/*
* Copyright © 2008 Intel Corporation
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*
* Authors:
* Eric Anholt <[email protected]>
*
*/
#include <linux/dma-buf.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/iosys-map.h>
#include <linux/mem_encrypt.h>
#include <linux/mm.h>
#include <linux/mman.h>
#include <linux/module.h>
#include <linux/pagemap.h>
#include <linux/pagevec.h>
#include <linux/shmem_fs.h>
#include <linux/slab.h>
#include <linux/string_helpers.h>
#include <linux/types.h>
#include <linux/uaccess.h>
#include <drm/drm.h>
#include <drm/drm_device.h>
#include <drm/drm_drv.h>
#include <drm/drm_file.h>
#include <drm/drm_gem.h>
#include <drm/drm_managed.h>
#include <drm/drm_print.h>
#include <drm/drm_vma_manager.h>
#include "drm_internal.h"
/** @file drm_gem.c
*
* This file provides some of the base ioctls and library routines for
* the graphics memory manager implemented by each device driver.
*
* Because various devices have different requirements in terms of
* synchronization and migration strategies, implementing that is left up to
* the driver, and all that the general API provides should be generic --
* allocating objects, reading/writing data with the cpu, freeing objects.
* Even there, platform-dependent optimizations for reading/writing data with
* the CPU mean we'll likely hook those out to driver-specific calls. However,
* the DRI2 implementation wants to have at least allocate/mmap be generic.
*
* The goal was to have swap-backed object allocation managed through
* struct file. However, file descriptors as handles to a struct file have
* two major failings:
* - Process limits prevent more than 1024 or so being used at a time by
* default.
* - Inability to allocate high fds will aggravate the X Server's select()
* handling, and likely that of many GL client applications as well.
*
* This led to a plan of using our own integer IDs (called handles, following
* DRM terminology) to mimic fds, and implement the fd syscalls we need as
* ioctls. The objects themselves will still include the struct file so
* that we can transition to fds if the required kernel infrastructure shows
* up at a later date, and as our interface with shmfs for memory allocation.
*/
static void
drm_gem_init_release(struct drm_device *dev, void *ptr)
{
drm_vma_offset_manager_destroy(dev->vma_offset_manager);
}
/**
* drm_gem_init - Initialize the GEM device fields
* @dev: drm_devic structure to initialize
*/
int
drm_gem_init(struct drm_device *dev)
{
struct drm_vma_offset_manager *vma_offset_manager;
mutex_init(&dev->object_name_lock);
idr_init_base(&dev->object_name_idr, 1);
vma_offset_manager = drmm_kzalloc(dev, sizeof(*vma_offset_manager),
GFP_KERNEL);
if (!vma_offset_manager) {
DRM_ERROR("out of memory\n");
return -ENOMEM;
}
dev->vma_offset_manager = vma_offset_manager;
drm_vma_offset_manager_init(vma_offset_manager,
DRM_FILE_PAGE_OFFSET_START,
DRM_FILE_PAGE_OFFSET_SIZE);
return drmm_add_action(dev, drm_gem_init_release, NULL);
}
/**
* drm_gem_object_init - initialize an allocated shmem-backed GEM object
* @dev: drm_device the object should be initialized for
* @obj: drm_gem_object to initialize
* @size: object size
*
* Initialize an already allocated GEM object of the specified size with
* shmfs backing store.
*/
int drm_gem_object_init(struct drm_device *dev,
struct drm_gem_object *obj, size_t size)
{
struct file *filp;
drm_gem_private_object_init(dev, obj, size);
filp = shmem_file_setup("drm mm object", size, VM_NORESERVE);
if (IS_ERR(filp))
return PTR_ERR(filp);
obj->filp = filp;
return 0;
}
EXPORT_SYMBOL(drm_gem_object_init);
/**
* drm_gem_private_object_init - initialize an allocated private GEM object
* @dev: drm_device the object should be initialized for
* @obj: drm_gem_object to initialize
* @size: object size
*
* Initialize an already allocated GEM object of the specified size with
* no GEM provided backing store. Instead the caller is responsible for
* backing the object and handling it.
*/
void drm_gem_private_object_init(struct drm_device *dev,
struct drm_gem_object *obj, size_t size)
{
BUG_ON((size & (PAGE_SIZE - 1)) != 0);
obj->dev = dev;
obj->filp = NULL;
kref_init(&obj->refcount);
obj->handle_count = 0;
obj->size = size;
dma_resv_init(&obj->_resv);
if (!obj->resv)
obj->resv = &obj->_resv;
if (drm_core_check_feature(dev, DRIVER_GEM_GPUVA))
drm_gem_gpuva_init(obj);
drm_vma_node_reset(&obj->vma_node);
INIT_LIST_HEAD(&obj->lru_node);
}
EXPORT_SYMBOL(drm_gem_private_object_init);
/**
* drm_gem_private_object_fini - Finalize a failed drm_gem_object
* @obj: drm_gem_object
*
* Uninitialize an already allocated GEM object when it initialized failed
*/
void drm_gem_private_object_fini(struct drm_gem_object *obj)
{
WARN_ON(obj->dma_buf);
dma_resv_fini(&obj->_resv);
}
EXPORT_SYMBOL(drm_gem_private_object_fini);
/**
* drm_gem_object_handle_free - release resources bound to userspace handles
* @obj: GEM object to clean up.
*
* Called after the last handle to the object has been closed
*
* Removes any name for the object. Note that this must be
* called before drm_gem_object_free or we'll be touching
* freed memory
*/
static void drm_gem_object_handle_free(struct drm_gem_object *obj)
{
struct drm_device *dev = obj->dev;
/* Remove any name for this object */
if (obj->name) {
idr_remove(&dev->object_name_idr, obj->name);
obj->name = 0;
}
}
static void drm_gem_object_exported_dma_buf_free(struct drm_gem_object *obj)
{
/* Unbreak the reference cycle if we have an exported dma_buf. */
if (obj->dma_buf) {
dma_buf_put(obj->dma_buf);
obj->dma_buf = NULL;
}
}
static void
drm_gem_object_handle_put_unlocked(struct drm_gem_object *obj)
{
struct drm_device *dev = obj->dev;
bool final = false;
if (WARN_ON(READ_ONCE(obj->handle_count) == 0))
return;
/*
* Must bump handle count first as this may be the last
* ref, in which case the object would disappear before we
* checked for a name
*/
mutex_lock(&dev->object_name_lock);
if (--obj->handle_count == 0) {
drm_gem_object_handle_free(obj);
drm_gem_object_exported_dma_buf_free(obj);
final = true;
}
mutex_unlock(&dev->object_name_lock);
if (final)
drm_gem_object_put(obj);
}
/*
* Called at device or object close to release the file's
* handle references on objects.
*/
static int
drm_gem_object_release_handle(int id, void *ptr, void *data)
{
struct drm_file *file_priv = data;
struct drm_gem_object *obj = ptr;
if (obj->funcs->close)
obj->funcs->close(obj, file_priv);
drm_prime_remove_buf_handle(&file_priv->prime, id);
drm_vma_node_revoke(&obj->vma_node, file_priv);
drm_gem_object_handle_put_unlocked(obj);
return 0;
}
/**
* drm_gem_handle_delete - deletes the given file-private handle
* @filp: drm file-private structure to use for the handle look up
* @handle: userspace handle to delete
*
* Removes the GEM handle from the @filp lookup table which has been added with
* drm_gem_handle_create(). If this is the last handle also cleans up linked
* resources like GEM names.
*/
int
drm_gem_handle_delete(struct drm_file *filp, u32 handle)
{
struct drm_gem_object *obj;
spin_lock(&filp->table_lock);
/* Check if we currently have a reference on the object */
obj = idr_replace(&filp->object_idr, NULL, handle);
spin_unlock(&filp->table_lock);
if (IS_ERR_OR_NULL(obj))
return -EINVAL;
/* Release driver's reference and decrement refcount. */
drm_gem_object_release_handle(handle, obj, filp);
/* And finally make the handle available for future allocations. */
spin_lock(&filp->table_lock);
idr_remove(&filp->object_idr, handle);
spin_unlock(&filp->table_lock);
return 0;
}
EXPORT_SYMBOL(drm_gem_handle_delete);
/**
* drm_gem_dumb_map_offset - return the fake mmap offset for a gem object
* @file: drm file-private structure containing the gem object
* @dev: corresponding drm_device
* @handle: gem object handle
* @offset: return location for the fake mmap offset
*
* This implements the &drm_driver.dumb_map_offset kms driver callback for
* drivers which use gem to manage their backing storage.
*
* Returns:
* 0 on success or a negative error code on failure.
*/
int drm_gem_dumb_map_offset(struct drm_file *file, struct drm_device *dev,
u32 handle, u64 *offset)
{
struct drm_gem_object *obj;
int ret;
obj = drm_gem_object_lookup(file, handle);
if (!obj)
return -ENOENT;
/* Don't allow imported objects to be mapped */
if (obj->import_attach) {
ret = -EINVAL;
goto out;
}
ret = drm_gem_create_mmap_offset(obj);
if (ret)
goto out;
*offset = drm_vma_node_offset_addr(&obj->vma_node);
out:
drm_gem_object_put(obj);
return ret;
}
EXPORT_SYMBOL_GPL(drm_gem_dumb_map_offset);
/**
* drm_gem_handle_create_tail - internal functions to create a handle
* @file_priv: drm file-private structure to register the handle for
* @obj: object to register
* @handlep: pointer to return the created handle to the caller
*
* This expects the &drm_device.object_name_lock to be held already and will
* drop it before returning. Used to avoid races in establishing new handles
* when importing an object from either an flink name or a dma-buf.
*
* Handles must be release again through drm_gem_handle_delete(). This is done
* when userspace closes @file_priv for all attached handles, or through the
* GEM_CLOSE ioctl for individual handles.
*/
int
drm_gem_handle_create_tail(struct drm_file *file_priv,
struct drm_gem_object *obj,
u32 *handlep)
{
struct drm_device *dev = obj->dev;
u32 handle;
int ret;
WARN_ON(!mutex_is_locked(&dev->object_name_lock));
if (obj->handle_count++ == 0)
drm_gem_object_get(obj);
/*
* Get the user-visible handle using idr. Preload and perform
* allocation under our spinlock.
*/
idr_preload(GFP_KERNEL);
spin_lock(&file_priv->table_lock);
ret = idr_alloc(&file_priv->object_idr, obj, 1, 0, GFP_NOWAIT);
spin_unlock(&file_priv->table_lock);
idr_preload_end();
mutex_unlock(&dev->object_name_lock);
if (ret < 0)
goto err_unref;
handle = ret;
ret = drm_vma_node_allow(&obj->vma_node, file_priv);
if (ret)
goto err_remove;
if (obj->funcs->open) {
ret = obj->funcs->open(obj, file_priv);
if (ret)
goto err_revoke;
}
*handlep = handle;
return 0;
err_revoke:
drm_vma_node_revoke(&obj->vma_node, file_priv);
err_remove:
spin_lock(&file_priv->table_lock);
idr_remove(&file_priv->object_idr, handle);
spin_unlock(&file_priv->table_lock);
err_unref:
drm_gem_object_handle_put_unlocked(obj);
return ret;
}
/**
* drm_gem_handle_create - create a gem handle for an object
* @file_priv: drm file-private structure to register the handle for
* @obj: object to register
* @handlep: pointer to return the created handle to the caller
*
* Create a handle for this object. This adds a handle reference to the object,
* which includes a regular reference count. Callers will likely want to
* dereference the object afterwards.
*
* Since this publishes @obj to userspace it must be fully set up by this point,
* drivers must call this last in their buffer object creation callbacks.
*/
int drm_gem_handle_create(struct drm_file *file_priv,
struct drm_gem_object *obj,
u32 *handlep)
{
mutex_lock(&obj->dev->object_name_lock);
return drm_gem_handle_create_tail(file_priv, obj, handlep);
}
EXPORT_SYMBOL(drm_gem_handle_create);
/**
* drm_gem_free_mmap_offset - release a fake mmap offset for an object
* @obj: obj in question
*
* This routine frees fake offsets allocated by drm_gem_create_mmap_offset().
*
* Note that drm_gem_object_release() already calls this function, so drivers
* don't have to take care of releasing the mmap offset themselves when freeing
* the GEM object.
*/
void
drm_gem_free_mmap_offset(struct drm_gem_object *obj)
{
struct drm_device *dev = obj->dev;
drm_vma_offset_remove(dev->vma_offset_manager, &obj->vma_node);
}
EXPORT_SYMBOL(drm_gem_free_mmap_offset);
/**
* drm_gem_create_mmap_offset_size - create a fake mmap offset for an object
* @obj: obj in question
* @size: the virtual size
*
* GEM memory mapping works by handing back to userspace a fake mmap offset
* it can use in a subsequent mmap(2) call. The DRM core code then looks
* up the object based on the offset and sets up the various memory mapping
* structures.
*
* This routine allocates and attaches a fake offset for @obj, in cases where
* the virtual size differs from the physical size (ie. &drm_gem_object.size).
* Otherwise just use drm_gem_create_mmap_offset().
*
* This function is idempotent and handles an already allocated mmap offset
* transparently. Drivers do not need to check for this case.
*/
int
drm_gem_create_mmap_offset_size(struct drm_gem_object *obj, size_t size)
{
struct drm_device *dev = obj->dev;
return drm_vma_offset_add(dev->vma_offset_manager, &obj->vma_node,
size / PAGE_SIZE);
}
EXPORT_SYMBOL(drm_gem_create_mmap_offset_size);
/**
* drm_gem_create_mmap_offset - create a fake mmap offset for an object
* @obj: obj in question
*
* GEM memory mapping works by handing back to userspace a fake mmap offset
* it can use in a subsequent mmap(2) call. The DRM core code then looks
* up the object based on the offset and sets up the various memory mapping
* structures.
*
* This routine allocates and attaches a fake offset for @obj.
*
* Drivers can call drm_gem_free_mmap_offset() before freeing @obj to release
* the fake offset again.
*/
int drm_gem_create_mmap_offset(struct drm_gem_object *obj)
{
return drm_gem_create_mmap_offset_size(obj, obj->size);
}
EXPORT_SYMBOL(drm_gem_create_mmap_offset);
/*
* Move folios to appropriate lru and release the folios, decrementing the
* ref count of those folios.
*/
static void drm_gem_check_release_batch(struct folio_batch *fbatch)
{
check_move_unevictable_folios(fbatch);
__folio_batch_release(fbatch);
cond_resched();
}
/**
* drm_gem_get_pages - helper to allocate backing pages for a GEM object
* from shmem
* @obj: obj in question
*
* This reads the page-array of the shmem-backing storage of the given gem
* object. An array of pages is returned. If a page is not allocated or
* swapped-out, this will allocate/swap-in the required pages. Note that the
* whole object is covered by the page-array and pinned in memory.
*
* Use drm_gem_put_pages() to release the array and unpin all pages.
*
* This uses the GFP-mask set on the shmem-mapping (see mapping_set_gfp_mask()).
* If you require other GFP-masks, you have to do those allocations yourself.
*
* Note that you are not allowed to change gfp-zones during runtime. That is,
* shmem_read_mapping_page_gfp() must be called with the same gfp_zone(gfp) as
* set during initialization. If you have special zone constraints, set them
* after drm_gem_object_init() via mapping_set_gfp_mask(). shmem-core takes care
* to keep pages in the required zone during swap-in.
*
* This function is only valid on objects initialized with
* drm_gem_object_init(), but not for those initialized with
* drm_gem_private_object_init() only.
*/
struct page **drm_gem_get_pages(struct drm_gem_object *obj)
{
struct address_space *mapping;
struct page **pages;
struct folio *folio;
struct folio_batch fbatch;
long i, j, npages;
if (WARN_ON(!obj->filp))
return ERR_PTR(-EINVAL);
/* This is the shared memory object that backs the GEM resource */
mapping = obj->filp->f_mapping;
/* We already BUG_ON() for non-page-aligned sizes in
* drm_gem_object_init(), so we should never hit this unless
* driver author is doing something really wrong:
*/
WARN_ON((obj->size & (PAGE_SIZE - 1)) != 0);
npages = obj->size >> PAGE_SHIFT;
pages = kvmalloc_array(npages, sizeof(struct page *), GFP_KERNEL);
if (pages == NULL)
return ERR_PTR(-ENOMEM);
mapping_set_unevictable(mapping);
i = 0;
while (i < npages) {
long nr;
folio = shmem_read_folio_gfp(mapping, i,
mapping_gfp_mask(mapping));
if (IS_ERR(folio))
goto fail;
nr = min(npages - i, folio_nr_pages(folio));
for (j = 0; j < nr; j++, i++)
pages[i] = folio_file_page(folio, i);
/* Make sure shmem keeps __GFP_DMA32 allocated pages in the
* correct region during swapin. Note that this requires
* __GFP_DMA32 to be set in mapping_gfp_mask(inode->i_mapping)
* so shmem can relocate pages during swapin if required.
*/
BUG_ON(mapping_gfp_constraint(mapping, __GFP_DMA32) &&
(folio_pfn(folio) >= 0x00100000UL));
}
return pages;
fail:
mapping_clear_unevictable(mapping);
folio_batch_init(&fbatch);
j = 0;
while (j < i) {
struct folio *f = page_folio(pages[j]);
if (!folio_batch_add(&fbatch, f))
drm_gem_check_release_batch(&fbatch);
j += folio_nr_pages(f);
}
if (fbatch.nr)
drm_gem_check_release_batch(&fbatch);
kvfree(pages);
return ERR_CAST(folio);
}
EXPORT_SYMBOL(drm_gem_get_pages);
/**
* drm_gem_put_pages - helper to free backing pages for a GEM object
* @obj: obj in question
* @pages: pages to free
* @dirty: if true, pages will be marked as dirty
* @accessed: if true, the pages will be marked as accessed
*/
void drm_gem_put_pages(struct drm_gem_object *obj, struct page **pages,
bool dirty, bool accessed)
{
int i, npages;
struct address_space *mapping;
struct folio_batch fbatch;
mapping = file_inode(obj->filp)->i_mapping;
mapping_clear_unevictable(mapping);
/* We already BUG_ON() for non-page-aligned sizes in
* drm_gem_object_init(), so we should never hit this unless
* driver author is doing something really wrong:
*/
WARN_ON((obj->size & (PAGE_SIZE - 1)) != 0);
npages = obj->size >> PAGE_SHIFT;
folio_batch_init(&fbatch);
for (i = 0; i < npages; i++) {
struct folio *folio;
if (!pages[i])
continue;
folio = page_folio(pages[i]);
if (dirty)
folio_mark_dirty(folio);
if (accessed)
folio_mark_accessed(folio);
/* Undo the reference we took when populating the table */
if (!folio_batch_add(&fbatch, folio))
drm_gem_check_release_batch(&fbatch);
i += folio_nr_pages(folio) - 1;
}
if (folio_batch_count(&fbatch))
drm_gem_check_release_batch(&fbatch);
kvfree(pages);
}
EXPORT_SYMBOL(drm_gem_put_pages);
static int objects_lookup(struct drm_file *filp, u32 *handle, int count,
struct drm_gem_object **objs)
{
int i, ret = 0;
struct drm_gem_object *obj;
spin_lock(&filp->table_lock);
for (i = 0; i < count; i++) {
/* Check if we currently have a reference on the object */
obj = idr_find(&filp->object_idr, handle[i]);
if (!obj) {
ret = -ENOENT;
break;
}
drm_gem_object_get(obj);
objs[i] = obj;
}
spin_unlock(&filp->table_lock);
return ret;
}
/**
* drm_gem_objects_lookup - look up GEM objects from an array of handles
* @filp: DRM file private date
* @bo_handles: user pointer to array of userspace handle
* @count: size of handle array
* @objs_out: returned pointer to array of drm_gem_object pointers
*
* Takes an array of userspace handles and returns a newly allocated array of
* GEM objects.
*
* For a single handle lookup, use drm_gem_object_lookup().
*
* Returns:
* @objs filled in with GEM object pointers. Returned GEM objects need to be
* released with drm_gem_object_put(). -ENOENT is returned on a lookup
* failure. 0 is returned on success.
*
*/
int drm_gem_objects_lookup(struct drm_file *filp, void __user *bo_handles,
int count, struct drm_gem_object ***objs_out)
{
int ret;
u32 *handles;
struct drm_gem_object **objs;
if (!count)
return 0;
objs = kvmalloc_array(count, sizeof(struct drm_gem_object *),
GFP_KERNEL | __GFP_ZERO);
if (!objs)
return -ENOMEM;
*objs_out = objs;
handles = kvmalloc_array(count, sizeof(u32), GFP_KERNEL);
if (!handles) {
ret = -ENOMEM;
goto out;
}
if (copy_from_user(handles, bo_handles, count * sizeof(u32))) {
ret = -EFAULT;
DRM_DEBUG("Failed to copy in GEM handles\n");
goto out;
}
ret = objects_lookup(filp, handles, count, objs);
out:
kvfree(handles);
return ret;
}
EXPORT_SYMBOL(drm_gem_objects_lookup);
/**
* drm_gem_object_lookup - look up a GEM object from its handle
* @filp: DRM file private date
* @handle: userspace handle
*
* If looking up an array of handles, use drm_gem_objects_lookup().
*
* Returns:
* A reference to the object named by the handle if such exists on @filp, NULL
* otherwise.
*/
struct drm_gem_object *
drm_gem_object_lookup(struct drm_file *filp, u32 handle)
{
struct drm_gem_object *obj = NULL;
objects_lookup(filp, &handle, 1, &obj);
return obj;
}
EXPORT_SYMBOL(drm_gem_object_lookup);
/**
* drm_gem_dma_resv_wait - Wait on GEM object's reservation's objects
* shared and/or exclusive fences.
* @filep: DRM file private date
* @handle: userspace handle
* @wait_all: if true, wait on all fences, else wait on just exclusive fence
* @timeout: timeout value in jiffies or zero to return immediately
*
* Returns:
* Returns -ERESTARTSYS if interrupted, 0 if the wait timed out, or
* greater than 0 on success.
*/
long drm_gem_dma_resv_wait(struct drm_file *filep, u32 handle,
bool wait_all, unsigned long timeout)
{
long ret;
struct drm_gem_object *obj;
obj = drm_gem_object_lookup(filep, handle);
if (!obj) {
DRM_DEBUG("Failed to look up GEM BO %d\n", handle);
return -EINVAL;
}
ret = dma_resv_wait_timeout(obj->resv, dma_resv_usage_rw(wait_all),
true, timeout);
if (ret == 0)
ret = -ETIME;
else if (ret > 0)
ret = 0;
drm_gem_object_put(obj);
return ret;
}
EXPORT_SYMBOL(drm_gem_dma_resv_wait);
/**
* drm_gem_close_ioctl - implementation of the GEM_CLOSE ioctl
* @dev: drm_device
* @data: ioctl data
* @file_priv: drm file-private structure
*
* Releases the handle to an mm object.
*/
int
drm_gem_close_ioctl(struct drm_device *dev, void *data,
struct drm_file *file_priv)
{
struct drm_gem_close *args = data;
int ret;
if (!drm_core_check_feature(dev, DRIVER_GEM))
return -EOPNOTSUPP;
ret = drm_gem_handle_delete(file_priv, args->handle);
return ret;
}
/**
* drm_gem_flink_ioctl - implementation of the GEM_FLINK ioctl
* @dev: drm_device
* @data: ioctl data
* @file_priv: drm file-private structure
*
* Create a global name for an object, returning the name.
*
* Note that the name does not hold a reference; when the object
* is freed, the name goes away.
*/
int
drm_gem_flink_ioctl(struct drm_device *dev, void *data,
struct drm_file *file_priv)
{
struct drm_gem_flink *args = data;
struct drm_gem_object *obj;
int ret;
if (!drm_core_check_feature(dev, DRIVER_GEM))
return -EOPNOTSUPP;
obj = drm_gem_object_lookup(file_priv, args->handle);
if (obj == NULL)
return -ENOENT;
mutex_lock(&dev->object_name_lock);
/* prevent races with concurrent gem_close. */
if (obj->handle_count == 0) {
ret = -ENOENT;
goto err;
}
if (!obj->name) {
ret = idr_alloc(&dev->object_name_idr, obj, 1, 0, GFP_KERNEL);
if (ret < 0)
goto err;
obj->name = ret;
}
args->name = (uint64_t) obj->name;
ret = 0;
err:
mutex_unlock(&dev->object_name_lock);
drm_gem_object_put(obj);
return ret;
}
/**
* drm_gem_open_ioctl - implementation of the GEM_OPEN ioctl
* @dev: drm_device
* @data: ioctl data
* @file_priv: drm file-private structure
*
* Open an object using the global name, returning a handle and the size.
*
* This handle (of course) holds a reference to the object, so the object
* will not go away until the handle is deleted.
*/
int
drm_gem_open_ioctl(struct drm_device *dev, void *data,
struct drm_file *file_priv)
{
struct drm_gem_open *args = data;
struct drm_gem_object *obj;
int ret;
u32 handle;
if (!drm_core_check_feature(dev, DRIVER_GEM))
return -EOPNOTSUPP;
mutex_lock(&dev->object_name_lock);
obj = idr_find(&dev->object_name_idr, (int) args->name);
if (obj) {
drm_gem_object_get(obj);
} else {
mutex_unlock(&dev->object_name_lock);
return -ENOENT;
}
/* drm_gem_handle_create_tail unlocks dev->object_name_lock. */
ret = drm_gem_handle_create_tail(file_priv, obj, &handle);
if (ret)
goto err;
args->handle = handle;
args->size = obj->size;
err:
drm_gem_object_put(obj);
return ret;
}
/**
* drm_gem_open - initializes GEM file-private structures at devnode open time
* @dev: drm_device which is being opened by userspace
* @file_private: drm file-private structure to set up
*
* Called at device open time, sets up the structure for handling refcounting
* of mm objects.
*/
void
drm_gem_open(struct drm_device *dev, struct drm_file *file_private)
{
idr_init_base(&file_private->object_idr, 1);
spin_lock_init(&file_private->table_lock);
}
/**
* drm_gem_release - release file-private GEM resources
* @dev: drm_device which is being closed by userspace
* @file_private: drm file-private structure to clean up
*
* Called at close time when the filp is going away.
*
* Releases any remaining references on objects by this filp.
*/
void
drm_gem_release(struct drm_device *dev, struct drm_file *file_private)
{
idr_for_each(&file_private->object_idr,
&drm_gem_object_release_handle, file_private);
idr_destroy(&file_private->object_idr);
}
/**
* drm_gem_object_release - release GEM buffer object resources
* @obj: GEM buffer object
*
* This releases any structures and resources used by @obj and is the inverse of
* drm_gem_object_init().
*/
void
drm_gem_object_release(struct drm_gem_object *obj)
{
if (obj->filp)
fput(obj->filp);
drm_gem_private_object_fini(obj);
drm_gem_free_mmap_offset(obj);
drm_gem_lru_remove(obj);
}
EXPORT_SYMBOL(drm_gem_object_release);
/**
* drm_gem_object_free - free a GEM object
* @kref: kref of the object to free
*
* Called after the last reference to the object has been lost.
*
* Frees the object
*/
void
drm_gem_object_free(struct kref *kref)
{
struct drm_gem_object *obj =
container_of(kref, struct drm_gem_object, refcount);
if (WARN_ON(!obj->funcs->free))
return;
obj->funcs->free(obj);
}
EXPORT_SYMBOL(drm_gem_object_free);
/**
* drm_gem_vm_open - vma->ops->open implementation for GEM
* @vma: VM area structure
*
* This function implements the #vm_operations_struct open() callback for GEM
* drivers. This must be used together with drm_gem_vm_close().
*/
void drm_gem_vm_open(struct vm_area_struct *vma)
{
struct drm_gem_object *obj = vma->vm_private_data;
drm_gem_object_get(obj);
}
EXPORT_SYMBOL(drm_gem_vm_open);
/**
* drm_gem_vm_close - vma->ops->close implementation for GEM
* @vma: VM area structure
*
* This function implements the #vm_operations_struct close() callback for GEM
* drivers. This must be used together with drm_gem_vm_open().
*/
void drm_gem_vm_close(struct vm_area_struct *vma)
{
struct drm_gem_object *obj = vma->vm_private_data;
drm_gem_object_put(obj);
}
EXPORT_SYMBOL(drm_gem_vm_close);
/**
* drm_gem_mmap_obj - memory map a GEM object
* @obj: the GEM object to map
* @obj_size: the object size to be mapped, in bytes
* @vma: VMA for the area to be mapped
*
* Set up the VMA to prepare mapping of the GEM object using the GEM object's
* vm_ops. Depending on their requirements, GEM objects can either
* provide a fault handler in their vm_ops (in which case any accesses to
* the object will be trapped, to perform migration, GTT binding, surface
* register allocation, or performance monitoring), or mmap the buffer memory
* synchronously after calling drm_gem_mmap_obj.
*
* This function is mainly intended to implement the DMABUF mmap operation, when
* the GEM object is not looked up based on its fake offset. To implement the
* DRM mmap operation, drivers should use the drm_gem_mmap() function.
*
* drm_gem_mmap_obj() assumes the user is granted access to the buffer while
* drm_gem_mmap() prevents unprivileged users from mapping random objects. So
* callers must verify access restrictions before calling this helper.
*
* Return 0 or success or -EINVAL if the object size is smaller than the VMA
* size, or if no vm_ops are provided.
*/
int drm_gem_mmap_obj(struct drm_gem_object *obj, unsigned long obj_size,
struct vm_area_struct *vma)
{
int ret;
/* Check for valid size. */
if (obj_size < vma->vm_end - vma->vm_start)
return -EINVAL;
/* Take a ref for this mapping of the object, so that the fault
* handler can dereference the mmap offset's pointer to the object.
* This reference is cleaned up by the corresponding vm_close
* (which should happen whether the vma was created by this call, or
* by a vm_open due to mremap or partial unmap or whatever).
*/
drm_gem_object_get(obj);
vma->vm_private_data = obj;
vma->vm_ops = obj->funcs->vm_ops;
if (obj->funcs->mmap) {
ret = obj->funcs->mmap(obj, vma);
if (ret)
goto err_drm_gem_object_put;
WARN_ON(!(vma->vm_flags & VM_DONTEXPAND));
} else {
if (!vma->vm_ops) {
ret = -EINVAL;
goto err_drm_gem_object_put;
}
vm_flags_set(vma, VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP);
vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot);
}
return 0;
err_drm_gem_object_put:
drm_gem_object_put(obj);
return ret;
}
EXPORT_SYMBOL(drm_gem_mmap_obj);
/**
* drm_gem_mmap - memory map routine for GEM objects
* @filp: DRM file pointer
* @vma: VMA for the area to be mapped
*
* If a driver supports GEM object mapping, mmap calls on the DRM file
* descriptor will end up here.
*
* Look up the GEM object based on the offset passed in (vma->vm_pgoff will
* contain the fake offset we created when the GTT map ioctl was called on
* the object) and map it with a call to drm_gem_mmap_obj().
*
* If the caller is not granted access to the buffer object, the mmap will fail
* with EACCES. Please see the vma manager for more information.
*/
int drm_gem_mmap(struct file *filp, struct vm_area_struct *vma)
{
struct drm_file *priv = filp->private_data;
struct drm_device *dev = priv->minor->dev;
struct drm_gem_object *obj = NULL;
struct drm_vma_offset_node *node;
int ret;
if (drm_dev_is_unplugged(dev))
return -ENODEV;
drm_vma_offset_lock_lookup(dev->vma_offset_manager);
node = drm_vma_offset_exact_lookup_locked(dev->vma_offset_manager,
vma->vm_pgoff,
vma_pages(vma));
if (likely(node)) {
obj = container_of(node, struct drm_gem_object, vma_node);
/*
* When the object is being freed, after it hits 0-refcnt it
* proceeds to tear down the object. In the process it will
* attempt to remove the VMA offset and so acquire this
* mgr->vm_lock. Therefore if we find an object with a 0-refcnt
* that matches our range, we know it is in the process of being
* destroyed and will be freed as soon as we release the lock -
* so we have to check for the 0-refcnted object and treat it as
* invalid.
*/
if (!kref_get_unless_zero(&obj->refcount))
obj = NULL;
}
drm_vma_offset_unlock_lookup(dev->vma_offset_manager);
if (!obj)
return -EINVAL;
if (!drm_vma_node_is_allowed(node, priv)) {
drm_gem_object_put(obj);
return -EACCES;
}
ret = drm_gem_mmap_obj(obj, drm_vma_node_size(node) << PAGE_SHIFT,
vma);
drm_gem_object_put(obj);
return ret;
}
EXPORT_SYMBOL(drm_gem_mmap);
void drm_gem_print_info(struct drm_printer *p, unsigned int indent,
const struct drm_gem_object *obj)
{
drm_printf_indent(p, indent, "name=%d\n", obj->name);
drm_printf_indent(p, indent, "refcount=%u\n",
kref_read(&obj->refcount));
drm_printf_indent(p, indent, "start=%08lx\n",
drm_vma_node_start(&obj->vma_node));
drm_printf_indent(p, indent, "size=%zu\n", obj->size);
drm_printf_indent(p, indent, "imported=%s\n",
str_yes_no(obj->import_attach));
if (obj->funcs->print_info)
obj->funcs->print_info(p, indent, obj);
}
int drm_gem_pin_locked(struct drm_gem_object *obj)
{
if (obj->funcs->pin)
return obj->funcs->pin(obj);
return 0;
}
void drm_gem_unpin_locked(struct drm_gem_object *obj)
{
if (obj->funcs->unpin)
obj->funcs->unpin(obj);
}
int drm_gem_pin(struct drm_gem_object *obj)
{
int ret;
dma_resv_lock(obj->resv, NULL);
ret = drm_gem_pin_locked(obj);
dma_resv_unlock(obj->resv);
return ret;
}
void drm_gem_unpin(struct drm_gem_object *obj)
{
dma_resv_lock(obj->resv, NULL);
drm_gem_unpin_locked(obj);
dma_resv_unlock(obj->resv);
}
int drm_gem_vmap(struct drm_gem_object *obj, struct iosys_map *map)
{
int ret;
dma_resv_assert_held(obj->resv);
if (!obj->funcs->vmap)
return -EOPNOTSUPP;
ret = obj->funcs->vmap(obj, map);
if (ret)
return ret;
else if (iosys_map_is_null(map))
return -ENOMEM;
return 0;
}
EXPORT_SYMBOL(drm_gem_vmap);
void drm_gem_vunmap(struct drm_gem_object *obj, struct iosys_map *map)
{
dma_resv_assert_held(obj->resv);
if (iosys_map_is_null(map))
return;
if (obj->funcs->vunmap)
obj->funcs->vunmap(obj, map);
/* Always set the mapping to NULL. Callers may rely on this. */
iosys_map_clear(map);
}
EXPORT_SYMBOL(drm_gem_vunmap);
void drm_gem_lock(struct drm_gem_object *obj)
{
dma_resv_lock(obj->resv, NULL);
}
EXPORT_SYMBOL(drm_gem_lock);
void drm_gem_unlock(struct drm_gem_object *obj)
{
dma_resv_unlock(obj->resv);
}
EXPORT_SYMBOL(drm_gem_unlock);
int drm_gem_vmap_unlocked(struct drm_gem_object *obj, struct iosys_map *map)
{
int ret;
dma_resv_lock(obj->resv, NULL);
ret = drm_gem_vmap(obj, map);
dma_resv_unlock(obj->resv);
return ret;
}
EXPORT_SYMBOL(drm_gem_vmap_unlocked);
void drm_gem_vunmap_unlocked(struct drm_gem_object *obj, struct iosys_map *map)
{
dma_resv_lock(obj->resv, NULL);
drm_gem_vunmap(obj, map);
dma_resv_unlock(obj->resv);
}
EXPORT_SYMBOL(drm_gem_vunmap_unlocked);
/**
* drm_gem_lock_reservations - Sets up the ww context and acquires
* the lock on an array of GEM objects.
*
* Once you've locked your reservations, you'll want to set up space
* for your shared fences (if applicable), submit your job, then
* drm_gem_unlock_reservations().
*
* @objs: drm_gem_objects to lock
* @count: Number of objects in @objs
* @acquire_ctx: struct ww_acquire_ctx that will be initialized as
* part of tracking this set of locked reservations.
*/
int
drm_gem_lock_reservations(struct drm_gem_object **objs, int count,
struct ww_acquire_ctx *acquire_ctx)
{
int contended = -1;
int i, ret;
ww_acquire_init(acquire_ctx, &reservation_ww_class);
retry:
if (contended != -1) {
struct drm_gem_object *obj = objs[contended];
ret = dma_resv_lock_slow_interruptible(obj->resv,
acquire_ctx);
if (ret) {
ww_acquire_fini(acquire_ctx);
return ret;
}
}
for (i = 0; i < count; i++) {
if (i == contended)
continue;
ret = dma_resv_lock_interruptible(objs[i]->resv,
acquire_ctx);
if (ret) {
int j;
for (j = 0; j < i; j++)
dma_resv_unlock(objs[j]->resv);
if (contended != -1 && contended >= i)
dma_resv_unlock(objs[contended]->resv);
if (ret == -EDEADLK) {
contended = i;
goto retry;
}
ww_acquire_fini(acquire_ctx);
return ret;
}
}
ww_acquire_done(acquire_ctx);
return 0;
}
EXPORT_SYMBOL(drm_gem_lock_reservations);
void
drm_gem_unlock_reservations(struct drm_gem_object **objs, int count,
struct ww_acquire_ctx *acquire_ctx)
{
int i;
for (i = 0; i < count; i++)
dma_resv_unlock(objs[i]->resv);
ww_acquire_fini(acquire_ctx);
}
EXPORT_SYMBOL(drm_gem_unlock_reservations);
/**
* drm_gem_lru_init - initialize a LRU
*
* @lru: The LRU to initialize
* @lock: The lock protecting the LRU
*/
void
drm_gem_lru_init(struct drm_gem_lru *lru, struct mutex *lock)
{
lru->lock = lock;
lru->count = 0;
INIT_LIST_HEAD(&lru->list);
}
EXPORT_SYMBOL(drm_gem_lru_init);
static void
drm_gem_lru_remove_locked(struct drm_gem_object *obj)
{
obj->lru->count -= obj->size >> PAGE_SHIFT;
WARN_ON(obj->lru->count < 0);
list_del(&obj->lru_node);
obj->lru = NULL;
}
/**
* drm_gem_lru_remove - remove object from whatever LRU it is in
*
* If the object is currently in any LRU, remove it.
*
* @obj: The GEM object to remove from current LRU
*/
void
drm_gem_lru_remove(struct drm_gem_object *obj)
{
struct drm_gem_lru *lru = obj->lru;
if (!lru)
return;
mutex_lock(lru->lock);
drm_gem_lru_remove_locked(obj);
mutex_unlock(lru->lock);
}
EXPORT_SYMBOL(drm_gem_lru_remove);
/**
* drm_gem_lru_move_tail_locked - move the object to the tail of the LRU
*
* Like &drm_gem_lru_move_tail but lru lock must be held
*
* @lru: The LRU to move the object into.
* @obj: The GEM object to move into this LRU
*/
void
drm_gem_lru_move_tail_locked(struct drm_gem_lru *lru, struct drm_gem_object *obj)
{
lockdep_assert_held_once(lru->lock);
if (obj->lru)
drm_gem_lru_remove_locked(obj);
lru->count += obj->size >> PAGE_SHIFT;
list_add_tail(&obj->lru_node, &lru->list);
obj->lru = lru;
}
EXPORT_SYMBOL(drm_gem_lru_move_tail_locked);
/**
* drm_gem_lru_move_tail - move the object to the tail of the LRU
*
* If the object is already in this LRU it will be moved to the
* tail. Otherwise it will be removed from whichever other LRU
* it is in (if any) and moved into this LRU.
*
* @lru: The LRU to move the object into.
* @obj: The GEM object to move into this LRU
*/
void
drm_gem_lru_move_tail(struct drm_gem_lru *lru, struct drm_gem_object *obj)
{
mutex_lock(lru->lock);
drm_gem_lru_move_tail_locked(lru, obj);
mutex_unlock(lru->lock);
}
EXPORT_SYMBOL(drm_gem_lru_move_tail);
/**
* drm_gem_lru_scan - helper to implement shrinker.scan_objects
*
* If the shrink callback succeeds, it is expected that the driver
* move the object out of this LRU.
*
* If the LRU possibly contain active buffers, it is the responsibility
* of the shrink callback to check for this (ie. dma_resv_test_signaled())
* or if necessary block until the buffer becomes idle.
*
* @lru: The LRU to scan
* @nr_to_scan: The number of pages to try to reclaim
* @remaining: The number of pages left to reclaim, should be initialized by caller
* @shrink: Callback to try to shrink/reclaim the object.
*/
unsigned long
drm_gem_lru_scan(struct drm_gem_lru *lru,
unsigned int nr_to_scan,
unsigned long *remaining,
bool (*shrink)(struct drm_gem_object *obj))
{
struct drm_gem_lru still_in_lru;
struct drm_gem_object *obj;
unsigned freed = 0;
drm_gem_lru_init(&still_in_lru, lru->lock);
mutex_lock(lru->lock);
while (freed < nr_to_scan) {
obj = list_first_entry_or_null(&lru->list, typeof(*obj), lru_node);
if (!obj)
break;
drm_gem_lru_move_tail_locked(&still_in_lru, obj);
/*
* If it's in the process of being freed, gem_object->free()
* may be blocked on lock waiting to remove it. So just
* skip it.
*/
if (!kref_get_unless_zero(&obj->refcount))
continue;
/*
* Now that we own a reference, we can drop the lock for the
* rest of the loop body, to reduce contention with other
* code paths that need the LRU lock
*/
mutex_unlock(lru->lock);
/*
* Note that this still needs to be trylock, since we can
* hit shrinker in response to trying to get backing pages
* for this obj (ie. while it's lock is already held)
*/
if (!dma_resv_trylock(obj->resv)) {
*remaining += obj->size >> PAGE_SHIFT;
goto tail;
}
if (shrink(obj)) {
freed += obj->size >> PAGE_SHIFT;
/*
* If we succeeded in releasing the object's backing
* pages, we expect the driver to have moved the object
* out of this LRU
*/
WARN_ON(obj->lru == &still_in_lru);
WARN_ON(obj->lru == lru);
}
dma_resv_unlock(obj->resv);
tail:
drm_gem_object_put(obj);
mutex_lock(lru->lock);
}
/*
* Move objects we've skipped over out of the temporary still_in_lru
* back into this LRU
*/
list_for_each_entry (obj, &still_in_lru.list, lru_node)
obj->lru = lru;
list_splice_tail(&still_in_lru.list, &lru->list);
lru->count += still_in_lru.count;
mutex_unlock(lru->lock);
return freed;
}
EXPORT_SYMBOL(drm_gem_lru_scan);
/**
* drm_gem_evict - helper to evict backing pages for a GEM object
* @obj: obj in question
*/
int drm_gem_evict(struct drm_gem_object *obj)
{
dma_resv_assert_held(obj->resv);
if (!dma_resv_test_signaled(obj->resv, DMA_RESV_USAGE_READ))
return -EBUSY;
if (obj->funcs->evict)
return obj->funcs->evict(obj);
return 0;
}
EXPORT_SYMBOL(drm_gem_evict);
Codebase Browser
linux