linux-kernel - [PATCH v3 1/4] usb: gadget: Support already-mapped DMA SGs

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date: Mon,  8 Jan 2024 13:00:53 +0100
From: Paul Cercueil <paul@...pouillou.net>
To: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Sumit Semwal <sumit.semwal@...aro.org>,
	Christian König <christian.koenig@....com>,
	Jonathan Corbet <corbet@....net>
Cc: Jonathan Cameron <jic23@...nel.org>,
	Nuno Sá <noname.nuno@...il.com>,
	Michael Hennerich <Michael.Hennerich@...log.com>,
	Andrzej Pietrasiewicz <andrzej.p@...labora.com>,
	linux-usb@...r.kernel.org,
	linux-doc@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	linux-media@...r.kernel.org,
	dri-devel@...ts.freedesktop.org,
	linaro-mm-sig@...ts.linaro.org,
	Paul Cercueil <paul@...pouillou.net>
Subject: [PATCH v3 1/4] 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@...pouillou.net>
---
 drivers/usb/gadget/udc/core.c | 7 ++++++-
 include/linux/usb/gadget.h    | 2 ++
 2 files changed, 8 insertions(+), 1 deletion(-)

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);
-- 
2.43.0