| // 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 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, |
| }; |
| |
| 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 that we have zero offset. */ |
| if (sgt->sgl->offset) { |
| ret = ERR_PTR(-EINVAL); |
| pr_debug("DMA buffer has %d bytes offset, user-space expects 0\n", |
| sgt->sgl->offset); |
| goto fail_unmap; |
| } |
| |
| /* 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); |
| } |