_SHIFT;
    DRM_DEBUG_KMS("offset = 0x%lx\n", (unsigned long)*offset);

out:
    drm_gem_object_unreference(obj);
unlock:
    mutex_unlock(&dev->struct_mutex);
    return ret;
}

int exynos_drm_gem_dumb_destroy(struct drm_file *file_priv,
                struct drm_device *dev,
                unsigned int handle)
{
    int ret;

    DRM_DEBUG_KMS("%s\n", __FILE__);

    /*
     * obj->refcount and obj->handle_count are decreased and
     * if both them are 0 then exynos_drm_gem_free_object()
     * would be called by callback to release resources.
     */
    ret = drm_gem_handle_delete(file_priv, handle);
    if (ret < 0) {
        DRM_ERROR("failed to delete drm_gem_handle.\n");
        return ret;
    }

    return 0;
}

int exynos_drm_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
{
    struct drm_gem_object *obj = vma->vm_private_data;
    struct drm_device *dev = obj->dev;
    unsigned long f_vaddr;
    pgoff_t page_offset;
    int ret;

    page_offset = ((unsigned long)vmf->virtual_address -
            vma->vm_start) >> PAGE_SHIFT;
    f_vaddr = (unsigned long)vmf->virtual_address;

    mutex_lock(&dev->struct_mutex);

    ret = exynos_drm_gem_map_pages(obj, vma, f_vaddr, page_offset);
    if (ret < 0)
        DRM_ERROR("failed to map pages.\n");

    mutex_unlock(&dev->struct_mutex);

    return convert_to_vm_err_msg(ret);
}

int exynos_drm_gem_mmap(struct file *filp, struct vm_area_struct *vma)
{
    struct exynos_drm_gem_obj *exynos_gem_obj;
    struct drm_gem_object *obj;
    int ret;

    DRM_DEBUG_KMS("%s\n", __FILE__);

    /* set vm_area_struct. */
    ret = drm_gem_mmap(filp, vma);
    if (ret < 0) {
        DRM_ERROR("failed to mmap.\n");
        return ret;
    }

    obj = vma->vm_private_data;
    exynos_gem_obj = to_exynos_gem_obj(obj);

    ret = check_gem_flags(exynos_gem_obj->flags);
    if (ret) {
        drm_gem_vm_close(vma);
        drm_gem_free_mmap_offset(obj);
        return ret;
    }

    vma->vm_flags &= ~VM_PFNMAP;
    vma->vm_flags |= VM_MIXEDMAP;

    update_vm_cache_attr(exynos_gem_obj, vma);

    return ret;
}