[PATCH 2/3] drm/xen: Implement mmap as GEM object function
Oleksandr Andrushchenko
Oleksandr_Andrushchenko at epam.com
Mon Nov 8 02:46:44 PST 2021
Hi, Thomas!
On 08.11.21 12:28, Thomas Zimmermann wrote:
> Moving the driver-specific mmap code into a GEM object function allows
> for using DRM helpers for various mmap callbacks.
>
> The respective xen functions are being removed. The file_operations
> structure fops is now being created by the helper macro
> DEFINE_DRM_GEM_FOPS().
>
> Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
Reviewed-by: Oleksandr Andrushchenko <oleksandr_andrushchenko at epam.com>
> ---
> drivers/gpu/drm/xen/xen_drm_front.c | 16 +---
> drivers/gpu/drm/xen/xen_drm_front_gem.c | 108 +++++++++---------------
> drivers/gpu/drm/xen/xen_drm_front_gem.h | 7 --
> 3 files changed, 44 insertions(+), 87 deletions(-)
>
> diff --git a/drivers/gpu/drm/xen/xen_drm_front.c b/drivers/gpu/drm/xen/xen_drm_front.c
> index 9f14d99c763c..434064c820e8 100644
> --- a/drivers/gpu/drm/xen/xen_drm_front.c
> +++ b/drivers/gpu/drm/xen/xen_drm_front.c
> @@ -469,19 +469,7 @@ static void xen_drm_drv_release(struct drm_device *dev)
> kfree(drm_info);
> }
>
> -static const struct file_operations xen_drm_dev_fops = {
> - .owner = THIS_MODULE,
> - .open = drm_open,
> - .release = drm_release,
> - .unlocked_ioctl = drm_ioctl,
> -#ifdef CONFIG_COMPAT
> - .compat_ioctl = drm_compat_ioctl,
> -#endif
> - .poll = drm_poll,
> - .read = drm_read,
> - .llseek = no_llseek,
> - .mmap = xen_drm_front_gem_mmap,
> -};
> +DEFINE_DRM_GEM_FOPS(xen_drm_dev_fops);
>
> static const struct drm_driver xen_drm_driver = {
> .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
> @@ -489,7 +477,7 @@ static const struct drm_driver xen_drm_driver = {
> .prime_handle_to_fd = drm_gem_prime_handle_to_fd,
> .prime_fd_to_handle = drm_gem_prime_fd_to_handle,
> .gem_prime_import_sg_table = xen_drm_front_gem_import_sg_table,
> - .gem_prime_mmap = xen_drm_front_gem_prime_mmap,
> + .gem_prime_mmap = drm_gem_prime_mmap,
> .dumb_create = xen_drm_drv_dumb_create,
> .fops = &xen_drm_dev_fops,
> .name = "xendrm-du",
> diff --git a/drivers/gpu/drm/xen/xen_drm_front_gem.c b/drivers/gpu/drm/xen/xen_drm_front_gem.c
> index b293c67230ef..dd358ba2bf8e 100644
> --- a/drivers/gpu/drm/xen/xen_drm_front_gem.c
> +++ b/drivers/gpu/drm/xen/xen_drm_front_gem.c
> @@ -57,6 +57,47 @@ static void gem_free_pages_array(struct xen_gem_object *xen_obj)
> xen_obj->pages = NULL;
> }
>
> +static int xen_drm_front_gem_object_mmap(struct drm_gem_object *gem_obj,
> + struct vm_area_struct *vma)
> +{
> + struct xen_gem_object *xen_obj = to_xen_gem_obj(gem_obj);
> + int ret;
> +
> + vma->vm_ops = gem_obj->funcs->vm_ops;
> +
> + /*
> + * Clear the VM_PFNMAP flag that was set by drm_gem_mmap(), and set the
> + * vm_pgoff (used as a fake buffer offset by DRM) to 0 as we want to map
> + * the whole buffer.
> + */
> + vma->vm_flags &= ~VM_PFNMAP;
> + vma->vm_flags |= VM_MIXEDMAP;
> + vma->vm_pgoff = 0;
> +
> + /*
> + * According to Xen on ARM ABI (xen/include/public/arch-arm.h):
> + * all memory which is shared with other entities in the system
> + * (including the hypervisor and other guests) must reside in memory
> + * which is mapped as Normal Inner Write-Back Outer Write-Back
> + * Inner-Shareable.
> + */
> + vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
> +
> + /*
> + * vm_operations_struct.fault handler will be called if CPU access
> + * to VM is here. For GPUs this isn't the case, because CPU doesn't
> + * touch the memory. Insert pages now, so both CPU and GPU are happy.
> + *
> + * FIXME: as we insert all the pages now then no .fault handler must
> + * be called, so don't provide one
> + */
> + ret = vm_map_pages(vma, xen_obj->pages, xen_obj->num_pages);
> + if (ret < 0)
> + DRM_ERROR("Failed to map pages into vma: %d\n", ret);
> +
> + return ret;
> +}
> +
> static const struct vm_operations_struct xen_drm_drv_vm_ops = {
> .open = drm_gem_vm_open,
> .close = drm_gem_vm_close,
> @@ -67,6 +108,7 @@ static const struct drm_gem_object_funcs xen_drm_front_gem_object_funcs = {
> .get_sg_table = xen_drm_front_gem_get_sg_table,
> .vmap = xen_drm_front_gem_prime_vmap,
> .vunmap = xen_drm_front_gem_prime_vunmap,
> + .mmap = xen_drm_front_gem_object_mmap,
> .vm_ops = &xen_drm_drv_vm_ops,
> };
>
> @@ -238,58 +280,6 @@ xen_drm_front_gem_import_sg_table(struct drm_device *dev,
> return &xen_obj->base;
> }
>
> -static int gem_mmap_obj(struct xen_gem_object *xen_obj,
> - struct vm_area_struct *vma)
> -{
> - int ret;
> -
> - /*
> - * clear the VM_PFNMAP flag that was set by drm_gem_mmap(), and set the
> - * vm_pgoff (used as a fake buffer offset by DRM) to 0 as we want to map
> - * the whole buffer.
> - */
> - vma->vm_flags &= ~VM_PFNMAP;
> - vma->vm_flags |= VM_MIXEDMAP;
> - vma->vm_pgoff = 0;
> - /*
> - * According to Xen on ARM ABI (xen/include/public/arch-arm.h):
> - * all memory which is shared with other entities in the system
> - * (including the hypervisor and other guests) must reside in memory
> - * which is mapped as Normal Inner Write-Back Outer Write-Back
> - * Inner-Shareable.
> - */
> - vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
> -
> - /*
> - * vm_operations_struct.fault handler will be called if CPU access
> - * to VM is here. For GPUs this isn't the case, because CPU
> - * doesn't touch the memory. Insert pages now, so both CPU and GPU are
> - * happy.
> - * FIXME: as we insert all the pages now then no .fault handler must
> - * be called, so don't provide one
> - */
> - ret = vm_map_pages(vma, xen_obj->pages, xen_obj->num_pages);
> - if (ret < 0)
> - DRM_ERROR("Failed to map pages into vma: %d\n", ret);
> -
> - return ret;
> -}
> -
> -int xen_drm_front_gem_mmap(struct file *filp, struct vm_area_struct *vma)
> -{
> - struct xen_gem_object *xen_obj;
> - struct drm_gem_object *gem_obj;
> - int ret;
> -
> - ret = drm_gem_mmap(filp, vma);
> - if (ret < 0)
> - return ret;
> -
> - gem_obj = vma->vm_private_data;
> - xen_obj = to_xen_gem_obj(gem_obj);
> - return gem_mmap_obj(xen_obj, vma);
> -}
> -
> int xen_drm_front_gem_prime_vmap(struct drm_gem_object *gem_obj, struct dma_buf_map *map)
> {
> struct xen_gem_object *xen_obj = to_xen_gem_obj(gem_obj);
> @@ -313,17 +303,3 @@ void xen_drm_front_gem_prime_vunmap(struct drm_gem_object *gem_obj,
> {
> vunmap(map->vaddr);
> }
> -
> -int xen_drm_front_gem_prime_mmap(struct drm_gem_object *gem_obj,
> - struct vm_area_struct *vma)
> -{
> - struct xen_gem_object *xen_obj;
> - int ret;
> -
> - ret = drm_gem_mmap_obj(gem_obj, gem_obj->size, vma);
> - if (ret < 0)
> - return ret;
> -
> - xen_obj = to_xen_gem_obj(gem_obj);
> - return gem_mmap_obj(xen_obj, vma);
> -}
> diff --git a/drivers/gpu/drm/xen/xen_drm_front_gem.h b/drivers/gpu/drm/xen/xen_drm_front_gem.h
> index a4e67d0a149c..eaea470f7001 100644
> --- a/drivers/gpu/drm/xen/xen_drm_front_gem.h
> +++ b/drivers/gpu/drm/xen/xen_drm_front_gem.h
> @@ -15,9 +15,7 @@ struct dma_buf_attachment;
> struct dma_buf_map;
> struct drm_device;
> struct drm_gem_object;
> -struct file;
> struct sg_table;
> -struct vm_area_struct;
>
> struct drm_gem_object *xen_drm_front_gem_create(struct drm_device *dev,
> size_t size);
> @@ -33,15 +31,10 @@ struct page **xen_drm_front_gem_get_pages(struct drm_gem_object *obj);
>
> void xen_drm_front_gem_free_object_unlocked(struct drm_gem_object *gem_obj);
>
> -int xen_drm_front_gem_mmap(struct file *filp, struct vm_area_struct *vma);
> -
> int xen_drm_front_gem_prime_vmap(struct drm_gem_object *gem_obj,
> struct dma_buf_map *map);
>
> void xen_drm_front_gem_prime_vunmap(struct drm_gem_object *gem_obj,
> struct dma_buf_map *map);
>
> -int xen_drm_front_gem_prime_mmap(struct drm_gem_object *gem_obj,
> - struct vm_area_struct *vma);
> -
> #endif /* __XEN_DRM_FRONT_GEM_H */
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