Commit 2194a63a authored by Noralf Trønnes's avatar Noralf Trønnes Committed by Eric Anholt
Browse files

drm: Add library for shmem backed GEM objects 



This adds a library for shmem backed GEM objects.

v8:
- export drm_gem_shmem_create_with_handle
- call mapping_set_gfp_mask to set default zone to GFP_HIGHUSER
- Add helper drm_gem_shmem_get_pages_sgt()

v7:
- Use write-combine for mmap instead. This is the more common
  case. (robher)

v6:
- Fix uninitialized variable issue in an error path (anholt).
- Add a drm_gem_shmem_vm_open() to the fops to get proper refcounting
  of the pages (anholt).

v5:
- Drop drm_gem_shmem_prime_mmap() (Daniel Vetter)
- drm_gem_shmem_mmap(): Subtract drm_vma_node_start() to get the real
  vma->vm_pgoff
- drm_gem_shmem_fault(): Use vmf->pgoff now that vma->vm_pgoff is correct

v4:
- Drop cache modes (Thomas Hellstrom)
- Add a GEM attached vtable

v3:
- Grammar (Sam Ravnborg)
- s/drm_gem_shmem_put_pages_unlocked/drm_gem_shmem_put_pages_locked/
  (Sam Ravnborg)
- Add debug output in error path (Sam Ravnborg)

Signed-off-by: default avatarNoralf Trønnes <noralf@tronnes.org>
Signed-off-by: default avatarEric Anholt <eric@anholt.net>
Signed-off-by: default avatarRob Herring <robh@kernel.org>
Signed-off-by: default avatarEric Anholt <eric@anholt.net>
Reviewed-by: default avatarEric Anholt <eric@anholt.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20190313004344.24169-1-robh@kernel.org
parent 2de3a078

Documentation/gpu/drm-kms-helpers.rst

+12 −0
Original line number Diff line number Diff line
@@ -369,3 +369,15 @@ Legacy CRTC/Modeset Helper Functions Reference 


.. kernel-doc:: drivers/gpu/drm/drm_crtc_helper.c

   :export:



SHMEM GEM Helper Reference

==========================



.. kernel-doc:: drivers/gpu/drm/drm_gem_shmem_helper.c

   :doc: overview



.. kernel-doc:: include/drm/drm_gem_shmem_helper.h

   :internal:



.. kernel-doc:: drivers/gpu/drm/drm_gem_shmem_helper.c

   :export:

drivers/gpu/drm/Kconfig

+6 −0
Original line number Diff line number Diff line
@@ -173,6 +173,12 @@ config DRM_KMS_CMA_HELPER 
	help

	  Choose this if you need the KMS CMA helper functions



config DRM_GEM_SHMEM_HELPER

	bool

	depends on DRM

	help

	  Choose this if you need the GEM shmem helper functions



config DRM_VM

	bool

	depends on DRM && MMU

drivers/gpu/drm/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -25,6 +25,7 @@ drm-$(CONFIG_DRM_LIB_RANDOM) += lib/drm_random.o 
drm-$(CONFIG_DRM_VM) += drm_vm.o

drm-$(CONFIG_COMPAT) += drm_ioc32.o

drm-$(CONFIG_DRM_GEM_CMA_HELPER) += drm_gem_cma_helper.o

drm-$(CONFIG_DRM_GEM_SHMEM_HELPER) += drm_gem_shmem_helper.o

drm-$(CONFIG_PCI) += ati_pcigart.o

drm-$(CONFIG_DRM_PANEL) += drm_panel.o

drm-$(CONFIG_OF) += drm_of.o

drivers/gpu/drm/drm_gem_shmem_helper.c

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+625 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/*

 * Copyright 2018 Noralf Trønnes

 */



#include <linux/dma-buf.h>

#include <linux/export.h>

#include <linux/mutex.h>

#include <linux/shmem_fs.h>

#include <linux/slab.h>

#include <linux/vmalloc.h>



#include <drm/drm_device.h>

#include <drm/drm_drv.h>

#include <drm/drm_gem_shmem_helper.h>

#include <drm/drm_prime.h>

#include <drm/drm_print.h>



/**

 * DOC: overview

 *

 * This library provides helpers for GEM objects backed by shmem buffers

 * allocated using anonymous pageable memory.

 */



static const struct drm_gem_object_funcs drm_gem_shmem_funcs = {

	.free = drm_gem_shmem_free_object,

	.print_info = drm_gem_shmem_print_info,

	.pin = drm_gem_shmem_pin,

	.unpin = drm_gem_shmem_unpin,

	.get_sg_table = drm_gem_shmem_get_sg_table,

	.vmap = drm_gem_shmem_vmap,

	.vunmap = drm_gem_shmem_vunmap,

	.vm_ops = &drm_gem_shmem_vm_ops,

};



/**

 * drm_gem_shmem_create - Allocate an object with the given size

 * @dev: DRM device

 * @size: Size of the object to allocate

 *

 * This function creates a shmem GEM object.

 *

 * Returns:

 * A struct drm_gem_shmem_object * on success or an ERR_PTR()-encoded negative

 * error code on failure.

 */

struct drm_gem_shmem_object *drm_gem_shmem_create(struct drm_device *dev, size_t size)

{

	struct drm_gem_shmem_object *shmem;

	struct drm_gem_object *obj;

	int ret;



	size = PAGE_ALIGN(size);



	if (dev->driver->gem_create_object)

		obj = dev->driver->gem_create_object(dev, size);

	else

		obj = kzalloc(sizeof(*shmem), GFP_KERNEL);

	if (!obj)

		return ERR_PTR(-ENOMEM);



	if (!obj->funcs)

		obj->funcs = &drm_gem_shmem_funcs;



	ret = drm_gem_object_init(dev, obj, size);

	if (ret)

		goto err_free;



	ret = drm_gem_create_mmap_offset(obj);

	if (ret)

		goto err_release;



	shmem = to_drm_gem_shmem_obj(obj);

	mutex_init(&shmem->pages_lock);

	mutex_init(&shmem->vmap_lock);



	/*

	 * Our buffers are kept pinned, so allocating them

	 * from the MOVABLE zone is a really bad idea, and

	 * conflicts with CMA. See comments above new_inode()

	 * why this is required _and_ expected if you're

	 * going to pin these pages.

	 */

	mapping_set_gfp_mask(obj->filp->f_mapping, GFP_HIGHUSER |

			     __GFP_RETRY_MAYFAIL | __GFP_NOWARN);



	return shmem;



err_release:

	drm_gem_object_release(obj);

err_free:

	kfree(obj);



	return ERR_PTR(ret);

}

EXPORT_SYMBOL_GPL(drm_gem_shmem_create);



/**

 * drm_gem_shmem_free_object - Free resources associated with a shmem GEM object

 * @obj: GEM object to free

 *

 * This function cleans up the GEM object state and frees the memory used to

 * store the object itself.

 */

void drm_gem_shmem_free_object(struct drm_gem_object *obj)

{

	struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);



	WARN_ON(shmem->vmap_use_count);



	if (obj->import_attach) {

		shmem->pages_use_count--;

		drm_prime_gem_destroy(obj, shmem->sgt);

		kvfree(shmem->pages);

	} else {

		if (shmem->sgt) {

			dma_unmap_sg(obj->dev->dev, shmem->sgt->sgl,

				     shmem->sgt->nents, DMA_BIDIRECTIONAL);



			drm_gem_shmem_put_pages(shmem);

			sg_free_table(shmem->sgt);

			kfree(shmem->sgt);

		}

	}



	WARN_ON(shmem->pages_use_count);



	drm_gem_object_release(obj);

	mutex_destroy(&shmem->pages_lock);

	mutex_destroy(&shmem->vmap_lock);

	kfree(shmem);

}

EXPORT_SYMBOL_GPL(drm_gem_shmem_free_object);



static int drm_gem_shmem_get_pages_locked(struct drm_gem_shmem_object *shmem)

{

	struct drm_gem_object *obj = &shmem->base;

	struct page **pages;



	if (shmem->pages_use_count++ > 0)

		return 0;



	pages = drm_gem_get_pages(obj);

	if (IS_ERR(pages)) {

		DRM_DEBUG_KMS("Failed to get pages (%ld)\n", PTR_ERR(pages));

		shmem->pages_use_count = 0;

		return PTR_ERR(pages);

	}



	shmem->pages = pages;



	return 0;

}



/*

 * drm_gem_shmem_get_pages - Allocate backing pages for a shmem GEM object

 * @shmem: shmem GEM object

 *

 * This function makes sure that backing pages exists for the shmem GEM object

 * and increases the use count.

 *

 * Returns:

 * 0 on success or a negative error code on failure.

 */

int drm_gem_shmem_get_pages(struct drm_gem_shmem_object *shmem)

{

	int ret;



	ret = mutex_lock_interruptible(&shmem->pages_lock);

	if (ret)

		return ret;

	ret = drm_gem_shmem_get_pages_locked(shmem);

	mutex_unlock(&shmem->pages_lock);



	return ret;

}

EXPORT_SYMBOL(drm_gem_shmem_get_pages);



static void drm_gem_shmem_put_pages_locked(struct drm_gem_shmem_object *shmem)

{

	struct drm_gem_object *obj = &shmem->base;



	if (WARN_ON_ONCE(!shmem->pages_use_count))

		return;



	if (--shmem->pages_use_count > 0)

		return;



	drm_gem_put_pages(obj, shmem->pages,

			  shmem->pages_mark_dirty_on_put,

			  shmem->pages_mark_accessed_on_put);

	shmem->pages = NULL;

}



/*

 * drm_gem_shmem_put_pages - Decrease use count on the backing pages for a shmem GEM object

 * @shmem: shmem GEM object

 *

 * This function decreases the use count and puts the backing pages when use drops to zero.

 */

void drm_gem_shmem_put_pages(struct drm_gem_shmem_object *shmem)

{

	mutex_lock(&shmem->pages_lock);

	drm_gem_shmem_put_pages_locked(shmem);

	mutex_unlock(&shmem->pages_lock);

}

EXPORT_SYMBOL(drm_gem_shmem_put_pages);



/**

 * drm_gem_shmem_pin - Pin backing pages for a shmem GEM object

 * @obj: GEM object

 *

 * This function makes sure the backing pages are pinned in memory while the

 * buffer is exported.

 *

 * Returns:

 * 0 on success or a negative error code on failure.

 */

int drm_gem_shmem_pin(struct drm_gem_object *obj)

{

	struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);



	return drm_gem_shmem_get_pages(shmem);

}

EXPORT_SYMBOL(drm_gem_shmem_pin);



/**

 * drm_gem_shmem_unpin - Unpin backing pages for a shmem GEM object

 * @obj: GEM object

 *

 * This function removes the requirement that the backing pages are pinned in

 * memory.

 */

void drm_gem_shmem_unpin(struct drm_gem_object *obj)

{

	struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);



	drm_gem_shmem_put_pages(shmem);

}

EXPORT_SYMBOL(drm_gem_shmem_unpin);



static void *drm_gem_shmem_vmap_locked(struct drm_gem_shmem_object *shmem)

{

	struct drm_gem_object *obj = &shmem->base;

	int ret;



	if (shmem->vmap_use_count++ > 0)

		return shmem->vaddr;



	ret = drm_gem_shmem_get_pages(shmem);

	if (ret)

		goto err_zero_use;



	if (obj->import_attach)

		shmem->vaddr = dma_buf_vmap(obj->import_attach->dmabuf);

	else

		shmem->vaddr = vmap(shmem->pages, obj->size >> PAGE_SHIFT, VM_MAP, PAGE_KERNEL);



	if (!shmem->vaddr) {

		DRM_DEBUG_KMS("Failed to vmap pages\n");

		ret = -ENOMEM;

		goto err_put_pages;

	}



	return shmem->vaddr;



err_put_pages:

	drm_gem_shmem_put_pages(shmem);

err_zero_use:

	shmem->vmap_use_count = 0;



	return ERR_PTR(ret);

}



/*

 * drm_gem_shmem_vmap - Create a virtual mapping for a shmem GEM object

 * @shmem: shmem GEM object

 *

 * This function makes sure that a virtual address exists for the buffer backing

 * the shmem GEM object.

 *

 * Returns:

 * 0 on success or a negative error code on failure.

 */

void *drm_gem_shmem_vmap(struct drm_gem_object *obj)

{

	struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);

	void *vaddr;

	int ret;



	ret = mutex_lock_interruptible(&shmem->vmap_lock);

	if (ret)

		return ERR_PTR(ret);

	vaddr = drm_gem_shmem_vmap_locked(shmem);

	mutex_unlock(&shmem->vmap_lock);



	return vaddr;

}

EXPORT_SYMBOL(drm_gem_shmem_vmap);



static void drm_gem_shmem_vunmap_locked(struct drm_gem_shmem_object *shmem)

{

	struct drm_gem_object *obj = &shmem->base;



	if (WARN_ON_ONCE(!shmem->vmap_use_count))

		return;



	if (--shmem->vmap_use_count > 0)

		return;



	if (obj->import_attach)

		dma_buf_vunmap(obj->import_attach->dmabuf, shmem->vaddr);

	else

		vunmap(shmem->vaddr);



	shmem->vaddr = NULL;

	drm_gem_shmem_put_pages(shmem);

}



/*

 * drm_gem_shmem_vunmap - Unmap a virtual mapping fo a shmem GEM object

 * @shmem: shmem GEM object

 *

 * This function removes the virtual address when use count drops to zero.

 */

void drm_gem_shmem_vunmap(struct drm_gem_object *obj, void *vaddr)

{

	struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);



	mutex_lock(&shmem->vmap_lock);

	drm_gem_shmem_vunmap_locked(shmem);

	mutex_unlock(&shmem->vmap_lock);

}

EXPORT_SYMBOL(drm_gem_shmem_vunmap);



struct drm_gem_shmem_object *

drm_gem_shmem_create_with_handle(struct drm_file *file_priv,

				 struct drm_device *dev, size_t size,

				 uint32_t *handle)

{

	struct drm_gem_shmem_object *shmem;

	int ret;



	shmem = drm_gem_shmem_create(dev, size);

	if (IS_ERR(shmem))

		return shmem;



	/*

	 * Allocate an 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, &shmem->base, handle);

	/* drop reference from allocate - handle holds it now. */

	drm_gem_object_put_unlocked(&shmem->base);

	if (ret)

		return ERR_PTR(ret);



	return shmem;

}

EXPORT_SYMBOL(drm_gem_shmem_create_with_handle);



/**

 * drm_gem_shmem_dumb_create - Create a dumb shmem buffer object

 * @file: DRM file structure to create the dumb buffer for

 * @dev: DRM device

 * @args: IOCTL data

 *

 * This function computes the pitch of the dumb buffer and rounds it up to an

 * integer number of bytes per pixel. Drivers for hardware that doesn't have

 * any additional restrictions on the pitch can directly use this function as

 * their &drm_driver.dumb_create callback.

 *

 * For hardware with additional restrictions, drivers can adjust the fields

 * set up by userspace before calling into this function.

 *

 * Returns:

 * 0 on success or a negative error code on failure.

 */

int drm_gem_shmem_dumb_create(struct drm_file *file, struct drm_device *dev,

			      struct drm_mode_create_dumb *args)

{

	u32 min_pitch = DIV_ROUND_UP(args->width * args->bpp, 8);

	struct drm_gem_shmem_object *shmem;



	if (!args->pitch || !args->size) {

		args->pitch = min_pitch;

		args->size = args->pitch * args->height;

	} else {

		/* ensure sane minimum values */

		if (args->pitch < min_pitch)

			args->pitch = min_pitch;

		if (args->size < args->pitch * args->height)

			args->size = args->pitch * args->height;

	}



	shmem = drm_gem_shmem_create_with_handle(file, dev, args->size, &args->handle);



	return PTR_ERR_OR_ZERO(shmem);

}

EXPORT_SYMBOL_GPL(drm_gem_shmem_dumb_create);



static vm_fault_t drm_gem_shmem_fault(struct vm_fault *vmf)

{

	struct vm_area_struct *vma = vmf->vma;

	struct drm_gem_object *obj = vma->vm_private_data;

	struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);

	loff_t num_pages = obj->size >> PAGE_SHIFT;

	struct page *page;



	if (vmf->pgoff > num_pages || WARN_ON_ONCE(!shmem->pages))

		return VM_FAULT_SIGBUS;



	page = shmem->pages[vmf->pgoff];



	return vmf_insert_page(vma, vmf->address, page);

}



static void drm_gem_shmem_vm_open(struct vm_area_struct *vma)

{

	struct drm_gem_object *obj = vma->vm_private_data;

	struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);

	int ret;



	ret = drm_gem_shmem_get_pages(shmem);

	WARN_ON_ONCE(ret != 0);



	drm_gem_vm_open(vma);

}



static void drm_gem_shmem_vm_close(struct vm_area_struct *vma)

{

	struct drm_gem_object *obj = vma->vm_private_data;

	struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);



	drm_gem_shmem_put_pages(shmem);

	drm_gem_vm_close(vma);

}



const struct vm_operations_struct drm_gem_shmem_vm_ops = {

	.fault = drm_gem_shmem_fault,

	.open = drm_gem_shmem_vm_open,

	.close = drm_gem_shmem_vm_close,

};

EXPORT_SYMBOL_GPL(drm_gem_shmem_vm_ops);



/**

 * drm_gem_shmem_mmap - Memory-map a shmem GEM object

 * @filp: File object

 * @vma: VMA for the area to be mapped

 *

 * This function implements an augmented version of the GEM DRM file mmap

 * operation for shmem objects. Drivers which employ the shmem helpers should

 * use this function as their &file_operations.mmap handler in the DRM device file's

 * file_operations structure.

 *

 * Instead of directly referencing this function, drivers should use the

 * DEFINE_DRM_GEM_SHMEM_FOPS() macro.

 *

 * Returns:

 * 0 on success or a negative error code on failure.

 */

int drm_gem_shmem_mmap(struct file *filp, struct vm_area_struct *vma)

{

	struct drm_gem_shmem_object *shmem;

	int ret;



	ret = drm_gem_mmap(filp, vma);

	if (ret)

		return ret;



	shmem = to_drm_gem_shmem_obj(vma->vm_private_data);



	ret = drm_gem_shmem_get_pages(shmem);

	if (ret) {

		drm_gem_vm_close(vma);

		return ret;

	}



	/* VM_PFNMAP was set by drm_gem_mmap() */

	vma->vm_flags &= ~VM_PFNMAP;

	vma->vm_flags |= VM_MIXEDMAP;



	/* Remove the fake offset */

	vma->vm_pgoff -= drm_vma_node_start(&shmem->base.vma_node);



	return 0;

}

EXPORT_SYMBOL_GPL(drm_gem_shmem_mmap);



/**

 * drm_gem_shmem_print_info() - Print &drm_gem_shmem_object info for debugfs

 * @p: DRM printer

 * @indent: Tab indentation level

 * @obj: GEM object

 */

void drm_gem_shmem_print_info(struct drm_printer *p, unsigned int indent,

			      const struct drm_gem_object *obj)

{

	const struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);



	drm_printf_indent(p, indent, "pages_use_count=%u\n", shmem->pages_use_count);

	drm_printf_indent(p, indent, "vmap_use_count=%u\n", shmem->vmap_use_count);

	drm_printf_indent(p, indent, "vaddr=%p\n", shmem->vaddr);

}

EXPORT_SYMBOL(drm_gem_shmem_print_info);



/**

 * drm_gem_shmem_get_sg_table - Provide a scatter/gather table of pinned

 *                              pages for a shmem GEM object

 * @obj: GEM object

 *

 * This function exports a scatter/gather table suitable for PRIME usage by

 * calling the standard DMA mapping API.

 *

 * Returns:

 * A pointer to the scatter/gather table of pinned pages or NULL on failure.

 */

struct sg_table *drm_gem_shmem_get_sg_table(struct drm_gem_object *obj)

{

	struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);



	return drm_prime_pages_to_sg(shmem->pages, obj->size >> PAGE_SHIFT);

}

EXPORT_SYMBOL_GPL(drm_gem_shmem_get_sg_table);



/**

 * drm_gem_shmem_get_pages_sgt - Pin pages, dma map them, and return a

 *				 scatter/gather table for a shmem GEM object.

 * @obj: GEM object

 *

 * This function returns a scatter/gather table suitable for driver usage. If

 * the sg table doesn't exist, the pages are pinned, dma-mapped, and a sg

 * table created.

 *

 * Returns:

 * A pointer to the scatter/gather table of pinned pages or errno on failure.

 */

struct sg_table *drm_gem_shmem_get_pages_sgt(struct drm_gem_object *obj)

{

	int ret;

	struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);

	struct sg_table *sgt;



	if (shmem->sgt)

		return shmem->sgt;



	WARN_ON(obj->import_attach);



	ret = drm_gem_shmem_get_pages(shmem);

	if (ret)

		return ERR_PTR(ret);



	sgt = drm_gem_shmem_get_sg_table(&shmem->base);

	if (IS_ERR(sgt)) {

		ret = PTR_ERR(sgt);

		goto err_put_pages;

	}

	/* Map the pages for use by the h/w. */

	dma_map_sg(obj->dev->dev, sgt->sgl, sgt->nents, DMA_BIDIRECTIONAL);



	shmem->sgt = sgt;



	return sgt;



err_put_pages:

	drm_gem_shmem_put_pages(shmem);

	return ERR_PTR(ret);

}

EXPORT_SYMBOL_GPL(drm_gem_shmem_get_pages_sgt);



/**

 * drm_gem_shmem_prime_import_sg_table - Produce a shmem GEM object from

 *                 another driver's scatter/gather table of pinned pages

 * @dev: Device to import into

 * @attach: DMA-BUF attachment

 * @sgt: Scatter/gather table of pinned pages

 *

 * This function imports a scatter/gather table exported via DMA-BUF by

 * another driver. Drivers that use the shmem helpers should set this as their

 * &drm_driver.gem_prime_import_sg_table callback.

 *

 * Returns:

 * A pointer to a newly created GEM object or an ERR_PTR-encoded negative

 * error code on failure.

 */

struct drm_gem_object *

drm_gem_shmem_prime_import_sg_table(struct drm_device *dev,

				    struct dma_buf_attachment *attach,

				    struct sg_table *sgt)

{

	size_t size = PAGE_ALIGN(attach->dmabuf->size);

	size_t npages = size >> PAGE_SHIFT;

	struct drm_gem_shmem_object *shmem;

	int ret;



	shmem = drm_gem_shmem_create(dev, size);

	if (IS_ERR(shmem))

		return ERR_CAST(shmem);



	shmem->pages = kvmalloc_array(npages, sizeof(struct page *), GFP_KERNEL);

	if (!shmem->pages) {

		ret = -ENOMEM;

		goto err_free_gem;

	}



	ret = drm_prime_sg_to_page_addr_arrays(sgt, shmem->pages, NULL, npages);

	if (ret < 0)

		goto err_free_array;



	shmem->sgt = sgt;

	shmem->pages_use_count = 1; /* Permanently pinned from our point of view */



	DRM_DEBUG_PRIME("size = %zu\n", size);



	return &shmem->base;



err_free_array:

	kvfree(shmem->pages);

err_free_gem:

	drm_gem_object_put_unlocked(&shmem->base);



	return ERR_PTR(ret);

}

EXPORT_SYMBOL_GPL(drm_gem_shmem_prime_import_sg_table);

include/drm/drm_gem_shmem_helper.h

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/* SPDX-License-Identifier: GPL-2.0 */



#ifndef __DRM_GEM_SHMEM_HELPER_H__

#define __DRM_GEM_SHMEM_HELPER_H__



#include <linux/fs.h>

#include <linux/mm.h>

#include <linux/mutex.h>



#include <drm/drm_file.h>

#include <drm/drm_gem.h>

#include <drm/drm_ioctl.h>

#include <drm/drm_prime.h>



struct dma_buf_attachment;

struct drm_mode_create_dumb;

struct drm_printer;

struct sg_table;



/**

 * struct drm_gem_shmem_object - GEM object backed by shmem

 */

struct drm_gem_shmem_object {

	/**

	 * @base: Base GEM object

	 */

	struct drm_gem_object base;



	/**

	 * @pages_lock: Protects the page table and use count

	 */

	struct mutex pages_lock;



	/**

	 * @pages: Page table

	 */

	struct page **pages;



	/**

	 * @pages_use_count:

	 *

	 * Reference count on the pages table.

	 * The pages are put when the count reaches zero.

	 */

	unsigned int pages_use_count;



	/**

	 * @pages_mark_dirty_on_put:

	 *

	 * Mark pages as dirty when they are put.

	 */

	unsigned int pages_mark_dirty_on_put    : 1;



	/**

	 * @pages_mark_accessed_on_put:

	 *

	 * Mark pages as accessed when they are put.

	 */

	unsigned int pages_mark_accessed_on_put : 1;



	/**

	 * @sgt: Scatter/gather table for imported PRIME buffers

	 */

	struct sg_table *sgt;



	/**

	 * @vmap_lock: Protects the vmap address and use count

	 */

	struct mutex vmap_lock;



	/**

	 * @vaddr: Kernel virtual address of the backing memory

	 */

	void *vaddr;



	/**

	 * @vmap_use_count:

	 *

	 * Reference count on the virtual address.

	 * The address are un-mapped when the count reaches zero.

	 */

	unsigned int vmap_use_count;

};



#define to_drm_gem_shmem_obj(obj) \

	container_of(obj, struct drm_gem_shmem_object, base)



/**

 * DEFINE_DRM_GEM_SHMEM_FOPS() - Macro to generate file operations for shmem drivers

 * @name: name for the generated structure

 *

 * This macro autogenerates a suitable &struct file_operations for shmem based

 * drivers, which can be assigned to &drm_driver.fops. Note that this structure

 * cannot be shared between drivers, because it contains a reference to the

 * current module using THIS_MODULE.

 *

 * Note that the declaration is already marked as static - if you need a

 * non-static version of this you're probably doing it wrong and will break the

 * THIS_MODULE reference by accident.

 */

#define DEFINE_DRM_GEM_SHMEM_FOPS(name) \

	static const struct file_operations name = {\

		.owner		= THIS_MODULE,\

		.open		= drm_open,\

		.release	= drm_release,\

		.unlocked_ioctl	= drm_ioctl,\

		.compat_ioctl	= drm_compat_ioctl,\

		.poll		= drm_poll,\

		.read		= drm_read,\

		.llseek		= noop_llseek,\

		.mmap		= drm_gem_shmem_mmap, \

	}



struct drm_gem_shmem_object *drm_gem_shmem_create(struct drm_device *dev, size_t size);

void drm_gem_shmem_free_object(struct drm_gem_object *obj);



int drm_gem_shmem_get_pages(struct drm_gem_shmem_object *shmem);

void drm_gem_shmem_put_pages(struct drm_gem_shmem_object *shmem);

int drm_gem_shmem_pin(struct drm_gem_object *obj);

void drm_gem_shmem_unpin(struct drm_gem_object *obj);

void *drm_gem_shmem_vmap(struct drm_gem_object *obj);

void drm_gem_shmem_vunmap(struct drm_gem_object *obj, void *vaddr);



struct drm_gem_shmem_object *

drm_gem_shmem_create_with_handle(struct drm_file *file_priv,

				 struct drm_device *dev, size_t size,

				 uint32_t *handle);

int drm_gem_shmem_dumb_create(struct drm_file *file, struct drm_device *dev,

			      struct drm_mode_create_dumb *args);



int drm_gem_shmem_mmap(struct file *filp, struct vm_area_struct *vma);



extern const struct vm_operations_struct drm_gem_shmem_vm_ops;



void drm_gem_shmem_print_info(struct drm_printer *p, unsigned int indent,

			      const struct drm_gem_object *obj);



struct sg_table *drm_gem_shmem_get_sg_table(struct drm_gem_object *obj);

struct drm_gem_object *

drm_gem_shmem_prime_import_sg_table(struct drm_device *dev,

				    struct dma_buf_attachment *attach,

				    struct sg_table *sgt);



struct sg_table *drm_gem_shmem_get_pages_sgt(struct drm_gem_object *obj);



/**

 * DRM_GEM_SHMEM_DRIVER_OPS - Default shmem GEM operations

 *

 * This macro provides a shortcut for setting the shmem GEM operations in

 * the &drm_driver structure.

 */

#define DRM_GEM_SHMEM_DRIVER_OPS \

	.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 = drm_gem_shmem_prime_import_sg_table, \

	.gem_prime_mmap		= drm_gem_prime_mmap, \

	.dumb_create		= drm_gem_shmem_dumb_create



#endif /* __DRM_GEM_SHMEM_HELPER_H__ */

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