/**************************************************************************
*
* Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
* All Rights Reserved.
*
* 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, sub license, 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 NON-INFRINGEMENT. IN NO EVENT SHALL
* THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS 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: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
*/
#ifndef _TTM_BO_API_H_
#define _TTM_BO_API_H_
#include <drm/drm_hashtab.h>
#include <linux/kref.h>
#include <linux/list.h>
#include <linux/wait.h>
#include <linux/mutex.h>
#include <linux/mm.h>
#include <linux/rbtree.h>
#include <linux/bitmap.h>
struct ttm_bo_device;
struct drm_mm_node;
/**
* struct ttm_placement
*
* @fpfn: first valid page frame number to put the object
* @lpfn: last valid page frame number to put the object
* @num_placement: number of preferred placements
* @placement: preferred placements
* @num_busy_placement: number of preferred placements when need to evict buffer
* @busy_placement: preferred placements when need to evict buffer
*
* Structure indicating the placement you request for an object.
*/
struct ttm_placement {
unsigned fpfn;
unsigned lpfn;
unsigned num_placement;
const uint32_t *placement;
unsigned num_busy_placement;
const uint32_t *busy_placement;
};
/**
* struct ttm_bus_placement
*
* @addr: mapped virtual address
* @base: bus base address
* @is_iomem: is this io memory ?
* @size: size in byte
* @offset: offset from the base address
* @io_reserved_vm: The VM system has a refcount in @io_reserved_count
* @io_reserved_count: Refcounting the numbers of callers to ttm_mem_io_reserve
*
* Structure indicating the bus placement of an object.
*/
struct ttm_bus_placement {
void *addr;
unsigned long base;
unsigned long size;
unsigned long offset;
bool is_iomem;
bool io_reserved_vm;
uint64_t io_reserved_count;
};
/**
* struct ttm_mem_reg
*
* @mm_node: Memory manager node.
* @size: Requested size of memory region.
* @num_pages: Actual size of memory region in pages.
* @page_alignment: Page alignment.
* @placement: Placement flags.
* @bus: Placement on io bus accessible to the CPU
*
* Structure indicating the placement and space resources used by a
* buffer object.
*/
struct ttm_mem_reg {
void *mm_node;
unsigned long start;
unsigned long size;
unsigned long num_pages;
uint32_t page_alignment;
uint32_t mem_type;
uint32_t placement;
struct ttm_bus_placement bus;
};
/**
* enum ttm_bo_type
*
* @ttm_bo_type_device: These are 'normal' buffers that can
* be mmapped by user space. Each of these bos occupy a slot in the
* device address space, that can be used for normal vm operations.
*
* @ttm_bo_type_kernel: These buffers are like ttm_bo_type_device buffers,
* but they cannot be accessed from user-space. For kernel-only use.
*
* @ttm_bo_type_sg: Buffer made from dmabuf sg table shared with another
* driver.
*/
enum ttm_bo_type {
ttm_bo_type_device,
ttm_bo_type_kernel,
ttm_bo_type_sg
};
struct ttm_tt;
/**
* struct ttm_buffer_object
*
* @bdev: Pointer to the buffer object device structure.
* @type: The bo type.
* @destroy: Destruction function. If NULL, kfree is used.
* @num_pages: Actual number of pages.
* @addr_space_offset: Address space offset.
* @acc_size: Accounted size for this object.
* @kref: Reference count of this buffer object. When this refcount reaches
* zero, the object is put on the delayed delete list.
* @list_kref: List reference count of this buffer object. This member is
* used to avoid destruction while the buffer object is still on a list.
* Lru lists may keep one refcount, the delayed delete list, and kref != 0
* keeps one refcount. When this refcount reaches zero,
* the object is destroyed.
* @event_queue: Queue for processes waiting on buffer object status change.
* @mem: structure describing current placement.
* @persistent_swap_storage: Usually the swap storage is deleted for buffers
* pinned in physical memory. If this behaviour is not desired, this member
* holds a pointer to a persistent shmem object.
* @ttm: TTM structure holding system pages.
* @evicted: Whether the object was evicted without user-space knowing.
* @cpu_writes: For synchronization. Number of cpu writers.
* @lru: List head for the lru list.
* @ddestroy: List head for the delayed destroy list.
* @swap: List head for swap LRU list.
* @val_seq: Sequence of the validation holding the @reserved lock.
* Used to avoid starvation when many processes compete to validate the
* buffer. This member is protected by the bo_device::lru_lock.
* @seq_valid: The value of @val_seq is valid. This value is protected by
* the bo_device::lru_lock.
* @reserved: Deadlock-free lock used for synchronization state transitions.
* @sync_obj: Pointer to a synchronization object.
* @priv_flags: Flags describing buffer object internal state.
* @vm_rb: Rb node for the vm rb tree.
* @vm_node: Address space manager node.
* @offset: The current GPU offset, which can have different meanings
* depending on the memory type. For SYSTEM type memory, it should be 0.
* @cur_placement: Hint of current placement.
*
* Base class for TTM buffer object, that deals with data placement and CPU
* mappings. GPU mappings are really up to the driver, but for simpler GPUs
* the driver can usually use the placement offset @offset directly as the
* GPU virtual address. For drivers implementing multiple
* GPU memory manager contexts, the driver should manage the address space
* in these contexts separately and use these objects to get the correct
* placement and caching for these GPU maps. This makes it possible to use
* these objects for even quite elaborate memory management schemes.
* The destroy member, the API visibility of this object makes it possible
* to derive driver specific types.
*/
struct ttm_buffer_object {
/**
* Members constant at init.
*/
struct ttm_bo_global *glob;
struct ttm_bo_device *bdev;
enum ttm_bo_type type;
void (*destroy) (struct ttm_buffer_object *);
unsigned long num_pages;
uint64_t addr_space_offset;
size_t acc_size;
/**
* Members not needing protection.
*/
struct kref kref;
struct kref list_kref;
wait_queue_head_t event_queue;
/**
* Members protected by the bo::reserved lock.
*/
struct ttm_mem_reg mem;
struct file *persistent_swap_storage;
struct ttm_tt *ttm;
bool evicted;
/**
* Members protected by the bo::reserved lock only when written to.
*/
atomic_t cpu_writers;
/**
* Members protected by the bdev::lru_lock.
*/
struct list_head lru;
struct list_head ddestroy;
struct list_head swap;
struct list_head io_reserve_lru;
uint32_t val_seq;
bool seq_valid;
/**
* Members protected by the bdev::lru_lock
* only when written to.
*/
atomic_t reserved;
/**
* Members protected by struct buffer_object_device::fence_lock
* In addition, setting sync_obj to anything else
* than NULL requires bo::reserved to be held. This allows for
* checking NULL while reserved but not holding the mentioned lock.
*/
void *sync_obj;
unsigned long priv_flags;
/**
* Members protected by the bdev::vm_lock
*/
// struct rb_node vm_rb;
struct drm_mm_node *vm_node;
/**
* Special members that are protected by the reserve lock
* and the bo::lock when written to. Can be read with
* either of these locks held.
*/
unsigned long offset;
uint32_t cur_placement;
struct sg_table *sg;
};
/**
* struct ttm_bo_kmap_obj
*
* @virtual: The current kernel virtual address.
* @page: The page when kmap'ing a single page.
* @bo_kmap_type: Type of bo_kmap.
*
* Object describing a kernel mapping. Since a TTM bo may be located
* in various memory types with various caching policies, the
* mapping can either be an ioremap, a vmap, a kmap or part of a
* premapped region.
*/
#define TTM_BO_MAP_IOMEM_MASK 0x80
struct ttm_bo_kmap_obj {
void *virtual;
struct page *page;
enum {
ttm_bo_map_iomap = 1 | TTM_BO_MAP_IOMEM_MASK,
ttm_bo_map_vmap = 2,
ttm_bo_map_kmap = 3,
ttm_bo_map_premapped = 4 | TTM_BO_MAP_IOMEM_MASK,
} bo_kmap_type;
struct ttm_buffer_object *bo;
};
/**
* ttm_bo_reference - reference a struct ttm_buffer_object
*
* @bo: The buffer object.
*
* Returns a refcounted pointer to a buffer object.
*/
static inline struct ttm_buffer_object *
ttm_bo_reference(struct ttm_buffer_object *bo)
{
kref_get(&bo->kref);
return bo;
}
/**
* ttm_bo_wait - wait for buffer idle.
*
* @bo: The buffer object.
* @interruptible: Use interruptible wait.
* @no_wait: Return immediately if buffer is busy.
*
* This function must be called with the bo::mutex held, and makes
* sure any previous rendering to the buffer is completed.
* Note: It might be necessary to block validations before the
* wait by reserving the buffer.
* Returns -EBUSY if no_wait is true and the buffer is busy.
* Returns -ERESTARTSYS if interrupted by a signal.
*/
extern int ttm_bo_wait(struct ttm_buffer_object *bo, bool lazy,
bool interruptible, bool no_wait);
/**
* ttm_bo_validate
*
* @bo: The buffer object.
* @placement: Proposed placement for the buffer object.
* @interruptible: Sleep interruptible if sleeping.
* @no_wait_gpu: Return immediately if the GPU is busy.
*
* Changes placement and caching policy of the buffer object
* according proposed placement.
* Returns
* -EINVAL on invalid proposed placement.
* -ENOMEM on out-of-memory condition.
* -EBUSY if no_wait is true and buffer busy.
* -ERESTARTSYS if interrupted by a signal.
*/
extern int ttm_bo_validate(struct ttm_buffer_object *bo,
struct ttm_placement *placement,
bool interruptible,
bool no_wait_gpu);
/**
* ttm_bo_unref
*
* @bo: The buffer object.
*
* Unreference and clear a pointer to a buffer object.
*/
extern void ttm_bo_unref(struct ttm_buffer_object **bo);
/**
* ttm_bo_list_ref_sub
*
* @bo: The buffer object.
* @count: The number of references with which to decrease @bo::list_kref;
* @never_free: The refcount should not reach zero with this operation.
*
* Release @count lru list references to this buffer object.
*/
extern void ttm_bo_list_ref_sub(struct ttm_buffer_object *bo, int count,
bool never_free);
/**
* ttm_bo_add_to_lru
*
* @bo: The buffer object.
*
* Add this bo to the relevant mem type lru and, if it's backed by
* system pages (ttms) to the swap list.
* This function must be called with struct ttm_bo_global::lru_lock held, and
* is typically called immediately prior to unreserving a bo.
*/
extern void ttm_bo_add_to_lru(struct ttm_buffer_object *bo);
/**
* ttm_bo_del_from_lru
*
* @bo: The buffer object.
*
* Remove this bo from all lru lists used to lookup and reserve an object.
* This function must be called with struct ttm_bo_global::lru_lock held,
* and is usually called just immediately after the bo has been reserved to
* avoid recursive reservation from lru lists.
*/
extern int ttm_bo_del_from_lru(struct ttm_buffer_object *bo);
/**
* ttm_bo_lock_delayed_workqueue
*
* Prevent the delayed workqueue from running.
* Returns
* True if the workqueue was queued at the time
*/
extern int ttm_bo_lock_delayed_workqueue(struct ttm_bo_device *bdev);
/**
* ttm_bo_unlock_delayed_workqueue
*
* Allows the delayed workqueue to run.
*/
extern void ttm_bo_unlock_delayed_workqueue(struct ttm_bo_device *bdev,
int resched);
/**
* ttm_bo_synccpu_write_grab
*
* @bo: The buffer object:
* @no_wait: Return immediately if buffer is busy.
*
* Synchronizes a buffer object for CPU RW access. This means
* command submission that affects the buffer will return -EBUSY
* until ttm_bo_synccpu_write_release is called.
*
* Returns
* -EBUSY if the buffer is busy and no_wait is true.
* -ERESTARTSYS if interrupted by a signal.
*/
extern int
ttm_bo_synccpu_write_grab(struct ttm_buffer_object *bo, bool no_wait);
/**
* ttm_bo_synccpu_write_release:
*
* @bo : The buffer object.
*
* Releases a synccpu lock.
*/
extern void ttm_bo_synccpu_write_release(struct ttm_buffer_object *bo);
/**
* ttm_bo_acc_size
*
* @bdev: Pointer to a ttm_bo_device struct.
* @bo_size: size of the buffer object in byte.
* @struct_size: size of the structure holding buffer object datas
*
* Returns size to account for a buffer object
*/
size_t ttm_bo_acc_size(struct ttm_bo_device *bdev,
unsigned long bo_size,
unsigned struct_size);
size_t ttm_bo_dma_acc_size(struct ttm_bo_device *bdev,
unsigned long bo_size,
unsigned struct_size);
/**
* ttm_bo_init
*
* @bdev: Pointer to a ttm_bo_device struct.
* @bo: Pointer to a ttm_buffer_object to be initialized.
* @size: Requested size of buffer object.
* @type: Requested type of buffer object.
* @flags: Initial placement flags.
* @page_alignment: Data alignment in pages.
* @interruptible: If needing to sleep to wait for GPU resources,
* sleep interruptible.
* @persistent_swap_storage: Usually the swap storage is deleted for buffers
* pinned in physical memory. If this behaviour is not desired, this member
* holds a pointer to a persistent shmem object. Typically, this would
* point to the shmem object backing a GEM object if TTM is used to back a
* GEM user interface.
* @acc_size: Accounted size for this object.
* @destroy: Destroy function. Use NULL for kfree().
*
* This function initializes a pre-allocated struct ttm_buffer_object.
* As this object may be part of a larger structure, this function,
* together with the @destroy function,
* enables driver-specific objects derived from a ttm_buffer_object.
* On successful return, the object kref and list_kref are set to 1.
* If a failure occurs, the function will call the @destroy function, or
* kfree() if @destroy is NULL. Thus, after a failure, dereferencing @bo is
* illegal and will likely cause memory corruption.
*
* Returns
* -ENOMEM: Out of memory.
* -EINVAL: Invalid placement flags.
* -ERESTARTSYS: Interrupted by signal while sleeping waiting for resources.
*/
extern int ttm_bo_init(struct ttm_bo_device *bdev,
struct ttm_buffer_object *bo,
unsigned long size,
enum ttm_bo_type type,
struct ttm_placement *placement,
uint32_t page_alignment,
bool interrubtible,
struct file *persistent_swap_storage,
size_t acc_size,
struct sg_table *sg,
void (*destroy) (struct ttm_buffer_object *));
/**
* ttm_bo_synccpu_object_init
*
* @bdev: Pointer to a ttm_bo_device struct.
* @bo: Pointer to a ttm_buffer_object to be initialized.
* @size: Requested size of buffer object.
* @type: Requested type of buffer object.
* @flags: Initial placement flags.
* @page_alignment: Data alignment in pages.
* @interruptible: If needing to sleep while waiting for GPU resources,
* sleep interruptible.
* @persistent_swap_storage: Usually the swap storage is deleted for buffers
* pinned in physical memory. If this behaviour is not desired, this member
* holds a pointer to a persistent shmem object. Typically, this would
* point to the shmem object backing a GEM object if TTM is used to back a
* GEM user interface.
* @p_bo: On successful completion *p_bo points to the created object.
*
* This function allocates a ttm_buffer_object, and then calls ttm_bo_init
* on that object. The destroy function is set to kfree().
* Returns
* -ENOMEM: Out of memory.
* -EINVAL: Invalid placement flags.
* -ERESTARTSYS: Interrupted by signal while waiting for resources.
*/
extern int ttm_bo_create(struct ttm_bo_device *bdev,
unsigned long size,
enum ttm_bo_type type,
struct ttm_placement *placement,
uint32_t page_alignment,
bool interruptible,
struct file *persistent_swap_storage,
struct ttm_buffer_object **p_bo);
/**
* ttm_bo_check_placement
*
* @bo: the buffer object.
* @placement: placements
*
* Performs minimal validity checking on an intended change of
* placement flags.
* Returns
* -EINVAL: Intended change is invalid or not allowed.
*/
extern int ttm_bo_check_placement(struct ttm_buffer_object *bo,
struct ttm_placement *placement);
/**
* ttm_bo_init_mm
*
* @bdev: Pointer to a ttm_bo_device struct.
* @mem_type: The memory type.
* @p_size: size managed area in pages.
*
* Initialize a manager for a given memory type.
* Note: if part of driver firstopen, it must be protected from a
* potentially racing lastclose.
* Returns:
* -EINVAL: invalid size or memory type.
* -ENOMEM: Not enough memory.
* May also return driver-specified errors.
*/
extern int ttm_bo_init_mm(struct ttm_bo_device *bdev, unsigned type,
unsigned long p_size);
/**
* ttm_bo_clean_mm
*
* @bdev: Pointer to a ttm_bo_device struct.
* @mem_type: The memory type.
*
* Take down a manager for a given memory type after first walking
* the LRU list to evict any buffers left alive.
*
* Normally, this function is part of lastclose() or unload(), and at that
* point there shouldn't be any buffers left created by user-space, since
* there should've been removed by the file descriptor release() method.
* However, before this function is run, make sure to signal all sync objects,
* and verify that the delayed delete queue is empty. The driver must also
* make sure that there are no NO_EVICT buffers present in this memory type
* when the call is made.
*
* If this function is part of a VT switch, the caller must make sure that
* there are no appications currently validating buffers before this
* function is called. The caller can do that by first taking the
* struct ttm_bo_device::ttm_lock in write mode.
*
* Returns:
* -EINVAL: invalid or uninitialized memory type.
* -EBUSY: There are still buffers left in this memory type.
*/
extern int ttm_bo_clean_mm(struct ttm_bo_device *bdev, unsigned mem_type);
/**
* ttm_bo_evict_mm
*
* @bdev: Pointer to a ttm_bo_device struct.
* @mem_type: The memory type.
*
* Evicts all buffers on the lru list of the memory type.
* This is normally part of a VT switch or an
* out-of-memory-space-due-to-fragmentation handler.
* The caller must make sure that there are no other processes
* currently validating buffers, and can do that by taking the
* struct ttm_bo_device::ttm_lock in write mode.
*
* Returns:
* -EINVAL: Invalid or uninitialized memory type.
* -ERESTARTSYS: The call was interrupted by a signal while waiting to
* evict a buffer.
*/
extern int ttm_bo_evict_mm(struct ttm_bo_device *bdev, unsigned mem_type);
/**
* ttm_kmap_obj_virtual
*
* @map: A struct ttm_bo_kmap_obj returned from ttm_bo_kmap.
* @is_iomem: Pointer to an integer that on return indicates 1 if the
* virtual map is io memory, 0 if normal memory.
*
* Returns the virtual address of a buffer object area mapped by ttm_bo_kmap.
* If *is_iomem is 1 on return, the virtual address points to an io memory area,
* that should strictly be accessed by the iowriteXX() and similar functions.
*/
static inline void *ttm_kmap_obj_virtual(struct ttm_bo_kmap_obj *map,
bool *is_iomem)
{
*is_iomem = !!(map->bo_kmap_type & TTM_BO_MAP_IOMEM_MASK);
return map->virtual;
}
/**
* ttm_bo_kmap
*
* @bo: The buffer object.
* @start_page: The first page to map.
* @num_pages: Number of pages to map.
* @map: pointer to a struct ttm_bo_kmap_obj representing the map.
*
* Sets up a kernel virtual mapping, using ioremap, vmap or kmap to the
* data in the buffer object. The ttm_kmap_obj_virtual function can then be
* used to obtain a virtual address to the data.
*
* Returns
* -ENOMEM: Out of memory.
* -EINVAL: Invalid range.
*/
extern int ttm_bo_kmap(struct ttm_buffer_object *bo, unsigned long start_page,
unsigned long num_pages, struct ttm_bo_kmap_obj *map);
/**
* ttm_bo_kunmap
*
* @map: Object describing the map to unmap.
*
* Unmaps a kernel map set up by ttm_bo_kmap.
*/
extern void ttm_bo_kunmap(struct ttm_bo_kmap_obj *map);
/**
* ttm_fbdev_mmap - mmap fbdev memory backed by a ttm buffer object.
*
* @vma: vma as input from the fbdev mmap method.
* @bo: The bo backing the address space. The address space will
* have the same size as the bo, and start at offset 0.
*
* This function is intended to be called by the fbdev mmap method
* if the fbdev address space is to be backed by a bo.
*/
extern int ttm_fbdev_mmap(struct vm_area_struct *vma,
struct ttm_buffer_object *bo);
/**
* ttm_bo_mmap - mmap out of the ttm device address space.
*
* @filp: filp as input from the mmap method.
* @vma: vma as input from the mmap method.
* @bdev: Pointer to the ttm_bo_device with the address space manager.
*
* This function is intended to be called by the device mmap method.
* if the device address space is to be backed by the bo manager.
*/
extern int ttm_bo_mmap(struct file *filp, struct vm_area_struct *vma,
struct ttm_bo_device *bdev);
/**
* ttm_bo_io
*
* @bdev: Pointer to the struct ttm_bo_device.
* @filp: Pointer to the struct file attempting to read / write.
* @wbuf: User-space pointer to address of buffer to write. NULL on read.
* @rbuf: User-space pointer to address of buffer to read into.
* Null on write.
* @count: Number of bytes to read / write.
* @f_pos: Pointer to current file position.
* @write: 1 for read, 0 for write.
*
* This function implements read / write into ttm buffer objects, and is
* intended to
* be called from the fops::read and fops::write method.
* Returns:
* See man (2) write, man(2) read. In particular,
* the function may return -ERESTARTSYS if
* interrupted by a signal.
*/
extern ssize_t ttm_bo_io(struct ttm_bo_device *bdev, struct file *filp,
const char __user *wbuf, char __user *rbuf,
size_t count, loff_t *f_pos, bool write);
extern void ttm_bo_swapout_all(struct ttm_bo_device *bdev);
/**
* ttm_bo_is_reserved - return an indication if a ttm buffer object is reserved
*
* @bo: The buffer object to check.
*
* This function returns an indication if a bo is reserved or not, and should
* only be used to print an error when it is not from incorrect api usage, since
* there's no guarantee that it is the caller that is holding the reservation.
*/
static inline bool ttm_bo_is_reserved(struct ttm_buffer_object *bo)
{
return atomic_read(&bo->reserved);
}
#endif