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usbip: add USBIP_URB_* URB transfer flags

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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: Hongren Zenithal Zheng <i@zenithal.me>
Suggested-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Link: https://lore.kernel.org/r/20220824002456.94605-1-skhan@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Shuah Khan 2022-08-23 18:24:56 -06:00 committed by Greg Kroah-Hartman
parent dff981842a
commit 8f36b3b4e1
4 changed files with 122 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
Documentation/usb/usbip_protocol.rst
View File

@ -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 |

4
drivers/usb/usbip/stub_rx.c
View File

@ -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);

91
drivers/usb/usbip/usbip_common.c
View File

@ -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;

26
include/uapi/linux/usbip.h
View File

@ -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 */