Commit 835fb5e4 authored by Alex Elder's avatar Alex Elder Committed by Greg Kroah-Hartman
Browse files

greybus: enforce a buffer headroom maximum size 



Define a maximum size that a host device can use for its private
area ahead of the payload space used by Greybus in a message buffer.

Signed-off-by: default avatarAlex Elder <elder@linaro.org>
Signed-off-by: default avatarGreg Kroah-Hartman <greg@kroah.com>
parent dc779229

drivers/staging/greybus/es1-ap-usb.c

+1 −0
Original line number Diff line number Diff line
@@ -127,6 +127,7 @@ static void hd_buffer_constraints(struct greybus_host_device *hd) 
	 */

	hd->buffer_headroom = sizeof(u32);	/* For cport id */

	hd->buffer_size_max = ES1_GBUF_MSG_SIZE_MAX;

	BUILD_BUG_ON(hd->buffer_headroom > GB_BUFFER_HEADROOM_MAX);

}



#define ES1_TIMEOUT	500	/* 500 ms for the SVC to do something */

drivers/staging/greybus/greybus.h

+8 −0
Original line number Diff line number Diff line
@@ -69,6 +69,14 @@ 
struct greybus_host_device;

struct svc_msg;



/*

 * When the Greybus code allocates a buffer it sets aside bytes

 * prior to the beginning of the payload area for the host device's

 * exclusive use.  The size is specified by hd->buffer_headroom, and

 * which can't be greater than GB_BUFFER_HEADROOM_MAX.

 */

#define GB_BUFFER_HEADROOM_MAX		sizeof(u64)



/* Buffers allocated from the host driver will be aligned to this multiple */

#define GB_BUFFER_ALIGN	sizeof(u32)