Hi,
This is the v6 of my patchset that adds a new DMABUF import interface to FunctionFS.
Given that the cache coherency issue that has been discussed after my v5 is a tangential problem and not directly related to this new interface, I decided to drop the dma_buf_begin/end_access() functions for now - but I'm open to the idea of re-introducing them in a subsequent patchset.
The patchset was rebased on next-20240129.
Cheers, -Paul
--- Changelog: * Drop v5's patches [1/6] and [2/6]. * [3/4]: - Drop use of dma_buf_begin/end_access(). We now make the assumption that the devices attached to the DMABUFs must be coherent between themselves. The cache coherency issue is a tangential problem, and those functions can be re-introduced in a subsequent patchset. - Unqueue pending requests on detach. Otherwise, when closing the data endpoint the DMABUF will never be signaled. - Use list_for_each_entry_safe() in ffs_dmabuf_detach(), because there is a list_del() in there. - use pr_vdebug() instead of pr_debug() - Rename ffs_dmabuf_unmap_work() -> ffs_dmabuf_cleanup()
--- Paul Cercueil (4): usb: gadget: Support already-mapped DMA SGs usb: gadget: functionfs: Factorize wait-for-endpoint code usb: gadget: functionfs: Add DMABUF import interface Documentation: usb: Document FunctionFS DMABUF API
Documentation/usb/functionfs.rst | 36 ++ drivers/usb/gadget/Kconfig | 1 + drivers/usb/gadget/function/f_fs.c | 513 ++++++++++++++++++++++++++-- drivers/usb/gadget/udc/core.c | 7 +- include/linux/usb/gadget.h | 2 + include/uapi/linux/usb/functionfs.h | 41 +++ 6 files changed, 579 insertions(+), 21 deletions(-)