Commit 8f36b3b4 authored by Shuah Khan's avatar Shuah Khan Committed by Greg Kroah-Hartman
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usbip: add USBIP_URB_* URB transfer flags 



USBIP driver packs URB transfer flags in network packets that are
exchanged between Server (usbip_host) and Client (vhci_hcd).

URB_* flags are internal to kernel and could change. Where as USBIP
URB flags exchanged in network packets are USBIP user API must not
change.

Add USBIP_URB* flags to make this an explicit API and change the
client and server to map them. Details as follows:

Client tx path (USBIP_CMD_SUBMIT):
- Maps URB_* to USBIP_URB_* when it sends USBIP_CMD_SUBMIT packet.

Server rx path (USBIP_CMD_SUBMIT):
- Maps USBIP_URB_* to URB_* when it receives USBIP_CMD_SUBMIT packet.

Flags aren't included in USBIP_CMD_UNLINK and USBIP_RET_SUBMIT packets
and no special handling is needed for them in the following cases:

- Server rx path (USBIP_CMD_UNLINK)
- Client rx path & Server tx path (USBIP_RET_SUBMIT)

Update protocol documentation to reflect the change.

Suggested-by: default avatarHongren Zenithal Zheng <i@zenithal.me>
Suggested-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: default avatarShuah Khan <skhan@linuxfoundation.org>
Link: https://lore.kernel.org/r/20220824002456.94605-1-skhan@linuxfoundation.org


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent dff98184

Documentation/usb/usbip_protocol.rst

+6 −7
Original line number Diff line number Diff line
@@ -340,13 +340,12 @@ USBIP_CMD_SUBMIT: 
| 0         | 20     | usbip_header_basic, 'command' shall be 0x00000001 |

+-----------+--------+---------------------------------------------------+

| 0x14      | 4      | transfer_flags: possible values depend on the     |

|           |        | URB transfer_flags (refer to URB doc in           |

|           |        | Documentation/driver-api/usb/URB.rst)             |

|           |        | but with URB_NO_TRANSFER_DMA_MAP masked. Refer to |

|           |        | function usbip_pack_cmd_submit and function       |

|           |        | tweak_transfer_flags in drivers/usb/usbip/        |

|           |        | usbip_common.c. The following fields may also ref |

|           |        | to function usbip_pack_cmd_submit and URB doc     |

|           |        | USBIP_URB transfer_flags.                         |

|           |        | Refer to include/uapi/linux/usbip.h and           |

|           |        | Documentation/driver-api/usb/URB.rst.             |

|           |        | Refer to usbip_pack_cmd_submit() and              |

|           |        | tweak_transfer_flags() in drivers/usb/usbip/      |

|           |        | usbip_common.c.                                   |

+-----------+--------+---------------------------------------------------+

| 0x18      | 4      | transfer_buffer_length:                           |

|           |        | use URB transfer_buffer_length                    |

drivers/usb/usbip/stub_rx.c

+2 −2
Original line number Diff line number Diff line
@@ -464,7 +464,7 @@ static void stub_recv_cmd_submit(struct stub_device *sdev, 
	int nents;

	int num_urbs = 1;

	int pipe = get_pipe(sdev, pdu);

	int use_sg = pdu->u.cmd_submit.transfer_flags & URB_DMA_MAP_SG;

	int use_sg = pdu->u.cmd_submit.transfer_flags & USBIP_URB_DMA_MAP_SG;

	int support_sg = 1;

	int np = 0;

	int ret, i;
@@ -514,7 +514,7 @@ static void stub_recv_cmd_submit(struct stub_device *sdev, 
				num_urbs = nents;

				priv->completed_urbs = 0;

				pdu->u.cmd_submit.transfer_flags &=

								~URB_DMA_MAP_SG;

								~USBIP_URB_DMA_MAP_SG;

			}

		} else {

			buffer = kzalloc(buf_len, GFP_KERNEL);

drivers/usb/usbip/usbip_common.c

+88 −3
Original line number Diff line number Diff line
@@ -344,6 +344,91 @@ static unsigned int tweak_transfer_flags(unsigned int flags) 
	return flags;

}



/*

 * USBIP driver packs URB transfer flags in PDUs that are exchanged

 * between Server (usbip_host) and Client (vhci_hcd). URB_* flags

 * are internal to kernel and could change. Where as USBIP URB flags

 * exchanged in PDUs are USBIP user API must not change.

 *

 * USBIP_URB* flags are exported as explicit API and client and server

 * do mapping from kernel flags to USBIP_URB*. Details as follows:

 *

 * Client tx path (USBIP_CMD_SUBMIT):

 * - Maps URB_* to USBIP_URB_* when it sends USBIP_CMD_SUBMIT packet.

 *

 * Server rx path (USBIP_CMD_SUBMIT):

 * - Maps USBIP_URB_* to URB_* when it receives USBIP_CMD_SUBMIT packet.

 *

 * Flags aren't included in USBIP_CMD_UNLINK and USBIP_RET_SUBMIT packets

 * and no special handling is needed for them in the following cases:

 * - Server rx path (USBIP_CMD_UNLINK)

 * - Client rx path & Server tx path (USBIP_RET_SUBMIT)

 *

 * Code paths:

 * usbip_pack_pdu() is the common routine that handles packing pdu from

 * urb and unpack pdu to an urb.

 *

 * usbip_pack_cmd_submit() and usbip_pack_ret_submit() handle

 * USBIP_CMD_SUBMIT and USBIP_RET_SUBMIT respectively.

 *

 * usbip_map_urb_to_usbip() and usbip_map_usbip_to_urb() are used

 * by usbip_pack_cmd_submit() and usbip_pack_ret_submit() to map

 * flags.

 */



struct urb_to_usbip_flags {

	u32 urb_flag;

	u32 usbip_flag;

};



#define NUM_USBIP_FLAGS	17



static const struct urb_to_usbip_flags flag_map[NUM_USBIP_FLAGS] = {

	{URB_SHORT_NOT_OK, USBIP_URB_SHORT_NOT_OK},

	{URB_ISO_ASAP, USBIP_URB_ISO_ASAP},

	{URB_NO_TRANSFER_DMA_MAP, USBIP_URB_NO_TRANSFER_DMA_MAP},

	{URB_ZERO_PACKET, USBIP_URB_ZERO_PACKET},

	{URB_NO_INTERRUPT, USBIP_URB_NO_INTERRUPT},

	{URB_FREE_BUFFER, USBIP_URB_FREE_BUFFER},

	{URB_DIR_IN, USBIP_URB_DIR_IN},

	{URB_DIR_OUT, USBIP_URB_DIR_OUT},

	{URB_DIR_MASK, USBIP_URB_DIR_MASK},

	{URB_DMA_MAP_SINGLE, USBIP_URB_DMA_MAP_SINGLE},

	{URB_DMA_MAP_PAGE, USBIP_URB_DMA_MAP_PAGE},

	{URB_DMA_MAP_SG, USBIP_URB_DMA_MAP_SG},

	{URB_MAP_LOCAL, USBIP_URB_MAP_LOCAL},

	{URB_SETUP_MAP_SINGLE, USBIP_URB_SETUP_MAP_SINGLE},

	{URB_SETUP_MAP_LOCAL, USBIP_URB_SETUP_MAP_LOCAL},

	{URB_DMA_SG_COMBINED, USBIP_URB_DMA_SG_COMBINED},

	{URB_ALIGNED_TEMP_BUFFER, USBIP_URB_ALIGNED_TEMP_BUFFER},

};



static unsigned int urb_to_usbip(unsigned int flags)

{

	unsigned int map_flags = 0;

	int loop;



	for (loop = 0; loop < NUM_USBIP_FLAGS; loop++) {

		if (flags & flag_map[loop].urb_flag)

			map_flags |= flag_map[loop].usbip_flag;

	}



	return map_flags;

}



static unsigned int usbip_to_urb(unsigned int flags)

{

	unsigned int map_flags = 0;

	int loop;



	for (loop = 0; loop < NUM_USBIP_FLAGS; loop++) {

		if (flags & flag_map[loop].usbip_flag)

			map_flags |= flag_map[loop].urb_flag;

	}



	return map_flags;

}



static void usbip_pack_cmd_submit(struct usbip_header *pdu, struct urb *urb,

				  int pack)

{
@@ -354,14 +439,14 @@ static void usbip_pack_cmd_submit(struct usbip_header *pdu, struct urb *urb, 
	 * will be discussed when usbip is ported to other operating systems.

	 */

	if (pack) {

		spdu->transfer_flags =

			tweak_transfer_flags(urb->transfer_flags);

		/* map after tweaking the urb flags */

		spdu->transfer_flags = urb_to_usbip(tweak_transfer_flags(urb->transfer_flags));

		spdu->transfer_buffer_length	= urb->transfer_buffer_length;

		spdu->start_frame		= urb->start_frame;

		spdu->number_of_packets		= urb->number_of_packets;

		spdu->interval			= urb->interval;

	} else  {

		urb->transfer_flags         = spdu->transfer_flags;

		urb->transfer_flags         = usbip_to_urb(spdu->transfer_flags);

		urb->transfer_buffer_length = spdu->transfer_buffer_length;

		urb->start_frame            = spdu->start_frame;

		urb->number_of_packets      = spdu->number_of_packets;

include/uapi/linux/usbip.h

+26 −0
Original line number Diff line number Diff line
@@ -24,4 +24,30 @@ enum usbip_device_status { 
	VDEV_ST_USED,

	VDEV_ST_ERROR

};



/* USB URB Transfer flags:

 *

 * USBIP server and client (vchi) pack URBs in TCP packets. The following

 * are the transfer type defines used in USBIP protocol.

 */



#define USBIP_URB_SHORT_NOT_OK		0x0001

#define USBIP_URB_ISO_ASAP		0x0002

#define USBIP_URB_NO_TRANSFER_DMA_MAP	0x0004

#define USBIP_URB_ZERO_PACKET		0x0040

#define USBIP_URB_NO_INTERRUPT		0x0080

#define USBIP_URB_FREE_BUFFER		0x0100

#define USBIP_URB_DIR_IN		0x0200

#define USBIP_URB_DIR_OUT		0

#define USBIP_URB_DIR_MASK		USBIP_URB_DIR_IN



#define USBIP_URB_DMA_MAP_SINGLE	0x00010000

#define USBIP_URB_DMA_MAP_PAGE		0x00020000

#define USBIP_URB_DMA_MAP_SG		0x00040000

#define USBIP_URB_MAP_LOCAL		0x00080000

#define USBIP_URB_SETUP_MAP_SINGLE	0x00100000

#define USBIP_URB_SETUP_MAP_LOCAL	0x00200000

#define USBIP_URB_DMA_SG_COMBINED	0x00400000

#define USBIP_URB_ALIGNED_TEMP_BUFFER	0x00800000



#endif /* _UAPI_LINUX_USBIP_H */