mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-23 01:10:04 +00:00
![Boris Brezillon](/assets/img/avatar_default.png)
Right now, the BO is mapped as a cached region when ->vmap() is called
and the underlying object is not a dmabuf.
Doing that makes cache management a bit more complicated (you'd need
to call dma_map/unmap_sg() on the ->sgt field everytime the BO is about
to be passed to the GPU/CPU), so let's map the BO with writecombine
attributes instead (as done in most drivers).
Fixes: 2194a63a81
("drm: Add library for shmem backed GEM objects")
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190529065121.13485-1-boris.brezillon@collabora.com
626 lines
16 KiB
C
626 lines
16 KiB
C
// 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, pgprot_writecombine(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);
|