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authorPaul Cercueil <paul@crapouillou.net>2024-01-30 13:23:37 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2024-02-17 17:00:09 +0100
commit99f638dd49ca80538addec6b3733ddb5784c9373 (patch)
treee121218bc1317ae33cd00ef896bfda2e2aaff720
parent7ad818eef647fa5d4614a335107ce28cbf1c13c3 (diff)
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 <paul@crapouillou.net> Link: https://lore.kernel.org/r/20240130122340.54813-2-paul@crapouillou.net Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/usb/gadget/udc/core.c7
-rw-r--r--include/linux/usb/gadget.h2
2 files changed, 8 insertions, 1 deletions
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) {
diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
index a771ccc038ac..c529e4e06997 100644
--- a/include/linux/usb/gadget.h
+++ b/include/linux/usb/gadget.h
@@ -52,6 +52,7 @@ struct usb_ep;
* @short_not_ok: When reading data, makes short packets be
* treated as errors (queue stops advancing till cleanup).
* @dma_mapped: Indicates if request has been mapped to DMA (internal)
+ * @sg_was_mapped: Set if the scatterlist has been mapped before the request
* @complete: Function called when request completes, so this request and
* its buffer may be re-used. The function will always be called with
* interrupts disabled, and it must not sleep.
@@ -111,6 +112,7 @@ struct usb_request {
unsigned zero:1;
unsigned short_not_ok:1;
unsigned dma_mapped:1;
+ unsigned sg_was_mapped:1;
void (*complete)(struct usb_ep *ep,
struct usb_request *req);