drm: Integrate VRAM MM into struct drm_device

There's now a pointer to struct drm_vram_mm stored in struct drm_device.
DRM drivers that use VRAM MM should use this field to refer to their
instance of the data structure. Appropriate helpers are now provided as
well.

Adding struct drm_vram_mm to struct drm_device further avoids wrappers
and boilerplate code in drivers. This patch implements default functions
for callbacks in struct drm_driver and struct file_operations that use
the struct drm_vram_mm stored in struct drm_device. Drivers that need to
provide their own implementations can still do so.

The patch also adds documentation for the VRAM helper library in general.

v5:
	* set .llseek to no_llseek() from DRM_VRAM_MM_FILE_OPERATIONS
v4:
	* cleanups from checkpatch.pl
	* document VRAM helper library

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: http://patchwork.freedesktop.org/patch/msgid/20190508082630.15116-9-tzimmermann@suse.de
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
This commit is contained in:
Thomas Zimmermann 2019-05-08 10:26:18 +02:00 committed by Gerd Hoffmann
parent 5c9dcacfe5
commit 59f5989ad4
7 changed files with 266 additions and 1 deletions

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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
-----------------------------------

View File

@ -1,6 +1,7 @@
// 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

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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");

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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);

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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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@ -11,6 +11,7 @@
struct drm_mode_create_dumb;
struct drm_vram_mm_funcs;
struct filp;
struct vm_area_struct;
#define DRM_GEM_VRAM_PL_FLAG_VRAM TTM_PL_FLAG_VRAM
#define DRM_GEM_VRAM_PL_FLAG_SYSTEM TTM_PL_FLAG_SYSTEM
@ -115,10 +116,26 @@ extern const struct drm_vram_mm_funcs drm_gem_vram_mm_funcs;
*/
void drm_gem_vram_driver_gem_free_object_unlocked(struct drm_gem_object *gem);
int drm_gem_vram_driver_dumb_create(struct drm_file *file,
struct drm_device *dev,
struct drm_mode_create_dumb *args);
int drm_gem_vram_driver_dumb_mmap_offset(struct drm_file *file,
struct drm_device *dev,
uint32_t handle, uint64_t *offset);
/**
* define DRM_GEM_VRAM_DRIVER - default callback functions for \
&struct drm_driver
*
* Drivers that use VRAM MM and GEM VRAM can use this macro to initialize
* &struct drm_driver with default functions.
*/
#define DRM_GEM_VRAM_DRIVER \
.gem_free_object_unlocked = \
drm_gem_vram_driver_gem_free_object_unlocked, \
.dumb_create = drm_gem_vram_driver_dumb_create, \
.dumb_map_offset = drm_gem_vram_driver_dumb_mmap_offset
/*
* PRIME helpers for struct drm_driver
*/

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@ -66,4 +66,37 @@ void drm_vram_mm_cleanup(struct drm_vram_mm *vmm);
int drm_vram_mm_mmap(struct file *filp, struct vm_area_struct *vma,
struct drm_vram_mm *vmm);
/*
* Helpers for integration with struct drm_device
*/
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);
void drm_vram_helper_release_mm(struct drm_device *dev);
/*
* Helpers for &struct file_operations
*/
int drm_vram_mm_file_operations_mmap(
struct file *filp, struct vm_area_struct *vma);
/**
* define DRM_VRAM_MM_FILE_OPERATIONS - default callback functions for \
&struct file_operations
*
* Drivers that use VRAM MM can use this macro to initialize
* &struct file_operations with default functions.
*/
#define DRM_VRAM_MM_FILE_OPERATIONS \
.llseek = no_llseek, \
.read = drm_read, \
.poll = drm_poll, \
.unlocked_ioctl = drm_ioctl, \
.compat_ioctl = drm_compat_ioctl, \
.mmap = drm_vram_mm_file_operations_mmap, \
.open = drm_open, \
.release = drm_release \
#endif