[RFC 2/3] drm/gem: Add drm_gem_object_funcs
Daniel Vetter
daniel at ffwll.ch
Sat Sep 22 10:41:48 UTC 2018
On Fri, Sep 21, 2018 at 06:42:29PM +0200, Noralf Trønnes wrote:
> This adds an optional function table on GEM objects.
> The main benefit is for drivers that support more than one type of
> memory (shmem,vram,cma) for their buffers depending on the hardware it
> runs on. With the callbacks attached to the GEM object itself, it is
> easier to have core helpers for the the various buffer types. The driver
> only has to make the decision about buffer type on GEM object creation
> and all other callbacks can be handled by the chosen helper.
>
> drm_driver->gem_prime_res_obj has not been added since there's a todo to
> put a reservation_object into drm_gem_object.
>
> The individual drm_driver callbacks take priority over the GEM attached
> callbacks.
I'd do this the other way round, make the new gem callbacks the clearly
favoured option.
> Signed-off-by: Noralf Trønnes <noralf at tronnes.org>
> ---
> drivers/gpu/drm/drm_client.c | 12 ++--
> drivers/gpu/drm/drm_fb_helper.c | 8 ++-
> drivers/gpu/drm/drm_gem.c | 108 +++++++++++++++++++++++++++++--
> drivers/gpu/drm/drm_prime.c | 40 ++++++------
> include/drm/drm_gem.h | 138 ++++++++++++++++++++++++++++++++++++++++
> 5 files changed, 272 insertions(+), 34 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_client.c b/drivers/gpu/drm/drm_client.c
> index 17d9a64e885e..eca7331762e4 100644
> --- a/drivers/gpu/drm/drm_client.c
> +++ b/drivers/gpu/drm/drm_client.c
> @@ -80,8 +80,7 @@ int drm_client_new(struct drm_device *dev, struct drm_client_dev *client,
> {
> int ret;
>
> - if (!drm_core_check_feature(dev, DRIVER_MODESET) ||
> - !dev->driver->dumb_create || !dev->driver->gem_prime_vmap)
> + if (!drm_core_check_feature(dev, DRIVER_MODESET) || !dev->driver->dumb_create)
> return -EOPNOTSUPP;
I guess the ->gem_prime_vmap check got lost, needs to be readded somewhere
I think.
>
> if (funcs && !try_module_get(funcs->owner))
> @@ -212,8 +211,7 @@ static void drm_client_buffer_delete(struct drm_client_buffer *buffer)
> {
> struct drm_device *dev = buffer->client->dev;
>
> - if (buffer->vaddr && dev->driver->gem_prime_vunmap)
> - dev->driver->gem_prime_vunmap(buffer->gem, buffer->vaddr);
> + drm_gem_vunmap(buffer->gem, buffer->vaddr);
>
> if (buffer->gem)
> drm_gem_object_put_unlocked(buffer->gem);
> @@ -266,9 +264,9 @@ drm_client_buffer_create(struct drm_client_dev *client, u32 width, u32 height, u
> * fd_install step out of the driver backend hooks, to make that
> * final step optional for internal users.
> */
> - vaddr = dev->driver->gem_prime_vmap(obj);
> - if (!vaddr) {
> - ret = -ENOMEM;
> + vaddr = drm_gem_vmap(obj);
> + if (IS_ERR(vaddr)) {
> + ret = PTR_ERR(vaddr);
> goto err_delete;
> }
>
> diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
> index 8e95d0f7c71d..66969f0facbb 100644
> --- a/drivers/gpu/drm/drm_fb_helper.c
> +++ b/drivers/gpu/drm/drm_fb_helper.c
> @@ -38,6 +38,7 @@
> #include <drm/drmP.h>
> #include <drm/drm_crtc.h>
> #include <drm/drm_fb_helper.h>
> +#include <drm/drm_gem.h>
> #include <drm/drm_crtc_helper.h>
> #include <drm/drm_atomic.h>
> #include <drm/drm_atomic_helper.h>
> @@ -3010,9 +3011,12 @@ static void drm_fbdev_fb_destroy(struct fb_info *info)
> static int drm_fbdev_fb_mmap(struct fb_info *info, struct vm_area_struct *vma)
> {
> struct drm_fb_helper *fb_helper = info->par;
> + struct drm_gem_object *obj = fb_helper->buffer->gem;
>
> - if (fb_helper->dev->driver->gem_prime_mmap)
> - return fb_helper->dev->driver->gem_prime_mmap(fb_helper->buffer->gem, vma);
> + if (obj->dev->driver->gem_prime_mmap)
> + return obj->dev->driver->gem_prime_mmap(obj, vma);
> + else if (obj->funcs && obj->funcs->mmap)
> + return drm_gem_mmap_obj(obj, obj->size, vma);
> else
> return -ENODEV;
> }
> diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
> index 512078ebd97b..7da2549667ce 100644
> --- a/drivers/gpu/drm/drm_gem.c
> +++ b/drivers/gpu/drm/drm_gem.c
> @@ -259,6 +259,8 @@ drm_gem_object_release_handle(int id, void *ptr, void *data)
>
> if (dev->driver->gem_close_object)
> dev->driver->gem_close_object(obj, file_priv);
> + else if (obj->funcs && obj->funcs->close)
> + obj->funcs->close(obj, file_priv);
>
> if (drm_core_check_feature(dev, DRIVER_PRIME))
> drm_gem_remove_prime_handles(obj, file_priv);
> @@ -414,6 +416,10 @@ drm_gem_handle_create_tail(struct drm_file *file_priv,
> ret = dev->driver->gem_open_object(obj, file_priv);
> if (ret)
> goto err_revoke;
> + } else if (obj->funcs && obj->funcs->open) {
> + ret = obj->funcs->open(obj, file_priv);
> + if (ret)
> + goto err_revoke;
> }
>
> *handlep = handle;
> @@ -841,6 +847,8 @@ drm_gem_object_free(struct kref *kref)
> WARN_ON(!mutex_is_locked(&dev->struct_mutex));
>
> dev->driver->gem_free_object(obj);
> + } else if (obj->funcs) {
> + obj->funcs->free(obj);
> }
> }
> EXPORT_SYMBOL(drm_gem_object_free);
> @@ -864,13 +872,13 @@ drm_gem_object_put_unlocked(struct drm_gem_object *obj)
>
> dev = obj->dev;
>
> - if (dev->driver->gem_free_object_unlocked) {
> - kref_put(&obj->refcount, drm_gem_object_free);
> - } else {
> + if (dev->driver->gem_free_object) {
> might_lock(&dev->struct_mutex);
> if (kref_put_mutex(&obj->refcount, drm_gem_object_free,
> &dev->struct_mutex))
> mutex_unlock(&dev->struct_mutex);
> + } else {
> + kref_put(&obj->refcount, drm_gem_object_free);
> }
> }
> EXPORT_SYMBOL(drm_gem_object_put_unlocked);
> @@ -955,20 +963,30 @@ int drm_gem_mmap_obj(struct drm_gem_object *obj, unsigned long obj_size,
> struct vm_area_struct *vma)
> {
> struct drm_device *dev = obj->dev;
> + int ret;
>
> /* Check for valid size. */
> if (obj_size < vma->vm_end - vma->vm_start)
> return -EINVAL;
>
> - if (!dev->driver->gem_vm_ops)
> + if (dev->driver->gem_vm_ops)
> + vma->vm_ops = dev->driver->gem_vm_ops;
> + else if (obj->funcs && obj->funcs->vm_ops)
> + vma->vm_ops = obj->funcs->vm_ops;
> + else
> return -EINVAL;
A bit a bikeshed, but if we go with these new ops, I'd put them first in
all the if ladders. Makes it a bit clearer while reading that they're the
recommended option.
>
> vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP;
> - vma->vm_ops = dev->driver->gem_vm_ops;
> vma->vm_private_data = obj;
> vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
> vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot);
>
> + if (obj->funcs && obj->funcs->mmap) {
> + ret = obj->funcs->mmap(obj, vma);
> + if (ret)
> + return ret;
> + }
I'm confused about this one here ... this is for prime mmap only iirc.
> +
> /* Take a ref for this mapping of the object, so that the fault
> * handler can dereference the mmap offset's pointer to the object.
> * This reference is cleaned up by the corresponding vm_close
> @@ -1068,4 +1086,84 @@ void drm_gem_print_info(struct drm_printer *p, unsigned int indent,
>
> if (obj->dev->driver->gem_print_info)
> obj->dev->driver->gem_print_info(p, indent, obj);
> + else if (obj->funcs && obj->funcs->print_info)
> + obj->funcs->print_info(p, indent, obj);
> }
> +
> +/**
> + * drm_gem_pin - Pin backing buffer in memory
> + * @obj: GEM object
> + *
> + * Make sure the backing buffer is pinned in memory.
> + *
> + * Returns:
> + * 0 on success or a negative error code on failure.
> + */
> +int drm_gem_pin(struct drm_gem_object *obj)
> +{
> + if (obj->dev->driver->gem_prime_pin)
> + return obj->dev->driver->gem_prime_pin(obj);
> + else if (obj->funcs && obj->funcs->pin)
> + return obj->funcs->pin(obj);
> + else
> + return 0;
> +}
> +EXPORT_SYMBOL(drm_gem_pin);
> +
> +/**
> + * drm_gem_pin - Unpin backing buffer from memory
> + * @obj: GEM object
> + *
> + * Relax the requirement that the backing buffer is pinned in memory.
> + */
> +void drm_gem_unpin(struct drm_gem_object *obj)
> +{
> + if (obj->dev->driver->gem_prime_unpin)
> + obj->dev->driver->gem_prime_unpin(obj);
> + else if (obj->funcs && obj->funcs->unpin)
> + obj->funcs->unpin(obj);
> +}
> +EXPORT_SYMBOL(drm_gem_unpin);
> +
> +/**
> + * drm_gem_vmap - Map buffer into kernel virtual address space
> + * @obj: GEM object
> + *
> + * Returns:
> + * A virtual pointer to a newly created GEM object or an ERR_PTR-encoded negative
> + * error code on failure.
> + */
> +void *drm_gem_vmap(struct drm_gem_object *obj)
> +{
> + void *vaddr;
> +
> + if (obj->dev->driver->gem_prime_vmap)
> + vaddr = obj->dev->driver->gem_prime_vmap(obj);
> + else if (obj->funcs && obj->funcs->vmap)
> + vaddr = obj->funcs->vmap(obj);
> + else
> + vaddr = ERR_PTR(-EOPNOTSUPP);
> +
> + if (!vaddr)
> + vaddr = ERR_PTR(-ENOMEM);
> +
> + return vaddr;
> +}
> +EXPORT_SYMBOL(drm_gem_vmap);
> +
> +/**
> + * drm_gem_vunmap - Remove buffer mapping from kernel virtual address space
> + * @obj: GEM object
> + * @vaddr: Virtual address (can be NULL)
> + */
> +void drm_gem_vunmap(struct drm_gem_object *obj, void *vaddr)
> +{
> + if (!vaddr)
> + return;
> +
> + if (obj->dev->driver->gem_prime_vunmap)
> + obj->dev->driver->gem_prime_vunmap(obj, vaddr);
> + else if (obj->funcs && obj->funcs->vunmap)
> + obj->funcs->vunmap(obj, vaddr);
> +}
> +EXPORT_SYMBOL(drm_gem_vunmap);
> diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c
> index 6721571749ff..7f5c9500136b 100644
> --- a/drivers/gpu/drm/drm_prime.c
> +++ b/drivers/gpu/drm/drm_prime.c
> @@ -199,7 +199,6 @@ int drm_gem_map_attach(struct dma_buf *dma_buf,
> {
> struct drm_prime_attachment *prime_attach;
> struct drm_gem_object *obj = dma_buf->priv;
> - struct drm_device *dev = obj->dev;
>
> prime_attach = kzalloc(sizeof(*prime_attach), GFP_KERNEL);
> if (!prime_attach)
> @@ -208,10 +207,7 @@ int drm_gem_map_attach(struct dma_buf *dma_buf,
> prime_attach->dir = DMA_NONE;
> attach->priv = prime_attach;
>
> - if (!dev->driver->gem_prime_pin)
> - return 0;
> -
> - return dev->driver->gem_prime_pin(obj);
> + return drm_gem_pin(obj);
> }
> EXPORT_SYMBOL(drm_gem_map_attach);
>
> @@ -228,7 +224,6 @@ void drm_gem_map_detach(struct dma_buf *dma_buf,
> {
> struct drm_prime_attachment *prime_attach = attach->priv;
> struct drm_gem_object *obj = dma_buf->priv;
> - struct drm_device *dev = obj->dev;
>
> if (prime_attach) {
> struct sg_table *sgt = prime_attach->sgt;
> @@ -247,8 +242,7 @@ void drm_gem_map_detach(struct dma_buf *dma_buf,
> attach->priv = NULL;
> }
>
> - if (dev->driver->gem_prime_unpin)
> - dev->driver->gem_prime_unpin(obj);
> + drm_gem_unpin(obj);
> }
> EXPORT_SYMBOL(drm_gem_map_detach);
>
> @@ -310,7 +304,10 @@ struct sg_table *drm_gem_map_dma_buf(struct dma_buf_attachment *attach,
> if (WARN_ON(prime_attach->dir != DMA_NONE))
> return ERR_PTR(-EBUSY);
>
> - sgt = obj->dev->driver->gem_prime_get_sg_table(obj);
I think if we just check for obj->funcs here and then unconditionally
call, we avoid a bunch of pointer chasing for the new recommended path :-)
> + if (obj->dev->driver->gem_prime_get_sg_table)
> + sgt = obj->dev->driver->gem_prime_get_sg_table(obj);
> + else
> + sgt = obj->funcs->get_sg_table(obj);
>
> if (!IS_ERR(sgt)) {
> if (!dma_map_sg_attrs(attach->dev, sgt->sgl, sgt->nents, dir,
> @@ -406,12 +403,13 @@ EXPORT_SYMBOL(drm_gem_dmabuf_release);
> void *drm_gem_dmabuf_vmap(struct dma_buf *dma_buf)
> {
> struct drm_gem_object *obj = dma_buf->priv;
> - struct drm_device *dev = obj->dev;
> + void *vaddr;
>
> - if (dev->driver->gem_prime_vmap)
> - return dev->driver->gem_prime_vmap(obj);
> - else
> - return NULL;
> + vaddr = drm_gem_vmap(obj);
> + if (IS_ERR(vaddr))
> + vaddr = NULL;
> +
> + return vaddr;
> }
> EXPORT_SYMBOL(drm_gem_dmabuf_vmap);
>
> @@ -426,10 +424,8 @@ EXPORT_SYMBOL(drm_gem_dmabuf_vmap);
> void drm_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr)
> {
> struct drm_gem_object *obj = dma_buf->priv;
> - struct drm_device *dev = obj->dev;
>
> - if (dev->driver->gem_prime_vunmap)
> - dev->driver->gem_prime_vunmap(obj, vaddr);
> + drm_gem_vunmap(obj, vaddr);
> }
> EXPORT_SYMBOL(drm_gem_dmabuf_vunmap);
>
> @@ -476,10 +472,12 @@ int drm_gem_dmabuf_mmap(struct dma_buf *dma_buf, struct vm_area_struct *vma)
> struct drm_gem_object *obj = dma_buf->priv;
> struct drm_device *dev = obj->dev;
>
> - if (!dev->driver->gem_prime_mmap)
> + if (dev->driver->gem_prime_mmap)
> + return dev->driver->gem_prime_mmap(obj, vma);
> + else if (obj->funcs && obj->funcs->mmap)
> + return drm_gem_mmap_obj(obj, obj->size, vma);
> + else
> return -ENOSYS;
> -
> - return dev->driver->gem_prime_mmap(obj, vma);
> }
> EXPORT_SYMBOL(drm_gem_dmabuf_mmap);
>
> @@ -561,6 +559,8 @@ static struct dma_buf *export_and_register_object(struct drm_device *dev,
>
> if (dev->driver->gem_prime_export)
> dmabuf = dev->driver->gem_prime_export(dev, obj, flags);
> + else if (obj->funcs && obj->funcs->export)
> + dmabuf = obj->funcs->export(obj, flags);
> else
> dmabuf = drm_gem_prime_export(dev, obj, flags);
> if (IS_ERR(dmabuf)) {
> diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h
> index 3583b98a1718..3ae3665bf4e7 100644
> --- a/include/drm/drm_gem.h
> +++ b/include/drm/drm_gem.h
> @@ -38,6 +38,130 @@
>
> #include <drm/drm_vma_manager.h>
>
> +struct drm_gem_object;
> +
> +/**
> + * struct drm_gem_object_funcs - GEM object functions
> + */
> +struct drm_gem_object_funcs {
> + /**
> + * @free:
> + *
> + * Deconstructor for drm_gem_objects.
> + *
> + * This callback is mandatory.
> + */
> + void (*free)(struct drm_gem_object *obj);
> +
> + /**
> + * @open:
> + *
> + * Called upon GEM handle creation.
> + *
> + * This callback is optional.
> + */
> + int (*open)(struct drm_gem_object *obj, struct drm_file *file);
> +
> + /**
> + * @close_object:
@close:
> + *
> + * Called upon GEM handle release.
> + *
> + * This callback is optional.
> + */
> + void (*close)(struct drm_gem_object *obj, struct drm_file *file);
> +
> + /**
> + * @print_info:
> + *
> + * If driver subclasses struct &drm_gem_object, it can implement this
> + * optional hook for printing additional driver specific info.
> + *
> + * drm_printf_indent() should be used in the callback passing it the
> + * indent argument.
> + *
> + * This callback is called from drm_gem_print_info().
> + *
> + * This callback is optional.
> + */
> + void (*print_info)(struct drm_printer *p, unsigned int indent,
> + const struct drm_gem_object *obj);
> +
> + /**
> + * @export:
> + *
> + * Export backing buffer as a &dma_buf.
> + * If this is not set drm_gem_prime_export() is used.
> + *
> + * This callback is optional.
> + */
> + struct dma_buf *(*export)(struct drm_gem_object *obj, int flags);
> +
> + /*
> + * @pin:
> + *
> + * Pin backing buffer in memory.
> + *
> + * This callback is optional.
> + */
> + int (*pin)(struct drm_gem_object *obj);
> +
> + /*
> + * @unpin:
> + *
> + * Unpin backing buffer.
> + *
> + * This callback is optional.
> + */
> + void (*unpin)(struct drm_gem_object *obj);
> +
> + /*
> + * @get_sg_table:
> + *
> + * Returns a Scatter-Gather table representation of the buffer.
> + * Used when exporting a buffer.
> + *
> + * This callback is mandatory if buffer export is supported.
> + */
> + struct sg_table *(*get_sg_table)(struct drm_gem_object *obj);
> +
> + /*
> + * @vmap:
> + *
> + * Returns a virtual address for the buffer.
> + *
> + * This callback is optional.
> + */
> + void *(*vmap)(struct drm_gem_object *obj);
> +
> + /*
> + * @vunmap:
> + *
> + * Releases the the address previously returned by @vmap.
> + *
> + * This callback is optional.
> + */
> + void (*vunmap)(struct drm_gem_object *obj, void *vaddr);
> +
> + /*
> + * @mmap:
> + *
> + * Setup userspace mapping with the given vma.
> + *
> + * This callback is optional.
> + */
> + int (*mmap)(struct drm_gem_object *obj, struct vm_area_struct *vma);
> +
> + /**
> + * @vm_ops:
> + *
> + * Virtual memory operations used with mmap.
> + *
> + * This is optional but necessary for mmap support.
> + */
> + const struct vm_operations_struct *vm_ops;
> +};
I think fleshing out the docs a bit is a good opportunity here (and adding
links to the old place that the new ones recommended). But probably best
in follow-up patches.
> +
> /**
> * struct drm_gem_object - GEM buffer object
> *
> @@ -146,6 +270,15 @@ struct drm_gem_object {
> * simply leave it as NULL.
> */
> struct dma_buf_attachment *import_attach;
> +
> + /*
> + * @funcs:
> + *
> + * Optional GEM object functions. If this is set, it will be used if the
> + * corresponding &drm_driver GEM callback is not set.
Maybe also here a note that this is recommended over the callbacks in
&drm_driver.
Aside from all the tiny style suggestions, I really like this.
-Daniel
> + *
> + */
> + const struct drm_gem_object_funcs *funcs;
> };
>
> /**
> @@ -293,4 +426,9 @@ int drm_gem_dumb_destroy(struct drm_file *file,
> struct drm_device *dev,
> uint32_t handle);
>
> +int drm_gem_pin(struct drm_gem_object *obj);
> +void drm_gem_unpin(struct drm_gem_object *obj);
> +void *drm_gem_vmap(struct drm_gem_object *obj);
> +void drm_gem_vunmap(struct drm_gem_object *obj, void *vaddr);
> +
> #endif /* __DRM_GEM_H__ */
> --
> 2.15.1
>
> _______________________________________________
> dri-devel mailing list
> dri-devel at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
More information about the dri-devel
mailing list