USB gadget stack only supports usb_request objects that point to buffers
located in memory. Support use cases where data is transferred from
physical addresses in device mmio regions
Added a bit "pre_mapped" to usb_request to bypass dma_map_single and
dma_map_sg for such requests
The caller must determine the dma address for the request before queuing
it
Signed-off-by: Manan Aurora <maurora@xxxxxxxxxx>
---
drivers/usb/gadget/udc/core.c | 4 ++--
include/linux/usb/gadget.h | 1 +
2 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c
index ded9531f141b..236165ba08f4 100644
--- a/drivers/usb/gadget/udc/core.c
+++ b/drivers/usb/gadget/udc/core.c
@@ -900,7 +900,7 @@ EXPORT_SYMBOL_GPL(usb_gadget_activate);
int usb_gadget_map_request_by_dev(struct device *dev,
struct usb_request *req, int is_in)
{
- if (req->length == 0)
+ if (req->pre_mapped || req->length == 0)
return 0;
if (req->num_sgs) {
@@ -948,7 +948,7 @@ 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->pre_mapped || req->length == 0)
return;
if (req->num_mapped_sgs) {
diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
index a771ccc038ac..6bc035439098 100644
--- a/include/linux/usb/gadget.h
+++ b/include/linux/usb/gadget.h
@@ -111,6 +111,7 @@ struct usb_request {
unsigned zero:1;
unsigned short_not_ok:1;
unsigned dma_mapped:1;
+ unsigned pre_mapped:1;
void (*complete)(struct usb_ep *ep,
struct usb_request *req);
--
2.42.0.820.g83a721a137-goog
