blob: 1203e585c92b1f6a54a450102169f3fd629347e3 [file] [log] [blame]
/*
* Copyright (C) 2014 Michael Brown <mbrown@fensystems.co.uk>.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*
* You can also choose to distribute this program under the terms of
* the Unmodified Binary Distribution Licence (as given in the file
* COPYING.UBDL), provided that you have satisfied its requirements.
*/
FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
#include <stdint.h>
#include <stdlib.h>
#include <errno.h>
#include <ipxe/netdevice.h>
#include <ipxe/ethernet.h>
#include <ipxe/if_ether.h>
#include <ipxe/malloc.h>
#include <ipxe/base16.h>
#include <ipxe/xen.h>
#include <ipxe/xenstore.h>
#include <ipxe/xenbus.h>
#include <ipxe/xengrant.h>
#include <ipxe/xenevent.h>
#include "netfront.h"
/** @file
*
* Xen netfront driver
*
*/
/* Disambiguate the various error causes */
#define EIO_NETIF_RSP_ERROR \
__einfo_error ( EINFO_EIO_NETIF_RSP_ERROR )
#define EINFO_EIO_NETIF_RSP_ERROR \
__einfo_uniqify ( EINFO_EIO, -NETIF_RSP_ERROR, \
"Unspecified network error" )
#define EIO_NETIF_RSP_DROPPED \
__einfo_error ( EINFO_EIO_NETIF_RSP_DROPPED )
#define EINFO_EIO_NETIF_RSP_DROPPED \
__einfo_uniqify ( EINFO_EIO, -NETIF_RSP_DROPPED, \
"Packet dropped" )
#define EIO_NETIF_RSP( status ) \
EUNIQ ( EINFO_EIO, ( -(status) & 0x1f ), \
EIO_NETIF_RSP_ERROR, EIO_NETIF_RSP_DROPPED )
/******************************************************************************
*
* XenStore interface
*
******************************************************************************
*/
/**
* Reset device
*
* @v netfront Netfront device
* @ret rc Return status code
*/
static int netfront_reset ( struct netfront_nic *netfront ) {
struct xen_device *xendev = netfront->xendev;
int state;
int rc;
/* Get current backend state */
if ( ( state = xenbus_backend_state ( xendev ) ) < 0 ) {
rc = state;
DBGC ( netfront, "NETFRONT %s could not read backend state: "
"%s\n", xendev->key, strerror ( rc ) );
return rc;
}
/* If the backend is not already in InitWait, then mark
* frontend as Closed to shut down the backend.
*/
if ( state != XenbusStateInitWait ) {
/* Set state to Closed */
xenbus_set_state ( xendev, XenbusStateClosed );
/* Wait for backend to reach Closed */
if ( ( rc = xenbus_backend_wait ( xendev,
XenbusStateClosed ) ) != 0 ) {
DBGC ( netfront, "NETFRONT %s backend did not reach "
"Closed: %s\n", xendev->key, strerror ( rc ) );
return rc;
}
}
/* Reset state to Initialising */
xenbus_set_state ( xendev, XenbusStateInitialising );
/* Wait for backend to reach InitWait */
if ( ( rc = xenbus_backend_wait ( xendev, XenbusStateInitWait ) ) != 0){
DBGC ( netfront, "NETFRONT %s backend did not reach InitWait: "
"%s\n", xendev->key, strerror ( rc ) );
return rc;
}
return 0;
}
/**
* Fetch MAC address
*
* @v netfront Netfront device
* @v hw_addr Hardware address to fill in
* @ret rc Return status code
*/
static int netfront_read_mac ( struct netfront_nic *netfront, void *hw_addr ) {
struct xen_device *xendev = netfront->xendev;
struct xen_hypervisor *xen = xendev->xen;
char *mac;
int len;
int rc;
/* Fetch MAC address */
if ( ( rc = xenstore_read ( xen, &mac, xendev->key, "mac", NULL ) )!=0){
DBGC ( netfront, "NETFRONT %s could not read MAC address: %s\n",
xendev->key, strerror ( rc ) );
goto err_xenstore_read;
}
DBGC2 ( netfront, "NETFRONT %s has MAC address \"%s\"\n",
xendev->key, mac );
/* Decode MAC address */
len = hex_decode ( ':', mac, hw_addr, ETH_ALEN );
if ( len < 0 ) {
rc = len;
DBGC ( netfront, "NETFRONT %s could not decode MAC address "
"\"%s\": %s\n", xendev->key, mac, strerror ( rc ) );
goto err_decode;
}
/* Success */
rc = 0;
err_decode:
free ( mac );
err_xenstore_read:
return rc;
}
/**
* Write XenStore numeric value
*
* @v netfront Netfront device
* @v subkey Subkey
* @v num Numeric value
* @ret rc Return status code
*/
static int netfront_write_num ( struct netfront_nic *netfront,
const char *subkey, unsigned long num ) {
struct xen_device *xendev = netfront->xendev;
struct xen_hypervisor *xen = xendev->xen;
int rc;
/* Write value */
if ( ( rc = xenstore_write_num ( xen, num, xendev->key, subkey,
NULL ) ) != 0 ) {
DBGC ( netfront, "NETFRONT %s could not set %s=\"%ld\": %s\n",
xendev->key, subkey, num, strerror ( rc ) );
return rc;
}
return 0;
}
/**
* Write XenStore flag value
*
* @v netfront Netfront device
* @v subkey Subkey
* @v num Numeric value
* @ret rc Return status code
*/
static int netfront_write_flag ( struct netfront_nic *netfront,
const char *subkey ) {
return netfront_write_num ( netfront, subkey, 1 );
}
/**
* Delete XenStore value
*
* @v netfront Netfront device
* @v subkey Subkey
* @ret rc Return status code
*/
static int netfront_rm ( struct netfront_nic *netfront, const char *subkey ) {
struct xen_device *xendev = netfront->xendev;
struct xen_hypervisor *xen = xendev->xen;
int rc;
/* Remove value */
if ( ( rc = xenstore_rm ( xen, xendev->key, subkey, NULL ) ) != 0 ) {
DBGC ( netfront, "NETFRONT %s could not delete %s: %s\n",
xendev->key, subkey, strerror ( rc ) );
return rc;
}
return 0;
}
/******************************************************************************
*
* Events
*
******************************************************************************
*/
/**
* Create event channel
*
* @v netfront Netfront device
* @ret rc Return status code
*/
static int netfront_create_event ( struct netfront_nic *netfront ) {
struct xen_device *xendev = netfront->xendev;
struct xen_hypervisor *xen = xendev->xen;
struct evtchn_alloc_unbound alloc_unbound;
struct evtchn_close close;
int xenrc;
int rc;
/* Allocate event */
alloc_unbound.dom = DOMID_SELF;
alloc_unbound.remote_dom = xendev->backend_id;
if ( ( xenrc = xenevent_alloc_unbound ( xen, &alloc_unbound ) ) != 0 ) {
rc = -EXEN ( xenrc );
DBGC ( netfront, "NETFRONT %s could not allocate event: %s\n",
xendev->key, strerror ( rc ) );
goto err_alloc_unbound;
}
netfront->event.port = alloc_unbound.port;
/* Publish event channel */
if ( ( rc = netfront_write_num ( netfront, "event-channel",
netfront->event.port ) ) != 0 )
goto err_write_num;
DBGC ( netfront, "NETFRONT %s event-channel=\"%d\"\n",
xendev->key, netfront->event.port );
return 0;
netfront_rm ( netfront, "event-channel" );
err_write_num:
close.port = netfront->event.port;
xenevent_close ( xen, &close );
err_alloc_unbound:
return rc;
}
/**
* Send event
*
* @v netfront Netfront device
* @ret rc Return status code
*/
static inline __attribute__ (( always_inline )) int
netfront_send_event ( struct netfront_nic *netfront ) {
struct xen_device *xendev = netfront->xendev;
struct xen_hypervisor *xen = xendev->xen;
int xenrc;
int rc;
/* Send event */
if ( ( xenrc = xenevent_send ( xen, &netfront->event ) ) != 0 ) {
rc = -EXEN ( xenrc );
DBGC ( netfront, "NETFRONT %s could not send event: %s\n",
xendev->key, strerror ( rc ) );
return rc;
}
return 0;
}
/**
* Destroy event channel
*
* @v netfront Netfront device
*/
static void netfront_destroy_event ( struct netfront_nic *netfront ) {
struct xen_device *xendev = netfront->xendev;
struct xen_hypervisor *xen = xendev->xen;
struct evtchn_close close;
/* Unpublish event channel */
netfront_rm ( netfront, "event-channel" );
/* Close event channel */
close.port = netfront->event.port;
xenevent_close ( xen, &close );
}
/******************************************************************************
*
* Descriptor rings
*
******************************************************************************
*/
/**
* Create descriptor ring
*
* @v netfront Netfront device
* @v ring Descriptor ring
* @ret rc Return status code
*/
static int netfront_create_ring ( struct netfront_nic *netfront,
struct netfront_ring *ring ) {
struct xen_device *xendev = netfront->xendev;
struct xen_hypervisor *xen = xendev->xen;
physaddr_t addr;
unsigned int i;
int rc;
/* Initialise buffer ID ring */
for ( i = 0 ; i < ring->count ; i++ ) {
ring->ids[i] = i;
assert ( ring->iobufs[i] == NULL );
}
ring->id_prod = 0;
ring->id_cons = 0;
/* Allocate and initialise shared ring */
ring->sring.raw = malloc_phys ( PAGE_SIZE, PAGE_SIZE );
if ( ! ring->sring.raw ) {
rc = -ENOMEM;
goto err_alloc;
}
/* Grant access to shared ring */
addr = virt_to_phys ( ring->sring.raw );
if ( ( rc = xengrant_permit_access ( xen, ring->ref, xendev->backend_id,
0, addr ) ) != 0 ) {
DBGC ( netfront, "NETFRONT %s could not permit access to "
"%#08lx: %s\n", xendev->key, addr, strerror ( rc ) );
goto err_permit_access;
}
/* Publish shared ring reference */
if ( ( rc = netfront_write_num ( netfront, ring->ref_key,
ring->ref ) ) != 0 )
goto err_write_num;
DBGC ( netfront, "NETFRONT %s %s=\"%d\" [%08lx,%08lx)\n", xendev->key,
ring->ref_key, ring->ref, addr, ( addr + PAGE_SIZE ) );
return 0;
netfront_rm ( netfront, ring->ref_key );
err_write_num:
xengrant_invalidate ( xen, ring->ref );
err_permit_access:
free_phys ( ring->sring.raw, PAGE_SIZE );
err_alloc:
return rc;
}
/**
* Add buffer to descriptor ring
*
* @v netfront Netfront device
* @v ring Descriptor ring
* @v addr Physical address
* @v iobuf Associated I/O buffer, or NULL
* @v id Buffer ID to fill in
* @v ref Grant reference to fill in
* @ret rc Return status code
*
* The caller is responsible for ensuring that there is space in the
* ring.
*/
static int netfront_push ( struct netfront_nic *netfront,
struct netfront_ring *ring, physaddr_t addr,
struct io_buffer *iobuf, uint16_t *id,
grant_ref_t *ref ) {
struct xen_device *xendev = netfront->xendev;
struct xen_hypervisor *xen = xendev->xen;
unsigned int next_id;
unsigned int next_ref;
int rc;
/* Sanity check */
assert ( ! netfront_ring_is_full ( ring ) );
/* Allocate buffer ID */
next_id = ring->ids[ ring->id_prod & ( ring->count - 1 ) ];
next_ref = ring->refs[next_id];
/* Grant access to page containing address */
if ( ( rc = xengrant_permit_access ( xen, next_ref, xendev->backend_id,
0, addr ) ) != 0 ) {
DBGC ( netfront, "NETFRONT %s could not permit access to "
"%#08lx: %s\n", xendev->key, addr, strerror ( rc ) );
return rc;
}
/* Store associated I/O buffer, if any */
assert ( ring->iobufs[next_id] == NULL );
ring->iobufs[next_id] = iobuf;
/* Consume buffer ID */
ring->id_prod++;
/* Return buffer ID and grant reference */
*id = next_id;
*ref = next_ref;
return 0;
}
/**
* Remove buffer from descriptor ring
*
* @v netfront Netfront device
* @v ring Descriptor ring
* @v id Buffer ID
* @ret iobuf Associated I/O buffer, if any
*/
static struct io_buffer * netfront_pull ( struct netfront_nic *netfront,
struct netfront_ring *ring,
unsigned int id ) {
struct xen_device *xendev = netfront->xendev;
struct xen_hypervisor *xen = xendev->xen;
struct io_buffer *iobuf;
/* Sanity check */
assert ( id < ring->count );
/* Revoke access from I/O buffer page */
xengrant_invalidate ( xen, ring->refs[id] );
/* Retrieve I/O buffer */
iobuf = ring->iobufs[id];
ring->iobufs[id] = NULL;
/* Free buffer ID */
ring->ids[ ( ring->id_cons++ ) & ( ring->count - 1 ) ] = id;
return iobuf;
}
/**
* Destroy descriptor ring
*
* @v netfront Netfront device
* @v ring Descriptor ring
* @v discard Method used to discard outstanding buffer, or NULL
*/
static void netfront_destroy_ring ( struct netfront_nic *netfront,
struct netfront_ring *ring,
void ( * discard ) ( struct io_buffer * ) ){
struct xen_device *xendev = netfront->xendev;
struct xen_hypervisor *xen = xendev->xen;
struct io_buffer *iobuf;
unsigned int id;
/* Flush any outstanding buffers */
while ( ! netfront_ring_is_empty ( ring ) ) {
id = ring->ids[ ring->id_cons & ( ring->count - 1 ) ];
iobuf = netfront_pull ( netfront, ring, id );
if ( discard )
discard ( iobuf );
}
/* Unpublish shared ring reference */
netfront_rm ( netfront, ring->ref_key );
/* Revoke access from shared ring */
xengrant_invalidate ( xen, ring->ref );
/* Free page */
free_phys ( ring->sring.raw, PAGE_SIZE );
ring->sring.raw = NULL;
}
/**
* Discard partially received I/O buffers
*
* @v netfront Netfront device
*/
static void netfront_discard ( struct netfront_nic *netfront ) {
struct io_buffer *iobuf;
struct io_buffer *tmp;
/* Discard all buffers in the list */
list_for_each_entry_safe ( iobuf, tmp, &netfront->rx_partial, list ) {
list_del ( &iobuf->list );
free_iob ( iobuf );
}
}
/******************************************************************************
*
* Network device interface
*
******************************************************************************
*/
/**
* Refill receive descriptor ring
*
* @v netdev Network device
*/
static void netfront_refill_rx ( struct net_device *netdev ) {
struct netfront_nic *netfront = netdev->priv;
struct xen_device *xendev = netfront->xendev;
struct io_buffer *iobuf;
struct netif_rx_request *request;
unsigned int refilled = 0;
physaddr_t addr;
int notify;
int rc;
/* Refill ring */
while ( netfront_ring_fill ( &netfront->rx ) < NETFRONT_RX_FILL ) {
/* Allocate I/O buffer */
iobuf = alloc_iob ( PAGE_SIZE );
if ( ! iobuf ) {
/* Wait for next refill */
break;
}
addr = virt_to_phys ( iobuf->data );
/* Add to descriptor ring */
request = RING_GET_REQUEST ( &netfront->rx_fring,
netfront->rx_fring.req_prod_pvt );
if ( ( rc = netfront_push ( netfront, &netfront->rx, addr,
iobuf, &request->id,
&request->gref ) ) != 0 ) {
netdev_rx_err ( netdev, iobuf, rc );
break;
}
DBGC2 ( netfront, "NETFRONT %s RX id %d ref %d is %#08lx+%zx\n",
xendev->key, request->id, request->gref, addr,
iob_tailroom ( iobuf ) );
/* Move to next descriptor */
netfront->rx_fring.req_prod_pvt++;
refilled++;
}
/* Push new descriptors and notify backend if applicable */
if ( refilled ) {
RING_PUSH_REQUESTS_AND_CHECK_NOTIFY ( &netfront->rx_fring,
notify );
if ( notify )
netfront_send_event ( netfront );
}
}
/**
* Open network device
*
* @v netdev Network device
* @ret rc Return status code
*/
static int netfront_open ( struct net_device *netdev ) {
struct netfront_nic *netfront = netdev->priv;
struct xen_device *xendev = netfront->xendev;
int rc;
/* Ensure device is in a suitable initial state */
if ( ( rc = netfront_reset ( netfront ) ) != 0 )
goto err_reset;
/* Create transmit descriptor ring */
if ( ( rc = netfront_create_ring ( netfront, &netfront->tx ) ) != 0 )
goto err_create_tx;
SHARED_RING_INIT ( netfront->tx_sring );
FRONT_RING_INIT ( &netfront->tx_fring, netfront->tx_sring, PAGE_SIZE );
assert ( RING_SIZE ( &netfront->tx_fring ) >= netfront->tx.count );
/* Create receive descriptor ring */
if ( ( rc = netfront_create_ring ( netfront, &netfront->rx ) ) != 0 )
goto err_create_rx;
SHARED_RING_INIT ( netfront->rx_sring );
FRONT_RING_INIT ( &netfront->rx_fring, netfront->rx_sring, PAGE_SIZE );
assert ( RING_SIZE ( &netfront->rx_fring ) >= netfront->rx.count );
/* Create event channel */
if ( ( rc = netfront_create_event ( netfront ) ) != 0 )
goto err_create_event;
/* "Request" the rx-copy feature. Current versions of
* xen_netback.ko will fail silently if this parameter is not
* present.
*/
if ( ( rc = netfront_write_flag ( netfront, "request-rx-copy" ) ) != 0 )
goto err_request_rx_copy;
/* Inform backend that we can support scatter-gather */
if ( ( rc = netfront_write_flag ( netfront, "feature-sg" ) ) != 0 )
goto err_feature_sg;
/* Disable checksum offload, since we will always do the work anyway */
if ( ( rc = netfront_write_flag ( netfront,
"feature-no-csum-offload" ) ) != 0 )
goto err_feature_no_csum_offload;
/* Inform backend that we will send notifications for RX requests */
if ( ( rc = netfront_write_flag ( netfront,
"feature-rx-notify" ) ) != 0 )
goto err_feature_rx_notify;
/* Set state to Connected */
if ( ( rc = xenbus_set_state ( xendev, XenbusStateConnected ) ) != 0 ) {
DBGC ( netfront, "NETFRONT %s could not set state=\"%d\": %s\n",
xendev->key, XenbusStateConnected, strerror ( rc ) );
goto err_set_state;
}
/* Wait for backend to connect */
if ( ( rc = xenbus_backend_wait ( xendev, XenbusStateConnected ) ) !=0){
DBGC ( netfront, "NETFRONT %s could not connect to backend: "
"%s\n", xendev->key, strerror ( rc ) );
goto err_backend_wait;
}
/* Refill receive descriptor ring */
netfront_refill_rx ( netdev );
/* Set link up */
netdev_link_up ( netdev );
return 0;
err_backend_wait:
netfront_reset ( netfront );
err_set_state:
netfront_rm ( netfront, "feature-rx-notify" );
err_feature_rx_notify:
netfront_rm ( netfront, "feature-no-csum-offload" );
err_feature_no_csum_offload:
netfront_rm ( netfront, "feature-sg" );
err_feature_sg:
netfront_rm ( netfront, "request-rx-copy" );
err_request_rx_copy:
netfront_destroy_event ( netfront );
err_create_event:
netfront_destroy_ring ( netfront, &netfront->rx, NULL );
err_create_rx:
netfront_destroy_ring ( netfront, &netfront->tx, NULL );
err_create_tx:
err_reset:
return rc;
}
/**
* Close network device
*
* @v netdev Network device
*/
static void netfront_close ( struct net_device *netdev ) {
struct netfront_nic *netfront = netdev->priv;
struct xen_device *xendev = netfront->xendev;
int rc;
/* Reset devic, thereby ensuring that grant references are no
* longer in use, etc.
*/
if ( ( rc = netfront_reset ( netfront ) ) != 0 ) {
DBGC ( netfront, "NETFRONT %s could not disconnect from "
"backend: %s\n", xendev->key, strerror ( rc ) );
/* Things will probably go _very_ badly wrong if this
* happens, since it means the backend may still write
* to the outstanding RX buffers that we are about to
* free. The best we can do is report the error via
* the link status, but there's a good chance the
* machine will crash soon.
*/
netdev_link_err ( netdev, rc );
} else {
netdev_link_down ( netdev );
}
/* Delete flags */
netfront_rm ( netfront, "feature-rx-notify" );
netfront_rm ( netfront, "feature-no-csum-offload" );
netfront_rm ( netfront, "feature-sg" );
netfront_rm ( netfront, "request-rx-copy" );
/* Destroy event channel */
netfront_destroy_event ( netfront );
/* Discard any partially received I/O buffers */
netfront_discard ( netfront );
/* Destroy receive descriptor ring, freeing any outstanding
* I/O buffers.
*/
netfront_destroy_ring ( netfront, &netfront->rx, free_iob );
/* Destroy transmit descriptor ring. Leave any outstanding
* I/O buffers to be freed by netdev_tx_flush().
*/
netfront_destroy_ring ( netfront, &netfront->tx, NULL );
}
/**
* Transmit packet
*
* @v netdev Network device
* @v iobuf I/O buffer
* @ret rc Return status code
*/
static int netfront_transmit ( struct net_device *netdev,
struct io_buffer *iobuf ) {
struct netfront_nic *netfront = netdev->priv;
struct xen_device *xendev = netfront->xendev;
struct netif_tx_request *request;
physaddr_t addr;
size_t len;
size_t remaining;
size_t frag_len;
unsigned int offset;
unsigned int count;
unsigned int more;
int notify;
int rc;
/* Calculate number of page buffers required */
addr = virt_to_phys ( iobuf->data );
len = iob_len ( iobuf );
offset = ( addr & ( PAGE_SIZE - 1 ) );
count = ( ( offset + len + PAGE_SIZE - 1 ) / PAGE_SIZE );
/* Check that we have space in the ring */
if ( netfront_ring_space ( &netfront->tx ) < count ) {
DBGC ( netfront, "NETFRONT %s out of transmit descriptors\n",
xendev->key );
return -ENOBUFS;
}
/* Add to descriptor ring */
remaining = len;
while ( remaining ) {
/* Calculate length of this fragment */
frag_len = ( PAGE_SIZE - offset );
if ( frag_len >= remaining ) {
frag_len = remaining;
more = 0;
} else {
more = NETTXF_more_data;
}
/* Populate request */
request = RING_GET_REQUEST ( &netfront->tx_fring,
netfront->tx_fring.req_prod_pvt );
if ( ( rc = netfront_push ( netfront, &netfront->tx, addr,
( more ? NULL : iobuf ),
&request->id,
&request->gref ) ) != 0 ) {
return rc;
}
request->flags = ( NETTXF_data_validated | more );
request->offset = offset;
request->size = ( ( remaining == len ) ? len : frag_len );
DBGC2 ( netfront, "NETFRONT %s TX id %d ref %d is "
"%#08lx+%zx%s\n", xendev->key, request->id,
request->gref, addr, frag_len, ( more ? "..." : "" ) );
/* Move to next descriptor */
netfront->tx_fring.req_prod_pvt++;
addr += frag_len;
remaining -= frag_len;
offset = 0;
}
/* Push new descriptors and notify backend if applicable */
RING_PUSH_REQUESTS_AND_CHECK_NOTIFY ( &netfront->tx_fring, notify );
if ( notify )
netfront_send_event ( netfront );
return 0;
}
/**
* Poll for completed packets
*
* @v netdev Network device
*/
static void netfront_poll_tx ( struct net_device *netdev ) {
struct netfront_nic *netfront = netdev->priv;
struct xen_device *xendev = netfront->xendev;
struct netif_tx_response *response;
struct io_buffer *iobuf;
int status;
int rc;
/* Consume any unconsumed responses */
while ( RING_HAS_UNCONSUMED_RESPONSES ( &netfront->tx_fring ) ) {
/* Get next response */
response = RING_GET_RESPONSE ( &netfront->tx_fring,
netfront->tx_fring.rsp_cons++ );
/* Retrieve from descriptor ring */
iobuf = netfront_pull ( netfront, &netfront->tx, response->id );
status = response->status;
if ( status >= NETIF_RSP_OKAY ) {
DBGC2 ( netfront, "NETFRONT %s TX id %d complete\n",
xendev->key, response->id );
if ( iobuf )
netdev_tx_complete ( netdev, iobuf );
} else {
rc = -EIO_NETIF_RSP ( status );
DBGC2 ( netfront, "NETFRONT %s TX id %d error %d: %s\n",
xendev->key, response->id, status,
strerror ( rc ) );
netdev_tx_complete_err ( netdev, iobuf, rc );
}
}
}
/**
* Poll for received packets
*
* @v netdev Network device
*/
static void netfront_poll_rx ( struct net_device *netdev ) {
struct netfront_nic *netfront = netdev->priv;
struct xen_device *xendev = netfront->xendev;
struct netif_rx_response *response;
struct io_buffer *iobuf;
int status;
int more;
size_t len;
int rc;
/* Consume any unconsumed responses */
while ( RING_HAS_UNCONSUMED_RESPONSES ( &netfront->rx_fring ) ) {
/* Get next response */
response = RING_GET_RESPONSE ( &netfront->rx_fring,
netfront->rx_fring.rsp_cons++ );
/* Retrieve from descriptor ring */
iobuf = netfront_pull ( netfront, &netfront->rx, response->id );
status = response->status;
more = ( response->flags & NETRXF_more_data );
/* Report errors */
if ( status < 0 ) {
rc = -EIO_NETIF_RSP ( status );
DBGC2 ( netfront, "NETFRONT %s RX id %d error %d: %s\n",
xendev->key, response->id, status,
strerror ( rc ) );
netfront_discard ( netfront );
netdev_rx_err ( netdev, iobuf, rc );
continue;
}
/* Add to partial receive list */
len = status;
iob_reserve ( iobuf, response->offset );
iob_put ( iobuf, len );
DBGC2 ( netfront, "NETFRONT %s RX id %d complete "
"%#08lx+%zx%s\n", xendev->key, response->id,
virt_to_phys ( iobuf->data ), len,
( more ? "..." : "" ) );
list_add_tail ( &iobuf->list, &netfront->rx_partial );
/* Wait until complete packet has been received */
if ( more )
continue;
/* Reassemble complete packet */
iobuf = iob_concatenate ( &netfront->rx_partial );
if ( ! iobuf ) {
DBGC2 ( netfront, "NETFRONT %s RX reassembly failed\n",
xendev->key );
netfront_discard ( netfront );
netdev_rx_err ( netdev, NULL, -ENOMEM );
continue;
}
/* Hand off to network stack */
netdev_rx ( netdev, iobuf );
}
}
/**
* Poll for completed and received packets
*
* @v netdev Network device
*/
static void netfront_poll ( struct net_device *netdev ) {
/* Poll for TX completions */
netfront_poll_tx ( netdev );
/* Poll for RX completions */
netfront_poll_rx ( netdev );
/* Refill RX descriptor ring */
netfront_refill_rx ( netdev );
}
/** Network device operations */
static struct net_device_operations netfront_operations = {
.open = netfront_open,
.close = netfront_close,
.transmit = netfront_transmit,
.poll = netfront_poll,
};
/******************************************************************************
*
* Xen device bus interface
*
******************************************************************************
*/
/**
* Probe Xen device
*
* @v xendev Xen device
* @ret rc Return status code
*/
static int netfront_probe ( struct xen_device *xendev ) {
struct xen_hypervisor *xen = xendev->xen;
struct net_device *netdev;
struct netfront_nic *netfront;
int rc;
/* Allocate and initialise structure */
netdev = alloc_etherdev ( sizeof ( *netfront ) );
if ( ! netdev ) {
rc = -ENOMEM;
goto err_alloc;
}
netdev_init ( netdev, &netfront_operations );
netdev->dev = &xendev->dev;
netfront = netdev->priv;
netfront->xendev = xendev;
INIT_LIST_HEAD ( &netfront->rx_partial );
DBGC ( netfront, "NETFRONT %s backend=\"%s\" in domain %ld\n",
xendev->key, xendev->backend, xendev->backend_id );
/* Allocate grant references and initialise descriptor rings */
if ( ( rc = xengrant_alloc ( xen, netfront->refs,
NETFRONT_REF_COUNT ) ) != 0 ) {
DBGC ( netfront, "NETFRONT %s could not allocate grant "
"references: %s\n", xendev->key, strerror ( rc ) );
goto err_grant_alloc;
}
netfront_init_ring ( &netfront->tx, "tx-ring-ref",
netfront->refs[NETFRONT_REF_TX_RING],
NETFRONT_NUM_TX_DESC, netfront->tx_iobufs,
&netfront->refs[NETFRONT_REF_TX_BASE],
netfront->tx_ids );
netfront_init_ring ( &netfront->rx, "rx-ring-ref",
netfront->refs[NETFRONT_REF_RX_RING],
NETFRONT_NUM_RX_DESC, netfront->rx_iobufs,
&netfront->refs[NETFRONT_REF_RX_BASE],
netfront->rx_ids );
/* Fetch MAC address */
if ( ( rc = netfront_read_mac ( netfront, netdev->hw_addr ) ) != 0 )
goto err_read_mac;
/* Reset device. Ignore failures; allow the device to be
* registered so that reset errors can be observed by the user
* when attempting to open the device.
*/
netfront_reset ( netfront );
/* Register network device */
if ( ( rc = register_netdev ( netdev ) ) != 0 )
goto err_register_netdev;
/* Set initial link state */
netdev_link_down ( netdev );
xen_set_drvdata ( xendev, netdev );
return 0;
unregister_netdev ( netdev );
err_register_netdev:
err_read_mac:
xengrant_free ( xen, netfront->refs, NETFRONT_REF_COUNT );
err_grant_alloc:
netdev_nullify ( netdev );
netdev_put ( netdev );
err_alloc:
return rc;
}
/**
* Remove Xen device
*
* @v xendev Xen device
*/
static void netfront_remove ( struct xen_device *xendev ) {
struct net_device *netdev = xen_get_drvdata ( xendev );
struct netfront_nic *netfront = netdev->priv;
struct xen_hypervisor *xen = xendev->xen;
/* Unregister network device */
unregister_netdev ( netdev );
/* Free resources */
xengrant_free ( xen, netfront->refs, NETFRONT_REF_COUNT );
/* Free network device */
netdev_nullify ( netdev );
netdev_put ( netdev );
}
/** Xen netfront driver */
struct xen_driver netfront_driver __xen_driver = {
.name = "netfront",
.type = "vif",
.probe = netfront_probe,
.remove = netfront_remove,
};