linux/drivers/xen/gntdev-dmabuf.c

// SPDX-License-Identifier: GPL-2.0

/*
 * Xen dma-buf functionality for gntdev.
 *
 * DMA buffer implementation is based on drivers/gpu/drm/drm_prime.c.
 *
 * Copyright (c) 2018 Oleksandr Andrushchenko, EPAM Systems Inc.
 */

#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/dma-buf.h>
#include <linux/dma-direct.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/uaccess.h>
#include <linux/module.h>

#include <xen/xen.h>
#include <xen/grant_table.h>

#include "gntdev-common.h"
#include "gntdev-dmabuf.h"

MODULE_IMPORT_NS(…);

struct gntdev_dmabuf { … };

struct gntdev_dmabuf_wait_obj { … };

struct gntdev_dmabuf_attachment { … };

struct gntdev_dmabuf_priv { … };

/* DMA buffer export support. */

/* Implementation of wait for exported DMA buffer to be released. */

static void dmabuf_exp_release(struct kref *kref);

static struct gntdev_dmabuf_wait_obj *
dmabuf_exp_wait_obj_new(struct gntdev_dmabuf_priv *priv,
			struct gntdev_dmabuf *gntdev_dmabuf)
{ … }

static void dmabuf_exp_wait_obj_free(struct gntdev_dmabuf_priv *priv,
				     struct gntdev_dmabuf_wait_obj *obj)
{ … }

static int dmabuf_exp_wait_obj_wait(struct gntdev_dmabuf_wait_obj *obj,
				    u32 wait_to_ms)
{ … }

static void dmabuf_exp_wait_obj_signal(struct gntdev_dmabuf_priv *priv,
				       struct gntdev_dmabuf *gntdev_dmabuf)
{ … }

static struct gntdev_dmabuf *
dmabuf_exp_wait_obj_get_dmabuf(struct gntdev_dmabuf_priv *priv, int fd)
{ … }

static int dmabuf_exp_wait_released(struct gntdev_dmabuf_priv *priv, int fd,
				    int wait_to_ms)
{ … }

/* DMA buffer export support. */

static struct sg_table *
dmabuf_pages_to_sgt(struct page **pages, unsigned int nr_pages)
{ … }

static int dmabuf_exp_ops_attach(struct dma_buf *dma_buf,
				 struct dma_buf_attachment *attach)
{ … }

static void dmabuf_exp_ops_detach(struct dma_buf *dma_buf,
				  struct dma_buf_attachment *attach)
{ … }

static struct sg_table *
dmabuf_exp_ops_map_dma_buf(struct dma_buf_attachment *attach,
			   enum dma_data_direction dir)
{ … }

static void dmabuf_exp_ops_unmap_dma_buf(struct dma_buf_attachment *attach,
					 struct sg_table *sgt,
					 enum dma_data_direction dir)
{ … }

static void dmabuf_exp_release(struct kref *kref)
{ … }

static void dmabuf_exp_remove_map(struct gntdev_priv *priv,
				  struct gntdev_grant_map *map)
{ … }

static void dmabuf_exp_ops_release(struct dma_buf *dma_buf)
{ … }

static const struct dma_buf_ops dmabuf_exp_ops = …;

struct gntdev_dmabuf_export_args { … };

static int dmabuf_exp_from_pages(struct gntdev_dmabuf_export_args *args)
{ … }

static struct gntdev_grant_map *
dmabuf_exp_alloc_backing_storage(struct gntdev_priv *priv, int dmabuf_flags,
				 int count)
{ … }

static int dmabuf_exp_from_refs(struct gntdev_priv *priv, int flags,
				int count, u32 domid, u32 *refs, u32 *fd)
{ … }

/* DMA buffer import support. */

static int
dmabuf_imp_grant_foreign_access(unsigned long *gfns, u32 *refs,
				int count, int domid)
{ … }

static void dmabuf_imp_end_foreign_access(u32 *refs, int count)
{ … }

static void dmabuf_imp_free_storage(struct gntdev_dmabuf *gntdev_dmabuf)
{ … }

static struct gntdev_dmabuf *dmabuf_imp_alloc_storage(int count)
{ … }

static struct gntdev_dmabuf *
dmabuf_imp_to_refs(struct gntdev_dmabuf_priv *priv, struct device *dev,
		   int fd, int count, int domid)
{ … }

/*
 * Find the hyper dma-buf by its file descriptor and remove
 * it from the buffer's list.
 */
static struct gntdev_dmabuf *
dmabuf_imp_find_unlink(struct gntdev_dmabuf_priv *priv, int fd)
{ … }

static int dmabuf_imp_release(struct gntdev_dmabuf_priv *priv, u32 fd)
{ … }

static void dmabuf_imp_release_all(struct gntdev_dmabuf_priv *priv)
{ … }

/* DMA buffer IOCTL support. */

long gntdev_ioctl_dmabuf_exp_from_refs(struct gntdev_priv *priv, int use_ptemod,
				       struct ioctl_gntdev_dmabuf_exp_from_refs __user *u)
{ … }

long gntdev_ioctl_dmabuf_exp_wait_released(struct gntdev_priv *priv,
					   struct ioctl_gntdev_dmabuf_exp_wait_released __user *u)
{ … }

long gntdev_ioctl_dmabuf_imp_to_refs(struct gntdev_priv *priv,
				     struct ioctl_gntdev_dmabuf_imp_to_refs __user *u)
{ … }

long gntdev_ioctl_dmabuf_imp_release(struct gntdev_priv *priv,
				     struct ioctl_gntdev_dmabuf_imp_release __user *u)
{ … }

struct gntdev_dmabuf_priv *gntdev_dmabuf_init(struct file *filp)
{ … }

void gntdev_dmabuf_fini(struct gntdev_dmabuf_priv *priv)
{ … }