[PATCH v3 6/9] xen/gntdev: Make private routines/structures accessible

Oleksandr Andrushchenko
2018-06-12T13:43:21Z

From: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>

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>
---
drivers/xen/gntdev-common.h | 86 +++++++++++++++++++++++
drivers/xen/gntdev.c | 132 ++++++++++++------------------------
2 files changed, 128 insertions(+), 90 deletions(-)
create mode 100644 drivers/xen/gntdev-common.h

diff --git a/drivers/xen/gntdev-common.h b/drivers/xen/gntdev-common.h
new file mode 100644
index 000000000000..7a9845a6bee9
--- /dev/null
+++ b/drivers/xen/gntdev-common.h
@@ -0,0 +1,86 @@
+/* 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
diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
index d6b79ad1cd6f..a09db23e9663 100644
--- a/drivers/xen/gntdev.c
+++ b/drivers/xen/gntdev.c
@@ -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(struct gntdev_grant_map), 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,
+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;

@@ -480,7 +431,7 @@ 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);
@@ -488,7 +439,7 @@ static void gntdev_vma_open(struct vm_area_struct *vma)

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;

--
2.17.1