mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-05 10:04:12 +08:00
3b06ac6707
Today there is a global limit of pages mapped via /dev/xen/gntdev set to 1 million pages per default. There is no reason why that limit is existing, as total number of grant mappings is limited by the hypervisor anyway and preferring kernel mappings over userspace ones doesn't make sense. It should be noted that the gntdev device is usable by root only. Additionally checking of that limit is fragile, as the number of pages to map via one call is specified in a 32-bit unsigned variable which isn't tested to stay within reasonable limits (the only test is the value to be <= zero, which basically excludes only calls without any mapping requested). So trying to map e.g. 0xffff0000 pages while already nearly 1000000 pages are mapped will effectively lower the global number of mapped pages such that a parallel call mapping a reasonable amount of pages can succeed in spite of the global limit being violated. So drop the global limit and introduce per call limit instead. This per call limit (default: 65536 grant mappings) protects against allocating insane large arrays in the kernel for doing a hypercall which will fail anyway in case a user is e.g. trying to map billions of pages. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com>
871 lines
21 KiB
C
871 lines
21 KiB
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/slab.h>
|
|
#include <linux/types.h>
|
|
#include <linux/uaccess.h>
|
|
|
|
#include <xen/xen.h>
|
|
#include <xen/grant_table.h>
|
|
|
|
#include "gntdev-common.h"
|
|
#include "gntdev-dmabuf.h"
|
|
|
|
#ifndef GRANT_INVALID_REF
|
|
/*
|
|
* Note on usage of grant reference 0 as invalid grant reference:
|
|
* grant reference 0 is valid, but never exposed to a driver,
|
|
* because of the fact it is already in use/reserved by the PV console.
|
|
*/
|
|
#define GRANT_INVALID_REF 0
|
|
#endif
|
|
|
|
struct gntdev_dmabuf {
|
|
struct gntdev_dmabuf_priv *priv;
|
|
struct dma_buf *dmabuf;
|
|
struct list_head next;
|
|
int fd;
|
|
|
|
union {
|
|
struct {
|
|
/* Exported buffers are reference counted. */
|
|
struct kref refcount;
|
|
|
|
struct gntdev_priv *priv;
|
|
struct gntdev_grant_map *map;
|
|
} exp;
|
|
struct {
|
|
/* Granted references of the imported buffer. */
|
|
grant_ref_t *refs;
|
|
/* Scatter-gather table of the imported buffer. */
|
|
struct sg_table *sgt;
|
|
/* dma-buf attachment of the imported buffer. */
|
|
struct dma_buf_attachment *attach;
|
|
} imp;
|
|
} u;
|
|
|
|
/* Number of pages this buffer has. */
|
|
int nr_pages;
|
|
/* Pages of this buffer. */
|
|
struct page **pages;
|
|
};
|
|
|
|
struct gntdev_dmabuf_wait_obj {
|
|
struct list_head next;
|
|
struct gntdev_dmabuf *gntdev_dmabuf;
|
|
struct completion completion;
|
|
};
|
|
|
|
struct gntdev_dmabuf_attachment {
|
|
struct sg_table *sgt;
|
|
enum dma_data_direction dir;
|
|
};
|
|
|
|
struct gntdev_dmabuf_priv {
|
|
/* List of exported DMA buffers. */
|
|
struct list_head exp_list;
|
|
/* List of wait objects. */
|
|
struct list_head exp_wait_list;
|
|
/* List of imported DMA buffers. */
|
|
struct list_head imp_list;
|
|
/* This is the lock which protects dma_buf_xxx lists. */
|
|
struct mutex lock;
|
|
/*
|
|
* We reference this file while exporting dma-bufs, so
|
|
* the grant device context is not destroyed while there are
|
|
* external users alive.
|
|
*/
|
|
struct file *filp;
|
|
};
|
|
|
|
/* 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)
|
|
{
|
|
struct gntdev_dmabuf_wait_obj *obj;
|
|
|
|
obj = kzalloc(sizeof(*obj), GFP_KERNEL);
|
|
if (!obj)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
init_completion(&obj->completion);
|
|
obj->gntdev_dmabuf = gntdev_dmabuf;
|
|
|
|
mutex_lock(&priv->lock);
|
|
list_add(&obj->next, &priv->exp_wait_list);
|
|
/* Put our reference and wait for gntdev_dmabuf's release to fire. */
|
|
kref_put(&gntdev_dmabuf->u.exp.refcount, dmabuf_exp_release);
|
|
mutex_unlock(&priv->lock);
|
|
return obj;
|
|
}
|
|
|
|
static void dmabuf_exp_wait_obj_free(struct gntdev_dmabuf_priv *priv,
|
|
struct gntdev_dmabuf_wait_obj *obj)
|
|
{
|
|
mutex_lock(&priv->lock);
|
|
list_del(&obj->next);
|
|
mutex_unlock(&priv->lock);
|
|
kfree(obj);
|
|
}
|
|
|
|
static int dmabuf_exp_wait_obj_wait(struct gntdev_dmabuf_wait_obj *obj,
|
|
u32 wait_to_ms)
|
|
{
|
|
if (wait_for_completion_timeout(&obj->completion,
|
|
msecs_to_jiffies(wait_to_ms)) <= 0)
|
|
return -ETIMEDOUT;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void dmabuf_exp_wait_obj_signal(struct gntdev_dmabuf_priv *priv,
|
|
struct gntdev_dmabuf *gntdev_dmabuf)
|
|
{
|
|
struct gntdev_dmabuf_wait_obj *obj;
|
|
|
|
list_for_each_entry(obj, &priv->exp_wait_list, next)
|
|
if (obj->gntdev_dmabuf == gntdev_dmabuf) {
|
|
pr_debug("Found gntdev_dmabuf in the wait list, wake\n");
|
|
complete_all(&obj->completion);
|
|
break;
|
|
}
|
|
}
|
|
|
|
static struct gntdev_dmabuf *
|
|
dmabuf_exp_wait_obj_get_dmabuf(struct gntdev_dmabuf_priv *priv, int fd)
|
|
{
|
|
struct gntdev_dmabuf *gntdev_dmabuf, *ret = ERR_PTR(-ENOENT);
|
|
|
|
mutex_lock(&priv->lock);
|
|
list_for_each_entry(gntdev_dmabuf, &priv->exp_list, next)
|
|
if (gntdev_dmabuf->fd == fd) {
|
|
pr_debug("Found gntdev_dmabuf in the wait list\n");
|
|
kref_get(&gntdev_dmabuf->u.exp.refcount);
|
|
ret = gntdev_dmabuf;
|
|
break;
|
|
}
|
|
mutex_unlock(&priv->lock);
|
|
return ret;
|
|
}
|
|
|
|
static int dmabuf_exp_wait_released(struct gntdev_dmabuf_priv *priv, int fd,
|
|
int wait_to_ms)
|
|
{
|
|
struct gntdev_dmabuf *gntdev_dmabuf;
|
|
struct gntdev_dmabuf_wait_obj *obj;
|
|
int ret;
|
|
|
|
pr_debug("Will wait for dma-buf with fd %d\n", fd);
|
|
/*
|
|
* Try to find the DMA buffer: if not found means that
|
|
* either the buffer has already been released or file descriptor
|
|
* provided is wrong.
|
|
*/
|
|
gntdev_dmabuf = dmabuf_exp_wait_obj_get_dmabuf(priv, fd);
|
|
if (IS_ERR(gntdev_dmabuf))
|
|
return PTR_ERR(gntdev_dmabuf);
|
|
|
|
/*
|
|
* gntdev_dmabuf still exists and is reference count locked by us now,
|
|
* so prepare to wait: allocate wait object and add it to the wait list,
|
|
* so we can find it on release.
|
|
*/
|
|
obj = dmabuf_exp_wait_obj_new(priv, gntdev_dmabuf);
|
|
if (IS_ERR(obj))
|
|
return PTR_ERR(obj);
|
|
|
|
ret = dmabuf_exp_wait_obj_wait(obj, wait_to_ms);
|
|
dmabuf_exp_wait_obj_free(priv, obj);
|
|
return ret;
|
|
}
|
|
|
|
/* DMA buffer export support. */
|
|
|
|
static struct sg_table *
|
|
dmabuf_pages_to_sgt(struct page **pages, unsigned int nr_pages)
|
|
{
|
|
struct sg_table *sgt;
|
|
int ret;
|
|
|
|
sgt = kmalloc(sizeof(*sgt), GFP_KERNEL);
|
|
if (!sgt) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
ret = sg_alloc_table_from_pages(sgt, pages, nr_pages, 0,
|
|
nr_pages << PAGE_SHIFT,
|
|
GFP_KERNEL);
|
|
if (ret)
|
|
goto out;
|
|
|
|
return sgt;
|
|
|
|
out:
|
|
kfree(sgt);
|
|
return ERR_PTR(ret);
|
|
}
|
|
|
|
static int dmabuf_exp_ops_attach(struct dma_buf *dma_buf,
|
|
struct dma_buf_attachment *attach)
|
|
{
|
|
struct gntdev_dmabuf_attachment *gntdev_dmabuf_attach;
|
|
|
|
gntdev_dmabuf_attach = kzalloc(sizeof(*gntdev_dmabuf_attach),
|
|
GFP_KERNEL);
|
|
if (!gntdev_dmabuf_attach)
|
|
return -ENOMEM;
|
|
|
|
gntdev_dmabuf_attach->dir = DMA_NONE;
|
|
attach->priv = gntdev_dmabuf_attach;
|
|
return 0;
|
|
}
|
|
|
|
static void dmabuf_exp_ops_detach(struct dma_buf *dma_buf,
|
|
struct dma_buf_attachment *attach)
|
|
{
|
|
struct gntdev_dmabuf_attachment *gntdev_dmabuf_attach = attach->priv;
|
|
|
|
if (gntdev_dmabuf_attach) {
|
|
struct sg_table *sgt = gntdev_dmabuf_attach->sgt;
|
|
|
|
if (sgt) {
|
|
if (gntdev_dmabuf_attach->dir != DMA_NONE)
|
|
dma_unmap_sg_attrs(attach->dev, sgt->sgl,
|
|
sgt->nents,
|
|
gntdev_dmabuf_attach->dir,
|
|
DMA_ATTR_SKIP_CPU_SYNC);
|
|
sg_free_table(sgt);
|
|
}
|
|
|
|
kfree(sgt);
|
|
kfree(gntdev_dmabuf_attach);
|
|
attach->priv = NULL;
|
|
}
|
|
}
|
|
|
|
static struct sg_table *
|
|
dmabuf_exp_ops_map_dma_buf(struct dma_buf_attachment *attach,
|
|
enum dma_data_direction dir)
|
|
{
|
|
struct gntdev_dmabuf_attachment *gntdev_dmabuf_attach = attach->priv;
|
|
struct gntdev_dmabuf *gntdev_dmabuf = attach->dmabuf->priv;
|
|
struct sg_table *sgt;
|
|
|
|
pr_debug("Mapping %d pages for dev %p\n", gntdev_dmabuf->nr_pages,
|
|
attach->dev);
|
|
|
|
if (dir == DMA_NONE || !gntdev_dmabuf_attach)
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
/* Return the cached mapping when possible. */
|
|
if (gntdev_dmabuf_attach->dir == dir)
|
|
return gntdev_dmabuf_attach->sgt;
|
|
|
|
/*
|
|
* Two mappings with different directions for the same attachment are
|
|
* not allowed.
|
|
*/
|
|
if (gntdev_dmabuf_attach->dir != DMA_NONE)
|
|
return ERR_PTR(-EBUSY);
|
|
|
|
sgt = dmabuf_pages_to_sgt(gntdev_dmabuf->pages,
|
|
gntdev_dmabuf->nr_pages);
|
|
if (!IS_ERR(sgt)) {
|
|
if (!dma_map_sg_attrs(attach->dev, sgt->sgl, sgt->nents, dir,
|
|
DMA_ATTR_SKIP_CPU_SYNC)) {
|
|
sg_free_table(sgt);
|
|
kfree(sgt);
|
|
sgt = ERR_PTR(-ENOMEM);
|
|
} else {
|
|
gntdev_dmabuf_attach->sgt = sgt;
|
|
gntdev_dmabuf_attach->dir = dir;
|
|
}
|
|
}
|
|
if (IS_ERR(sgt))
|
|
pr_debug("Failed to map sg table for dev %p\n", attach->dev);
|
|
return sgt;
|
|
}
|
|
|
|
static void dmabuf_exp_ops_unmap_dma_buf(struct dma_buf_attachment *attach,
|
|
struct sg_table *sgt,
|
|
enum dma_data_direction dir)
|
|
{
|
|
/* Not implemented. The unmap is done at dmabuf_exp_ops_detach(). */
|
|
}
|
|
|
|
static void dmabuf_exp_release(struct kref *kref)
|
|
{
|
|
struct gntdev_dmabuf *gntdev_dmabuf =
|
|
container_of(kref, struct gntdev_dmabuf, u.exp.refcount);
|
|
|
|
dmabuf_exp_wait_obj_signal(gntdev_dmabuf->priv, gntdev_dmabuf);
|
|
list_del(&gntdev_dmabuf->next);
|
|
fput(gntdev_dmabuf->priv->filp);
|
|
kfree(gntdev_dmabuf);
|
|
}
|
|
|
|
static void dmabuf_exp_remove_map(struct gntdev_priv *priv,
|
|
struct gntdev_grant_map *map)
|
|
{
|
|
mutex_lock(&priv->lock);
|
|
list_del(&map->next);
|
|
gntdev_put_map(NULL /* already removed */, map);
|
|
mutex_unlock(&priv->lock);
|
|
}
|
|
|
|
static void dmabuf_exp_ops_release(struct dma_buf *dma_buf)
|
|
{
|
|
struct gntdev_dmabuf *gntdev_dmabuf = dma_buf->priv;
|
|
struct gntdev_dmabuf_priv *priv = gntdev_dmabuf->priv;
|
|
|
|
dmabuf_exp_remove_map(gntdev_dmabuf->u.exp.priv,
|
|
gntdev_dmabuf->u.exp.map);
|
|
mutex_lock(&priv->lock);
|
|
kref_put(&gntdev_dmabuf->u.exp.refcount, dmabuf_exp_release);
|
|
mutex_unlock(&priv->lock);
|
|
}
|
|
|
|
static void *dmabuf_exp_ops_kmap(struct dma_buf *dma_buf,
|
|
unsigned long page_num)
|
|
{
|
|
/* Not implemented. */
|
|
return NULL;
|
|
}
|
|
|
|
static void dmabuf_exp_ops_kunmap(struct dma_buf *dma_buf,
|
|
unsigned long page_num, void *addr)
|
|
{
|
|
/* Not implemented. */
|
|
}
|
|
|
|
static int dmabuf_exp_ops_mmap(struct dma_buf *dma_buf,
|
|
struct vm_area_struct *vma)
|
|
{
|
|
/* Not implemented. */
|
|
return 0;
|
|
}
|
|
|
|
static const struct dma_buf_ops dmabuf_exp_ops = {
|
|
.attach = dmabuf_exp_ops_attach,
|
|
.detach = dmabuf_exp_ops_detach,
|
|
.map_dma_buf = dmabuf_exp_ops_map_dma_buf,
|
|
.unmap_dma_buf = dmabuf_exp_ops_unmap_dma_buf,
|
|
.release = dmabuf_exp_ops_release,
|
|
.map = dmabuf_exp_ops_kmap,
|
|
.unmap = dmabuf_exp_ops_kunmap,
|
|
.mmap = dmabuf_exp_ops_mmap,
|
|
};
|
|
|
|
struct gntdev_dmabuf_export_args {
|
|
struct gntdev_priv *priv;
|
|
struct gntdev_grant_map *map;
|
|
struct gntdev_dmabuf_priv *dmabuf_priv;
|
|
struct device *dev;
|
|
int count;
|
|
struct page **pages;
|
|
u32 fd;
|
|
};
|
|
|
|
static int dmabuf_exp_from_pages(struct gntdev_dmabuf_export_args *args)
|
|
{
|
|
DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
|
|
struct gntdev_dmabuf *gntdev_dmabuf;
|
|
int ret;
|
|
|
|
gntdev_dmabuf = kzalloc(sizeof(*gntdev_dmabuf), GFP_KERNEL);
|
|
if (!gntdev_dmabuf)
|
|
return -ENOMEM;
|
|
|
|
kref_init(&gntdev_dmabuf->u.exp.refcount);
|
|
|
|
gntdev_dmabuf->priv = args->dmabuf_priv;
|
|
gntdev_dmabuf->nr_pages = args->count;
|
|
gntdev_dmabuf->pages = args->pages;
|
|
gntdev_dmabuf->u.exp.priv = args->priv;
|
|
gntdev_dmabuf->u.exp.map = args->map;
|
|
|
|
exp_info.exp_name = KBUILD_MODNAME;
|
|
if (args->dev->driver && args->dev->driver->owner)
|
|
exp_info.owner = args->dev->driver->owner;
|
|
else
|
|
exp_info.owner = THIS_MODULE;
|
|
exp_info.ops = &dmabuf_exp_ops;
|
|
exp_info.size = args->count << PAGE_SHIFT;
|
|
exp_info.flags = O_RDWR;
|
|
exp_info.priv = gntdev_dmabuf;
|
|
|
|
gntdev_dmabuf->dmabuf = dma_buf_export(&exp_info);
|
|
if (IS_ERR(gntdev_dmabuf->dmabuf)) {
|
|
ret = PTR_ERR(gntdev_dmabuf->dmabuf);
|
|
gntdev_dmabuf->dmabuf = NULL;
|
|
goto fail;
|
|
}
|
|
|
|
ret = dma_buf_fd(gntdev_dmabuf->dmabuf, O_CLOEXEC);
|
|
if (ret < 0)
|
|
goto fail;
|
|
|
|
gntdev_dmabuf->fd = ret;
|
|
args->fd = ret;
|
|
|
|
pr_debug("Exporting DMA buffer with fd %d\n", ret);
|
|
|
|
mutex_lock(&args->dmabuf_priv->lock);
|
|
list_add(&gntdev_dmabuf->next, &args->dmabuf_priv->exp_list);
|
|
mutex_unlock(&args->dmabuf_priv->lock);
|
|
get_file(gntdev_dmabuf->priv->filp);
|
|
return 0;
|
|
|
|
fail:
|
|
if (gntdev_dmabuf->dmabuf)
|
|
dma_buf_put(gntdev_dmabuf->dmabuf);
|
|
kfree(gntdev_dmabuf);
|
|
return ret;
|
|
}
|
|
|
|
static struct gntdev_grant_map *
|
|
dmabuf_exp_alloc_backing_storage(struct gntdev_priv *priv, int dmabuf_flags,
|
|
int count)
|
|
{
|
|
struct gntdev_grant_map *map;
|
|
|
|
if (unlikely(gntdev_test_page_count(count)))
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
if ((dmabuf_flags & GNTDEV_DMA_FLAG_WC) &&
|
|
(dmabuf_flags & GNTDEV_DMA_FLAG_COHERENT)) {
|
|
pr_debug("Wrong dma-buf flags: 0x%x\n", dmabuf_flags);
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
|
|
map = gntdev_alloc_map(priv, count, dmabuf_flags);
|
|
if (!map)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
return map;
|
|
}
|
|
|
|
static int dmabuf_exp_from_refs(struct gntdev_priv *priv, int flags,
|
|
int count, u32 domid, u32 *refs, u32 *fd)
|
|
{
|
|
struct gntdev_grant_map *map;
|
|
struct gntdev_dmabuf_export_args args;
|
|
int i, ret;
|
|
|
|
map = dmabuf_exp_alloc_backing_storage(priv, flags, count);
|
|
if (IS_ERR(map))
|
|
return PTR_ERR(map);
|
|
|
|
for (i = 0; i < count; i++) {
|
|
map->grants[i].domid = domid;
|
|
map->grants[i].ref = refs[i];
|
|
}
|
|
|
|
mutex_lock(&priv->lock);
|
|
gntdev_add_map(priv, map);
|
|
mutex_unlock(&priv->lock);
|
|
|
|
map->flags |= GNTMAP_host_map;
|
|
#if defined(CONFIG_X86)
|
|
map->flags |= GNTMAP_device_map;
|
|
#endif
|
|
|
|
ret = gntdev_map_grant_pages(map);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
args.priv = priv;
|
|
args.map = map;
|
|
args.dev = priv->dma_dev;
|
|
args.dmabuf_priv = priv->dmabuf_priv;
|
|
args.count = map->count;
|
|
args.pages = map->pages;
|
|
args.fd = -1; /* Shut up unnecessary gcc warning for i386 */
|
|
|
|
ret = dmabuf_exp_from_pages(&args);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
*fd = args.fd;
|
|
return 0;
|
|
|
|
out:
|
|
dmabuf_exp_remove_map(priv, map);
|
|
return ret;
|
|
}
|
|
|
|
/* DMA buffer import support. */
|
|
|
|
static int
|
|
dmabuf_imp_grant_foreign_access(struct page **pages, u32 *refs,
|
|
int count, int domid)
|
|
{
|
|
grant_ref_t priv_gref_head;
|
|
int i, ret;
|
|
|
|
ret = gnttab_alloc_grant_references(count, &priv_gref_head);
|
|
if (ret < 0) {
|
|
pr_debug("Cannot allocate grant references, ret %d\n", ret);
|
|
return ret;
|
|
}
|
|
|
|
for (i = 0; i < count; i++) {
|
|
int cur_ref;
|
|
|
|
cur_ref = gnttab_claim_grant_reference(&priv_gref_head);
|
|
if (cur_ref < 0) {
|
|
ret = cur_ref;
|
|
pr_debug("Cannot claim grant reference, ret %d\n", ret);
|
|
goto out;
|
|
}
|
|
|
|
gnttab_grant_foreign_access_ref(cur_ref, domid,
|
|
xen_page_to_gfn(pages[i]), 0);
|
|
refs[i] = cur_ref;
|
|
}
|
|
|
|
return 0;
|
|
|
|
out:
|
|
gnttab_free_grant_references(priv_gref_head);
|
|
return ret;
|
|
}
|
|
|
|
static void dmabuf_imp_end_foreign_access(u32 *refs, int count)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < count; i++)
|
|
if (refs[i] != GRANT_INVALID_REF)
|
|
gnttab_end_foreign_access(refs[i], 0, 0UL);
|
|
}
|
|
|
|
static void dmabuf_imp_free_storage(struct gntdev_dmabuf *gntdev_dmabuf)
|
|
{
|
|
kfree(gntdev_dmabuf->pages);
|
|
kfree(gntdev_dmabuf->u.imp.refs);
|
|
kfree(gntdev_dmabuf);
|
|
}
|
|
|
|
static struct gntdev_dmabuf *dmabuf_imp_alloc_storage(int count)
|
|
{
|
|
struct gntdev_dmabuf *gntdev_dmabuf;
|
|
int i;
|
|
|
|
gntdev_dmabuf = kzalloc(sizeof(*gntdev_dmabuf), GFP_KERNEL);
|
|
if (!gntdev_dmabuf)
|
|
goto fail_no_free;
|
|
|
|
gntdev_dmabuf->u.imp.refs = kcalloc(count,
|
|
sizeof(gntdev_dmabuf->u.imp.refs[0]),
|
|
GFP_KERNEL);
|
|
if (!gntdev_dmabuf->u.imp.refs)
|
|
goto fail;
|
|
|
|
gntdev_dmabuf->pages = kcalloc(count,
|
|
sizeof(gntdev_dmabuf->pages[0]),
|
|
GFP_KERNEL);
|
|
if (!gntdev_dmabuf->pages)
|
|
goto fail;
|
|
|
|
gntdev_dmabuf->nr_pages = count;
|
|
|
|
for (i = 0; i < count; i++)
|
|
gntdev_dmabuf->u.imp.refs[i] = GRANT_INVALID_REF;
|
|
|
|
return gntdev_dmabuf;
|
|
|
|
fail:
|
|
dmabuf_imp_free_storage(gntdev_dmabuf);
|
|
fail_no_free:
|
|
return ERR_PTR(-ENOMEM);
|
|
}
|
|
|
|
static struct gntdev_dmabuf *
|
|
dmabuf_imp_to_refs(struct gntdev_dmabuf_priv *priv, struct device *dev,
|
|
int fd, int count, int domid)
|
|
{
|
|
struct gntdev_dmabuf *gntdev_dmabuf, *ret;
|
|
struct dma_buf *dma_buf;
|
|
struct dma_buf_attachment *attach;
|
|
struct sg_table *sgt;
|
|
struct sg_page_iter sg_iter;
|
|
int i;
|
|
|
|
dma_buf = dma_buf_get(fd);
|
|
if (IS_ERR(dma_buf))
|
|
return ERR_CAST(dma_buf);
|
|
|
|
gntdev_dmabuf = dmabuf_imp_alloc_storage(count);
|
|
if (IS_ERR(gntdev_dmabuf)) {
|
|
ret = gntdev_dmabuf;
|
|
goto fail_put;
|
|
}
|
|
|
|
gntdev_dmabuf->priv = priv;
|
|
gntdev_dmabuf->fd = fd;
|
|
|
|
attach = dma_buf_attach(dma_buf, dev);
|
|
if (IS_ERR(attach)) {
|
|
ret = ERR_CAST(attach);
|
|
goto fail_free_obj;
|
|
}
|
|
|
|
gntdev_dmabuf->u.imp.attach = attach;
|
|
|
|
sgt = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
|
|
if (IS_ERR(sgt)) {
|
|
ret = ERR_CAST(sgt);
|
|
goto fail_detach;
|
|
}
|
|
|
|
/* Check number of pages that imported buffer has. */
|
|
if (attach->dmabuf->size != gntdev_dmabuf->nr_pages << PAGE_SHIFT) {
|
|
ret = ERR_PTR(-EINVAL);
|
|
pr_debug("DMA buffer has %zu pages, user-space expects %d\n",
|
|
attach->dmabuf->size, gntdev_dmabuf->nr_pages);
|
|
goto fail_unmap;
|
|
}
|
|
|
|
gntdev_dmabuf->u.imp.sgt = sgt;
|
|
|
|
/* Now convert sgt to array of pages and check for page validity. */
|
|
i = 0;
|
|
for_each_sg_page(sgt->sgl, &sg_iter, sgt->nents, 0) {
|
|
struct page *page = sg_page_iter_page(&sg_iter);
|
|
/*
|
|
* Check if page is valid: this can happen if we are given
|
|
* a page from VRAM or other resources which are not backed
|
|
* by a struct page.
|
|
*/
|
|
if (!pfn_valid(page_to_pfn(page))) {
|
|
ret = ERR_PTR(-EINVAL);
|
|
goto fail_unmap;
|
|
}
|
|
|
|
gntdev_dmabuf->pages[i++] = page;
|
|
}
|
|
|
|
ret = ERR_PTR(dmabuf_imp_grant_foreign_access(gntdev_dmabuf->pages,
|
|
gntdev_dmabuf->u.imp.refs,
|
|
count, domid));
|
|
if (IS_ERR(ret))
|
|
goto fail_end_access;
|
|
|
|
pr_debug("Imported DMA buffer with fd %d\n", fd);
|
|
|
|
mutex_lock(&priv->lock);
|
|
list_add(&gntdev_dmabuf->next, &priv->imp_list);
|
|
mutex_unlock(&priv->lock);
|
|
|
|
return gntdev_dmabuf;
|
|
|
|
fail_end_access:
|
|
dmabuf_imp_end_foreign_access(gntdev_dmabuf->u.imp.refs, count);
|
|
fail_unmap:
|
|
dma_buf_unmap_attachment(attach, sgt, DMA_BIDIRECTIONAL);
|
|
fail_detach:
|
|
dma_buf_detach(dma_buf, attach);
|
|
fail_free_obj:
|
|
dmabuf_imp_free_storage(gntdev_dmabuf);
|
|
fail_put:
|
|
dma_buf_put(dma_buf);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* 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)
|
|
{
|
|
struct gntdev_dmabuf *q, *gntdev_dmabuf, *ret = ERR_PTR(-ENOENT);
|
|
|
|
mutex_lock(&priv->lock);
|
|
list_for_each_entry_safe(gntdev_dmabuf, q, &priv->imp_list, next) {
|
|
if (gntdev_dmabuf->fd == fd) {
|
|
pr_debug("Found gntdev_dmabuf in the import list\n");
|
|
ret = gntdev_dmabuf;
|
|
list_del(&gntdev_dmabuf->next);
|
|
break;
|
|
}
|
|
}
|
|
mutex_unlock(&priv->lock);
|
|
return ret;
|
|
}
|
|
|
|
static int dmabuf_imp_release(struct gntdev_dmabuf_priv *priv, u32 fd)
|
|
{
|
|
struct gntdev_dmabuf *gntdev_dmabuf;
|
|
struct dma_buf_attachment *attach;
|
|
struct dma_buf *dma_buf;
|
|
|
|
gntdev_dmabuf = dmabuf_imp_find_unlink(priv, fd);
|
|
if (IS_ERR(gntdev_dmabuf))
|
|
return PTR_ERR(gntdev_dmabuf);
|
|
|
|
pr_debug("Releasing DMA buffer with fd %d\n", fd);
|
|
|
|
dmabuf_imp_end_foreign_access(gntdev_dmabuf->u.imp.refs,
|
|
gntdev_dmabuf->nr_pages);
|
|
|
|
attach = gntdev_dmabuf->u.imp.attach;
|
|
|
|
if (gntdev_dmabuf->u.imp.sgt)
|
|
dma_buf_unmap_attachment(attach, gntdev_dmabuf->u.imp.sgt,
|
|
DMA_BIDIRECTIONAL);
|
|
dma_buf = attach->dmabuf;
|
|
dma_buf_detach(attach->dmabuf, attach);
|
|
dma_buf_put(dma_buf);
|
|
|
|
dmabuf_imp_free_storage(gntdev_dmabuf);
|
|
return 0;
|
|
}
|
|
|
|
static void dmabuf_imp_release_all(struct gntdev_dmabuf_priv *priv)
|
|
{
|
|
struct gntdev_dmabuf *q, *gntdev_dmabuf;
|
|
|
|
list_for_each_entry_safe(gntdev_dmabuf, q, &priv->imp_list, next)
|
|
dmabuf_imp_release(priv, gntdev_dmabuf->fd);
|
|
}
|
|
|
|
/* 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)
|
|
{
|
|
struct ioctl_gntdev_dmabuf_exp_from_refs op;
|
|
u32 *refs;
|
|
long ret;
|
|
|
|
if (use_ptemod) {
|
|
pr_debug("Cannot provide dma-buf: use_ptemode %d\n",
|
|
use_ptemod);
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (copy_from_user(&op, u, sizeof(op)) != 0)
|
|
return -EFAULT;
|
|
|
|
if (unlikely(gntdev_test_page_count(op.count)))
|
|
return -EINVAL;
|
|
|
|
refs = kcalloc(op.count, sizeof(*refs), GFP_KERNEL);
|
|
if (!refs)
|
|
return -ENOMEM;
|
|
|
|
if (copy_from_user(refs, u->refs, sizeof(*refs) * op.count) != 0) {
|
|
ret = -EFAULT;
|
|
goto out;
|
|
}
|
|
|
|
ret = dmabuf_exp_from_refs(priv, op.flags, op.count,
|
|
op.domid, refs, &op.fd);
|
|
if (ret)
|
|
goto out;
|
|
|
|
if (copy_to_user(u, &op, sizeof(op)) != 0)
|
|
ret = -EFAULT;
|
|
|
|
out:
|
|
kfree(refs);
|
|
return ret;
|
|
}
|
|
|
|
long gntdev_ioctl_dmabuf_exp_wait_released(struct gntdev_priv *priv,
|
|
struct ioctl_gntdev_dmabuf_exp_wait_released __user *u)
|
|
{
|
|
struct ioctl_gntdev_dmabuf_exp_wait_released op;
|
|
|
|
if (copy_from_user(&op, u, sizeof(op)) != 0)
|
|
return -EFAULT;
|
|
|
|
return dmabuf_exp_wait_released(priv->dmabuf_priv, op.fd,
|
|
op.wait_to_ms);
|
|
}
|
|
|
|
long gntdev_ioctl_dmabuf_imp_to_refs(struct gntdev_priv *priv,
|
|
struct ioctl_gntdev_dmabuf_imp_to_refs __user *u)
|
|
{
|
|
struct ioctl_gntdev_dmabuf_imp_to_refs op;
|
|
struct gntdev_dmabuf *gntdev_dmabuf;
|
|
long ret;
|
|
|
|
if (copy_from_user(&op, u, sizeof(op)) != 0)
|
|
return -EFAULT;
|
|
|
|
if (unlikely(gntdev_test_page_count(op.count)))
|
|
return -EINVAL;
|
|
|
|
gntdev_dmabuf = dmabuf_imp_to_refs(priv->dmabuf_priv,
|
|
priv->dma_dev, op.fd,
|
|
op.count, op.domid);
|
|
if (IS_ERR(gntdev_dmabuf))
|
|
return PTR_ERR(gntdev_dmabuf);
|
|
|
|
if (copy_to_user(u->refs, gntdev_dmabuf->u.imp.refs,
|
|
sizeof(*u->refs) * op.count) != 0) {
|
|
ret = -EFAULT;
|
|
goto out_release;
|
|
}
|
|
return 0;
|
|
|
|
out_release:
|
|
dmabuf_imp_release(priv->dmabuf_priv, op.fd);
|
|
return ret;
|
|
}
|
|
|
|
long gntdev_ioctl_dmabuf_imp_release(struct gntdev_priv *priv,
|
|
struct ioctl_gntdev_dmabuf_imp_release __user *u)
|
|
{
|
|
struct ioctl_gntdev_dmabuf_imp_release op;
|
|
|
|
if (copy_from_user(&op, u, sizeof(op)) != 0)
|
|
return -EFAULT;
|
|
|
|
return dmabuf_imp_release(priv->dmabuf_priv, op.fd);
|
|
}
|
|
|
|
struct gntdev_dmabuf_priv *gntdev_dmabuf_init(struct file *filp)
|
|
{
|
|
struct gntdev_dmabuf_priv *priv;
|
|
|
|
priv = kzalloc(sizeof(*priv), GFP_KERNEL);
|
|
if (!priv)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
mutex_init(&priv->lock);
|
|
INIT_LIST_HEAD(&priv->exp_list);
|
|
INIT_LIST_HEAD(&priv->exp_wait_list);
|
|
INIT_LIST_HEAD(&priv->imp_list);
|
|
|
|
priv->filp = filp;
|
|
|
|
return priv;
|
|
}
|
|
|
|
void gntdev_dmabuf_fini(struct gntdev_dmabuf_priv *priv)
|
|
{
|
|
dmabuf_imp_release_all(priv);
|
|
kfree(priv);
|
|
}
|