[Intel-gfx] [PATCH] drm/vgem: Replace vgem_object_funcs with the common drm shmem helper

Daniel Vetter daniel at ffwll.ch
Fri Oct 9 22:43:23 UTC 2020


On Fri, Oct 09, 2020 at 06:16:06PM +0200, Daniel Vetter wrote:
> On Fri, Oct 9, 2020 at 12:21 PM Chris Wilson <chris at chris-wilson.co.uk> wrote:
> >
> > vgem is a minimalistic driver that provides shmemfs objects to
> > userspace that may then be used as an in-memory surface and transported
> > across dma-buf to other drivers. Since it's introduction,
> > drm_gem_shmem_helper now provides the same shmemfs facilities and so we
> > can trim vgem to wrap the helper.
> >
> > Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> > ---
> >  drivers/gpu/drm/Kconfig         |   1 +
> >  drivers/gpu/drm/vgem/vgem_drv.c | 281 ++------------------------------
> >  drivers/gpu/drm/vgem/vgem_drv.h |  11 --
> >  3 files changed, 13 insertions(+), 280 deletions(-)
> 
> Nice diffstat :-)
> 
> Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>

Just noticed, but I think with

	.dumb_create		= drm_gem_shmem_dumb_create,

you can delete a bunhc more :-)
-Daniel

> 
> >
> > diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
> > index 147d61b9674e..db2ff76638cd 100644
> > --- a/drivers/gpu/drm/Kconfig
> > +++ b/drivers/gpu/drm/Kconfig
> > @@ -278,6 +278,7 @@ source "drivers/gpu/drm/i915/Kconfig"
> >  config DRM_VGEM
> >         tristate "Virtual GEM provider"
> >         depends on DRM
> > +       select DRM_GEM_SHMEM_HELPER
> >         help
> >           Choose this option to get a virtual graphics memory manager,
> >           as used by Mesa's software renderer for enhanced performance.
> > diff --git a/drivers/gpu/drm/vgem/vgem_drv.c b/drivers/gpu/drm/vgem/vgem_drv.c
> > index fa54a6d1403d..73cb17c4f7a8 100644
> > --- a/drivers/gpu/drm/vgem/vgem_drv.c
> > +++ b/drivers/gpu/drm/vgem/vgem_drv.c
> > @@ -38,6 +38,7 @@
> >
> >  #include <drm/drm_drv.h>
> >  #include <drm/drm_file.h>
> > +#include <drm/drm_gem_shmem_helper.h>
> >  #include <drm/drm_ioctl.h>
> >  #include <drm/drm_managed.h>
> >  #include <drm/drm_prime.h>
> > @@ -50,87 +51,11 @@
> >  #define DRIVER_MAJOR   1
> >  #define DRIVER_MINOR   0
> >
> > -static const struct drm_gem_object_funcs vgem_gem_object_funcs;
> > -
> >  static struct vgem_device {
> >         struct drm_device drm;
> >         struct platform_device *platform;
> >  } *vgem_device;
> >
> > -static void vgem_gem_free_object(struct drm_gem_object *obj)
> > -{
> > -       struct drm_vgem_gem_object *vgem_obj = to_vgem_bo(obj);
> > -
> > -       kvfree(vgem_obj->pages);
> > -       mutex_destroy(&vgem_obj->pages_lock);
> > -
> > -       if (obj->import_attach)
> > -               drm_prime_gem_destroy(obj, vgem_obj->table);
> > -
> > -       drm_gem_object_release(obj);
> > -       kfree(vgem_obj);
> > -}
> > -
> > -static vm_fault_t vgem_gem_fault(struct vm_fault *vmf)
> > -{
> > -       struct vm_area_struct *vma = vmf->vma;
> > -       struct drm_vgem_gem_object *obj = vma->vm_private_data;
> > -       /* We don't use vmf->pgoff since that has the fake offset */
> > -       unsigned long vaddr = vmf->address;
> > -       vm_fault_t ret = VM_FAULT_SIGBUS;
> > -       loff_t num_pages;
> > -       pgoff_t page_offset;
> > -       page_offset = (vaddr - vma->vm_start) >> PAGE_SHIFT;
> > -
> > -       num_pages = DIV_ROUND_UP(obj->base.size, PAGE_SIZE);
> > -
> > -       if (page_offset >= num_pages)
> > -               return VM_FAULT_SIGBUS;
> > -
> > -       mutex_lock(&obj->pages_lock);
> > -       if (obj->pages) {
> > -               get_page(obj->pages[page_offset]);
> > -               vmf->page = obj->pages[page_offset];
> > -               ret = 0;
> > -       }
> > -       mutex_unlock(&obj->pages_lock);
> > -       if (ret) {
> > -               struct page *page;
> > -
> > -               page = shmem_read_mapping_page(
> > -                                       file_inode(obj->base.filp)->i_mapping,
> > -                                       page_offset);
> > -               if (!IS_ERR(page)) {
> > -                       vmf->page = page;
> > -                       ret = 0;
> > -               } else switch (PTR_ERR(page)) {
> > -                       case -ENOSPC:
> > -                       case -ENOMEM:
> > -                               ret = VM_FAULT_OOM;
> > -                               break;
> > -                       case -EBUSY:
> > -                               ret = VM_FAULT_RETRY;
> > -                               break;
> > -                       case -EFAULT:
> > -                       case -EINVAL:
> > -                               ret = VM_FAULT_SIGBUS;
> > -                               break;
> > -                       default:
> > -                               WARN_ON(PTR_ERR(page));
> > -                               ret = VM_FAULT_SIGBUS;
> > -                               break;
> > -               }
> > -
> > -       }
> > -       return ret;
> > -}
> > -
> > -static const struct vm_operations_struct vgem_gem_vm_ops = {
> > -       .fault = vgem_gem_fault,
> > -       .open = drm_gem_vm_open,
> > -       .close = drm_gem_vm_close,
> > -};
> > -
> >  static int vgem_open(struct drm_device *dev, struct drm_file *file)
> >  {
> >         struct vgem_file *vfile;
> > @@ -159,41 +84,25 @@ static void vgem_postclose(struct drm_device *dev, struct drm_file *file)
> >         kfree(vfile);
> >  }
> >
> > -static struct drm_vgem_gem_object *__vgem_gem_create(struct drm_device *dev,
> > +static struct drm_gem_shmem_object *__vgem_gem_create(struct drm_device *dev,
> >                                                 unsigned long size)
> >  {
> > -       struct drm_vgem_gem_object *obj;
> > -       int ret;
> > -
> > -       obj = kzalloc(sizeof(*obj), GFP_KERNEL);
> > -       if (!obj)
> > -               return ERR_PTR(-ENOMEM);
> > +       struct drm_gem_shmem_object *obj;
> >
> > -       obj->base.funcs = &vgem_gem_object_funcs;
> > -
> > -       ret = drm_gem_object_init(dev, &obj->base, roundup(size, PAGE_SIZE));
> > -       if (ret) {
> > -               kfree(obj);
> > -               return ERR_PTR(ret);
> > -       }
> > -
> > -       mutex_init(&obj->pages_lock);
> > +       obj = drm_gem_shmem_create(dev, round_up(size, PAGE_SIZE));
> > +       if (IS_ERR(obj))
> > +               return obj;
> >
> > +       obj->map_cached = true;
> >         return obj;
> >  }
> >
> > -static void __vgem_gem_destroy(struct drm_vgem_gem_object *obj)
> > -{
> > -       drm_gem_object_release(&obj->base);
> > -       kfree(obj);
> > -}
> > -
> >  static struct drm_gem_object *vgem_gem_create(struct drm_device *dev,
> >                                               struct drm_file *file,
> >                                               unsigned int *handle,
> >                                               unsigned long size)
> >  {
> > -       struct drm_vgem_gem_object *obj;
> > +       struct drm_gem_shmem_object *obj;
> >         int ret;
> >
> >         obj = __vgem_gem_create(dev, size);
> > @@ -239,96 +148,9 @@ static struct drm_ioctl_desc vgem_ioctls[] = {
> >         DRM_IOCTL_DEF_DRV(VGEM_FENCE_SIGNAL, vgem_fence_signal_ioctl, DRM_RENDER_ALLOW),
> >  };
> >
> > -static int vgem_mmap(struct file *filp, struct vm_area_struct *vma)
> > -{
> > -       unsigned long flags = vma->vm_flags;
> > -       int ret;
> > -
> > -       ret = drm_gem_mmap(filp, vma);
> > -       if (ret)
> > -               return ret;
> > -
> > -       /* Keep the WC mmaping set by drm_gem_mmap() but our pages
> > -        * are ordinary and not special.
> > -        */
> > -       vma->vm_flags = flags | VM_DONTEXPAND | VM_DONTDUMP;
> > -       return 0;
> > -}
> > -
> > -static const struct file_operations vgem_driver_fops = {
> > -       .owner          = THIS_MODULE,
> > -       .open           = drm_open,
> > -       .mmap           = vgem_mmap,
> > -       .poll           = drm_poll,
> > -       .read           = drm_read,
> > -       .unlocked_ioctl = drm_ioctl,
> > -       .compat_ioctl   = drm_compat_ioctl,
> > -       .release        = drm_release,
> > -};
> > -
> > -static struct page **vgem_pin_pages(struct drm_vgem_gem_object *bo)
> > -{
> > -       mutex_lock(&bo->pages_lock);
> > -       if (bo->pages_pin_count++ == 0) {
> > -               struct page **pages;
> > -
> > -               pages = drm_gem_get_pages(&bo->base);
> > -               if (IS_ERR(pages)) {
> > -                       bo->pages_pin_count--;
> > -                       mutex_unlock(&bo->pages_lock);
> > -                       return pages;
> > -               }
> > -
> > -               bo->pages = pages;
> > -       }
> > -       mutex_unlock(&bo->pages_lock);
> > -
> > -       return bo->pages;
> > -}
> > -
> > -static void vgem_unpin_pages(struct drm_vgem_gem_object *bo)
> > -{
> > -       mutex_lock(&bo->pages_lock);
> > -       if (--bo->pages_pin_count == 0) {
> > -               drm_gem_put_pages(&bo->base, bo->pages, true, true);
> > -               bo->pages = NULL;
> > -       }
> > -       mutex_unlock(&bo->pages_lock);
> > -}
> > -
> > -static int vgem_prime_pin(struct drm_gem_object *obj)
> > -{
> > -       struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
> > -       long n_pages = obj->size >> PAGE_SHIFT;
> > -       struct page **pages;
> > +DEFINE_DRM_GEM_FOPS(vgem_driver_fops);
> >
> > -       pages = vgem_pin_pages(bo);
> > -       if (IS_ERR(pages))
> > -               return PTR_ERR(pages);
> > -
> > -       /* Flush the object from the CPU cache so that importers can rely
> > -        * on coherent indirect access via the exported dma-address.
> > -        */
> > -       drm_clflush_pages(pages, n_pages);
> > -
> > -       return 0;
> > -}
> > -
> > -static void vgem_prime_unpin(struct drm_gem_object *obj)
> > -{
> > -       struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
> > -
> > -       vgem_unpin_pages(bo);
> > -}
> > -
> > -static struct sg_table *vgem_prime_get_sg_table(struct drm_gem_object *obj)
> > -{
> > -       struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
> > -
> > -       return drm_prime_pages_to_sg(obj->dev, bo->pages, bo->base.size >> PAGE_SHIFT);
> > -}
> > -
> > -static struct drm_gem_object* vgem_prime_import(struct drm_device *dev,
> > +static struct drm_gem_object *vgem_prime_import(struct drm_device *dev,
> >                                                 struct dma_buf *dma_buf)
> >  {
> >         struct vgem_device *vgem = container_of(dev, typeof(*vgem), drm);
> > @@ -336,85 +158,6 @@ static struct drm_gem_object* vgem_prime_import(struct drm_device *dev,
> >         return drm_gem_prime_import_dev(dev, dma_buf, &vgem->platform->dev);
> >  }
> >
> > -static struct drm_gem_object *vgem_prime_import_sg_table(struct drm_device *dev,
> > -                       struct dma_buf_attachment *attach, struct sg_table *sg)
> > -{
> > -       struct drm_vgem_gem_object *obj;
> > -       int npages;
> > -
> > -       obj = __vgem_gem_create(dev, attach->dmabuf->size);
> > -       if (IS_ERR(obj))
> > -               return ERR_CAST(obj);
> > -
> > -       npages = PAGE_ALIGN(attach->dmabuf->size) / PAGE_SIZE;
> > -
> > -       obj->table = sg;
> > -       obj->pages = kvmalloc_array(npages, sizeof(struct page *), GFP_KERNEL);
> > -       if (!obj->pages) {
> > -               __vgem_gem_destroy(obj);
> > -               return ERR_PTR(-ENOMEM);
> > -       }
> > -
> > -       obj->pages_pin_count++; /* perma-pinned */
> > -       drm_prime_sg_to_page_addr_arrays(obj->table, obj->pages, NULL,
> > -                                       npages);
> > -       return &obj->base;
> > -}
> > -
> > -static void *vgem_prime_vmap(struct drm_gem_object *obj)
> > -{
> > -       struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
> > -       long n_pages = obj->size >> PAGE_SHIFT;
> > -       struct page **pages;
> > -
> > -       pages = vgem_pin_pages(bo);
> > -       if (IS_ERR(pages))
> > -               return NULL;
> > -
> > -       return vmap(pages, n_pages, 0, pgprot_writecombine(PAGE_KERNEL));
> > -}
> > -
> > -static void vgem_prime_vunmap(struct drm_gem_object *obj, void *vaddr)
> > -{
> > -       struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
> > -
> > -       vunmap(vaddr);
> > -       vgem_unpin_pages(bo);
> > -}
> > -
> > -static int vgem_prime_mmap(struct drm_gem_object *obj,
> > -                          struct vm_area_struct *vma)
> > -{
> > -       int ret;
> > -
> > -       if (obj->size < vma->vm_end - vma->vm_start)
> > -               return -EINVAL;
> > -
> > -       if (!obj->filp)
> > -               return -ENODEV;
> > -
> > -       ret = call_mmap(obj->filp, vma);
> > -       if (ret)
> > -               return ret;
> > -
> > -       fput(vma->vm_file);
> > -       vma->vm_file = get_file(obj->filp);
> > -       vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
> > -       vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
> > -
> > -       return 0;
> > -}
> > -
> > -static const struct drm_gem_object_funcs vgem_gem_object_funcs = {
> > -       .free = vgem_gem_free_object,
> > -       .pin = vgem_prime_pin,
> > -       .unpin = vgem_prime_unpin,
> > -       .get_sg_table = vgem_prime_get_sg_table,
> > -       .vmap = vgem_prime_vmap,
> > -       .vunmap = vgem_prime_vunmap,
> > -       .vm_ops = &vgem_gem_vm_ops,
> > -};
> > -
> >  static struct drm_driver vgem_driver = {
> >         .driver_features                = DRIVER_GEM | DRIVER_RENDER,
> >         .open                           = vgem_open,
> > @@ -428,8 +171,8 @@ static struct drm_driver vgem_driver = {
> >         .prime_handle_to_fd = drm_gem_prime_handle_to_fd,
> >         .prime_fd_to_handle = drm_gem_prime_fd_to_handle,
> >         .gem_prime_import = vgem_prime_import,
> > -       .gem_prime_import_sg_table = vgem_prime_import_sg_table,
> > -       .gem_prime_mmap = vgem_prime_mmap,
> > +       .gem_prime_import_sg_table = drm_gem_shmem_prime_import_sg_table,
> > +       .gem_prime_mmap = drm_gem_prime_mmap,
> >
> >         .name   = DRIVER_NAME,
> >         .desc   = DRIVER_DESC,
> > diff --git a/drivers/gpu/drm/vgem/vgem_drv.h b/drivers/gpu/drm/vgem/vgem_drv.h
> > index 0ed300317f87..34cf63e6fb3d 100644
> > --- a/drivers/gpu/drm/vgem/vgem_drv.h
> > +++ b/drivers/gpu/drm/vgem/vgem_drv.h
> > @@ -39,17 +39,6 @@ struct vgem_file {
> >         struct mutex fence_mutex;
> >  };
> >
> > -#define to_vgem_bo(x) container_of(x, struct drm_vgem_gem_object, base)
> > -struct drm_vgem_gem_object {
> > -       struct drm_gem_object base;
> > -
> > -       struct page **pages;
> > -       unsigned int pages_pin_count;
> > -       struct mutex pages_lock;
> > -
> > -       struct sg_table *table;
> > -};
> > -
> >  int vgem_fence_open(struct vgem_file *file);
> >  int vgem_fence_attach_ioctl(struct drm_device *dev,
> >                             void *data,
> > --
> > 2.20.1
> >
> > _______________________________________________
> > Intel-gfx mailing list
> > Intel-gfx at lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/intel-gfx
> 
> 
> 
> -- 
> Daniel Vetter
> Software Engineer, Intel Corporation
> http://blog.ffwll.ch

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch


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