From 99f638dd49ca80538addec6b3733ddb5784c9373 Mon Sep 17 00:00:00 2001 From: Paul Cercueil Date: Tue, 30 Jan 2024 13:23:37 +0100 Subject: usb: gadget: Support already-mapped DMA SGs Add a new 'sg_was_mapped' field to the struct usb_request. This field can be used to indicate that the scatterlist associated to the USB transfer has already been mapped into the DMA space, and it does not have to be done internally. Signed-off-by: Paul Cercueil Link: https://lore.kernel.org/r/20240130122340.54813-2-paul@crapouillou.net Signed-off-by: Greg Kroah-Hartman --- drivers/usb/gadget/udc/core.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'drivers/usb/gadget/udc') diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c index d59f94464b87..9d4150124fdb 100644 --- a/drivers/usb/gadget/udc/core.c +++ b/drivers/usb/gadget/udc/core.c @@ -903,6 +903,11 @@ int usb_gadget_map_request_by_dev(struct device *dev, if (req->length == 0) return 0; + if (req->sg_was_mapped) { + req->num_mapped_sgs = req->num_sgs; + return 0; + } + if (req->num_sgs) { int mapped; @@ -948,7 +953,7 @@ EXPORT_SYMBOL_GPL(usb_gadget_map_request); void usb_gadget_unmap_request_by_dev(struct device *dev, struct usb_request *req, int is_in) { - if (req->length == 0) + if (req->length == 0 || req->sg_was_mapped) return; if (req->num_mapped_sgs) { -- cgit v1.2.3