blob: fd751078bae1de66877f88482efcccd4354ea5c0 [file] [log] [blame]
// 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>
#include <drm/ttm/ttm_page_alloc.h>
static const struct drm_gem_object_funcs drm_gem_vram_object_funcs;
/**
* DOC: overview
*
* This library provides a GEM buffer object that is backed by video RAM
* (VRAM). It can be used for framebuffer devices with dedicated memory.
*/
/*
* Buffer-objects helpers
*/
static void drm_gem_vram_cleanup(struct drm_gem_vram_object *gbo)
{
/* We got here via ttm_bo_put(), which means that the
* TTM buffer object in 'bo' has already been cleaned
* up; only release the GEM object.
*/
drm_gem_object_release(&gbo->bo.base);
}
static void drm_gem_vram_destroy(struct drm_gem_vram_object *gbo)
{
drm_gem_vram_cleanup(gbo);
kfree(gbo);
}
static void ttm_buffer_object_destroy(struct ttm_buffer_object *bo)
{
struct drm_gem_vram_object *gbo = drm_gem_vram_of_bo(bo);
drm_gem_vram_destroy(gbo);
}
static void drm_gem_vram_placement(struct drm_gem_vram_object *gbo,
unsigned long pl_flag)
{
unsigned int i;
unsigned int c = 0;
gbo->placement.placement = gbo->placements;
gbo->placement.busy_placement = gbo->placements;
if (pl_flag & TTM_PL_FLAG_VRAM)
gbo->placements[c++].flags = TTM_PL_FLAG_WC |
TTM_PL_FLAG_UNCACHED |
TTM_PL_FLAG_VRAM;
if (pl_flag & TTM_PL_FLAG_SYSTEM)
gbo->placements[c++].flags = TTM_PL_MASK_CACHING |
TTM_PL_FLAG_SYSTEM;
if (!c)
gbo->placements[c++].flags = TTM_PL_MASK_CACHING |
TTM_PL_FLAG_SYSTEM;
gbo->placement.num_placement = c;
gbo->placement.num_busy_placement = c;
for (i = 0; i < c; ++i) {
gbo->placements[i].fpfn = 0;
gbo->placements[i].lpfn = 0;
}
}
static int drm_gem_vram_init(struct drm_device *dev,
struct ttm_bo_device *bdev,
struct drm_gem_vram_object *gbo,
size_t size, unsigned long pg_align,
bool interruptible)
{
int ret;
size_t acc_size;
if (!gbo->bo.base.funcs)
gbo->bo.base.funcs = &drm_gem_vram_object_funcs;
ret = drm_gem_object_init(dev, &gbo->bo.base, size);
if (ret)
return ret;
acc_size = ttm_bo_dma_acc_size(bdev, size, sizeof(*gbo));
gbo->bo.bdev = bdev;
drm_gem_vram_placement(gbo, TTM_PL_FLAG_VRAM | TTM_PL_FLAG_SYSTEM);
ret = ttm_bo_init(bdev, &gbo->bo, size, ttm_bo_type_device,
&gbo->placement, pg_align, interruptible, acc_size,
NULL, NULL, ttm_buffer_object_destroy);
if (ret)
goto err_drm_gem_object_release;
return 0;
err_drm_gem_object_release:
drm_gem_object_release(&gbo->bo.base);
return ret;
}
/**
* drm_gem_vram_create() - Creates a VRAM-backed GEM object
* @dev: the DRM device
* @bdev: the TTM BO device backing the object
* @size: the buffer size in bytes
* @pg_align: the buffer's alignment in multiples of the page size
* @interruptible: sleep interruptible if waiting for memory
*
* Returns:
* A new instance of &struct drm_gem_vram_object on success, or
* an ERR_PTR()-encoded error code otherwise.
*/
struct drm_gem_vram_object *drm_gem_vram_create(struct drm_device *dev,
struct ttm_bo_device *bdev,
size_t size,
unsigned long pg_align,
bool interruptible)
{
struct drm_gem_vram_object *gbo;
int ret;
gbo = kzalloc(sizeof(*gbo), GFP_KERNEL);
if (!gbo)
return ERR_PTR(-ENOMEM);
ret = drm_gem_vram_init(dev, bdev, gbo, size, pg_align, interruptible);
if (ret < 0)
goto err_kfree;
return gbo;
err_kfree:
kfree(gbo);
return ERR_PTR(ret);
}
EXPORT_SYMBOL(drm_gem_vram_create);
/**
* drm_gem_vram_put() - Releases a reference to a VRAM-backed GEM object
* @gbo: the GEM VRAM object
*
* See ttm_bo_put() for more information.
*/
void drm_gem_vram_put(struct drm_gem_vram_object *gbo)
{
ttm_bo_put(&gbo->bo);
}
EXPORT_SYMBOL(drm_gem_vram_put);
/**
* drm_gem_vram_mmap_offset() - Returns a GEM VRAM object's mmap offset
* @gbo: the GEM VRAM object
*
* See drm_vma_node_offset_addr() for more information.
*
* Returns:
* The buffer object's offset for userspace mappings on success, or
* 0 if no offset is allocated.
*/
u64 drm_gem_vram_mmap_offset(struct drm_gem_vram_object *gbo)
{
return drm_vma_node_offset_addr(&gbo->bo.base.vma_node);
}
EXPORT_SYMBOL(drm_gem_vram_mmap_offset);
/**
* drm_gem_vram_offset() - \
Returns a GEM VRAM object's offset in video memory
* @gbo: the GEM VRAM object
*
* This function returns the buffer object's offset in the device's video
* memory. The buffer object has to be pinned to %TTM_PL_VRAM.
*
* Returns:
* The buffer object's offset in video memory on success, or
* a negative errno code otherwise.
*/
s64 drm_gem_vram_offset(struct drm_gem_vram_object *gbo)
{
if (WARN_ON_ONCE(!gbo->pin_count))
return (s64)-ENODEV;
return gbo->bo.offset;
}
EXPORT_SYMBOL(drm_gem_vram_offset);
/**
* drm_gem_vram_pin() - Pins a GEM VRAM object in a region.
* @gbo: the GEM VRAM object
* @pl_flag: a bitmask of possible memory regions
*
* Pinning a buffer object ensures that it is not evicted from
* a memory region. A pinned buffer object has to be unpinned before
* it can be pinned to another region. If the pl_flag argument is 0,
* the buffer is pinned at its current location (video RAM or system
* memory).
*
* Returns:
* 0 on success, or
* a negative error code otherwise.
*/
int drm_gem_vram_pin(struct drm_gem_vram_object *gbo, unsigned long pl_flag)
{
int i, ret;
struct ttm_operation_ctx ctx = { false, false };
ret = ttm_bo_reserve(&gbo->bo, true, false, NULL);
if (ret < 0)
return ret;
if (gbo->pin_count)
goto out;
if (pl_flag)
drm_gem_vram_placement(gbo, pl_flag);
for (i = 0; i < gbo->placement.num_placement; ++i)
gbo->placements[i].flags |= TTM_PL_FLAG_NO_EVICT;
ret = ttm_bo_validate(&gbo->bo, &gbo->placement, &ctx);
if (ret < 0)
goto err_ttm_bo_unreserve;
out:
++gbo->pin_count;
ttm_bo_unreserve(&gbo->bo);
return 0;
err_ttm_bo_unreserve:
ttm_bo_unreserve(&gbo->bo);
return ret;
}
EXPORT_SYMBOL(drm_gem_vram_pin);
/**
* drm_gem_vram_unpin() - Unpins a GEM VRAM object
* @gbo: the GEM VRAM object
*
* Returns:
* 0 on success, or
* a negative error code otherwise.
*/
int drm_gem_vram_unpin(struct drm_gem_vram_object *gbo)
{
int i, ret;
struct ttm_operation_ctx ctx = { false, false };
ret = ttm_bo_reserve(&gbo->bo, true, false, NULL);
if (ret < 0)
return ret;
if (WARN_ON_ONCE(!gbo->pin_count))
goto out;
--gbo->pin_count;
if (gbo->pin_count)
goto out;
for (i = 0; i < gbo->placement.num_placement ; ++i)
gbo->placements[i].flags &= ~TTM_PL_FLAG_NO_EVICT;
ret = ttm_bo_validate(&gbo->bo, &gbo->placement, &ctx);
if (ret < 0)
goto err_ttm_bo_unreserve;
out:
ttm_bo_unreserve(&gbo->bo);
return 0;
err_ttm_bo_unreserve:
ttm_bo_unreserve(&gbo->bo);
return ret;
}
EXPORT_SYMBOL(drm_gem_vram_unpin);
/**
* drm_gem_vram_kmap() - Maps a GEM VRAM object into kernel address space
* @gbo: the GEM VRAM object
* @map: establish a mapping if necessary
* @is_iomem: returns true if the mapped memory is I/O memory, or false \
otherwise; can be NULL
*
* This function maps the buffer object into the kernel's address space
* or returns the current mapping. If the parameter map is false, the
* function only queries the current mapping, but does not establish a
* new one.
*
* Returns:
* The buffers virtual address if mapped, or
* NULL if not mapped, or
* an ERR_PTR()-encoded error code otherwise.
*/
void *drm_gem_vram_kmap(struct drm_gem_vram_object *gbo, bool map,
bool *is_iomem)
{
int ret;
struct ttm_bo_kmap_obj *kmap = &gbo->kmap;
if (kmap->virtual || !map)
goto out;
ret = ttm_bo_kmap(&gbo->bo, 0, gbo->bo.num_pages, kmap);
if (ret)
return ERR_PTR(ret);
out:
if (!is_iomem)
return kmap->virtual;
if (!kmap->virtual) {
*is_iomem = false;
return NULL;
}
return ttm_kmap_obj_virtual(kmap, is_iomem);
}
EXPORT_SYMBOL(drm_gem_vram_kmap);
/**
* drm_gem_vram_kunmap() - Unmaps a GEM VRAM object
* @gbo: the GEM VRAM object
*/
void drm_gem_vram_kunmap(struct drm_gem_vram_object *gbo)
{
struct ttm_bo_kmap_obj *kmap = &gbo->kmap;
if (!kmap->virtual)
return;
ttm_bo_kunmap(kmap);
kmap->virtual = NULL;
}
EXPORT_SYMBOL(drm_gem_vram_kunmap);
/**
* drm_gem_vram_fill_create_dumb() - \
Helper for implementing &struct drm_driver.dumb_create
* @file: the DRM file
* @dev: the DRM device
* @bdev: the TTM BO device managing the buffer object
* @pg_align: the buffer's alignment in multiples of the page size
* @interruptible: sleep interruptible if waiting for memory
* @args: the arguments as provided to \
&struct drm_driver.dumb_create
*
* This helper function fills &struct drm_mode_create_dumb, which is used
* by &struct drm_driver.dumb_create. Implementations of this interface
* should forwards their arguments to this helper, plus the driver-specific
* parameters.
*
* Returns:
* 0 on success, or
* a negative error code otherwise.
*/
int drm_gem_vram_fill_create_dumb(struct drm_file *file,
struct drm_device *dev,
struct ttm_bo_device *bdev,
unsigned long pg_align,
bool interruptible,
struct drm_mode_create_dumb *args)
{
size_t pitch, size;
struct drm_gem_vram_object *gbo;
int ret;
u32 handle;
pitch = args->width * ((args->bpp + 7) / 8);
size = pitch * args->height;
size = roundup(size, PAGE_SIZE);
if (!size)
return -EINVAL;
gbo = drm_gem_vram_create(dev, bdev, size, pg_align, interruptible);
if (IS_ERR(gbo))
return PTR_ERR(gbo);
ret = drm_gem_handle_create(file, &gbo->bo.base, &handle);
if (ret)
goto err_drm_gem_object_put_unlocked;
drm_gem_object_put_unlocked(&gbo->bo.base);
args->pitch = pitch;
args->size = size;
args->handle = handle;
return 0;
err_drm_gem_object_put_unlocked:
drm_gem_object_put_unlocked(&gbo->bo.base);
return ret;
}
EXPORT_SYMBOL(drm_gem_vram_fill_create_dumb);
/*
* Helpers for struct ttm_bo_driver
*/
static bool drm_is_gem_vram(struct ttm_buffer_object *bo)
{
return (bo->destroy == ttm_buffer_object_destroy);
}
/**
* drm_gem_vram_bo_driver_evict_flags() - \
Implements &struct ttm_bo_driver.evict_flags
* @bo: TTM buffer object. Refers to &struct drm_gem_vram_object.bo
* @pl: TTM placement information.
*/
void drm_gem_vram_bo_driver_evict_flags(struct ttm_buffer_object *bo,
struct ttm_placement *pl)
{
struct drm_gem_vram_object *gbo;
/* TTM may pass BOs that are not GEM VRAM BOs. */
if (!drm_is_gem_vram(bo))
return;
gbo = drm_gem_vram_of_bo(bo);
drm_gem_vram_placement(gbo, TTM_PL_FLAG_SYSTEM);
*pl = gbo->placement;
}
EXPORT_SYMBOL(drm_gem_vram_bo_driver_evict_flags);
/**
* drm_gem_vram_bo_driver_verify_access() - \
Implements &struct ttm_bo_driver.verify_access
* @bo: TTM buffer object. Refers to &struct drm_gem_vram_object.bo
* @filp: File pointer.
*
* Returns:
* 0 on success, or
* a negative errno code otherwise.
*/
int drm_gem_vram_bo_driver_verify_access(struct ttm_buffer_object *bo,
struct file *filp)
{
struct drm_gem_vram_object *gbo = drm_gem_vram_of_bo(bo);
return drm_vma_node_verify_access(&gbo->bo.base.vma_node,
filp->private_data);
}
EXPORT_SYMBOL(drm_gem_vram_bo_driver_verify_access);
/*
* drm_gem_vram_mm_funcs - Functions for &struct drm_vram_mm
*
* Most users of @struct drm_gem_vram_object will also use
* @struct drm_vram_mm. This instance of &struct drm_vram_mm_funcs
* can be used to connect both.
*/
const struct drm_vram_mm_funcs drm_gem_vram_mm_funcs = {
.evict_flags = drm_gem_vram_bo_driver_evict_flags,
.verify_access = drm_gem_vram_bo_driver_verify_access
};
EXPORT_SYMBOL(drm_gem_vram_mm_funcs);
/*
* Helpers for struct drm_gem_object_funcs
*/
/**
* drm_gem_vram_object_free() - \
Implements &struct drm_gem_object_funcs.free
* @gem: GEM object. Refers to &struct drm_gem_vram_object.gem
*/
static void drm_gem_vram_object_free(struct drm_gem_object *gem)
{
struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
drm_gem_vram_put(gbo);
}
/*
* Helpers for dump buffers
*/
/**
* 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
* @file: DRM file pointer.
* @dev: DRM device.
* @handle: GEM handle
* @offset: Returns the mapping's memory offset on success
*
* Returns:
* 0 on success, or
* a negative errno code otherwise.
*/
int drm_gem_vram_driver_dumb_mmap_offset(struct drm_file *file,
struct drm_device *dev,
uint32_t handle, uint64_t *offset)
{
struct drm_gem_object *gem;
struct drm_gem_vram_object *gbo;
gem = drm_gem_object_lookup(file, handle);
if (!gem)
return -ENOENT;
gbo = drm_gem_vram_of_gem(gem);
*offset = drm_gem_vram_mmap_offset(gbo);
drm_gem_object_put_unlocked(gem);
return 0;
}
EXPORT_SYMBOL(drm_gem_vram_driver_dumb_mmap_offset);
/*
* PRIME helpers
*/
/**
* drm_gem_vram_object_pin() - \
Implements &struct drm_gem_object_funcs.pin
* @gem: The GEM object to pin
*
* Returns:
* 0 on success, or
* a negative errno code otherwise.
*/
static int drm_gem_vram_object_pin(struct drm_gem_object *gem)
{
struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
/* Fbdev console emulation is the use case of these PRIME
* helpers. This may involve updating a hardware buffer from
* a shadow FB. We pin the buffer to it's current location
* (either video RAM or system memory) to prevent it from
* being relocated during the update operation. If you require
* the buffer to be pinned to VRAM, implement a callback that
* sets the flags accordingly.
*/
return drm_gem_vram_pin(gbo, 0);
}
/**
* drm_gem_vram_object_unpin() - \
Implements &struct drm_gem_object_funcs.unpin
* @gem: The GEM object to unpin
*/
static void drm_gem_vram_object_unpin(struct drm_gem_object *gem)
{
struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
drm_gem_vram_unpin(gbo);
}
/**
* drm_gem_vram_object_vmap() - \
Implements &struct drm_gem_object_funcs.vmap
* @gem: The GEM object to map
*
* Returns:
* The buffers virtual address on success, or
* NULL otherwise.
*/
static void *drm_gem_vram_object_vmap(struct drm_gem_object *gem)
{
struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
int ret;
void *base;
ret = drm_gem_vram_pin(gbo, 0);
if (ret)
return NULL;
base = drm_gem_vram_kmap(gbo, true, NULL);
if (IS_ERR(base)) {
drm_gem_vram_unpin(gbo);
return NULL;
}
return base;
}
/**
* drm_gem_vram_object_vunmap() - \
Implements &struct drm_gem_object_funcs.vunmap
* @gem: The GEM object to unmap
* @vaddr: The mapping's base address
*/
static void drm_gem_vram_object_vunmap(struct drm_gem_object *gem,
void *vaddr)
{
struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
drm_gem_vram_kunmap(gbo);
drm_gem_vram_unpin(gbo);
}
/*
* GEM object funcs
*/
static const struct drm_gem_object_funcs drm_gem_vram_object_funcs = {
.free = drm_gem_vram_object_free,
.pin = drm_gem_vram_object_pin,
.unpin = drm_gem_vram_object_unpin,
.vmap = drm_gem_vram_object_vmap,
.vunmap = drm_gem_vram_object_vunmap
};