// SPDX-License-Identifier: GPL-2.0-or-later
#include <drm/drm_device.h>
#include <drm/drm_file.h>
#include <drm/drm_vram_mm_helper.h>
#include <drm/ttm/ttm_page_alloc.h>
/**
* DOC: overview
*
* The data structure &struct drm_vram_mm and its helpers implement a memory
* manager for simple framebuffer devices with dedicated video memory. Buffer
* objects are either placed in video RAM or evicted to system memory. These
* helper functions work well with &struct drm_gem_vram_object.
*/
/*
* TTM TT
*/
static void backend_func_destroy(struct ttm_tt *tt)
{
ttm_tt_fini(tt);
kfree(tt);
}
static struct ttm_backend_func backend_func = {
.destroy = backend_func_destroy
};
/*
* TTM BO device
*/
static struct ttm_tt *bo_driver_ttm_tt_create(struct ttm_buffer_object *bo,
uint32_t page_flags)
{
struct ttm_tt *tt;
int ret;
tt = kzalloc(sizeof(*tt), GFP_KERNEL);
if (!tt)
return NULL;
tt->func = &backend_func;
ret = ttm_tt_init(tt, bo, page_flags);
if (ret < 0)
goto err_ttm_tt_init;
return tt;
err_ttm_tt_init:
kfree(tt);
return NULL;
}
static int bo_driver_init_mem_type(struct ttm_bo_device *bdev, uint32_t type,
struct ttm_mem_type_manager *man)
{
switch (type) {
case TTM_PL_SYSTEM:
man->flags = TTM_MEMTYPE_FLAG_MAPPABLE;
man->available_caching = TTM_PL_MASK_CACHING;
man->default_caching = TTM_PL_FLAG_CACHED;
break;
case TTM_PL_VRAM:
man->func = &ttm_bo_manager_func;
man->flags = TTM_MEMTYPE_FLAG_FIXED |
TTM_MEMTYPE_FLAG_MAPPABLE;
man->available_caching = TTM_PL_FLAG_UNCACHED |
TTM_PL_FLAG_WC;
man->default_caching = TTM_PL_FLAG_WC;
break;
default:
return -EINVAL;
}
return 0;
}
static void bo_driver_evict_flags(struct ttm_buffer_object *bo,
struct ttm_placement *placement)
{
struct drm_vram_mm *vmm = drm_vram_mm_of_bdev(bo->bdev);
if (vmm->funcs && vmm->funcs->evict_flags)
vmm->funcs->evict_flags(bo, placement);
}
static int bo_driver_verify_access(struct ttm_buffer_object *bo,
struct file *filp)
{
struct drm_vram_mm *vmm = drm_vram_mm_of_bdev(bo->bdev);
if (!vmm->funcs || !vmm->funcs->verify_access)
return 0;
return vmm->funcs->verify_access(bo, filp);
}
static int bo_driver_io_mem_reserve(struct ttm_bo_device *bdev,
struct ttm_mem_reg *mem)
{
struct ttm_mem_type_manager *man = bdev->man + mem->mem_type;
struct drm_vram_mm *vmm = drm_vram_mm_of_bdev(bdev);
if (!(man->flags & TTM_MEMTYPE_FLAG_MAPPABLE))
return -EINVAL;
mem->bus.addr = NULL;
mem->bus.size = mem->num_pages << PAGE_SHIFT;
switch (mem->mem_type) {
case TTM_PL_SYSTEM: /* nothing to do */
mem->bus.offset = 0;
mem->bus.base = 0;
mem->bus.is_iomem = false;
break;
case TTM_PL_VRAM:
mem->bus.offset = mem->start << PAGE_SHIFT;
mem->bus.base = vmm->vram_base;
mem->bus.is_iomem = true;
break;
default:
return -EINVAL;
}
return 0;
}
static void bo_driver_io_mem_free(struct ttm_bo_device *bdev,
struct ttm_mem_reg *mem)
{ }
static struct ttm_bo_driver bo_driver = {
.ttm_tt_create = bo_driver_ttm_tt_create,
.ttm_tt_populate = ttm_pool_populate,
.ttm_tt_unpopulate = ttm_pool_unpopulate,
.init_mem_type = bo_driver_init_mem_type,
.eviction_valuable = ttm_bo_eviction_valuable,
.evict_flags = bo_driver_evict_flags,
.verify_access = bo_driver_verify_access,
.io_mem_reserve = bo_driver_io_mem_reserve,
.io_mem_free = bo_driver_io_mem_free,
};
/*
* struct drm_vram_mm
*/
/**
* drm_vram_mm_init() - Initialize an instance of VRAM MM.
* @vmm: the VRAM MM instance to initialize
* @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:
* 0 on success, or
* a negative error code otherwise.
*/
int drm_vram_mm_init(struct drm_vram_mm *vmm, struct drm_device *dev,
uint64_t vram_base, size_t vram_size,
const struct drm_vram_mm_funcs *funcs)
{
int ret;
vmm->vram_base = vram_base;
vmm->vram_size = vram_size;
vmm->funcs = funcs;
ret = ttm_bo_device_init(&vmm->bdev, &bo_driver,
dev->anon_inode->i_mapping,
true);
if (ret)
return ret;
ret = ttm_bo_init_mm(&vmm->bdev, TTM_PL_VRAM, vram_size >> PAGE_SHIFT);
if (ret)
return ret;
return 0;
}
EXPORT_SYMBOL(drm_vram_mm_init);
/**
* drm_vram_mm_cleanup() - Cleans up an initialized instance of VRAM MM.
* @vmm: the VRAM MM instance to clean up
*/
void drm_vram_mm_cleanup(struct drm_vram_mm *vmm)
{
ttm_bo_device_release(&vmm->bdev);
}
EXPORT_SYMBOL(drm_vram_mm_cleanup);
/**
* drm_vram_mm_mmap() - Helper for implementing &struct file_operations.mmap()
* @filp: the mapping's file structure
* @vma: the mapping's memory area
* @vmm: the VRAM MM instance
*
* Returns:
* 0 on success, or
* a negative error code otherwise.
*/
int drm_vram_mm_mmap(struct file *filp, struct vm_area_struct *vma,
struct drm_vram_mm *vmm)
{
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);
