On Mon, Apr 23, 2012 at 7:43 AM, Inki Dae <inki.dae@xxxxxxxxxxx> wrote:
> this feature could be used to use memory region allocated by malloc() in user
> mode and mmaped memory region allocated by other memory allocators. userptr
> interface can identify memory type through vm_flags value and would get
> pages or page frame numbers to user space appropriately.
I apologize for being a little late to jump in on this thread, but...
I must confess to not being a huge fan of userptr. It really is
opening a can of worms, and seems best avoided if at all possible.
I'm not entirely sure the use-case for which you require this, but I
wonder if there isn't an alternative way? I mean, the main case I
could think of for mapping userspace memory would be something like
texture upload. But could that be handled in an alternative way,
something like a pwrite or texture_upload API, which could temporarily
pin the userspace memory, kick off a dma from that user buffer to a
proper GEM buffer, and then unpin the user buffer when the DMA
completes?
BR,
-R
> Signed-off-by: Inki Dae <inki.dae@xxxxxxxxxxx>
> Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
> ---
> drivers/gpu/drm/exynos/exynos_drm_drv.c | 2 +
> drivers/gpu/drm/exynos/exynos_drm_gem.c | 258 +++++++++++++++++++++++++++++++
> drivers/gpu/drm/exynos/exynos_drm_gem.h | 13 ++-
> include/drm/exynos_drm.h | 25 +++-
> 4 files changed, 296 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/exynos/exynos_drm_drv.c b/drivers/gpu/drm/exynos/exynos_drm_drv.c
> index f58a487..5bb0361 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_drv.c
> +++ b/drivers/gpu/drm/exynos/exynos_drm_drv.c
> @@ -211,6 +211,8 @@ static struct drm_ioctl_desc exynos_ioctls[] = {
> DRM_AUTH),
> DRM_IOCTL_DEF_DRV(EXYNOS_GEM_MMAP,
> exynos_drm_gem_mmap_ioctl, DRM_UNLOCKED | DRM_AUTH),
> + DRM_IOCTL_DEF_DRV(EXYNOS_GEM_USERPTR,
> + exynos_drm_gem_userptr_ioctl, DRM_UNLOCKED),
> DRM_IOCTL_DEF_DRV(EXYNOS_PLANE_SET_ZPOS, exynos_plane_set_zpos_ioctl,
> DRM_UNLOCKED | DRM_AUTH),
> DRM_IOCTL_DEF_DRV(EXYNOS_VIDI_CONNECTION,
> diff --git a/drivers/gpu/drm/exynos/exynos_drm_gem.c b/drivers/gpu/drm/exynos/exynos_drm_gem.c
> index afd0cd4..b68d4ea 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_gem.c
> +++ b/drivers/gpu/drm/exynos/exynos_drm_gem.c
> @@ -66,6 +66,43 @@ static int check_gem_flags(unsigned int flags)
> return 0;
> }
>
> +static struct vm_area_struct *get_vma(struct vm_area_struct *vma)
> +{
> + struct vm_area_struct *vma_copy;
> +
> + vma_copy = kmalloc(sizeof(*vma_copy), GFP_KERNEL);
> + if (!vma_copy)
> + return NULL;
> +
> + if (vma->vm_ops && vma->vm_ops->open)
> + vma->vm_ops->open(vma);
> +
> + if (vma->vm_file)
> + get_file(vma->vm_file);
> +
> + memcpy(vma_copy, vma, sizeof(*vma));
> +
> + vma_copy->vm_mm = NULL;
> + vma_copy->vm_next = NULL;
> + vma_copy->vm_prev = NULL;
> +
> + return vma_copy;
> +}
> +
> +static void put_vma(struct vm_area_struct *vma)
> +{
> + if (!vma)
> + return;
> +
> + if (vma->vm_ops && vma->vm_ops->close)
> + vma->vm_ops->close(vma);
> +
> + if (vma->vm_file)
> + fput(vma->vm_file);
> +
> + kfree(vma);
> +}
> +
> static void update_vm_cache_attr(struct exynos_drm_gem_obj *obj,
> struct vm_area_struct *vma)
> {
> @@ -254,6 +291,41 @@ static void exynos_drm_gem_put_pages(struct drm_gem_object *obj)
> /* add some codes for UNCACHED type here. TODO */
> }
>
> +static void exynos_drm_put_userptr(struct drm_gem_object *obj)
> +{
> + struct exynos_drm_gem_obj *exynos_gem_obj;
> + struct exynos_drm_gem_buf *buf;
> + struct vm_area_struct *vma;
> + int npages;
> +
> + exynos_gem_obj = to_exynos_gem_obj(obj);
> + buf = exynos_gem_obj->buffer;
> + vma = exynos_gem_obj->vma;
> +
> + if (vma && (vma->vm_flags & VM_PFNMAP) && (vma->vm_pgoff)) {
> + put_vma(exynos_gem_obj->vma);
> + goto out;
> + }
> +
> + npages = buf->size >> PAGE_SHIFT;
> +
> + npages--;
> + while (npages >= 0) {
> + if (buf->write)
> + set_page_dirty_lock(buf->pages[npages]);
> +
> + put_page(buf->pages[npages]);
> + npages--;
> + }
> +
> +out:
> + kfree(buf->pages);
> + buf->pages = NULL;
> +
> + kfree(buf->sgt);
> + buf->sgt = NULL;
> +}
> +
> static int exynos_drm_gem_handle_create(struct drm_gem_object *obj,
> struct drm_file *file_priv,
> unsigned int *handle)
> @@ -293,6 +365,8 @@ void exynos_drm_gem_destroy(struct exynos_drm_gem_obj *exynos_gem_obj)
>
> if (exynos_gem_obj->flags & EXYNOS_BO_NONCONTIG)
> exynos_drm_gem_put_pages(obj);
> + else if (exynos_gem_obj->flags & EXYNOS_BO_USERPTR)
> + exynos_drm_put_userptr(obj);
> else
> exynos_drm_free_buf(obj->dev, exynos_gem_obj->flags, buf);
>
> @@ -606,6 +680,190 @@ int exynos_drm_gem_mmap_ioctl(struct drm_device *dev, void *data,
> return 0;
> }
>
> +static int exynos_drm_get_userptr(struct drm_device *dev,
> + struct exynos_drm_gem_obj *obj,
> + unsigned long userptr,
> + unsigned int write)
> +{
> + unsigned int get_npages;
> + unsigned long npages = 0;
> + struct vm_area_struct *vma;
> + struct exynos_drm_gem_buf *buf = obj->buffer;
> +
> + vma = find_vma(current->mm, userptr);
> +
> + /* the memory region mmaped with VM_PFNMAP. */
> + if (vma && (vma->vm_flags & VM_PFNMAP) && (vma->vm_pgoff)) {
> + unsigned long this_pfn, prev_pfn, pa;
> + unsigned long start, end, offset;
> + struct scatterlist *sgl;
> +
> + start = userptr;
> + offset = userptr & ~PAGE_MASK;
> + end = start + buf->size;
> + sgl = buf->sgt->sgl;
> +
> + for (prev_pfn = 0; start < end; start += PAGE_SIZE) {
> + int ret = follow_pfn(vma, start, &this_pfn);
> + if (ret)
> + return ret;
> +
> + if (prev_pfn == 0)
> + pa = this_pfn << PAGE_SHIFT;
> + else if (this_pfn != prev_pfn + 1)
> + return -EFAULT;
> +
> + sg_dma_address(sgl) = (pa + offset);
> + sg_dma_len(sgl) = PAGE_SIZE;
> + prev_pfn = this_pfn;
> + pa += PAGE_SIZE;
> + npages++;
> + sgl = sg_next(sgl);
> + }
> +
> + buf->dma_addr = pa + offset;
> +
> + obj->vma = get_vma(vma);
> + if (!obj->vma)
> + return -ENOMEM;
> +
> + buf->pfnmap = true;
> +
> + return npages;
> + }
> +
> + buf->write = write;
> + npages = buf->size >> PAGE_SHIFT;
> +
> + down_read(¤t->mm->mmap_sem);
> + get_npages = get_user_pages(current, current->mm, userptr,
> + npages, write, 1, buf->pages, NULL);
> + up_read(¤t->mm->mmap_sem);
> + if (get_npages != npages)
> + DRM_ERROR("failed to get user_pages.\n");
> +
> + buf->pfnmap = false;
> +
> + return get_npages;
> +}
> +
> +int exynos_drm_gem_userptr_ioctl(struct drm_device *dev, void *data,
> + struct drm_file *file_priv)
> +{
> + struct exynos_drm_gem_obj *exynos_gem_obj;
> + struct drm_exynos_gem_userptr *args = data;
> + struct exynos_drm_gem_buf *buf;
> + struct scatterlist *sgl;
> + unsigned long size, userptr;
> + unsigned int npages;
> + int ret, get_npages;
> +
> + DRM_DEBUG_KMS("%s\n", __FILE__);
> +
> + if (!args->size) {
> + DRM_ERROR("invalid size.\n");
> + return -EINVAL;
> + }
> +
> + ret = check_gem_flags(args->flags);
> + if (ret)
> + return ret;
> +
> + size = roundup_gem_size(args->size, EXYNOS_BO_USERPTR);
> + userptr = args->userptr;
> +
> + buf = exynos_drm_init_buf(dev, size);
> + if (!buf)
> + return -ENOMEM;
> +
> + exynos_gem_obj = exynos_drm_gem_init(dev, size);
> + if (!exynos_gem_obj) {
> + ret = -ENOMEM;
> + goto err_free_buffer;
> + }
> +
> + buf->sgt = kzalloc(sizeof(struct sg_table), GFP_KERNEL);
> + if (!buf->sgt) {
> + DRM_ERROR("failed to allocate buf->sgt.\n");
> + ret = -ENOMEM;
> + goto err_release_gem;
> + }
> +
> + npages = size >> PAGE_SHIFT;
> +
> + ret = sg_alloc_table(buf->sgt, npages, GFP_KERNEL);
> + if (ret < 0) {
> + DRM_ERROR("failed to initailize sg table.\n");
> + goto err_free_sgt;
> + }
> +
> + buf->pages = kzalloc(npages * sizeof(struct page *), GFP_KERNEL);
> + if (!buf->pages) {
> + DRM_ERROR("failed to allocate buf->pages\n");
> + ret = -ENOMEM;
> + goto err_free_table;
> + }
> +
> + exynos_gem_obj->buffer = buf;
> +
> + get_npages = exynos_drm_get_userptr(dev, exynos_gem_obj, userptr, 1);
> + if (get_npages != npages) {
> + DRM_ERROR("failed to get user_pages.\n");
> + ret = get_npages;
> + goto err_release_userptr;
> + }
> +
> + ret = exynos_drm_gem_handle_create(&exynos_gem_obj->base, file_priv,
> + &args->handle);
> + if (ret < 0) {
> + DRM_ERROR("failed to create gem handle.\n");
> + goto err_release_userptr;
> + }
> +
> + sgl = buf->sgt->sgl;
> +
> + /*
> + * if buf->pfnmap is true then update sgl of sgt with pages but
> + * if buf->pfnmap is false then it means the sgl was updated already
> + * so it doesn't need to update the sgl.
> + */
> + if (!buf->pfnmap) {
> + unsigned int i = 0;
> +
> + /* set all pages to sg list. */
> + while (i < npages) {
> + sg_set_page(sgl, buf->pages[i], PAGE_SIZE, 0);
> + sg_dma_address(sgl) = page_to_phys(buf->pages[i]);
> + i++;
> + sgl = sg_next(sgl);
> + }
> + }
> +
> + /* always use EXYNOS_BO_USERPTR as memory type for userptr. */
> + exynos_gem_obj->flags |= EXYNOS_BO_USERPTR;
> +
> + return 0;
> +
> +err_release_userptr:
> + get_npages--;
> + while (get_npages >= 0)
> + put_page(buf->pages[get_npages--]);
> + kfree(buf->pages);
> + buf->pages = NULL;
> +err_free_table:
> + sg_free_table(buf->sgt);
> +err_free_sgt:
> + kfree(buf->sgt);
> + buf->sgt = NULL;
> +err_release_gem:
> + drm_gem_object_release(&exynos_gem_obj->base);
> + kfree(exynos_gem_obj);
> + exynos_gem_obj = NULL;
> +err_free_buffer:
> + exynos_drm_free_buf(dev, 0, buf);
> + return ret;
> +}
> +
> int exynos_drm_gem_init_object(struct drm_gem_object *obj)
> {
> DRM_DEBUG_KMS("%s\n", __FILE__);
> diff --git a/drivers/gpu/drm/exynos/exynos_drm_gem.h b/drivers/gpu/drm/exynos/exynos_drm_gem.h
> index efc8252..1de2241 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_gem.h
> +++ b/drivers/gpu/drm/exynos/exynos_drm_gem.h
> @@ -29,7 +29,8 @@
> #define to_exynos_gem_obj(x) container_of(x,\
> struct exynos_drm_gem_obj, base)
>
> -#define IS_NONCONTIG_BUFFER(f) (f & EXYNOS_BO_NONCONTIG)
> +#define IS_NONCONTIG_BUFFER(f) ((f & EXYNOS_BO_NONCONTIG) ||\
> + (f & EXYNOS_BO_USERPTR))
>
> /*
> * exynos drm gem buffer structure.
> @@ -38,18 +39,23 @@
> * @dma_addr: bus address(accessed by dma) to allocated memory region.
> * - this address could be physical address without IOMMU and
> * device address with IOMMU.
> + * @write: whether pages will be written to by the caller.
> * @sgt: sg table to transfer page data.
> * @pages: contain all pages to allocated memory region.
> * @page_size: could be 4K, 64K or 1MB.
> * @size: size of allocated memory region.
> + * @pfnmap: indicate whether memory region from userptr is mmaped with
> + * VM_PFNMAP or not.
> */
> struct exynos_drm_gem_buf {
> void __iomem *kvaddr;
> dma_addr_t dma_addr;
> + unsigned int write;
> struct sg_table *sgt;
> struct page **pages;
> unsigned long page_size;
> unsigned long size;
> + bool pfnmap;
> };
>
> /*
> @@ -73,6 +79,7 @@ struct exynos_drm_gem_obj {
> struct drm_gem_object base;
> struct exynos_drm_gem_buf *buffer;
> unsigned long size;
> + struct vm_area_struct *vma;
> unsigned int flags;
> };
>
> @@ -127,6 +134,10 @@ int exynos_drm_gem_map_offset_ioctl(struct drm_device *dev, void *data,
> int exynos_drm_gem_mmap_ioctl(struct drm_device *dev, void *data,
> struct drm_file *file_priv);
>
> +/* map user space allocated by malloc to pages. */
> +int exynos_drm_gem_userptr_ioctl(struct drm_device *dev, void *data,
> + struct drm_file *file_priv);
> +
> /* initialize gem object. */
> int exynos_drm_gem_init_object(struct drm_gem_object *obj);
>
> diff --git a/include/drm/exynos_drm.h b/include/drm/exynos_drm.h
> index 2d6eb06..48eda6e 100644
> --- a/include/drm/exynos_drm.h
> +++ b/include/drm/exynos_drm.h
> @@ -75,6 +75,23 @@ struct drm_exynos_gem_mmap {
> };
>
> /**
> + * User-requested user space importing structure
> + *
> + * @userptr: user space address allocated by malloc.
> + * @size: size to the buffer allocated by malloc.
> + * @flags: indicate user-desired cache attribute to map the allocated buffer
> + * to kernel space.
> + * @handle: a returned handle to created gem object.
> + * - this handle will be set by gem module of kernel side.
> + */
> +struct drm_exynos_gem_userptr {
> + uint64_t userptr;
> + uint64_t size;
> + unsigned int flags;
> + unsigned int handle;
> +};
> +
> +/**
> * A structure for user connection request of virtual display.
> *
> * @connection: indicate whether doing connetion or not by user.
> @@ -105,13 +122,16 @@ enum e_drm_exynos_gem_mem_type {
> EXYNOS_BO_CACHABLE = 1 << 1,
> /* write-combine mapping. */
> EXYNOS_BO_WC = 1 << 2,
> + /* user space memory allocated by malloc. */
> + EXYNOS_BO_USERPTR = 1 << 3,
> EXYNOS_BO_MASK = EXYNOS_BO_NONCONTIG | EXYNOS_BO_CACHABLE |
> - EXYNOS_BO_WC
> + EXYNOS_BO_WC | EXYNOS_BO_USERPTR
> };
>
> #define DRM_EXYNOS_GEM_CREATE 0x00
> #define DRM_EXYNOS_GEM_MAP_OFFSET 0x01
> #define DRM_EXYNOS_GEM_MMAP 0x02
> +#define DRM_EXYNOS_GEM_USERPTR 0x03
> /* Reserved 0x03 ~ 0x05 for exynos specific gem ioctl */
> #define DRM_EXYNOS_PLANE_SET_ZPOS 0x06
> #define DRM_EXYNOS_VIDI_CONNECTION 0x07
> @@ -125,6 +145,9 @@ enum e_drm_exynos_gem_mem_type {
> #define DRM_IOCTL_EXYNOS_GEM_MMAP DRM_IOWR(DRM_COMMAND_BASE + \
> DRM_EXYNOS_GEM_MMAP, struct drm_exynos_gem_mmap)
>
> +#define DRM_IOCTL_EXYNOS_GEM_USERPTR DRM_IOWR(DRM_COMMAND_BASE + \
> + DRM_EXYNOS_GEM_USERPTR, struct drm_exynos_gem_userptr)
> +
> #define DRM_IOCTL_EXYNOS_PLANE_SET_ZPOS DRM_IOWR(DRM_COMMAND_BASE + \
> DRM_EXYNOS_PLANE_SET_ZPOS, struct drm_exynos_plane_set_zpos)
>
> --
> 1.7.4.1
>
> _______________________________________________
> dri-devel mailing list
> dri-devel@xxxxxxxxxxxxxxxxxxxxx
> http://lists.freedesktop.org/mailman/listinfo/dri-devel
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