linux-stable/include/drm/drm_gem_cma_helper.h
Paul Cercueil cf8ccbc72d
drm: Add support for GEM buffers backed by non-coherent memory
Having GEM buffers backed by non-coherent memory is interesting in the
particular case where it is faster to render to a non-coherent buffer
then sync the data cache, than to render to a write-combine buffer, and
(by extension) much faster than using a shadow buffer. This is true for
instance on some Ingenic SoCs, where even simple blits (e.g. memcpy)
are about three times faster using this method.

Add a 'map_noncoherent' flag to the drm_gem_cma_object structure, which
can be set by the drivers when they create the dumb buffer.

Since this really only applies to software rendering, disable this flag
as soon as the CMA objects are exported via PRIME.

v3: New patch. Now uses a simple 'map_noncoherent' flag to control how
    the objects are mapped, and use the new dma_mmap_pages function.

v4: Make sure map_noncoherent is always disabled when creating GEM
    objects meant to be used with dma-buf.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20210523170415.90410-2-paul@crapouillou.net
2021-05-25 11:41:07 +01:00

188 lines
6.8 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __DRM_GEM_CMA_HELPER_H__
#define __DRM_GEM_CMA_HELPER_H__
#include <drm/drm_file.h>
#include <drm/drm_ioctl.h>
#include <drm/drm_gem.h>
struct drm_mode_create_dumb;
/**
* struct drm_gem_cma_object - GEM object backed by CMA memory allocations
* @base: base GEM object
* @paddr: physical address of the backing memory
* @sgt: scatter/gather table for imported PRIME buffers. The table can have
* more than one entry but they are guaranteed to have contiguous
* DMA addresses.
* @vaddr: kernel virtual address of the backing memory
* @map_noncoherent: if true, the GEM object is backed by non-coherent memory
*/
struct drm_gem_cma_object {
struct drm_gem_object base;
dma_addr_t paddr;
struct sg_table *sgt;
/* For objects with DMA memory allocated by GEM CMA */
void *vaddr;
bool map_noncoherent;
};
#define to_drm_gem_cma_obj(gem_obj) \
container_of(gem_obj, struct drm_gem_cma_object, base)
#ifndef CONFIG_MMU
#define DRM_GEM_CMA_UNMAPPED_AREA_FOPS \
.get_unmapped_area = drm_gem_cma_get_unmapped_area,
#else
#define DRM_GEM_CMA_UNMAPPED_AREA_FOPS
#endif
/**
* DEFINE_DRM_GEM_CMA_FOPS() - macro to generate file operations for CMA drivers
* @name: name for the generated structure
*
* This macro autogenerates a suitable &struct file_operations for CMA based
* drivers, which can be assigned to &drm_driver.fops. Note that this structure
* cannot be shared between drivers, because it contains a reference to the
* current module using THIS_MODULE.
*
* Note that the declaration is already marked as static - if you need a
* non-static version of this you're probably doing it wrong and will break the
* THIS_MODULE reference by accident.
*/
#define DEFINE_DRM_GEM_CMA_FOPS(name) \
static const struct file_operations name = {\
.owner = THIS_MODULE,\
.open = drm_open,\
.release = drm_release,\
.unlocked_ioctl = drm_ioctl,\
.compat_ioctl = drm_compat_ioctl,\
.poll = drm_poll,\
.read = drm_read,\
.llseek = noop_llseek,\
.mmap = drm_gem_mmap,\
DRM_GEM_CMA_UNMAPPED_AREA_FOPS \
}
/* free GEM object */
void drm_gem_cma_free_object(struct drm_gem_object *gem_obj);
/* create memory region for DRM framebuffer */
int drm_gem_cma_dumb_create_internal(struct drm_file *file_priv,
struct drm_device *drm,
struct drm_mode_create_dumb *args);
/* create memory region for DRM framebuffer */
int drm_gem_cma_dumb_create(struct drm_file *file_priv,
struct drm_device *drm,
struct drm_mode_create_dumb *args);
/* allocate physical memory */
struct drm_gem_cma_object *drm_gem_cma_create(struct drm_device *drm,
size_t size);
extern const struct vm_operations_struct drm_gem_cma_vm_ops;
#ifndef CONFIG_MMU
unsigned long drm_gem_cma_get_unmapped_area(struct file *filp,
unsigned long addr,
unsigned long len,
unsigned long pgoff,
unsigned long flags);
#endif
void drm_gem_cma_print_info(struct drm_printer *p, unsigned int indent,
const struct drm_gem_object *obj);
struct sg_table *drm_gem_cma_get_sg_table(struct drm_gem_object *obj);
struct drm_gem_object *
drm_gem_cma_prime_import_sg_table(struct drm_device *dev,
struct dma_buf_attachment *attach,
struct sg_table *sgt);
int drm_gem_cma_vmap(struct drm_gem_object *obj, struct dma_buf_map *map);
int drm_gem_cma_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma);
/**
* DRM_GEM_CMA_DRIVER_OPS_WITH_DUMB_CREATE - CMA GEM driver operations
* @dumb_create_func: callback function for .dumb_create
*
* This macro provides a shortcut for setting the default GEM operations in the
* &drm_driver structure.
*
* This macro is a variant of DRM_GEM_CMA_DRIVER_OPS for drivers that
* override the default implementation of &struct rm_driver.dumb_create. Use
* DRM_GEM_CMA_DRIVER_OPS if possible. Drivers that require a virtual address
* on imported buffers should use
* DRM_GEM_CMA_DRIVER_OPS_VMAP_WITH_DUMB_CREATE() instead.
*/
#define DRM_GEM_CMA_DRIVER_OPS_WITH_DUMB_CREATE(dumb_create_func) \
.dumb_create = (dumb_create_func), \
.prime_handle_to_fd = drm_gem_prime_handle_to_fd, \
.prime_fd_to_handle = drm_gem_prime_fd_to_handle, \
.gem_prime_import_sg_table = drm_gem_cma_prime_import_sg_table, \
.gem_prime_mmap = drm_gem_prime_mmap
/**
* DRM_GEM_CMA_DRIVER_OPS - CMA GEM driver operations
*
* This macro provides a shortcut for setting the default GEM operations in the
* &drm_driver structure.
*
* Drivers that come with their own implementation of
* &struct drm_driver.dumb_create should use
* DRM_GEM_CMA_DRIVER_OPS_WITH_DUMB_CREATE() instead. Use
* DRM_GEM_CMA_DRIVER_OPS if possible. Drivers that require a virtual address
* on imported buffers should use DRM_GEM_CMA_DRIVER_OPS_VMAP instead.
*/
#define DRM_GEM_CMA_DRIVER_OPS \
DRM_GEM_CMA_DRIVER_OPS_WITH_DUMB_CREATE(drm_gem_cma_dumb_create)
/**
* DRM_GEM_CMA_DRIVER_OPS_VMAP_WITH_DUMB_CREATE - CMA GEM driver operations
* ensuring a virtual address
* on the buffer
* @dumb_create_func: callback function for .dumb_create
*
* This macro provides a shortcut for setting the default GEM operations in the
* &drm_driver structure for drivers that need the virtual address also on
* imported buffers.
*
* This macro is a variant of DRM_GEM_CMA_DRIVER_OPS_VMAP for drivers that
* override the default implementation of &struct drm_driver.dumb_create. Use
* DRM_GEM_CMA_DRIVER_OPS_VMAP if possible. Drivers that do not require a
* virtual address on imported buffers should use
* DRM_GEM_CMA_DRIVER_OPS_WITH_DUMB_CREATE() instead.
*/
#define DRM_GEM_CMA_DRIVER_OPS_VMAP_WITH_DUMB_CREATE(dumb_create_func) \
.dumb_create = dumb_create_func, \
.prime_handle_to_fd = drm_gem_prime_handle_to_fd, \
.prime_fd_to_handle = drm_gem_prime_fd_to_handle, \
.gem_prime_import_sg_table = drm_gem_cma_prime_import_sg_table_vmap, \
.gem_prime_mmap = drm_gem_prime_mmap
/**
* DRM_GEM_CMA_DRIVER_OPS_VMAP - CMA GEM driver operations ensuring a virtual
* address on the buffer
*
* This macro provides a shortcut for setting the default GEM operations in the
* &drm_driver structure for drivers that need the virtual address also on
* imported buffers.
*
* Drivers that come with their own implementation of
* &struct drm_driver.dumb_create should use
* DRM_GEM_CMA_DRIVER_OPS_VMAP_WITH_DUMB_CREATE() instead. Use
* DRM_GEM_CMA_DRIVER_OPS_VMAP if possible. Drivers that do not require a
* virtual address on imported buffers should use DRM_GEM_CMA_DRIVER_OPS
* instead.
*/
#define DRM_GEM_CMA_DRIVER_OPS_VMAP \
DRM_GEM_CMA_DRIVER_OPS_VMAP_WITH_DUMB_CREATE(drm_gem_cma_dumb_create)
struct drm_gem_object *
drm_gem_cma_prime_import_sg_table_vmap(struct drm_device *drm,
struct dma_buf_attachment *attach,
struct sg_table *sgt);
#endif /* __DRM_GEM_CMA_HELPER_H__ */