linux/drivers/xen/gntdev.c

/******************************************************************************
 * gntdev.c
 *
 * Device for accessing (in user-space) pages that have been granted by other
 * domains.
 *
 * Copyright (c) 2006-2007, D G Murray.
 *           (c) 2009 Gerd Hoffmann <[email protected]>
 *           (c) 2018 Oleksandr Andrushchenko, EPAM Systems Inc.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#undef DEBUG

#define pr_fmt(fmt) …

#include <linux/dma-mapping.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/miscdevice.h>
#include <linux/fs.h>
#include <linux/uaccess.h>
#include <linux/sched.h>
#include <linux/sched/mm.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/highmem.h>
#include <linux/refcount.h>
#include <linux/workqueue.h>

#include <xen/xen.h>
#include <xen/grant_table.h>
#include <xen/balloon.h>
#include <xen/gntdev.h>
#include <xen/events.h>
#include <xen/page.h>
#include <asm/xen/hypervisor.h>
#include <asm/xen/hypercall.h>

#include "gntdev-common.h"
#ifdef CONFIG_XEN_GNTDEV_DMABUF
#include "gntdev-dmabuf.h"
#endif

MODULE_LICENSE(…) …;
MODULE_AUTHOR(…) …;
MODULE_DESCRIPTION(…) …;

static unsigned int limit = …;
module_param(limit, uint, 0644);
MODULE_PARM_DESC(…) …;

/* True in PV mode, false otherwise */
static int use_ptemod;

static void unmap_grant_pages(struct gntdev_grant_map *map,
			      int offset, int pages);

static struct miscdevice gntdev_miscdev;

/* ------------------------------------------------------------------ */

bool gntdev_test_page_count(unsigned int count)
{ … }

static void gntdev_print_maps(struct gntdev_priv *priv,
			      char *text, int text_index)
{ … }

static void gntdev_free_map(struct gntdev_grant_map *map)
{ … }

struct gntdev_grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count,
					  int dma_flags)
{ … }

void gntdev_add_map(struct gntdev_priv *priv, struct gntdev_grant_map *add)
{ … }

static struct gntdev_grant_map *gntdev_find_map_index(struct gntdev_priv *priv,
						      int index, int count)
{ … }

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

/* ------------------------------------------------------------------ */

static int find_grant_ptes(pte_t *pte, unsigned long addr, void *data)
{ … }

int gntdev_map_grant_pages(struct gntdev_grant_map *map)
{ … }

static void __unmap_grant_pages_done(int result,
		struct gntab_unmap_queue_data *data)
{ … }

static void __unmap_grant_pages(struct gntdev_grant_map *map, int offset,
			       int pages)
{ … }

static void unmap_grant_pages(struct gntdev_grant_map *map, int offset,
			      int pages)
{ … }

/* ------------------------------------------------------------------ */

static void gntdev_vma_open(struct vm_area_struct *vma)
{ … }

static void gntdev_vma_close(struct vm_area_struct *vma)
{ … }

static struct page *gntdev_vma_find_special_page(struct vm_area_struct *vma,
						 unsigned long addr)
{ … }

static const struct vm_operations_struct gntdev_vmops = …;

/* ------------------------------------------------------------------ */

static bool gntdev_invalidate(struct mmu_interval_notifier *mn,
			      const struct mmu_notifier_range *range,
			      unsigned long cur_seq)
{ … }

static const struct mmu_interval_notifier_ops gntdev_mmu_ops = …;

/* ------------------------------------------------------------------ */

static int gntdev_open(struct inode *inode, struct file *flip)
{ … }

static int gntdev_release(struct inode *inode, struct file *flip)
{ … }

static long gntdev_ioctl_map_grant_ref(struct gntdev_priv *priv,
				       struct ioctl_gntdev_map_grant_ref __user *u)
{ … }

static long gntdev_ioctl_unmap_grant_ref(struct gntdev_priv *priv,
					 struct ioctl_gntdev_unmap_grant_ref __user *u)
{ … }

static long gntdev_ioctl_get_offset_for_vaddr(struct gntdev_priv *priv,
					      struct ioctl_gntdev_get_offset_for_vaddr __user *u)
{ … }

static long gntdev_ioctl_notify(struct gntdev_priv *priv, void __user *u)
{ … }

#define GNTDEV_COPY_BATCH …

struct gntdev_copy_batch { … };

static int gntdev_get_page(struct gntdev_copy_batch *batch, void __user *virt,
				unsigned long *gfn)
{ … }

static void gntdev_put_pages(struct gntdev_copy_batch *batch)
{ … }

static int gntdev_copy(struct gntdev_copy_batch *batch)
{ … }

static int gntdev_grant_copy_seg(struct gntdev_copy_batch *batch,
				 struct gntdev_grant_copy_segment *seg,
				 s16 __user *status)
{ … }

static long gntdev_ioctl_grant_copy(struct gntdev_priv *priv, void __user *u)
{ … }

static long gntdev_ioctl(struct file *flip,
			 unsigned int cmd, unsigned long arg)
{ … }

static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma)
{ … }

static const struct file_operations gntdev_fops = …;

static struct miscdevice gntdev_miscdev = …;

/* ------------------------------------------------------------------ */

static int __init gntdev_init(void)
{ … }

static void __exit gntdev_exit(void)
{ … }

module_init(…) …;
module_exit(gntdev_exit);

/* ------------------------------------------------------------------ */