drm: Integrate VRAM MM into struct drm_device (59f5989a) · Commits · 戴 / test

Documentation/gpu/drm-mm.rst

+6 −0

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		@@ -382,6 +382,12 @@ GEM CMA Helper Functions Reference
		VRAM Helper Function Reference
		==============================

		.. kernel-doc:: drivers/gpu/drm/drm_vram_helper_common.c
		:doc: overview

		.. kernel-doc:: include/drm/drm_gem_vram_helper.h
		:internal:

		GEM VRAM Helper Functions Reference
		-----------------------------------

drivers/gpu/drm/drm_gem_vram_helper.c

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		// SPDX-License-Identifier: GPL-2.0-or-later

		#include <drm/drm_gem_vram_helper.h>
		#include <drm/drm_device.h>
		#include <drm/drm_mode.h>
		#include <drm/drm_prime.h>
		#include <drm/drm_vram_mm_helper.h>
		@@ -555,6 +556,33 @@ void drm_gem_vram_driver_gem_free_object_unlocked(struct drm_gem_object *gem)
		}
		EXPORT_SYMBOL(drm_gem_vram_driver_gem_free_object_unlocked);

		/**
		* drm_gem_vram_driver_create_dumb() - \
		Implements &struct drm_driver.dumb_create
		* @file: the DRM file
		* @dev: the DRM device
		* @args: the arguments as provided to \
		&struct drm_driver.dumb_create
		*
		* This function requires the driver to use @drm_device.vram_mm for its
		* instance of VRAM MM.
		*
		* Returns:
		* 0 on success, or
		* a negative error code otherwise.
		*/
		int drm_gem_vram_driver_dumb_create(struct drm_file *file,
		struct drm_device *dev,
		struct drm_mode_create_dumb *args)
		{
		if (WARN_ONCE(!dev->vram_mm, "VRAM MM not initialized"))
		return -EINVAL;

		return drm_gem_vram_fill_create_dumb(file, dev, &dev->vram_mm->bdev, 0,
		false, args);
		}
		EXPORT_SYMBOL(drm_gem_vram_driver_dumb_create);

		/**
		* drm_gem_vram_driver_dumb_mmap_offset() - \
		Implements &struct drm_driver.dumb_mmap_offset

drivers/gpu/drm/drm_vram_helper_common.c

+92 −0

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		@@ -2,5 +2,97 @@

		#include <linux/module.h>

		/**
		* DOC: overview
		*
		* This library provides &struct drm_gem_vram_object (GEM VRAM), a GEM
		* buffer object that is backed by video RAM. It can be used for
		* framebuffer devices with dedicated memory. The video RAM can be
		* managed with &struct drm_vram_mm (VRAM MM). Both data structures are
		* supposed to be used together, but can also be used individually.
		*
		* With the GEM interface userspace applications create, manage and destroy
		* graphics buffers, such as an on-screen framebuffer. GEM does not provide
		* an implementation of these interfaces. It's up to the DRM driver to
		* provide an implementation that suits the hardware. If the hardware device
		* contains dedicated video memory, the DRM driver can use the VRAM helper
		* library. Each active buffer object is stored in video RAM. Active
		* buffer are used for drawing the current frame, typically something like
		* the frame's scanout buffer or the cursor image. If there's no more space
		* left in VRAM, inactive GEM objects can be moved to system memory.
		*
		* The easiest way to use the VRAM helper library is to call
		* drm_vram_helper_alloc_mm(). The function allocates and initializes an
		* instance of &struct drm_vram_mm in &struct drm_device.vram_mm . Use
		* &DRM_GEM_VRAM_DRIVER to initialize &struct drm_driver and
		* &DRM_VRAM_MM_FILE_OPERATIONS to initialize &struct file_operations;
		* as illustrated below.
		*
		* .. code-block:: c
		*
		* struct file_operations fops ={
		* .owner = THIS_MODULE,
		* DRM_VRAM_MM_FILE_OPERATION
		* };
		* struct drm_driver drv = {
		* .driver_feature = DRM_ ... ,
		* .fops = &fops,
		* DRM_GEM_VRAM_DRIVER
		* };
		*
		* int init_drm_driver()
		* {
		* struct drm_device *dev;
		* uint64_t vram_base;
		* unsigned long vram_size;
		* int ret;
		*
		* // setup device, vram base and size
		* // ...
		*
		* ret = drm_vram_helper_alloc_mm(dev, vram_base, vram_size,
		* &drm_gem_vram_mm_funcs);
		* if (ret)
		* return ret;
		* return 0;
		* }
		*
		* This creates an instance of &struct drm_vram_mm, exports DRM userspace
		* interfaces for GEM buffer management and initializes file operations to
		* allow for accessing created GEM buffers. With this setup, the DRM driver
		* manages an area of video RAM with VRAM MM and provides GEM VRAM objects
		* to userspace.
		*
		* To clean up the VRAM memory management, call drm_vram_helper_release_mm()
		* in the driver's clean-up code.
		*
		* .. code-block:: c
		*
		* void fini_drm_driver()
		* {
		* struct drm_device *dev = ...;
		*
		* drm_vram_helper_release_mm(dev);
		* }
		*
		* For drawing or scanout operations, buffer object have to be pinned in video
		* RAM. Call drm_gem_vram_pin() with &DRM_GEM_VRAM_PL_FLAG_VRAM or
		* &DRM_GEM_VRAM_PL_FLAG_SYSTEM to pin a buffer object in video RAM or system
		* memory. Call drm_gem_vram_unpin() to release the pinned object afterwards.
		* If you have to evict a buffer object from video RAM (e.g., for freeing up
		* memory), unpin the buffer and call drm_gem_vram_push_to_system().
		*
		* A buffer object that is pinned in video RAM has a fixed address within that
		* memory region. Call drm_gem_vram_offset() to retrieve this value. Typically
		* it's used to program the hardware's scanout engine for framebuffers, set
		* the cursor overlay's image for a mouse cursor, or use it as input to the
		* hardware's draing engine.
		*
		* To access a buffer object's memory from the DRM driver, call
		* drm_gem_vram_kmap(). It (optionally) maps the buffer into kernel address
		* space and returns the memory address. Use drm_gem_vram_kunmap() to
		* release the mapping.
		*/

		MODULE_DESCRIPTION("DRM VRAM memory-management helpers");
		MODULE_LICENSE("GPL");

drivers/gpu/drm/drm_vram_mm_helper.c

+85 −0

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		@@ -208,3 +208,88 @@ int drm_vram_mm_mmap(struct file filp, struct vm_area_struct vma,
		return ttm_bo_mmap(filp, vma, &vmm->bdev);
		}
		EXPORT_SYMBOL(drm_vram_mm_mmap);

		/*
		* Helpers for integration with struct drm_device
		*/

		/**
		* drm_vram_helper_alloc_mm - Allocates a device's instance of \
		&struct drm_vram_mm
		* @dev: the DRM device
		* @vram_base: the base address of the video memory
		* @vram_size: the size of the video memory in bytes
		* @funcs: callback functions for buffer objects
		*
		* Returns:
		* The new instance of &struct drm_vram_mm on success, or
		* an ERR_PTR()-encoded errno code otherwise.
		*/
		struct drm_vram_mm *drm_vram_helper_alloc_mm(
		struct drm_device *dev, uint64_t vram_base, size_t vram_size,
		const struct drm_vram_mm_funcs *funcs)
		{
		int ret;

		if (WARN_ON(dev->vram_mm))
		return dev->vram_mm;

		dev->vram_mm = kzalloc(sizeof(*dev->vram_mm), GFP_KERNEL);
		if (!dev->vram_mm)
		return ERR_PTR(-ENOMEM);

		ret = drm_vram_mm_init(dev->vram_mm, dev, vram_base, vram_size, funcs);
		if (ret)
		goto err_kfree;

		return dev->vram_mm;

		err_kfree:
		kfree(dev->vram_mm);
		dev->vram_mm = NULL;
		return ERR_PTR(ret);
		}
		EXPORT_SYMBOL(drm_vram_helper_alloc_mm);

		/**
		* drm_vram_helper_release_mm - Releases a device's instance of \
		&struct drm_vram_mm
		* @dev: the DRM device
		*/
		void drm_vram_helper_release_mm(struct drm_device *dev)
		{
		if (!dev->vram_mm)
		return;

		drm_vram_mm_cleanup(dev->vram_mm);
		kfree(dev->vram_mm);
		dev->vram_mm = NULL;
		}
		EXPORT_SYMBOL(drm_vram_helper_release_mm);

		/*
		* Helpers for &struct file_operations
		*/

		/**
		* drm_vram_mm_file_operations_mmap() - \
		Implements &struct file_operations.mmap()
		* @filp: the mapping's file structure
		* @vma: the mapping's memory area
		*
		* Returns:
		* 0 on success, or
		* a negative error code otherwise.
		*/
		int drm_vram_mm_file_operations_mmap(
		struct file filp, struct vm_area_struct vma)
		{
		struct drm_file *file_priv = filp->private_data;
		struct drm_device *dev = file_priv->minor->dev;

		if (WARN_ONCE(!dev->vram_mm, "VRAM MM not initialized"))
		return -EINVAL;

		return drm_vram_mm_mmap(filp, vma, dev->vram_mm);
		}
		EXPORT_SYMBOL(drm_vram_mm_file_operations_mmap);

include/drm/drm_device.h

+4 −0

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		@@ -17,6 +17,7 @@ struct drm_vblank_crtc;
		struct drm_sg_mem;
		struct drm_local_map;
		struct drm_vma_offset_manager;
		struct drm_vram_mm;
		struct drm_fb_helper;

		struct inode;
		@@ -286,6 +287,9 @@ struct drm_device {
		/** @vma_offset_manager: GEM information */
		struct drm_vma_offset_manager *vma_offset_manager;

		/** @vram_mm: VRAM MM memory manager */
		struct drm_vram_mm *vram_mm;

		/**
		* @switch_power_state:
		*

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