| Message ID | 20240117122646.41616-4-paul@crapouillou.net (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | usb: gadget: functionfs: DMABUF import interface | expand |
Am 17.01.24 um 13:26 schrieb Paul Cercueil: > This patch introduces three new ioctls. They all should be called on a > data endpoint (ie. not ep0). They are: > > - FUNCTIONFS_DMABUF_ATTACH, which takes the file descriptor of a DMABUF > object to attach to the endpoint. > > - FUNCTIONFS_DMABUF_DETACH, which takes the file descriptor of the > DMABUF to detach from the endpoint. Note that closing the endpoint's > file descriptor will automatically detach all attached DMABUFs. > > - FUNCTIONFS_DMABUF_TRANSFER, which requests a data transfer from / to > the given DMABUF. Its argument is a structure that packs the DMABUF's > file descriptor, the size in bytes to transfer (which should generally > be set to the size of the DMABUF), and a 'flags' field which is unused > for now. > Before this ioctl can be used, the related DMABUF must be attached > with FUNCTIONFS_DMABUF_ATTACH. > > These three ioctls enable the FunctionFS code to transfer data between > the USB stack and a DMABUF object, which can be provided by a driver > from a completely different subsystem, in a zero-copy fashion. > > Signed-off-by: Paul Cercueil <paul@crapouillou.net> > Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> I only looked at it from the DMA-buf maintainer point of view and especially the fence signaling (which people often get wrong) looks correct to me. Can't judge if the USB side will work or not, so I can only give my Acked-by for this as well. Regards, Christian. > > --- > v2: > - Make ffs_dma_resv_lock() static > - Add MODULE_IMPORT_NS(DMA_BUF); > - The attach/detach functions are now performed without locking the > eps_lock spinlock. The transfer function starts with the spinlock > unlocked, then locks it before allocating and queueing the USB > transfer. > > v3: > - Inline to_ffs_dma_fence() which was called only once. > - Simplify ffs_dma_resv_lock() > - Add comment explaining why we unref twice in ffs_dmabuf_detach() > - Document uapi struct usb_ffs_dmabuf_transfer_req and IOCTLs > > v4: > - Protect the dmabufs list with a mutex > - Use incremental sequence number for the dma_fences > - Unref attachments and DMABUFs in workers > - Remove dead code in ffs_dma_resv_lock() > - Fix non-block actually blocking > - Use dma_fence_begin/end_signalling() > - Add comment about cache-management and dma_buf_unmap_attachment() > - Make sure dma_buf_map_attachment() is called with the dma-resv locked > --- > drivers/usb/gadget/function/f_fs.c | 454 ++++++++++++++++++++++++++++ > include/uapi/linux/usb/functionfs.h | 41 +++ > 2 files changed, 495 insertions(+) > > diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c > index ed2a6d5fcef7..64dfd084c857 100644 > --- a/drivers/usb/gadget/function/f_fs.c > +++ b/drivers/usb/gadget/function/f_fs.c > @@ -15,6 +15,9 @@ > /* #define VERBOSE_DEBUG */ > > #include <linux/blkdev.h> > +#include <linux/dma-buf.h> > +#include <linux/dma-fence.h> > +#include <linux/dma-resv.h> > #include <linux/pagemap.h> > #include <linux/export.h> > #include <linux/fs_parser.h> > @@ -43,6 +46,8 @@ > > #define FUNCTIONFS_MAGIC 0xa647361 /* Chosen by a honest dice roll ;) */ > > +MODULE_IMPORT_NS(DMA_BUF); > + > /* Reference counter handling */ > static void ffs_data_get(struct ffs_data *ffs); > static void ffs_data_put(struct ffs_data *ffs); > @@ -124,6 +129,23 @@ struct ffs_ep { > u8 num; > }; > > +struct ffs_dmabuf_priv { > + struct list_head entry; > + struct kref ref; > + struct ffs_data *ffs; > + struct dma_buf_attachment *attach; > + spinlock_t lock; > + u64 context; > +}; > + > +struct ffs_dma_fence { > + struct dma_fence base; > + struct ffs_dmabuf_priv *priv; > + struct sg_table *sgt; > + enum dma_data_direction dir; > + struct work_struct work; > +}; > + > struct ffs_epfile { > /* Protects ep->ep and ep->req. */ > struct mutex mutex; > @@ -197,6 +219,11 @@ struct ffs_epfile { > unsigned char isoc; /* P: ffs->eps_lock */ > > unsigned char _pad; > + > + /* Protects dmabufs */ > + struct mutex dmabufs_mutex; > + struct list_head dmabufs; /* P: dmabufs_mutex */ > + atomic_t seqno; > }; > > struct ffs_buffer { > @@ -1271,10 +1298,47 @@ static ssize_t ffs_epfile_read_iter(struct kiocb *kiocb, struct iov_iter *to) > return res; > } > > +static void ffs_dmabuf_release(struct kref *ref) > +{ > + struct ffs_dmabuf_priv *priv = container_of(ref, struct ffs_dmabuf_priv, ref); > + struct dma_buf_attachment *attach = priv->attach; > + struct dma_buf *dmabuf = attach->dmabuf; > + > + pr_debug("FFS DMABUF release\n"); > + dma_buf_detach(attach->dmabuf, attach); > + dma_buf_put(dmabuf); > + kfree(priv); > +} > + > +static void ffs_dmabuf_get(struct dma_buf_attachment *attach) > +{ > + struct ffs_dmabuf_priv *priv = attach->importer_priv; > + > + kref_get(&priv->ref); > +} > + > +static void ffs_dmabuf_put(struct dma_buf_attachment *attach) > +{ > + struct ffs_dmabuf_priv *priv = attach->importer_priv; > + > + kref_put(&priv->ref, ffs_dmabuf_release); > +} > + > static int > ffs_epfile_release(struct inode *inode, struct file *file) > { > struct ffs_epfile *epfile = inode->i_private; > + struct ffs_dmabuf_priv *priv, *tmp; > + > + mutex_lock(&epfile->dmabufs_mutex); > + > + /* Close all attached DMABUFs */ > + list_for_each_entry_safe(priv, tmp, &epfile->dmabufs, entry) { > + list_del(&priv->entry); > + ffs_dmabuf_put(priv->attach); > + } > + > + mutex_unlock(&epfile->dmabufs_mutex); > > __ffs_epfile_read_buffer_free(epfile); > ffs_data_closed(epfile->ffs); > @@ -1282,6 +1346,356 @@ ffs_epfile_release(struct inode *inode, struct file *file) > return 0; > } > > +static void ffs_dmabuf_unmap_work(struct work_struct *work) > +{ > + struct ffs_dma_fence *dma_fence = > + container_of(work, struct ffs_dma_fence, work); > + struct ffs_dmabuf_priv *priv = dma_fence->priv; > + struct dma_buf_attachment *attach = priv->attach; > + struct dma_fence *fence = &dma_fence->base; > + > + dma_resv_lock(attach->dmabuf->resv, NULL); > + dma_buf_unmap_attachment(attach, dma_fence->sgt, dma_fence->dir); > + dma_resv_unlock(attach->dmabuf->resv); > + > + ffs_dmabuf_put(attach); > + dma_fence_put(fence); > +} > + > +static void ffs_dmabuf_signal_done(struct ffs_dma_fence *dma_fence, int ret) > +{ > + struct ffs_dmabuf_priv *priv = dma_fence->priv; > + struct dma_fence *fence = &dma_fence->base; > + bool cookie = dma_fence_begin_signalling(); > + > + /* > + * The dma_buf_unmap_attachment() also perform cache-management. > + * In a perfect world this would be done before the DMA fence is > + * signaled; however this is not yet possible as > + * dma_buf_unmap_attachment() is not safe to use in the DMA fence's > + * critical section. > + */ > + > + dma_fence_get(fence); > + fence->error = ret; > + dma_fence_signal(fence); > + dma_fence_end_signalling(cookie); > + > + /* > + * The fence will be unref'd in ffs_dmabuf_unmap_work. > + * It can't be done here, as the unref functions might try to lock > + * the resv object, which would deadlock. > + */ > + INIT_WORK(&dma_fence->work, ffs_dmabuf_unmap_work); > + queue_work(priv->ffs->io_completion_wq, &dma_fence->work); > +} > + > +static void ffs_epfile_dmabuf_io_complete(struct usb_ep *ep, > + struct usb_request *req) > +{ > + pr_debug("FFS: DMABUF transfer complete, status=%d\n", req->status); > + ffs_dmabuf_signal_done(req->context, req->status); > + usb_ep_free_request(ep, req); > +} > + > +static const char *ffs_dmabuf_get_driver_name(struct dma_fence *fence) > +{ > + return "functionfs"; > +} > + > +static const char *ffs_dmabuf_get_timeline_name(struct dma_fence *fence) > +{ > + return ""; > +} > + > +static void ffs_dmabuf_fence_release(struct dma_fence *fence) > +{ > + struct ffs_dma_fence *dma_fence = > + container_of(fence, struct ffs_dma_fence, base); > + > + kfree(dma_fence); > +} > + > +static const struct dma_fence_ops ffs_dmabuf_fence_ops = { > + .get_driver_name = ffs_dmabuf_get_driver_name, > + .get_timeline_name = ffs_dmabuf_get_timeline_name, > + .release = ffs_dmabuf_fence_release, > +}; > + > +static int ffs_dma_resv_lock(struct dma_buf *dmabuf, bool nonblock) > +{ > + if (!nonblock) > + return dma_resv_lock_interruptible(dmabuf->resv, NULL); > + > + if (!dma_resv_trylock(dmabuf->resv)) > + return -EBUSY; > + > + return 0; > +} > + > +static struct dma_buf_attachment * > +ffs_dmabuf_find_attachment(struct ffs_epfile *epfile, struct dma_buf *dmabuf) > +{ > + struct device *dev = epfile->ffs->gadget->dev.parent; > + struct dma_buf_attachment *attach = NULL; > + struct ffs_dmabuf_priv *priv; > + > + mutex_lock(&epfile->dmabufs_mutex); > + > + list_for_each_entry(priv, &epfile->dmabufs, entry) { > + if (priv->attach->dev == dev > + && priv->attach->dmabuf == dmabuf) { > + attach = priv->attach; > + break; > + } > + } > + > + if (attach) > + ffs_dmabuf_get(attach); > + > + mutex_unlock(&epfile->dmabufs_mutex); > + > + return attach ?: ERR_PTR(-EPERM); > +} > + > +static int ffs_dmabuf_attach(struct file *file, int fd) > +{ > + struct ffs_epfile *epfile = file->private_data; > + struct usb_gadget *gadget = epfile->ffs->gadget; > + struct dma_buf_attachment *attach; > + struct ffs_dmabuf_priv *priv; > + struct dma_buf *dmabuf; > + int err; > + > + if (!gadget || !gadget->sg_supported) > + return -EPERM; > + > + dmabuf = dma_buf_get(fd); > + if (IS_ERR(dmabuf)) > + return PTR_ERR(dmabuf); > + > + attach = dma_buf_attach(dmabuf, gadget->dev.parent); > + if (IS_ERR(attach)) { > + err = PTR_ERR(attach); > + goto err_dmabuf_put; > + } > + > + priv = kzalloc(sizeof(*priv), GFP_KERNEL); > + if (!priv) { > + err = -ENOMEM; > + goto err_dmabuf_detach; > + } > + > + attach->importer_priv = priv; > + > + priv->ffs = epfile->ffs; > + priv->attach = attach; > + spin_lock_init(&priv->lock); > + kref_init(&priv->ref); > + priv->context = dma_fence_context_alloc(1); > + > + mutex_lock(&epfile->dmabufs_mutex); > + list_add(&priv->entry, &epfile->dmabufs); > + mutex_unlock(&epfile->dmabufs_mutex); > + > + return 0; > + > +err_dmabuf_detach: > + dma_buf_detach(dmabuf, attach); > +err_dmabuf_put: > + dma_buf_put(dmabuf); > + > + return err; > +} > + > +static int ffs_dmabuf_detach(struct file *file, int fd) > +{ > + struct ffs_epfile *epfile = file->private_data; > + struct device *dev = epfile->ffs->gadget->dev.parent; > + struct ffs_dmabuf_priv *priv; > + struct dma_buf *dmabuf; > + int ret = -EPERM; > + > + dmabuf = dma_buf_get(fd); > + if (IS_ERR(dmabuf)) > + return PTR_ERR(dmabuf); > + > + mutex_lock(&epfile->dmabufs_mutex); > + > + list_for_each_entry(priv, &epfile->dmabufs, entry) { > + if (priv->attach->dev == dev > + && priv->attach->dmabuf == dmabuf) { > + list_del(&priv->entry); > + > + /* Unref the reference from ffs_dmabuf_attach() */ > + ffs_dmabuf_put(priv->attach); > + ret = 0; > + break; > + } > + } > + > + mutex_unlock(&epfile->dmabufs_mutex); > + dma_buf_put(dmabuf); > + > + return ret; > +} > + > +static int ffs_dmabuf_transfer(struct file *file, > + const struct usb_ffs_dmabuf_transfer_req *req) > +{ > + bool dma_to_ram, nonblock = file->f_flags & O_NONBLOCK; > + struct ffs_epfile *epfile = file->private_data; > + struct dma_buf_attachment *attach; > + struct ffs_dmabuf_priv *priv; > + enum dma_data_direction dir; > + struct ffs_dma_fence *fence; > + struct usb_request *usb_req; > + struct sg_table *sg_table; > + struct dma_buf *dmabuf; > + struct ffs_ep *ep; > + bool cookie; > + u32 seqno; > + int ret; > + > + if (req->flags & ~USB_FFS_DMABUF_TRANSFER_MASK) > + return -EINVAL; > + > + dmabuf = dma_buf_get(req->fd); > + if (IS_ERR(dmabuf)) > + return PTR_ERR(dmabuf); > + > + if (req->length > dmabuf->size || req->length == 0) { > + ret = -EINVAL; > + goto err_dmabuf_put; > + } > + > + attach = ffs_dmabuf_find_attachment(epfile, dmabuf); > + if (IS_ERR(attach)) { > + ret = PTR_ERR(attach); > + goto err_dmabuf_put; > + } > + > + priv = attach->importer_priv; > + > + if (epfile->in) > + dir = DMA_FROM_DEVICE; > + else > + dir = DMA_TO_DEVICE; > + > + ep = ffs_epfile_wait_ep(file); > + if (IS_ERR(ep)) { > + ret = PTR_ERR(ep); > + goto err_attachment_put; > + } > + > + ret = ffs_dma_resv_lock(dmabuf, nonblock); > + if (ret) > + goto err_attachment_put; > + > + /* Make sure we don't have writers */ > + if (!dma_resv_test_signaled(dmabuf->resv, DMA_RESV_USAGE_WRITE)) { > + pr_debug("FFS WRITE fence is not signaled\n"); > + ret = -EBUSY; > + goto err_resv_unlock; > + } > + > + dma_to_ram = dir == DMA_FROM_DEVICE; > + > + /* If we're writing to the DMABUF, make sure we don't have readers */ > + if (dma_to_ram && > + !dma_resv_test_signaled(dmabuf->resv, DMA_RESV_USAGE_READ)) { > + pr_debug("FFS READ fence is not signaled\n"); > + ret = -EBUSY; > + goto err_resv_unlock; > + } > + > + sg_table = dma_buf_map_attachment(attach, dir); > + if (IS_ERR(sg_table)) { > + ret = PTR_ERR(sg_table); > + goto err_resv_unlock; > + } > + > + ret = dma_resv_reserve_fences(dmabuf->resv, 1); > + if (ret) > + goto err_unmap_attachment; > + > + fence = kmalloc(sizeof(*fence), GFP_KERNEL); > + if (!fence) { > + ret = -ENOMEM; > + goto err_resv_unlock; > + } > + > + fence->sgt = sg_table; > + fence->dir = dir; > + fence->priv = priv; > + > + spin_lock_irq(&epfile->ffs->eps_lock); > + > + /* In the meantime, endpoint got disabled or changed. */ > + if (epfile->ep != ep) { > + ret = -ESHUTDOWN; > + goto err_fence_put; > + } > + > + usb_req = usb_ep_alloc_request(ep->ep, GFP_ATOMIC); > + if (!usb_req) { > + ret = -ENOMEM; > + goto err_fence_put; > + } > + > + /* > + * usb_ep_queue() guarantees that all transfers are processed in the > + * order they are enqueued, so we can use a simple incrementing > + * sequence number for the dma_fence. > + */ > + seqno = atomic_add_return(1, &epfile->seqno); > + > + dma_fence_init(&fence->base, &ffs_dmabuf_fence_ops, > + &priv->lock, priv->context, seqno); > + > + dma_resv_add_fence(dmabuf->resv, &fence->base, > + dma_resv_usage_rw(dma_to_ram)); > + dma_resv_unlock(dmabuf->resv); > + > + /* Now that the dma_fence is in place, queue the transfer. */ > + > + usb_req->length = req->length; > + usb_req->buf = NULL; > + usb_req->sg = sg_table->sgl; > + usb_req->num_sgs = sg_nents_for_len(sg_table->sgl, req->length); > + usb_req->sg_was_mapped = true; > + usb_req->context = fence; > + usb_req->complete = ffs_epfile_dmabuf_io_complete; > + > + cookie = dma_fence_begin_signalling(); > + ret = usb_ep_queue(ep->ep, usb_req, GFP_ATOMIC); > + dma_fence_end_signalling(cookie); > + if (ret) { > + pr_warn("FFS: Failed to queue DMABUF: %d\n", ret); > + ffs_dmabuf_signal_done(fence, ret); > + usb_ep_free_request(ep->ep, usb_req); > + } > + > + spin_unlock_irq(&epfile->ffs->eps_lock); > + dma_buf_put(dmabuf); > + > + return ret; > + > +err_fence_put: > + spin_unlock_irq(&epfile->ffs->eps_lock); > + dma_fence_put(&fence->base); > +err_unmap_attachment: > + dma_buf_unmap_attachment(attach, sg_table, dir); > +err_resv_unlock: > + dma_resv_unlock(dmabuf->resv); > +err_attachment_put: > + ffs_dmabuf_put(attach); > +err_dmabuf_put: > + dma_buf_put(dmabuf); > + > + return ret; > +} > + > static long ffs_epfile_ioctl(struct file *file, unsigned code, > unsigned long value) > { > @@ -1292,6 +1706,44 @@ static long ffs_epfile_ioctl(struct file *file, unsigned code, > if (WARN_ON(epfile->ffs->state != FFS_ACTIVE)) > return -ENODEV; > > + switch (code) { > + case FUNCTIONFS_DMABUF_ATTACH: > + { > + int fd; > + > + if (copy_from_user(&fd, (void __user *)value, sizeof(fd))) { > + ret = -EFAULT; > + break; > + } > + > + return ffs_dmabuf_attach(file, fd); > + } > + case FUNCTIONFS_DMABUF_DETACH: > + { > + int fd; > + > + if (copy_from_user(&fd, (void __user *)value, sizeof(fd))) { > + ret = -EFAULT; > + break; > + } > + > + return ffs_dmabuf_detach(file, fd); > + } > + case FUNCTIONFS_DMABUF_TRANSFER: > + { > + struct usb_ffs_dmabuf_transfer_req req; > + > + if (copy_from_user(&req, (void __user *)value, sizeof(req))) { > + ret = -EFAULT; > + break; > + } > + > + return ffs_dmabuf_transfer(file, &req); > + } > + default: > + break; > + } > + > /* Wait for endpoint to be enabled */ > ep = ffs_epfile_wait_ep(file); > if (IS_ERR(ep)) > @@ -1869,6 +2321,8 @@ static int ffs_epfiles_create(struct ffs_data *ffs) > for (i = 1; i <= count; ++i, ++epfile) { > epfile->ffs = ffs; > mutex_init(&epfile->mutex); > + mutex_init(&epfile->dmabufs_mutex); > + INIT_LIST_HEAD(&epfile->dmabufs); > if (ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR) > sprintf(epfile->name, "ep%02x", ffs->eps_addrmap[i]); > else > diff --git a/include/uapi/linux/usb/functionfs.h b/include/uapi/linux/usb/functionfs.h > index 078098e73fd3..9f88de9c3d66 100644 > --- a/include/uapi/linux/usb/functionfs.h > +++ b/include/uapi/linux/usb/functionfs.h > @@ -86,6 +86,22 @@ struct usb_ext_prop_desc { > __le16 wPropertyNameLength; > } __attribute__((packed)); > > +/* Flags for usb_ffs_dmabuf_transfer_req->flags (none for now) */ > +#define USB_FFS_DMABUF_TRANSFER_MASK 0x0 > + > +/** > + * struct usb_ffs_dmabuf_transfer_req - Transfer request for a DMABUF object > + * @fd: file descriptor of the DMABUF object > + * @flags: one or more USB_FFS_DMABUF_TRANSFER_* flags > + * @length: number of bytes used in this DMABUF for the data transfer. > + * Should generally be set to the DMABUF's size. > + */ > +struct usb_ffs_dmabuf_transfer_req { > + int fd; > + __u32 flags; > + __u64 length; > +} __attribute__((packed)); > + > #ifndef __KERNEL__ > > /* > @@ -290,6 +306,31 @@ struct usb_functionfs_event { > #define FUNCTIONFS_ENDPOINT_DESC _IOR('g', 130, \ > struct usb_endpoint_descriptor) > > +/* > + * Attach the DMABUF object, identified by its file descriptor, to the > + * data endpoint. Returns zero on success, and a negative errno value > + * on error. > + */ > +#define FUNCTIONFS_DMABUF_ATTACH _IOW('g', 131, int) > + > > +/* > + * Detach the given DMABUF object, identified by its file descriptor, > + * from the data endpoint. Returns zero on success, and a negative > + * errno value on error. Note that closing the endpoint's file > + * descriptor will automatically detach all attached DMABUFs. > + */ > +#define FUNCTIONFS_DMABUF_DETACH _IOW('g', 132, int) > + > +/* > + * Enqueue the previously attached DMABUF to the transfer queue. > + * The argument is a structure that packs the DMABUF's file descriptor, > + * the size in bytes to transfer (which should generally correspond to > + * the size of the DMABUF), and a 'flags' field which is unused > + * for now. Returns zero on success, and a negative errno value on > + * error. > + */ > +#define FUNCTIONFS_DMABUF_TRANSFER _IOW('g', 133, \ > + struct usb_ffs_dmabuf_transfer_req) > > #endif /* _UAPI__LINUX_FUNCTIONFS_H__ */
Hi Paul, kernel test robot noticed the following build errors: [auto build test ERROR on usb/usb-testing] [also build test ERROR on usb/usb-next usb/usb-linus lwn/docs-next linus/master v6.7 next-20240119] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/Paul-Cercueil/usb-gadget-Support-already-mapped-DMA-SGs/20240117-203111 base: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing patch link: https://lore.kernel.org/r/20240117122646.41616-4-paul%40crapouillou.net patch subject: [PATCH v4 3/4] usb: gadget: functionfs: Add DMABUF import interface config: arm-randconfig-r112-20240119 (https://download.01.org/0day-ci/archive/20240119/202401192043.6DTnLlKn-lkp@intel.com/config) compiler: ClangBuiltLinux clang version 17.0.6 (https://github.com/llvm/llvm-project 6009708b4367171ccdbf4b5905cb6a803753fe18) reproduce: (https://download.01.org/0day-ci/archive/20240119/202401192043.6DTnLlKn-lkp@intel.com/reproduce) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@intel.com> | Closes: https://lore.kernel.org/oe-kbuild-all/202401192043.6DTnLlKn-lkp@intel.com/ All errors (new ones prefixed by >>): >> ld.lld: error: undefined symbol: dma_buf_get >>> referenced by f_fs.c >>> drivers/usb/gadget/function/f_fs.o:(ffs_epfile_ioctl) in archive vmlinux.a >>> referenced by f_fs.c >>> drivers/usb/gadget/function/f_fs.o:(ffs_epfile_ioctl) in archive vmlinux.a >>> referenced by f_fs.c >>> drivers/usb/gadget/function/f_fs.o:(ffs_epfile_ioctl) in archive vmlinux.a -- >> ld.lld: error: undefined symbol: dma_buf_detach >>> referenced by f_fs.c >>> drivers/usb/gadget/function/f_fs.o:(ffs_epfile_ioctl) in archive vmlinux.a >>> referenced by f_fs.c >>> drivers/usb/gadget/function/f_fs.o:(ffs_epfile_ioctl) in archive vmlinux.a >>> referenced by f_fs.c >>> drivers/usb/gadget/function/f_fs.o:(ffs_epfile_ioctl) in archive vmlinux.a >>> referenced 2 more times -- >> ld.lld: error: undefined symbol: dma_fence_init >>> referenced by f_fs.c >>> drivers/usb/gadget/function/f_fs.o:(ffs_epfile_ioctl) in archive vmlinux.a -- >> ld.lld: error: undefined symbol: dma_resv_add_fence >>> referenced by f_fs.c >>> drivers/usb/gadget/function/f_fs.o:(ffs_epfile_ioctl) in archive vmlinux.a -- >> ld.lld: error: undefined symbol: dma_fence_signal >>> referenced by f_fs.c >>> drivers/usb/gadget/function/f_fs.o:(ffs_epfile_dmabuf_io_complete) in archive vmlinux.a >>> referenced by f_fs.c >>> drivers/usb/gadget/function/f_fs.o:(ffs_dmabuf_signal_done) in archive vmlinux.a -- >> ld.lld: error: undefined symbol: dma_fence_release >>> referenced by f_fs.c >>> drivers/usb/gadget/function/f_fs.o:(dma_fence_put) in archive vmlinux.a >>> referenced by f_fs.c >>> drivers/usb/gadget/function/f_fs.o:(ffs_dmabuf_unmap_work) in archive vmlinux.a -- >> ld.lld: error: undefined symbol: dma_buf_put >>> referenced by f_fs.c >>> drivers/usb/gadget/function/f_fs.o:(ffs_epfile_ioctl) in archive vmlinux.a >>> referenced by f_fs.c >>> drivers/usb/gadget/function/f_fs.o:(ffs_epfile_ioctl) in archive vmlinux.a >>> referenced by f_fs.c >>> drivers/usb/gadget/function/f_fs.o:(ffs_epfile_ioctl) in archive vmlinux.a >>> referenced 2 more times -- >> ld.lld: error: undefined symbol: dma_buf_attach >>> referenced by f_fs.c >>> drivers/usb/gadget/function/f_fs.o:(ffs_epfile_ioctl) in archive vmlinux.a -- >> ld.lld: error: undefined symbol: dma_fence_context_alloc >>> referenced by f_fs.c >>> drivers/usb/gadget/function/f_fs.o:(ffs_epfile_ioctl) in archive vmlinux.a -- >> ld.lld: error: undefined symbol: dma_resv_test_signaled >>> referenced by f_fs.c >>> drivers/usb/gadget/function/f_fs.o:(ffs_epfile_ioctl) in archive vmlinux.a >>> referenced by f_fs.c >>> drivers/usb/gadget/function/f_fs.o:(ffs_epfile_ioctl) in archive vmlinux.a -- >> ld.lld: error: undefined symbol: dma_buf_map_attachment >>> referenced by f_fs.c >>> drivers/usb/gadget/function/f_fs.o:(ffs_epfile_ioctl) in archive vmlinux.a ..
Hi Paul, kernel test robot noticed the following build errors: [auto build test ERROR on usb/usb-testing] [also build test ERROR on usb/usb-next usb/usb-linus lwn/docs-next linus/master v6.7 next-20240119] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/Paul-Cercueil/usb-gadget-Support-already-mapped-DMA-SGs/20240117-203111 base: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing patch link: https://lore.kernel.org/r/20240117122646.41616-4-paul%40crapouillou.net patch subject: [PATCH v4 3/4] usb: gadget: functionfs: Add DMABUF import interface config: sh-randconfig-r052-20240119 (https://download.01.org/0day-ci/archive/20240119/202401192234.0uzq25ka-lkp@intel.com/config) compiler: sh4-linux-gcc (GCC) 13.2.0 reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240119/202401192234.0uzq25ka-lkp@intel.com/reproduce) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@intel.com> | Closes: https://lore.kernel.org/oe-kbuild-all/202401192234.0uzq25ka-lkp@intel.com/ All errors (new ones prefixed by >>): sh4-linux-ld: drivers/usb/gadget/function/f_fs.o: in function `ffs_dmabuf_signal_done': >> f_fs.c:(.text+0x254c): undefined reference to `dma_fence_begin_signalling' >> sh4-linux-ld: f_fs.c:(.text+0x2560): undefined reference to `dma_fence_signal' >> sh4-linux-ld: f_fs.c:(.text+0x2564): undefined reference to `dma_fence_end_signalling' sh4-linux-ld: drivers/usb/gadget/function/f_fs.o: in function `ffs_epfile_release': >> f_fs.c:(.text+0x28a0): undefined reference to `dma_buf_detach' >> sh4-linux-ld: f_fs.c:(.text+0x28a4): undefined reference to `dma_buf_put' sh4-linux-ld: drivers/usb/gadget/function/f_fs.o: in function `ffs_dmabuf_unmap_work': >> f_fs.c:(.text+0x2c6c): undefined reference to `dma_buf_unmap_attachment' >> sh4-linux-ld: f_fs.c:(.text+0x2c70): undefined reference to `dma_resv_reset_max_fences' >> sh4-linux-ld: f_fs.c:(.text+0x2c84): undefined reference to `dma_buf_detach' sh4-linux-ld: f_fs.c:(.text+0x2c88): undefined reference to `dma_buf_put' >> sh4-linux-ld: f_fs.c:(.text+0x2c94): undefined reference to `dma_fence_release' sh4-linux-ld: drivers/usb/gadget/function/f_fs.o: in function `ffs_dmabuf_transfer': >> f_fs.c:(.text+0x2e30): undefined reference to `dma_buf_get' sh4-linux-ld: f_fs.c:(.text+0x2e3c): undefined reference to `dma_buf_put' >> sh4-linux-ld: f_fs.c:(.text+0x2ef4): undefined reference to `dma_resv_test_signaled' >> sh4-linux-ld: f_fs.c:(.text+0x2efc): undefined reference to `dma_buf_map_attachment' >> sh4-linux-ld: f_fs.c:(.text+0x3098): undefined reference to `dma_resv_reserve_fences' >> sh4-linux-ld: f_fs.c:(.text+0x30bc): undefined reference to `dma_fence_init' >> sh4-linux-ld: f_fs.c:(.text+0x30c0): undefined reference to `dma_resv_add_fence' sh4-linux-ld: f_fs.c:(.text+0x30c4): undefined reference to `dma_resv_reset_max_fences' >> sh4-linux-ld: f_fs.c:(.text+0x30d4): undefined reference to `dma_fence_begin_signalling' sh4-linux-ld: f_fs.c:(.text+0x30e0): undefined reference to `dma_fence_end_signalling' sh4-linux-ld: f_fs.c:(.text+0x30f0): undefined reference to `dma_buf_put' sh4-linux-ld: f_fs.c:(.text+0x321c): undefined reference to `dma_fence_release' >> sh4-linux-ld: f_fs.c:(.text+0x3224): undefined reference to `dma_buf_unmap_attachment' sh4-linux-ld: f_fs.c:(.text+0x3228): undefined reference to `dma_resv_reset_max_fences' sh4-linux-ld: f_fs.c:(.text+0x3230): undefined reference to `dma_buf_detach' sh4-linux-ld: f_fs.c:(.text+0x3234): undefined reference to `dma_buf_put' sh4-linux-ld: drivers/usb/gadget/function/f_fs.o: in function `ffs_epfile_ioctl': f_fs.c:(.text+0x41f0): undefined reference to `dma_buf_get' >> sh4-linux-ld: f_fs.c:(.text+0x41f4): undefined reference to `dma_buf_attach' sh4-linux-ld: f_fs.c:(.text+0x4200): undefined reference to `dma_buf_detach' >> sh4-linux-ld: f_fs.c:(.text+0x4210): undefined reference to `dma_fence_context_alloc' sh4-linux-ld: f_fs.c:(.text+0x4220): undefined reference to `dma_buf_put' sh4-linux-ld: f_fs.c:(.text+0x43b0): undefined reference to `dma_buf_detach' sh4-linux-ld: f_fs.c:(.text+0x43b4): undefined reference to `dma_buf_put'
diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c index ed2a6d5fcef7..64dfd084c857 100644 --- a/drivers/usb/gadget/function/f_fs.c +++ b/drivers/usb/gadget/function/f_fs.c @@ -15,6 +15,9 @@ /* #define VERBOSE_DEBUG */ #include <linux/blkdev.h> +#include <linux/dma-buf.h> +#include <linux/dma-fence.h> +#include <linux/dma-resv.h> #include <linux/pagemap.h> #include <linux/export.h> #include <linux/fs_parser.h> @@ -43,6 +46,8 @@ #define FUNCTIONFS_MAGIC 0xa647361 /* Chosen by a honest dice roll ;) */ +MODULE_IMPORT_NS(DMA_BUF); + /* Reference counter handling */ static void ffs_data_get(struct ffs_data *ffs); static void ffs_data_put(struct ffs_data *ffs); @@ -124,6 +129,23 @@ struct ffs_ep { u8 num; }; +struct ffs_dmabuf_priv { + struct list_head entry; + struct kref ref; + struct ffs_data *ffs; + struct dma_buf_attachment *attach; + spinlock_t lock; + u64 context; +}; + +struct ffs_dma_fence { + struct dma_fence base; + struct ffs_dmabuf_priv *priv; + struct sg_table *sgt; + enum dma_data_direction dir; + struct work_struct work; +}; + struct ffs_epfile { /* Protects ep->ep and ep->req. */ struct mutex mutex; @@ -197,6 +219,11 @@ struct ffs_epfile { unsigned char isoc; /* P: ffs->eps_lock */ unsigned char _pad; + + /* Protects dmabufs */ + struct mutex dmabufs_mutex; + struct list_head dmabufs; /* P: dmabufs_mutex */ + atomic_t seqno; }; struct ffs_buffer { @@ -1271,10 +1298,47 @@ static ssize_t ffs_epfile_read_iter(struct kiocb *kiocb, struct iov_iter *to) return res; } +static void ffs_dmabuf_release(struct kref *ref) +{ + struct ffs_dmabuf_priv *priv = container_of(ref, struct ffs_dmabuf_priv, ref); + struct dma_buf_attachment *attach = priv->attach; + struct dma_buf *dmabuf = attach->dmabuf; + + pr_debug("FFS DMABUF release\n"); + dma_buf_detach(attach->dmabuf, attach); + dma_buf_put(dmabuf); + kfree(priv); +} + +static void ffs_dmabuf_get(struct dma_buf_attachment *attach) +{ + struct ffs_dmabuf_priv *priv = attach->importer_priv; + + kref_get(&priv->ref); +} + +static void ffs_dmabuf_put(struct dma_buf_attachment *attach) +{ + struct ffs_dmabuf_priv *priv = attach->importer_priv; + + kref_put(&priv->ref, ffs_dmabuf_release); +} + static int ffs_epfile_release(struct inode *inode, struct file *file) { struct ffs_epfile *epfile = inode->i_private; + struct ffs_dmabuf_priv *priv, *tmp; + + mutex_lock(&epfile->dmabufs_mutex); + + /* Close all attached DMABUFs */ + list_for_each_entry_safe(priv, tmp, &epfile->dmabufs, entry) { + list_del(&priv->entry); + ffs_dmabuf_put(priv->attach); + } + + mutex_unlock(&epfile->dmabufs_mutex); __ffs_epfile_read_buffer_free(epfile); ffs_data_closed(epfile->ffs); @@ -1282,6 +1346,356 @@ ffs_epfile_release(struct inode *inode, struct file *file) return 0; } +static void ffs_dmabuf_unmap_work(struct work_struct *work) +{ + struct ffs_dma_fence *dma_fence = + container_of(work, struct ffs_dma_fence, work); + struct ffs_dmabuf_priv *priv = dma_fence->priv; + struct dma_buf_attachment *attach = priv->attach; + struct dma_fence *fence = &dma_fence->base; + + dma_resv_lock(attach->dmabuf->resv, NULL); + dma_buf_unmap_attachment(attach, dma_fence->sgt, dma_fence->dir); + dma_resv_unlock(attach->dmabuf->resv); + + ffs_dmabuf_put(attach); + dma_fence_put(fence); +} + +static void ffs_dmabuf_signal_done(struct ffs_dma_fence *dma_fence, int ret) +{ + struct ffs_dmabuf_priv *priv = dma_fence->priv; + struct dma_fence *fence = &dma_fence->base; + bool cookie = dma_fence_begin_signalling(); + + /* + * The dma_buf_unmap_attachment() also perform cache-management. + * In a perfect world this would be done before the DMA fence is + * signaled; however this is not yet possible as + * dma_buf_unmap_attachment() is not safe to use in the DMA fence's + * critical section. + */ + + dma_fence_get(fence); + fence->error = ret; + dma_fence_signal(fence); + dma_fence_end_signalling(cookie); + + /* + * The fence will be unref'd in ffs_dmabuf_unmap_work. + * It can't be done here, as the unref functions might try to lock + * the resv object, which would deadlock. + */ + INIT_WORK(&dma_fence->work, ffs_dmabuf_unmap_work); + queue_work(priv->ffs->io_completion_wq, &dma_fence->work); +} + +static void ffs_epfile_dmabuf_io_complete(struct usb_ep *ep, + struct usb_request *req) +{ + pr_debug("FFS: DMABUF transfer complete, status=%d\n", req->status); + ffs_dmabuf_signal_done(req->context, req->status); + usb_ep_free_request(ep, req); +} + +static const char *ffs_dmabuf_get_driver_name(struct dma_fence *fence) +{ + return "functionfs"; +} + +static const char *ffs_dmabuf_get_timeline_name(struct dma_fence *fence) +{ + return ""; +} + +static void ffs_dmabuf_fence_release(struct dma_fence *fence) +{ + struct ffs_dma_fence *dma_fence = + container_of(fence, struct ffs_dma_fence, base); + + kfree(dma_fence); +} + +static const struct dma_fence_ops ffs_dmabuf_fence_ops = { + .get_driver_name = ffs_dmabuf_get_driver_name, + .get_timeline_name = ffs_dmabuf_get_timeline_name, + .release = ffs_dmabuf_fence_release, +}; + +static int ffs_dma_resv_lock(struct dma_buf *dmabuf, bool nonblock) +{ + if (!nonblock) + return dma_resv_lock_interruptible(dmabuf->resv, NULL); + + if (!dma_resv_trylock(dmabuf->resv)) + return -EBUSY; + + return 0; +} + +static struct dma_buf_attachment * +ffs_dmabuf_find_attachment(struct ffs_epfile *epfile, struct dma_buf *dmabuf) +{ + struct device *dev = epfile->ffs->gadget->dev.parent; + struct dma_buf_attachment *attach = NULL; + struct ffs_dmabuf_priv *priv; + + mutex_lock(&epfile->dmabufs_mutex); + + list_for_each_entry(priv, &epfile->dmabufs, entry) { + if (priv->attach->dev == dev + && priv->attach->dmabuf == dmabuf) { + attach = priv->attach; + break; + } + } + + if (attach) + ffs_dmabuf_get(attach); + + mutex_unlock(&epfile->dmabufs_mutex); + + return attach ?: ERR_PTR(-EPERM); +} + +static int ffs_dmabuf_attach(struct file *file, int fd) +{ + struct ffs_epfile *epfile = file->private_data; + struct usb_gadget *gadget = epfile->ffs->gadget; + struct dma_buf_attachment *attach; + struct ffs_dmabuf_priv *priv; + struct dma_buf *dmabuf; + int err; + + if (!gadget || !gadget->sg_supported) + return -EPERM; + + dmabuf = dma_buf_get(fd); + if (IS_ERR(dmabuf)) + return PTR_ERR(dmabuf); + + attach = dma_buf_attach(dmabuf, gadget->dev.parent); + if (IS_ERR(attach)) { + err = PTR_ERR(attach); + goto err_dmabuf_put; + } + + priv = kzalloc(sizeof(*priv), GFP_KERNEL); + if (!priv) { + err = -ENOMEM; + goto err_dmabuf_detach; + } + + attach->importer_priv = priv; + + priv->ffs = epfile->ffs; + priv->attach = attach; + spin_lock_init(&priv->lock); + kref_init(&priv->ref); + priv->context = dma_fence_context_alloc(1); + + mutex_lock(&epfile->dmabufs_mutex); + list_add(&priv->entry, &epfile->dmabufs); + mutex_unlock(&epfile->dmabufs_mutex); + + return 0; + +err_dmabuf_detach: + dma_buf_detach(dmabuf, attach); +err_dmabuf_put: + dma_buf_put(dmabuf); + + return err; +} + +static int ffs_dmabuf_detach(struct file *file, int fd) +{ + struct ffs_epfile *epfile = file->private_data; + struct device *dev = epfile->ffs->gadget->dev.parent; + struct ffs_dmabuf_priv *priv; + struct dma_buf *dmabuf; + int ret = -EPERM; + + dmabuf = dma_buf_get(fd); + if (IS_ERR(dmabuf)) + return PTR_ERR(dmabuf); + + mutex_lock(&epfile->dmabufs_mutex); + + list_for_each_entry(priv, &epfile->dmabufs, entry) { + if (priv->attach->dev == dev + && priv->attach->dmabuf == dmabuf) { + list_del(&priv->entry); + + /* Unref the reference from ffs_dmabuf_attach() */ + ffs_dmabuf_put(priv->attach); + ret = 0; + break; + } + } + + mutex_unlock(&epfile->dmabufs_mutex); + dma_buf_put(dmabuf); + + return ret; +} + +static int ffs_dmabuf_transfer(struct file *file, + const struct usb_ffs_dmabuf_transfer_req *req) +{ + bool dma_to_ram, nonblock = file->f_flags & O_NONBLOCK; + struct ffs_epfile *epfile = file->private_data; + struct dma_buf_attachment *attach; + struct ffs_dmabuf_priv *priv; + enum dma_data_direction dir; + struct ffs_dma_fence *fence; + struct usb_request *usb_req; + struct sg_table *sg_table; + struct dma_buf *dmabuf; + struct ffs_ep *ep; + bool cookie; + u32 seqno; + int ret; + + if (req->flags & ~USB_FFS_DMABUF_TRANSFER_MASK) + return -EINVAL; + + dmabuf = dma_buf_get(req->fd); + if (IS_ERR(dmabuf)) + return PTR_ERR(dmabuf); + + if (req->length > dmabuf->size || req->length == 0) { + ret = -EINVAL; + goto err_dmabuf_put; + } + + attach = ffs_dmabuf_find_attachment(epfile, dmabuf); + if (IS_ERR(attach)) { + ret = PTR_ERR(attach); + goto err_dmabuf_put; + } + + priv = attach->importer_priv; + + if (epfile->in) + dir = DMA_FROM_DEVICE; + else + dir = DMA_TO_DEVICE; + + ep = ffs_epfile_wait_ep(file); + if (IS_ERR(ep)) { + ret = PTR_ERR(ep); + goto err_attachment_put; + } + + ret = ffs_dma_resv_lock(dmabuf, nonblock); + if (ret) + goto err_attachment_put; + + /* Make sure we don't have writers */ + if (!dma_resv_test_signaled(dmabuf->resv, DMA_RESV_USAGE_WRITE)) { + pr_debug("FFS WRITE fence is not signaled\n"); + ret = -EBUSY; + goto err_resv_unlock; + } + + dma_to_ram = dir == DMA_FROM_DEVICE; + + /* If we're writing to the DMABUF, make sure we don't have readers */ + if (dma_to_ram && + !dma_resv_test_signaled(dmabuf->resv, DMA_RESV_USAGE_READ)) { + pr_debug("FFS READ fence is not signaled\n"); + ret = -EBUSY; + goto err_resv_unlock; + } + + sg_table = dma_buf_map_attachment(attach, dir); + if (IS_ERR(sg_table)) { + ret = PTR_ERR(sg_table); + goto err_resv_unlock; + } + + ret = dma_resv_reserve_fences(dmabuf->resv, 1); + if (ret) + goto err_unmap_attachment; + + fence = kmalloc(sizeof(*fence), GFP_KERNEL); + if (!fence) { + ret = -ENOMEM; + goto err_resv_unlock; + } + + fence->sgt = sg_table; + fence->dir = dir; + fence->priv = priv; + + spin_lock_irq(&epfile->ffs->eps_lock); + + /* In the meantime, endpoint got disabled or changed. */ + if (epfile->ep != ep) { + ret = -ESHUTDOWN; + goto err_fence_put; + } + + usb_req = usb_ep_alloc_request(ep->ep, GFP_ATOMIC); + if (!usb_req) { + ret = -ENOMEM; + goto err_fence_put; + } + + /* + * usb_ep_queue() guarantees that all transfers are processed in the + * order they are enqueued, so we can use a simple incrementing + * sequence number for the dma_fence. + */ + seqno = atomic_add_return(1, &epfile->seqno); + + dma_fence_init(&fence->base, &ffs_dmabuf_fence_ops, + &priv->lock, priv->context, seqno); + + dma_resv_add_fence(dmabuf->resv, &fence->base, + dma_resv_usage_rw(dma_to_ram)); + dma_resv_unlock(dmabuf->resv); + + /* Now that the dma_fence is in place, queue the transfer. */ + + usb_req->length = req->length; + usb_req->buf = NULL; + usb_req->sg = sg_table->sgl; + usb_req->num_sgs = sg_nents_for_len(sg_table->sgl, req->length); + usb_req->sg_was_mapped = true; + usb_req->context = fence; + usb_req->complete = ffs_epfile_dmabuf_io_complete; + + cookie = dma_fence_begin_signalling(); + ret = usb_ep_queue(ep->ep, usb_req, GFP_ATOMIC); + dma_fence_end_signalling(cookie); + if (ret) { + pr_warn("FFS: Failed to queue DMABUF: %d\n", ret); + ffs_dmabuf_signal_done(fence, ret); + usb_ep_free_request(ep->ep, usb_req); + } + + spin_unlock_irq(&epfile->ffs->eps_lock); + dma_buf_put(dmabuf); + + return ret; + +err_fence_put: + spin_unlock_irq(&epfile->ffs->eps_lock); + dma_fence_put(&fence->base); +err_unmap_attachment: + dma_buf_unmap_attachment(attach, sg_table, dir); +err_resv_unlock: + dma_resv_unlock(dmabuf->resv); +err_attachment_put: + ffs_dmabuf_put(attach); +err_dmabuf_put: + dma_buf_put(dmabuf); + + return ret; +} + static long ffs_epfile_ioctl(struct file *file, unsigned code, unsigned long value) { @@ -1292,6 +1706,44 @@ static long ffs_epfile_ioctl(struct file *file, unsigned code, if (WARN_ON(epfile->ffs->state != FFS_ACTIVE)) return -ENODEV; + switch (code) { + case FUNCTIONFS_DMABUF_ATTACH: + { + int fd; + + if (copy_from_user(&fd, (void __user *)value, sizeof(fd))) { + ret = -EFAULT; + break; + } + + return ffs_dmabuf_attach(file, fd); + } + case FUNCTIONFS_DMABUF_DETACH: + { + int fd; + + if (copy_from_user(&fd, (void __user *)value, sizeof(fd))) { + ret = -EFAULT; + break; + } + + return ffs_dmabuf_detach(file, fd); + } + case FUNCTIONFS_DMABUF_TRANSFER: + { + struct usb_ffs_dmabuf_transfer_req req; + + if (copy_from_user(&req, (void __user *)value, sizeof(req))) { + ret = -EFAULT; + break; + } + + return ffs_dmabuf_transfer(file, &req); + } + default: + break; + } + /* Wait for endpoint to be enabled */ ep = ffs_epfile_wait_ep(file); if (IS_ERR(ep)) @@ -1869,6 +2321,8 @@ static int ffs_epfiles_create(struct ffs_data *ffs) for (i = 1; i <= count; ++i, ++epfile) { epfile->ffs = ffs; mutex_init(&epfile->mutex); + mutex_init(&epfile->dmabufs_mutex); + INIT_LIST_HEAD(&epfile->dmabufs); if (ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR) sprintf(epfile->name, "ep%02x", ffs->eps_addrmap[i]); else diff --git a/include/uapi/linux/usb/functionfs.h b/include/uapi/linux/usb/functionfs.h index 078098e73fd3..9f88de9c3d66 100644 --- a/include/uapi/linux/usb/functionfs.h +++ b/include/uapi/linux/usb/functionfs.h @@ -86,6 +86,22 @@ struct usb_ext_prop_desc { __le16 wPropertyNameLength; } __attribute__((packed)); +/* Flags for usb_ffs_dmabuf_transfer_req->flags (none for now) */ +#define USB_FFS_DMABUF_TRANSFER_MASK 0x0 + +/** + * struct usb_ffs_dmabuf_transfer_req - Transfer request for a DMABUF object + * @fd: file descriptor of the DMABUF object + * @flags: one or more USB_FFS_DMABUF_TRANSFER_* flags + * @length: number of bytes used in this DMABUF for the data transfer. + * Should generally be set to the DMABUF's size. + */ +struct usb_ffs_dmabuf_transfer_req { + int fd; + __u32 flags; + __u64 length; +} __attribute__((packed)); + #ifndef __KERNEL__ /* @@ -290,6 +306,31 @@ struct usb_functionfs_event { #define FUNCTIONFS_ENDPOINT_DESC _IOR('g', 130, \ struct usb_endpoint_descriptor) +/* + * Attach the DMABUF object, identified by its file descriptor, to the + * data endpoint. Returns zero on success, and a negative errno value + * on error. + */ +#define FUNCTIONFS_DMABUF_ATTACH _IOW('g', 131, int) + +/* + * Detach the given DMABUF object, identified by its file descriptor, + * from the data endpoint. Returns zero on success, and a negative + * errno value on error. Note that closing the endpoint's file + * descriptor will automatically detach all attached DMABUFs. + */ +#define FUNCTIONFS_DMABUF_DETACH _IOW('g', 132, int) + +/* + * Enqueue the previously attached DMABUF to the transfer queue. + * The argument is a structure that packs the DMABUF's file descriptor, + * the size in bytes to transfer (which should generally correspond to + * the size of the DMABUF), and a 'flags' field which is unused + * for now. Returns zero on success, and a negative errno value on + * error. + */ +#define FUNCTIONFS_DMABUF_TRANSFER _IOW('g', 133, \ + struct usb_ffs_dmabuf_transfer_req) #endif /* _UAPI__LINUX_FUNCTIONFS_H__ */