Skip to content

Commit

Permalink
xen/gntdev: Make private routines/structures accessible
Browse files Browse the repository at this point in the history 
This is in preparation for adding support of DMA buffer
functionality: make map/unmap related code and structures, used
privately by gntdev, ready for dma-buf extension, which will re-use
these. Rename corresponding structures as those become non-private
to gntdev now.

Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Oleksandr Andrushchenko authored and Boris Ostrovsky committed Jul 27, 2018
1 parent 975ef7f commit 1d31456
Showing 2 changed files with 131 additions and 91 deletions.
88 changes: 88 additions & 0 deletions drivers/xen/gntdev-common.h
View file
Original file line number Diff line number Diff line change
@@ -0,0 +1,88 @@
/* SPDX-License-Identifier: GPL-2.0 */

/*
* Common functionality of grant device.
*
* Copyright (c) 2006-2007, D G Murray.
* (c) 2009 Gerd Hoffmann <kraxel@redhat.com>
* (c) 2018 Oleksandr Andrushchenko, EPAM Systems Inc.
*/

#ifndef _GNTDEV_COMMON_H
#define _GNTDEV_COMMON_H

#include <linux/mm.h>
#include <linux/mman.h>
#include <linux/mmu_notifier.h>
#include <linux/types.h>

struct gntdev_priv {
/* Maps with visible offsets in the file descriptor. */
struct list_head maps;
/*
* Maps that are not visible; will be freed on munmap.
* Only populated if populate_freeable_maps == 1
*/
struct list_head freeable_maps;
/* lock protects maps and freeable_maps. */
struct mutex lock;
struct mm_struct *mm;
struct mmu_notifier mn;

#ifdef CONFIG_XEN_GRANT_DMA_ALLOC
/* Device for which DMA memory is allocated. */
struct device *dma_dev;
#endif
};

struct gntdev_unmap_notify {
int flags;
/* Address relative to the start of the gntdev_grant_map. */
int addr;
int event;
};

struct gntdev_grant_map {
struct list_head next;
struct vm_area_struct *vma;
int index;
int count;
int flags;
refcount_t users;
struct gntdev_unmap_notify notify;
struct ioctl_gntdev_grant_ref *grants;
struct gnttab_map_grant_ref *map_ops;
struct gnttab_unmap_grant_ref *unmap_ops;
struct gnttab_map_grant_ref *kmap_ops;
struct gnttab_unmap_grant_ref *kunmap_ops;
struct page **pages;
unsigned long pages_vm_start;

#ifdef CONFIG_XEN_GRANT_DMA_ALLOC
/*
* If dmabuf_vaddr is not NULL then this mapping is backed by DMA
* capable memory.
*/

struct device *dma_dev;
/* Flags used to create this DMA buffer: GNTDEV_DMA_FLAG_XXX. */
int dma_flags;
void *dma_vaddr;
dma_addr_t dma_bus_addr;
/* Needed to avoid allocation in gnttab_dma_free_pages(). */
xen_pfn_t *frames;
#endif
};

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);

void gntdev_put_map(struct gntdev_priv *priv, struct gntdev_grant_map *map);

bool gntdev_account_mapped_pages(int count);

int gntdev_map_grant_pages(struct gntdev_grant_map *map);

#endif
134 changes: 43 additions & 91 deletions drivers/xen/gntdev.c
View file
Original file line number Diff line number Diff line change
@@ -6,6 +6,7 @@
*
* Copyright (c) 2006-2007, D G Murray.
* (c) 2009 Gerd Hoffmann <kraxel@redhat.com>
* (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
@@ -26,10 +27,6 @@
#include <linux/init.h>
#include <linux/miscdevice.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/mman.h>
#include <linux/mmu_notifier.h>
#include <linux/types.h>
#include <linux/uaccess.h>
#include <linux/sched.h>
#include <linux/sched/mm.h>
@@ -50,6 +47,8 @@
#include <asm/xen/hypervisor.h>
#include <asm/xen/hypercall.h>

#include "gntdev-common.h"

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Derek G. Murray <Derek.Murray@cl.cam.ac.uk>, "
"Gerd Hoffmann <kraxel@redhat.com>");
@@ -65,73 +64,23 @@ static atomic_t pages_mapped = ATOMIC_INIT(0);
static int use_ptemod;
#define populate_freeable_maps use_ptemod

struct gntdev_priv {
/* maps with visible offsets in the file descriptor */
struct list_head maps;
/* maps that are not visible; will be freed on munmap.
* Only populated if populate_freeable_maps == 1 */
struct list_head freeable_maps;
/* lock protects maps and freeable_maps */
struct mutex lock;
struct mm_struct *mm;
struct mmu_notifier mn;

#ifdef CONFIG_XEN_GRANT_DMA_ALLOC
/* Device for which DMA memory is allocated. */
struct device *dma_dev;
#endif
};

struct unmap_notify {
int flags;
/* Address relative to the start of the grant_map */
int addr;
int event;
};

struct grant_map {
struct list_head next;
struct vm_area_struct *vma;
int index;
int count;
int flags;
refcount_t users;
struct unmap_notify notify;
struct ioctl_gntdev_grant_ref *grants;
struct gnttab_map_grant_ref *map_ops;
struct gnttab_unmap_grant_ref *unmap_ops;
struct gnttab_map_grant_ref *kmap_ops;
struct gnttab_unmap_grant_ref *kunmap_ops;
struct page **pages;
unsigned long pages_vm_start;

#ifdef CONFIG_XEN_GRANT_DMA_ALLOC
/*
* If dmabuf_vaddr is not NULL then this mapping is backed by DMA
* capable memory.
*/

struct device *dma_dev;
/* Flags used to create this DMA buffer: GNTDEV_DMA_FLAG_XXX. */
int dma_flags;
void *dma_vaddr;
dma_addr_t dma_bus_addr;
/* Needed to avoid allocation in gnttab_dma_free_pages(). */
xen_pfn_t *frames;
#endif
};

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

static struct miscdevice gntdev_miscdev;

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

bool gntdev_account_mapped_pages(int count)
{
return atomic_add_return(count, &pages_mapped) > limit;
}

static void gntdev_print_maps(struct gntdev_priv *priv,
char *text, int text_index)
{
#ifdef DEBUG
struct grant_map *map;
struct gntdev_grant_map *map;

pr_debug("%s: maps list (priv %p)\n", __func__, priv);
list_for_each_entry(map, &priv->maps, next)
@@ -141,7 +90,7 @@ static void gntdev_print_maps(struct gntdev_priv *priv,
#endif
}

static void gntdev_free_map(struct grant_map *map)
static void gntdev_free_map(struct gntdev_grant_map *map)
{
if (map == NULL)
return;
@@ -176,13 +125,13 @@ static void gntdev_free_map(struct grant_map *map)
kfree(map);
}

static struct grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count,
struct gntdev_grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count,
int dma_flags)
{
struct grant_map *add;
struct gntdev_grant_map *add;
int i;

add = kzalloc(sizeof(struct grant_map), GFP_KERNEL);
add = kzalloc(sizeof(*add), GFP_KERNEL);
if (NULL == add)
return NULL;

@@ -252,9 +201,9 @@ static struct grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count,
return NULL;
}

static void gntdev_add_map(struct gntdev_priv *priv, struct grant_map *add)
void gntdev_add_map(struct gntdev_priv *priv, struct gntdev_grant_map *add)
{
struct grant_map *map;
struct gntdev_grant_map *map;

list_for_each_entry(map, &priv->maps, next) {
if (add->index + add->count < map->index) {
@@ -269,10 +218,10 @@ static void gntdev_add_map(struct gntdev_priv *priv, struct grant_map *add)
gntdev_print_maps(priv, "[new]", add->index);
}

static struct grant_map *gntdev_find_map_index(struct gntdev_priv *priv,
int index, int count)
static struct gntdev_grant_map *gntdev_find_map_index(struct gntdev_priv *priv,
int index, int count)
{
struct grant_map *map;
struct gntdev_grant_map *map;

list_for_each_entry(map, &priv->maps, next) {
if (map->index != index)
@@ -284,7 +233,7 @@ static struct grant_map *gntdev_find_map_index(struct gntdev_priv *priv,
return NULL;
}

static void gntdev_put_map(struct gntdev_priv *priv, struct grant_map *map)
void gntdev_put_map(struct gntdev_priv *priv, struct gntdev_grant_map *map)
{
if (!map)
return;
@@ -315,7 +264,7 @@ static void gntdev_put_map(struct gntdev_priv *priv, struct grant_map *map)
static int find_grant_ptes(pte_t *pte, pgtable_t token,
unsigned long addr, void *data)
{
struct grant_map *map = data;
struct gntdev_grant_map *map = data;
unsigned int pgnr = (addr - map->vma->vm_start) >> PAGE_SHIFT;
int flags = map->flags | GNTMAP_application_map | GNTMAP_contains_pte;
u64 pte_maddr;
@@ -348,7 +297,7 @@ static int set_grant_ptes_as_special(pte_t *pte, pgtable_t token,
}
#endif

static int map_grant_pages(struct grant_map *map)
int gntdev_map_grant_pages(struct gntdev_grant_map *map)
{
int i, err = 0;

@@ -413,7 +362,8 @@ static int map_grant_pages(struct grant_map *map)
return err;
}

static int __unmap_grant_pages(struct grant_map *map, int offset, int pages)
static int __unmap_grant_pages(struct gntdev_grant_map *map, int offset,
int pages)
{
int i, err = 0;
struct gntab_unmap_queue_data unmap_data;
@@ -448,7 +398,8 @@ static int __unmap_grant_pages(struct grant_map *map, int offset, int pages)
return err;
}

static int unmap_grant_pages(struct grant_map *map, int offset, int pages)
static int unmap_grant_pages(struct gntdev_grant_map *map, int offset,
int pages)
{
int range, err = 0;

@@ -480,15 +431,15 @@ static int unmap_grant_pages(struct grant_map *map, int offset, int pages)

static void gntdev_vma_open(struct vm_area_struct *vma)
{
struct grant_map *map = vma->vm_private_data;
struct gntdev_grant_map *map = vma->vm_private_data;

pr_debug("gntdev_vma_open %p\n", vma);
refcount_inc(&map->users);
}

static void gntdev_vma_close(struct vm_area_struct *vma)
{
struct grant_map *map = vma->vm_private_data;
struct gntdev_grant_map *map = vma->vm_private_data;
struct file *file = vma->vm_file;
struct gntdev_priv *priv = file->private_data;

@@ -512,7 +463,7 @@ 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)
{
struct grant_map *map = vma->vm_private_data;
struct gntdev_grant_map *map = vma->vm_private_data;

return map->pages[(addr - map->pages_vm_start) >> PAGE_SHIFT];
}
@@ -525,7 +476,7 @@ static const struct vm_operations_struct gntdev_vmops = {

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

static void unmap_if_in_range(struct grant_map *map,
static void unmap_if_in_range(struct gntdev_grant_map *map,
unsigned long start, unsigned long end)
{
unsigned long mstart, mend;
@@ -554,7 +505,7 @@ static void mn_invl_range_start(struct mmu_notifier *mn,
unsigned long start, unsigned long end)
{
struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn);
struct grant_map *map;
struct gntdev_grant_map *map;

mutex_lock(&priv->lock);
list_for_each_entry(map, &priv->maps, next) {
@@ -570,7 +521,7 @@ static void mn_release(struct mmu_notifier *mn,
struct mm_struct *mm)
{
struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn);
struct grant_map *map;
struct gntdev_grant_map *map;
int err;

mutex_lock(&priv->lock);
@@ -651,13 +602,14 @@ static int gntdev_open(struct inode *inode, struct file *flip)
static int gntdev_release(struct inode *inode, struct file *flip)
{
struct gntdev_priv *priv = flip->private_data;
struct grant_map *map;
struct gntdev_grant_map *map;

pr_debug("priv %p\n", priv);

mutex_lock(&priv->lock);
while (!list_empty(&priv->maps)) {
map = list_entry(priv->maps.next, struct grant_map, next);
map = list_entry(priv->maps.next,
struct gntdev_grant_map, next);
list_del(&map->next);
gntdev_put_map(NULL /* already removed */, map);
}
@@ -674,7 +626,7 @@ static long gntdev_ioctl_map_grant_ref(struct gntdev_priv *priv,
struct ioctl_gntdev_map_grant_ref __user *u)
{
struct ioctl_gntdev_map_grant_ref op;
struct grant_map *map;
struct gntdev_grant_map *map;
int err;

if (copy_from_user(&op, u, sizeof(op)) != 0)
@@ -688,7 +640,7 @@ static long gntdev_ioctl_map_grant_ref(struct gntdev_priv *priv,
if (!map)
return err;

if (unlikely(atomic_add_return(op.count, &pages_mapped) > limit)) {
if (unlikely(gntdev_account_mapped_pages(op.count))) {
pr_debug("can't map: over limit\n");
gntdev_put_map(NULL, map);
return err;
@@ -715,7 +667,7 @@ static long gntdev_ioctl_unmap_grant_ref(struct gntdev_priv *priv,
struct ioctl_gntdev_unmap_grant_ref __user *u)
{
struct ioctl_gntdev_unmap_grant_ref op;
struct grant_map *map;
struct gntdev_grant_map *map;
int err = -ENOENT;

if (copy_from_user(&op, u, sizeof(op)) != 0)
@@ -741,7 +693,7 @@ static long gntdev_ioctl_get_offset_for_vaddr(struct gntdev_priv *priv,
{
struct ioctl_gntdev_get_offset_for_vaddr op;
struct vm_area_struct *vma;
struct grant_map *map;
struct gntdev_grant_map *map;
int rv = -EINVAL;

if (copy_from_user(&op, u, sizeof(op)) != 0)
@@ -772,7 +724,7 @@ static long gntdev_ioctl_get_offset_for_vaddr(struct gntdev_priv *priv,
static long gntdev_ioctl_notify(struct gntdev_priv *priv, void __user *u)
{
struct ioctl_gntdev_unmap_notify op;
struct grant_map *map;
struct gntdev_grant_map *map;
int rc;
int out_flags;
unsigned int out_event;
@@ -1070,7 +1022,7 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma)
struct gntdev_priv *priv = flip->private_data;
int index = vma->vm_pgoff;
int count = vma_pages(vma);
struct grant_map *map;
struct gntdev_grant_map *map;
int i, err = -EINVAL;

if ((vma->vm_flags & VM_WRITE) && !(vma->vm_flags & VM_SHARED))
@@ -1127,7 +1079,7 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma)
}
}

err = map_grant_pages(map);
err = gntdev_map_grant_pages(map);
if (err)
goto out_put_map;

0 comments on commit 1d31456

Please sign in to comment.