d/freebsd-dev
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
1be8a2635c
freebsd-dev/sys/dev/ntb/ntb_transport.c
Alexander Motin 1be8a2635c Create separate RX taskqueue for each qp.
2016-07-09 11:46:32 +00:00

1492 lines
38 KiB
C
Raw Blame History

/*-
* Copyright (c) 2016 Alexander Motin <mav@FreeBSD.org>
* Copyright (C) 2013 Intel Corporation
* Copyright (C) 2015 EMC Corporation
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*
* The Non-Transparent Bridge (NTB) is a device that allows you to connect
* two or more systems using a PCI-e links, providing remote memory access.
*
* This module contains a transport for sending and receiving messages by
* writing to remote memory window(s) provided by underlying NTB device.
*
* NOTE: Much of the code in this module is shared with Linux. Any patches may
* be picked up and redistributed in Linux with a dual GPL/BSD license.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/bitset.h>
#include <sys/bus.h>
#include <sys/ktr.h>
#include <sys/limits.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/queue.h>
#include <sys/sysctl.h>
#include <sys/taskqueue.h>
#include <vm/vm.h>
#include <vm/pmap.h>
#include <machine/bus.h>
#include "ntb.h"
#include "ntb_transport.h"
#define QP_SETSIZE 64
BITSET_DEFINE(_qpset, QP_SETSIZE);
#define test_bit(pos, addr) BIT_ISSET(QP_SETSIZE, (pos), (addr))
#define set_bit(pos, addr) BIT_SET(QP_SETSIZE, (pos), (addr))
#define clear_bit(pos, addr) BIT_CLR(QP_SETSIZE, (pos), (addr))
#define ffs_bit(addr) BIT_FFS(QP_SETSIZE, (addr))
#define KTR_NTB KTR_SPARE3
#define NTB_TRANSPORT_VERSION 4
static SYSCTL_NODE(_hw, OID_AUTO, ntb_transport, CTLFLAG_RW, 0, "ntb_transport");
static unsigned g_ntb_transport_debug_level;
SYSCTL_UINT(_hw_ntb_transport, OID_AUTO, debug_level, CTLFLAG_RWTUN,
&g_ntb_transport_debug_level, 0,
"ntb_transport log level -- higher is more verbose");
#define ntb_printf(lvl, ...) do { \
if ((lvl) <= g_ntb_transport_debug_level) { \
printf(__VA_ARGS__); \
} \
} while (0)
static unsigned transport_mtu = 0x10000;
static uint64_t max_mw_size;
SYSCTL_UQUAD(_hw_ntb_transport, OID_AUTO, max_mw_size, CTLFLAG_RDTUN, &max_mw_size, 0,
"If enabled (non-zero), limit the size of large memory windows. "
"Both sides of the NTB MUST set the same value here.");
static unsigned max_num_clients;
SYSCTL_UINT(_hw_ntb_transport, OID_AUTO, max_num_clients, CTLFLAG_RDTUN,
&max_num_clients, 0, "Maximum number of NTB transport clients. "
"0 (default) - use all available NTB memory windows; "
"positive integer N - Limit to N memory windows.");
static unsigned enable_xeon_watchdog;
SYSCTL_UINT(_hw_ntb_transport, OID_AUTO, enable_xeon_watchdog, CTLFLAG_RDTUN,
&enable_xeon_watchdog, 0, "If non-zero, write a register every second to "
"keep a watchdog from tearing down the NTB link");
STAILQ_HEAD(ntb_queue_list, ntb_queue_entry);
typedef uint32_t ntb_q_idx_t;
struct ntb_queue_entry {
/* ntb_queue list reference */
STAILQ_ENTRY(ntb_queue_entry) entry;
/* info on data to be transferred */
void *cb_data;
void *buf;
uint32_t len;
uint32_t flags;
struct ntb_transport_qp *qp;
struct ntb_payload_header *x_hdr;
ntb_q_idx_t index;
};
struct ntb_rx_info {
ntb_q_idx_t entry;
};
struct ntb_transport_qp {
struct ntb_transport_ctx *transport;
device_t ntb;
void *cb_data;
bool client_ready;
volatile bool link_is_up;
uint8_t qp_num; /* Only 64 QPs are allowed. 0-63 */
struct ntb_rx_info *rx_info;
struct ntb_rx_info *remote_rx_info;
void (*tx_handler)(struct ntb_transport_qp *qp, void *qp_data,
void *data, int len);
struct ntb_queue_list tx_free_q;
struct mtx ntb_tx_free_q_lock;
caddr_t tx_mw;
bus_addr_t tx_mw_phys;
ntb_q_idx_t tx_index;
ntb_q_idx_t tx_max_entry;
uint64_t tx_max_frame;
void (*rx_handler)(struct ntb_transport_qp *qp, void *qp_data,
void *data, int len);
struct ntb_queue_list rx_post_q;
struct ntb_queue_list rx_pend_q;
/* ntb_rx_q_lock: synchronize access to rx_XXXX_q */
struct mtx ntb_rx_q_lock;
struct task rxc_db_work;
struct taskqueue *rxc_tq;
caddr_t rx_buff;
ntb_q_idx_t rx_index;
ntb_q_idx_t rx_max_entry;
uint64_t rx_max_frame;
void (*event_handler)(void *data, enum ntb_link_event status);
struct callout link_work;
struct callout rx_full;
uint64_t last_rx_no_buf;
/* Stats */
uint64_t rx_bytes;
uint64_t rx_pkts;
uint64_t rx_ring_empty;
uint64_t rx_err_no_buf;
uint64_t rx_err_oflow;
uint64_t rx_err_ver;
uint64_t tx_bytes;
uint64_t tx_pkts;
uint64_t tx_ring_full;
uint64_t tx_err_no_buf;
struct mtx tx_lock;
};
struct ntb_transport_mw {
vm_paddr_t phys_addr;
size_t phys_size;
size_t xlat_align;
size_t xlat_align_size;
bus_addr_t addr_limit;
/* Tx buff is off vbase / phys_addr */
caddr_t vbase;
size_t xlat_size;
size_t buff_size;
/* Rx buff is off virt_addr / dma_addr */
caddr_t virt_addr;
bus_addr_t dma_addr;
};
struct ntb_transport_ctx {
device_t dev;
device_t ntb;
struct ntb_transport_mw *mw_vec;
struct ntb_transport_qp *qp_vec;
struct _qpset qp_bitmap;
struct _qpset qp_bitmap_free;
unsigned mw_count;
unsigned qp_count;
volatile bool link_is_up;
struct callout link_work;
struct callout link_watchdog;
struct task link_cleanup;
};
enum {
NTBT_DESC_DONE_FLAG = 1 << 0,
NTBT_LINK_DOWN_FLAG = 1 << 1,
};
struct ntb_payload_header {
ntb_q_idx_t ver;
uint32_t len;
uint32_t flags;
};
enum {
/*
* The order of this enum is part of the remote protocol. Do not
* reorder without bumping protocol version (and it's probably best
* to keep the protocol in lock-step with the Linux NTB driver.
*/
NTBT_VERSION = 0,
NTBT_QP_LINKS,
NTBT_NUM_QPS,
NTBT_NUM_MWS,
/*
* N.B.: transport_link_work assumes MW1 enums = MW0 + 2.
*/
NTBT_MW0_SZ_HIGH,
NTBT_MW0_SZ_LOW,
NTBT_MW1_SZ_HIGH,
NTBT_MW1_SZ_LOW,
NTBT_MAX_SPAD,
/*
* Some NTB-using hardware have a watchdog to work around NTB hangs; if
* a register or doorbell isn't written every few seconds, the link is
* torn down. Write an otherwise unused register every few seconds to
* work around this watchdog.
*/
NTBT_WATCHDOG_SPAD = 15
};
#define QP_TO_MW(nt, qp) ((qp) % nt->mw_count)
#define NTB_QP_DEF_NUM_ENTRIES 100
#define NTB_LINK_DOWN_TIMEOUT 10
static int ntb_transport_probe(device_t dev);
static int ntb_transport_attach(device_t dev);
static int ntb_transport_detach(device_t dev);
static void ntb_transport_init_queue(struct ntb_transport_ctx *nt,
unsigned int qp_num);
static int ntb_process_tx(struct ntb_transport_qp *qp,
struct ntb_queue_entry *entry);
static void ntb_transport_rxc_db(void *arg, int pending);
static int ntb_process_rxc(struct ntb_transport_qp *qp);
static void ntb_memcpy_rx(struct ntb_transport_qp *qp,
struct ntb_queue_entry *entry, void *offset);
static inline void ntb_rx_copy_callback(struct ntb_transport_qp *qp,
void *data);
static void ntb_complete_rxc(struct ntb_transport_qp *qp);
static void ntb_transport_doorbell_callback(void *data, uint32_t vector);
static void ntb_transport_event_callback(void *data);
static void ntb_transport_link_work(void *arg);
static int ntb_set_mw(struct ntb_transport_ctx *, int num_mw, size_t size);
static void ntb_free_mw(struct ntb_transport_ctx *nt, int num_mw);
static int ntb_transport_setup_qp_mw(struct ntb_transport_ctx *nt,
unsigned int qp_num);
static void ntb_qp_link_work(void *arg);
static void ntb_transport_link_cleanup(struct ntb_transport_ctx *nt);
static void ntb_transport_link_cleanup_work(void *, int);
static void ntb_qp_link_down(struct ntb_transport_qp *qp);
static void ntb_qp_link_down_reset(struct ntb_transport_qp *qp);
static void ntb_qp_link_cleanup(struct ntb_transport_qp *qp);
static void ntb_send_link_down(struct ntb_transport_qp *qp);
static void ntb_list_add(struct mtx *lock, struct ntb_queue_entry *entry,
struct ntb_queue_list *list);
static struct ntb_queue_entry *ntb_list_rm(struct mtx *lock,
struct ntb_queue_list *list);
static struct ntb_queue_entry *ntb_list_mv(struct mtx *lock,
struct ntb_queue_list *from, struct ntb_queue_list *to);
static void xeon_link_watchdog_hb(void *);
static const struct ntb_ctx_ops ntb_transport_ops = {
.link_event = ntb_transport_event_callback,
.db_event = ntb_transport_doorbell_callback,
};
MALLOC_DEFINE(M_NTB_T, "ntb_transport", "ntb transport driver");
static inline void
iowrite32(uint32_t val, void *addr)
{
bus_space_write_4(X86_BUS_SPACE_MEM, 0/* HACK */, (uintptr_t)addr,
val);
}
/* Transport Init and teardown */
static void
xeon_link_watchdog_hb(void *arg)
{
struct ntb_transport_ctx *nt;
nt = arg;
NTB_SPAD_WRITE(nt->ntb, NTBT_WATCHDOG_SPAD, 0);
callout_reset(&nt->link_watchdog, 1 * hz, xeon_link_watchdog_hb, nt);
}
static int
ntb_transport_probe(device_t dev)
{
device_set_desc(dev, "NTB Transport");
return (0);
}
static int
ntb_transport_attach(device_t dev)
{
struct ntb_transport_ctx *nt = device_get_softc(dev);
device_t ntb = device_get_parent(dev);
struct ntb_transport_mw *mw;
uint64_t qp_bitmap;
int rc;
unsigned i;
nt->dev = dev;
nt->ntb = ntb;
nt->mw_count = NTB_MW_COUNT(ntb);
nt->mw_vec = malloc(nt->mw_count * sizeof(*nt->mw_vec), M_NTB_T,
M_WAITOK | M_ZERO);
for (i = 0; i < nt->mw_count; i++) {
mw = &nt->mw_vec[i];
rc = NTB_MW_GET_RANGE(ntb, i, &mw->phys_addr, &mw->vbase,
&mw->phys_size, &mw->xlat_align, &mw->xlat_align_size,
&mw->addr_limit);
if (rc != 0)
goto err;
mw->buff_size = 0;
mw->xlat_size = 0;
mw->virt_addr = NULL;
mw->dma_addr = 0;
rc = NTB_MW_SET_WC(nt->ntb, i, VM_MEMATTR_WRITE_COMBINING);
if (rc)
ntb_printf(0, "Unable to set mw%d caching\n", i);
}
qp_bitmap = NTB_DB_VALID_MASK(ntb);
nt->qp_count = flsll(qp_bitmap);
KASSERT(nt->qp_count != 0, ("bogus db bitmap"));
nt->qp_count -= 1;
if (max_num_clients != 0 && max_num_clients < nt->qp_count)
nt->qp_count = max_num_clients;
else if (nt->mw_count < nt->qp_count)
nt->qp_count = nt->mw_count;
KASSERT(nt->qp_count <= QP_SETSIZE, ("invalid qp_count"));
nt->qp_vec = malloc(nt->qp_count * sizeof(*nt->qp_vec), M_NTB_T,
M_WAITOK | M_ZERO);
for (i = 0; i < nt->qp_count; i++) {
set_bit(i, &nt->qp_bitmap);
set_bit(i, &nt->qp_bitmap_free);
ntb_transport_init_queue(nt, i);
}
callout_init(&nt->link_work, 0);
callout_init(&nt->link_watchdog, 0);
TASK_INIT(&nt->link_cleanup, 0, ntb_transport_link_cleanup_work, nt);
rc = NTB_SET_CTX(ntb, nt, &ntb_transport_ops);
if (rc != 0)
goto err;
nt->link_is_up = false;
NTB_LINK_ENABLE(ntb, NTB_SPEED_AUTO, NTB_WIDTH_AUTO);
callout_reset(&nt->link_work, 0, ntb_transport_link_work, nt);
if (enable_xeon_watchdog != 0)
callout_reset(&nt->link_watchdog, 0, xeon_link_watchdog_hb, nt);
/* Attach children to this transport */
device_add_child(dev, NULL, -1);
bus_generic_attach(dev);
return (0);
err:
free(nt->qp_vec, M_NTB_T);
free(nt->mw_vec, M_NTB_T);
return (rc);
}
static int
ntb_transport_detach(device_t dev)
{
struct ntb_transport_ctx *nt = device_get_softc(dev);
device_t ntb = nt->ntb;
struct _qpset qp_bitmap_alloc;
uint8_t i;
/* Detach & delete all children */
device_delete_children(dev);
ntb_transport_link_cleanup(nt);
taskqueue_drain(taskqueue_swi, &nt->link_cleanup);
callout_drain(&nt->link_work);
callout_drain(&nt->link_watchdog);
BIT_COPY(QP_SETSIZE, &nt->qp_bitmap, &qp_bitmap_alloc);
BIT_NAND(QP_SETSIZE, &qp_bitmap_alloc, &nt->qp_bitmap_free);
/* Verify that all the QPs are freed */
for (i = 0; i < nt->qp_count; i++)
if (test_bit(i, &qp_bitmap_alloc))
ntb_transport_free_queue(&nt->qp_vec[i]);
NTB_LINK_DISABLE(ntb);
NTB_CLEAR_CTX(ntb);
for (i = 0; i < nt->mw_count; i++)
ntb_free_mw(nt, i);
free(nt->qp_vec, M_NTB_T);
free(nt->mw_vec, M_NTB_T);
return (0);
}
static void
ntb_transport_init_queue(struct ntb_transport_ctx *nt, unsigned int qp_num)
{
struct ntb_transport_mw *mw;
struct ntb_transport_qp *qp;
vm_paddr_t mw_base;
uint64_t mw_size, qp_offset;
size_t tx_size;
unsigned num_qps_mw, mw_num, mw_count;
mw_count = nt->mw_count;
mw_num = QP_TO_MW(nt, qp_num);
mw = &nt->mw_vec[mw_num];
qp = &nt->qp_vec[qp_num];
qp->qp_num = qp_num;
qp->transport = nt;
qp->ntb = nt->ntb;
qp->client_ready = false;
qp->event_handler = NULL;
ntb_qp_link_down_reset(qp);
if (mw_num < nt->qp_count % mw_count)
num_qps_mw = nt->qp_count / mw_count + 1;
else
num_qps_mw = nt->qp_count / mw_count;
mw_base = mw->phys_addr;
mw_size = mw->phys_size;
tx_size = mw_size / num_qps_mw;
qp_offset = tx_size * (qp_num / mw_count);
qp->tx_mw = mw->vbase + qp_offset;
KASSERT(qp->tx_mw != NULL, ("uh oh?"));
/* XXX Assumes that a vm_paddr_t is equivalent to bus_addr_t */
qp->tx_mw_phys = mw_base + qp_offset;
KASSERT(qp->tx_mw_phys != 0, ("uh oh?"));
tx_size -= sizeof(struct ntb_rx_info);
qp->rx_info = (void *)(qp->tx_mw + tx_size);
/* Due to house-keeping, there must be at least 2 buffs */
qp->tx_max_frame = qmin(tx_size / 2,
transport_mtu + sizeof(struct ntb_payload_header));
qp->tx_max_entry = tx_size / qp->tx_max_frame;
callout_init(&qp->link_work, 0);
callout_init(&qp->rx_full, 1);
mtx_init(&qp->ntb_rx_q_lock, "ntb rx q", NULL, MTX_SPIN);
mtx_init(&qp->ntb_tx_free_q_lock, "ntb tx free q", NULL, MTX_SPIN);
mtx_init(&qp->tx_lock, "ntb transport tx", NULL, MTX_DEF);
TASK_INIT(&qp->rxc_db_work, 0, ntb_transport_rxc_db, qp);
qp->rxc_tq = taskqueue_create("ntbt_rx", M_WAITOK,
taskqueue_thread_enqueue, &qp->rxc_tq);
taskqueue_start_threads(&qp->rxc_tq, 1, PI_NET, "%s rx%d",
device_get_nameunit(nt->dev), qp_num);
STAILQ_INIT(&qp->rx_post_q);
STAILQ_INIT(&qp->rx_pend_q);
STAILQ_INIT(&qp->tx_free_q);
callout_reset(&qp->link_work, 0, ntb_qp_link_work, qp);
}
void
ntb_transport_free_queue(struct ntb_transport_qp *qp)
{
struct ntb_queue_entry *entry;
if (qp == NULL)
return;
callout_drain(&qp->link_work);
NTB_DB_SET_MASK(qp->ntb, 1ull << qp->qp_num);
taskqueue_drain_all(qp->rxc_tq);
taskqueue_free(qp->rxc_tq);
qp->cb_data = NULL;
qp->rx_handler = NULL;
qp->tx_handler = NULL;
qp->event_handler = NULL;
while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_pend_q)))
free(entry, M_NTB_T);
while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_post_q)))
free(entry, M_NTB_T);
while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
free(entry, M_NTB_T);
set_bit(qp->qp_num, &qp->transport->qp_bitmap_free);
}
/**
* ntb_transport_create_queue - Create a new NTB transport layer queue
* @rx_handler: receive callback function
* @tx_handler: transmit callback function
* @event_handler: event callback function
*
* Create a new NTB transport layer queue and provide the queue with a callback
* routine for both transmit and receive. The receive callback routine will be
* used to pass up data when the transport has received it on the queue. The
* transmit callback routine will be called when the transport has completed the
* transmission of the data on the queue and the data is ready to be freed.
*
* RETURNS: pointer to newly created ntb_queue, NULL on error.
*/
struct ntb_transport_qp *
ntb_transport_create_queue(void *data, device_t dev,
const struct ntb_queue_handlers *handlers)
{
struct ntb_transport_ctx *nt = device_get_softc(dev);
device_t ntb = device_get_parent(dev);
struct ntb_queue_entry *entry;
struct ntb_transport_qp *qp;
unsigned int free_queue;
int i;
free_queue = ffs_bit(&nt->qp_bitmap_free);
if (free_queue == 0)
return (NULL);
/* decrement free_queue to make it zero based */
free_queue--;
qp = &nt->qp_vec[free_queue];
clear_bit(qp->qp_num, &nt->qp_bitmap_free);
qp->cb_data = data;
qp->rx_handler = handlers->rx_handler;
qp->tx_handler = handlers->tx_handler;
qp->event_handler = handlers->event_handler;
for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {
entry = malloc(sizeof(*entry), M_NTB_T, M_WAITOK | M_ZERO);
entry->cb_data = data;
entry->buf = NULL;
entry->len = transport_mtu;
entry->qp = qp;
ntb_list_add(&qp->ntb_rx_q_lock, entry, &qp->rx_pend_q);
}
for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {
entry = malloc(sizeof(*entry), M_NTB_T, M_WAITOK | M_ZERO);
entry->qp = qp;
ntb_list_add(&qp->ntb_tx_free_q_lock, entry, &qp->tx_free_q);
}
NTB_DB_CLEAR(ntb, 1ull << qp->qp_num);
NTB_DB_CLEAR_MASK(ntb, 1ull << qp->qp_num);
return (qp);
}
/**
* ntb_transport_link_up - Notify NTB transport of client readiness to use queue
* @qp: NTB transport layer queue to be enabled
*
* Notify NTB transport layer of client readiness to use queue
*/
void
ntb_transport_link_up(struct ntb_transport_qp *qp)
{
struct ntb_transport_ctx *nt = qp->transport;
qp->client_ready = true;
ntb_printf(2, "qp %d client ready\n", qp->qp_num);
if (nt->link_is_up)
callout_reset(&qp->link_work, 0, ntb_qp_link_work, qp);
}
/* Transport Tx */
/**
* ntb_transport_tx_enqueue - Enqueue a new NTB queue entry
* @qp: NTB transport layer queue the entry is to be enqueued on
* @cb: per buffer pointer for callback function to use
* @data: pointer to data buffer that will be sent
* @len: length of the data buffer
*
* Enqueue a new transmit buffer onto the transport queue from which a NTB
* payload will be transmitted. This assumes that a lock is being held to
* serialize access to the qp.
*
* RETURNS: An appropriate ERRNO error value on error, or zero for success.
*/
int
ntb_transport_tx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
unsigned int len)
{
struct ntb_queue_entry *entry;
int rc;
if (qp == NULL || !qp->link_is_up || len == 0) {
CTR0(KTR_NTB, "TX: link not up");
return (EINVAL);
}
entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
if (entry == NULL) {
CTR0(KTR_NTB, "TX: could not get entry from tx_free_q");
qp->tx_err_no_buf++;
return (EBUSY);
}
CTR1(KTR_NTB, "TX: got entry %p from tx_free_q", entry);
entry->cb_data = cb;
entry->buf = data;
entry->len = len;
entry->flags = 0;
mtx_lock(&qp->tx_lock);
rc = ntb_process_tx(qp, entry);
mtx_unlock(&qp->tx_lock);
if (rc != 0) {
ntb_list_add(&qp->ntb_tx_free_q_lock, entry, &qp->tx_free_q);
CTR1(KTR_NTB,
"TX: process_tx failed. Returning entry %p to tx_free_q",
entry);
}
return (rc);
}
static void
ntb_tx_copy_callback(void *data)
{
struct ntb_queue_entry *entry = data;
struct ntb_transport_qp *qp = entry->qp;
struct ntb_payload_header *hdr = entry->x_hdr;
iowrite32(entry->flags | NTBT_DESC_DONE_FLAG, &hdr->flags);
CTR1(KTR_NTB, "TX: hdr %p set DESC_DONE", hdr);
NTB_PEER_DB_SET(qp->ntb, 1ull << qp->qp_num);
/*
* The entry length can only be zero if the packet is intended to be a
* "link down" or similar. Since no payload is being sent in these
* cases, there is nothing to add to the completion queue.
*/
if (entry->len > 0) {
qp->tx_bytes += entry->len;
if (qp->tx_handler)
qp->tx_handler(qp, qp->cb_data, entry->buf,
entry->len);
else
m_freem(entry->buf);
entry->buf = NULL;
}
CTR3(KTR_NTB,
"TX: entry %p sent. hdr->ver = %u, hdr->flags = 0x%x, Returning "
"to tx_free_q", entry, hdr->ver, hdr->flags);
ntb_list_add(&qp->ntb_tx_free_q_lock, entry, &qp->tx_free_q);
}
static void
ntb_memcpy_tx(struct ntb_queue_entry *entry, void *offset)
{
CTR2(KTR_NTB, "TX: copying %d bytes to offset %p", entry->len, offset);
if (entry->buf != NULL) {
m_copydata((struct mbuf *)entry->buf, 0, entry->len, offset);
/*
* Ensure that the data is fully copied before setting the
* flags
*/
wmb();
}
ntb_tx_copy_callback(entry);
}
static void
ntb_async_tx(struct ntb_transport_qp *qp, struct ntb_queue_entry *entry)
{
struct ntb_payload_header *hdr;
void *offset;
offset = qp->tx_mw + qp->tx_max_frame * qp->tx_index;
hdr = (struct ntb_payload_header *)((char *)offset + qp->tx_max_frame -
sizeof(struct ntb_payload_header));
entry->x_hdr = hdr;
iowrite32(entry->len, &hdr->len);
iowrite32(qp->tx_pkts, &hdr->ver);
ntb_memcpy_tx(entry, offset);
}
static int
ntb_process_tx(struct ntb_transport_qp *qp, struct ntb_queue_entry *entry)
{
CTR3(KTR_NTB,
"TX: process_tx: tx_pkts=%lu, tx_index=%u, remote entry=%u",
qp->tx_pkts, qp->tx_index, qp->remote_rx_info->entry);
if (qp->tx_index == qp->remote_rx_info->entry) {
CTR0(KTR_NTB, "TX: ring full");
qp->tx_ring_full++;
return (EAGAIN);
}
if (entry->len > qp->tx_max_frame - sizeof(struct ntb_payload_header)) {
if (qp->tx_handler != NULL)
qp->tx_handler(qp, qp->cb_data, entry->buf,
EIO);
else
m_freem(entry->buf);
entry->buf = NULL;
ntb_list_add(&qp->ntb_tx_free_q_lock, entry, &qp->tx_free_q);
CTR1(KTR_NTB,
"TX: frame too big. returning entry %p to tx_free_q",
entry);
return (0);
}
CTR2(KTR_NTB, "TX: copying entry %p to index %u", entry, qp->tx_index);
ntb_async_tx(qp, entry);
qp->tx_index++;
qp->tx_index %= qp->tx_max_entry;
qp->tx_pkts++;
return (0);
}
/* Transport Rx */
static void
ntb_transport_rxc_db(void *arg, int pending __unused)
{
struct ntb_transport_qp *qp = arg;
int rc;
CTR0(KTR_NTB, "RX: transport_rx");
again:
while ((rc = ntb_process_rxc(qp)) == 0)
;
CTR1(KTR_NTB, "RX: process_rxc returned %d", rc);
if ((NTB_DB_READ(qp->ntb) & (1ull << qp->qp_num)) != 0) {
/* If db is set, clear it and check queue once more. */
NTB_DB_CLEAR(qp->ntb, 1ull << qp->qp_num);
goto again;
}
}
static int
ntb_process_rxc(struct ntb_transport_qp *qp)
{
struct ntb_payload_header *hdr;
struct ntb_queue_entry *entry;
caddr_t offset;
offset = qp->rx_buff + qp->rx_max_frame * qp->rx_index;
hdr = (void *)(offset + qp->rx_max_frame -
sizeof(struct ntb_payload_header));
CTR1(KTR_NTB, "RX: process_rxc rx_index = %u", qp->rx_index);
if ((hdr->flags & NTBT_DESC_DONE_FLAG) == 0) {
CTR0(KTR_NTB, "RX: hdr not done");
qp->rx_ring_empty++;
return (EAGAIN);
}
if ((hdr->flags & NTBT_LINK_DOWN_FLAG) != 0) {
CTR0(KTR_NTB, "RX: link down");
ntb_qp_link_down(qp);
hdr->flags = 0;
return (EAGAIN);
}
if (hdr->ver != (uint32_t)qp->rx_pkts) {
CTR2(KTR_NTB,"RX: ver != rx_pkts (%x != %lx). "
"Returning entry to rx_pend_q", hdr->ver, qp->rx_pkts);
qp->rx_err_ver++;
return (EIO);
}
entry = ntb_list_mv(&qp->ntb_rx_q_lock, &qp->rx_pend_q, &qp->rx_post_q);
if (entry == NULL) {
qp->rx_err_no_buf++;
CTR0(KTR_NTB, "RX: No entries in rx_pend_q");
return (EAGAIN);
}
callout_stop(&qp->rx_full);
CTR1(KTR_NTB, "RX: rx entry %p from rx_pend_q", entry);
entry->x_hdr = hdr;
entry->index = qp->rx_index;
if (hdr->len > entry->len) {
CTR2(KTR_NTB, "RX: len too long. Wanted %ju got %ju",
(uintmax_t)hdr->len, (uintmax_t)entry->len);
qp->rx_err_oflow++;
entry->len = -EIO;
entry->flags |= NTBT_DESC_DONE_FLAG;
ntb_complete_rxc(qp);
} else {
qp->rx_bytes += hdr->len;
qp->rx_pkts++;
CTR1(KTR_NTB, "RX: received %ld rx_pkts", qp->rx_pkts);
entry->len = hdr->len;
ntb_memcpy_rx(qp, entry, offset);
}
qp->rx_index++;
qp->rx_index %= qp->rx_max_entry;
return (0);
}
static void
ntb_memcpy_rx(struct ntb_transport_qp *qp, struct ntb_queue_entry *entry,
void *offset)
{
struct ifnet *ifp = entry->cb_data;
unsigned int len = entry->len;
CTR2(KTR_NTB, "RX: copying %d bytes from offset %p", len, offset);
entry->buf = (void *)m_devget(offset, len, 0, ifp, NULL);
/* Ensure that the data is globally visible before clearing the flag */
wmb();
CTR2(KTR_NTB, "RX: copied entry %p to mbuf %p.", entry, m);
ntb_rx_copy_callback(qp, entry);
}
static inline void
ntb_rx_copy_callback(struct ntb_transport_qp *qp, void *data)
{
struct ntb_queue_entry *entry;
entry = data;
entry->flags |= NTBT_DESC_DONE_FLAG;
ntb_complete_rxc(qp);
}
static void
ntb_complete_rxc(struct ntb_transport_qp *qp)
{
struct ntb_queue_entry *entry;
struct mbuf *m;
unsigned len;
CTR0(KTR_NTB, "RX: rx_completion_task");
mtx_lock_spin(&qp->ntb_rx_q_lock);
while (!STAILQ_EMPTY(&qp->rx_post_q)) {
entry = STAILQ_FIRST(&qp->rx_post_q);
if ((entry->flags & NTBT_DESC_DONE_FLAG) == 0)
break;
entry->x_hdr->flags = 0;
iowrite32(entry->index, &qp->rx_info->entry);
STAILQ_REMOVE_HEAD(&qp->rx_post_q, entry);
len = entry->len;
m = entry->buf;
/*
* Re-initialize queue_entry for reuse; rx_handler takes
* ownership of the mbuf.
*/
entry->buf = NULL;
entry->len = transport_mtu;
entry->cb_data = qp->cb_data;
STAILQ_INSERT_TAIL(&qp->rx_pend_q, entry, entry);
mtx_unlock_spin(&qp->ntb_rx_q_lock);
CTR2(KTR_NTB, "RX: completing entry %p, mbuf %p", entry, m);
if (qp->rx_handler != NULL && qp->client_ready)
qp->rx_handler(qp, qp->cb_data, m, len);
else
m_freem(m);
mtx_lock_spin(&qp->ntb_rx_q_lock);
}
mtx_unlock_spin(&qp->ntb_rx_q_lock);
}
static void
ntb_transport_doorbell_callback(void *data, uint32_t vector)
{
struct ntb_transport_ctx *nt = data;
struct ntb_transport_qp *qp;
struct _qpset db_bits;
uint64_t vec_mask;
unsigned qp_num;
BIT_COPY(QP_SETSIZE, &nt->qp_bitmap, &db_bits);
BIT_NAND(QP_SETSIZE, &db_bits, &nt->qp_bitmap_free);
vec_mask = NTB_DB_VECTOR_MASK(nt->ntb, vector);
if ((vec_mask & (vec_mask - 1)) != 0)
vec_mask &= NTB_DB_READ(nt->ntb);
while (vec_mask != 0) {
qp_num = ffsll(vec_mask) - 1;
if (test_bit(qp_num, &db_bits)) {
qp = &nt->qp_vec[qp_num];
taskqueue_enqueue(qp->rxc_tq, &qp->rxc_db_work);
}
vec_mask &= ~(1ull << qp_num);
}
}
/* Link Event handler */
static void
ntb_transport_event_callback(void *data)
{
struct ntb_transport_ctx *nt = data;
if (NTB_LINK_IS_UP(nt->ntb, NULL, NULL)) {
ntb_printf(1, "HW link up\n");
callout_reset(&nt->link_work, 0, ntb_transport_link_work, nt);
} else {
ntb_printf(1, "HW link down\n");
taskqueue_enqueue(taskqueue_swi, &nt->link_cleanup);
}
}
/* Link bring up */
static void
ntb_transport_link_work(void *arg)
{
struct ntb_transport_ctx *nt = arg;
device_t ntb = nt->ntb;
struct ntb_transport_qp *qp;
uint64_t val64, size;
uint32_t val;
unsigned i;
int rc;
/* send the local info, in the opposite order of the way we read it */
for (i = 0; i < nt->mw_count; i++) {
size = nt->mw_vec[i].phys_size;
if (max_mw_size != 0 && size > max_mw_size)
size = max_mw_size;
NTB_PEER_SPAD_WRITE(ntb, NTBT_MW0_SZ_HIGH + (i * 2),
size >> 32);
NTB_PEER_SPAD_WRITE(ntb, NTBT_MW0_SZ_LOW + (i * 2), size);
}
NTB_PEER_SPAD_WRITE(ntb, NTBT_NUM_MWS, nt->mw_count);
NTB_PEER_SPAD_WRITE(ntb, NTBT_NUM_QPS, nt->qp_count);
NTB_PEER_SPAD_WRITE(ntb, NTBT_VERSION, NTB_TRANSPORT_VERSION);
/* Query the remote side for its info */
val = 0;
NTB_SPAD_READ(ntb, NTBT_VERSION, &val);
if (val != NTB_TRANSPORT_VERSION)
goto out;
NTB_SPAD_READ(ntb, NTBT_NUM_QPS, &val);
if (val != nt->qp_count)
goto out;
NTB_SPAD_READ(ntb, NTBT_NUM_MWS, &val);
if (val != nt->mw_count)
goto out;
for (i = 0; i < nt->mw_count; i++) {
NTB_SPAD_READ(ntb, NTBT_MW0_SZ_HIGH + (i * 2), &val);
val64 = (uint64_t)val << 32;
NTB_SPAD_READ(ntb, NTBT_MW0_SZ_LOW + (i * 2), &val);
val64 |= val;
rc = ntb_set_mw(nt, i, val64);
if (rc != 0)
goto free_mws;
}
nt->link_is_up = true;
ntb_printf(1, "transport link up\n");
for (i = 0; i < nt->qp_count; i++) {
qp = &nt->qp_vec[i];
ntb_transport_setup_qp_mw(nt, i);
if (qp->client_ready)
callout_reset(&qp->link_work, 0, ntb_qp_link_work, qp);
}
return;
free_mws:
for (i = 0; i < nt->mw_count; i++)
ntb_free_mw(nt, i);
out:
if (NTB_LINK_IS_UP(ntb, NULL, NULL))
callout_reset(&nt->link_work,
NTB_LINK_DOWN_TIMEOUT * hz / 1000, ntb_transport_link_work, nt);
}
static int
ntb_set_mw(struct ntb_transport_ctx *nt, int num_mw, size_t size)
{
struct ntb_transport_mw *mw = &nt->mw_vec[num_mw];
size_t xlat_size, buff_size;
int rc;
if (size == 0)
return (EINVAL);
xlat_size = roundup(size, mw->xlat_align_size);
buff_size = xlat_size;
/* No need to re-setup */
if (mw->xlat_size == xlat_size)
return (0);
if (mw->buff_size != 0)
ntb_free_mw(nt, num_mw);
/* Alloc memory for receiving data. Must be aligned */
mw->xlat_size = xlat_size;
mw->buff_size = buff_size;
mw->virt_addr = contigmalloc(mw->buff_size, M_NTB_T, M_ZERO, 0,
mw->addr_limit, mw->xlat_align, 0);
if (mw->virt_addr == NULL) {
ntb_printf(0, "Unable to allocate MW buffer of size %zu/%zu\n",
mw->buff_size, mw->xlat_size);
mw->xlat_size = 0;
mw->buff_size = 0;
return (ENOMEM);
}
/* TODO: replace with bus_space_* functions */
mw->dma_addr = vtophys(mw->virt_addr);
/*
* Ensure that the allocation from contigmalloc is aligned as
* requested. XXX: This may not be needed -- brought in for parity
* with the Linux driver.
*/
if (mw->dma_addr % mw->xlat_align != 0) {
ntb_printf(0,
"DMA memory 0x%jx not aligned to BAR size 0x%zx\n",
(uintmax_t)mw->dma_addr, size);
ntb_free_mw(nt, num_mw);
return (ENOMEM);
}
/* Notify HW the memory location of the receive buffer */
rc = NTB_MW_SET_TRANS(nt->ntb, num_mw, mw->dma_addr, mw->xlat_size);
if (rc) {
ntb_printf(0, "Unable to set mw%d translation\n", num_mw);
ntb_free_mw(nt, num_mw);
return (rc);
}
return (0);
}
static void
ntb_free_mw(struct ntb_transport_ctx *nt, int num_mw)
{
struct ntb_transport_mw *mw = &nt->mw_vec[num_mw];
if (mw->virt_addr == NULL)
return;
NTB_MW_CLEAR_TRANS(nt->ntb, num_mw);
contigfree(mw->virt_addr, mw->xlat_size, M_NTB_T);
mw->xlat_size = 0;
mw->buff_size = 0;
mw->virt_addr = NULL;
}
static int
ntb_transport_setup_qp_mw(struct ntb_transport_ctx *nt, unsigned int qp_num)
{
struct ntb_transport_qp *qp = &nt->qp_vec[qp_num];
struct ntb_transport_mw *mw;
void *offset;
ntb_q_idx_t i;
size_t rx_size;
unsigned num_qps_mw, mw_num, mw_count;
mw_count = nt->mw_count;
mw_num = QP_TO_MW(nt, qp_num);
mw = &nt->mw_vec[mw_num];
if (mw->virt_addr == NULL)
return (ENOMEM);
if (mw_num < nt->qp_count % mw_count)
num_qps_mw = nt->qp_count / mw_count + 1;
else
num_qps_mw = nt->qp_count / mw_count;
rx_size = mw->xlat_size / num_qps_mw;
qp->rx_buff = mw->virt_addr + rx_size * (qp_num / mw_count);
rx_size -= sizeof(struct ntb_rx_info);
qp->remote_rx_info = (void*)(qp->rx_buff + rx_size);
/* Due to house-keeping, there must be at least 2 buffs */
qp->rx_max_frame = qmin(rx_size / 2,
transport_mtu + sizeof(struct ntb_payload_header));
qp->rx_max_entry = rx_size / qp->rx_max_frame;
qp->rx_index = 0;
qp->remote_rx_info->entry = qp->rx_max_entry - 1;
/* Set up the hdr offsets with 0s */
for (i = 0; i < qp->rx_max_entry; i++) {
offset = (void *)(qp->rx_buff + qp->rx_max_frame * (i + 1) -
sizeof(struct ntb_payload_header));
memset(offset, 0, sizeof(struct ntb_payload_header));
}
qp->rx_pkts = 0;
qp->tx_pkts = 0;
qp->tx_index = 0;
return (0);
}
static void
ntb_qp_link_work(void *arg)
{
struct ntb_transport_qp *qp = arg;
device_t ntb = qp->ntb;
struct ntb_transport_ctx *nt = qp->transport;
uint32_t val, dummy;
NTB_SPAD_READ(ntb, NTBT_QP_LINKS, &val);
NTB_PEER_SPAD_WRITE(ntb, NTBT_QP_LINKS, val | (1ull << qp->qp_num));
/* query remote spad for qp ready bits */
NTB_PEER_SPAD_READ(ntb, NTBT_QP_LINKS, &dummy);
/* See if the remote side is up */
if ((val & (1ull << qp->qp_num)) != 0) {
ntb_printf(2, "qp %d link up\n", qp->qp_num);
qp->link_is_up = true;
if (qp->event_handler != NULL)
qp->event_handler(qp->cb_data, NTB_LINK_UP);
taskqueue_enqueue(qp->rxc_tq, &qp->rxc_db_work);
} else if (nt->link_is_up)
callout_reset(&qp->link_work,
NTB_LINK_DOWN_TIMEOUT * hz / 1000, ntb_qp_link_work, qp);
}
/* Link down event*/
static void
ntb_transport_link_cleanup(struct ntb_transport_ctx *nt)
{
struct ntb_transport_qp *qp;
struct _qpset qp_bitmap_alloc;
unsigned i;
BIT_COPY(QP_SETSIZE, &nt->qp_bitmap, &qp_bitmap_alloc);
BIT_NAND(QP_SETSIZE, &qp_bitmap_alloc, &nt->qp_bitmap_free);
/* Pass along the info to any clients */
for (i = 0; i < nt->qp_count; i++)
if (test_bit(i, &qp_bitmap_alloc)) {
qp = &nt->qp_vec[i];
ntb_qp_link_cleanup(qp);
callout_drain(&qp->link_work);
}
if (!nt->link_is_up)
callout_drain(&nt->link_work);
/*
* The scratchpad registers keep the values if the remote side
* goes down, blast them now to give them a sane value the next
* time they are accessed
*/
for (i = 0; i < NTBT_MAX_SPAD; i++)
NTB_SPAD_WRITE(nt->ntb, i, 0);
}
static void
ntb_transport_link_cleanup_work(void *arg, int pending __unused)
{
ntb_transport_link_cleanup(arg);
}
static void
ntb_qp_link_down(struct ntb_transport_qp *qp)
{
ntb_qp_link_cleanup(qp);
}
static void
ntb_qp_link_down_reset(struct ntb_transport_qp *qp)
{
qp->link_is_up = false;
qp->tx_index = qp->rx_index = 0;
qp->tx_bytes = qp->rx_bytes = 0;
qp->tx_pkts = qp->rx_pkts = 0;
qp->rx_ring_empty = 0;
qp->tx_ring_full = 0;
qp->rx_err_no_buf = qp->tx_err_no_buf = 0;
qp->rx_err_oflow = qp->rx_err_ver = 0;
}
static void
ntb_qp_link_cleanup(struct ntb_transport_qp *qp)
{
struct ntb_transport_ctx *nt = qp->transport;
callout_drain(&qp->link_work);
ntb_qp_link_down_reset(qp);
if (qp->event_handler != NULL)
qp->event_handler(qp->cb_data, NTB_LINK_DOWN);
if (nt->link_is_up)
callout_reset(&qp->link_work,
NTB_LINK_DOWN_TIMEOUT * hz / 1000, ntb_qp_link_work, qp);
}
/* Link commanded down */
/**
* ntb_transport_link_down - Notify NTB transport to no longer enqueue data
* @qp: NTB transport layer queue to be disabled
*
* Notify NTB transport layer of client's desire to no longer receive data on
* transport queue specified. It is the client's responsibility to ensure all
* entries on queue are purged or otherwise handled appropriately.
*/
void
ntb_transport_link_down(struct ntb_transport_qp *qp)
{
uint32_t val;
if (qp == NULL)
return;
qp->client_ready = false;
NTB_SPAD_READ(qp->ntb, NTBT_QP_LINKS, &val);
NTB_PEER_SPAD_WRITE(qp->ntb, NTBT_QP_LINKS,
val & ~(1 << qp->qp_num));
if (qp->link_is_up)
ntb_send_link_down(qp);
else
callout_drain(&qp->link_work);
}
/**
* ntb_transport_link_query - Query transport link state
* @qp: NTB transport layer queue to be queried
*
* Query connectivity to the remote system of the NTB transport queue
*
* RETURNS: true for link up or false for link down
*/
bool
ntb_transport_link_query(struct ntb_transport_qp *qp)
{
if (qp == NULL)
return (false);
return (qp->link_is_up);
}
static void
ntb_send_link_down(struct ntb_transport_qp *qp)
{
struct ntb_queue_entry *entry;
int i, rc;
if (!qp->link_is_up)
return;
for (i = 0; i < NTB_LINK_DOWN_TIMEOUT; i++) {
entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
if (entry != NULL)
break;
pause("NTB Wait for link down", hz / 10);
}
if (entry == NULL)
return;
entry->cb_data = NULL;
entry->buf = NULL;
entry->len = 0;
entry->flags = NTBT_LINK_DOWN_FLAG;
mtx_lock(&qp->tx_lock);
rc = ntb_process_tx(qp, entry);
mtx_unlock(&qp->tx_lock);
if (rc != 0)
printf("ntb: Failed to send link down\n");
ntb_qp_link_down_reset(qp);
}
/* List Management */
static void
ntb_list_add(struct mtx *lock, struct ntb_queue_entry *entry,
struct ntb_queue_list *list)
{
mtx_lock_spin(lock);
STAILQ_INSERT_TAIL(list, entry, entry);
mtx_unlock_spin(lock);
}
static struct ntb_queue_entry *
ntb_list_rm(struct mtx *lock, struct ntb_queue_list *list)
{
struct ntb_queue_entry *entry;
mtx_lock_spin(lock);
if (STAILQ_EMPTY(list)) {
entry = NULL;
goto out;
}
entry = STAILQ_FIRST(list);
STAILQ_REMOVE_HEAD(list, entry);
out:
mtx_unlock_spin(lock);
return (entry);
}
static struct ntb_queue_entry *
ntb_list_mv(struct mtx *lock, struct ntb_queue_list *from,
struct ntb_queue_list *to)
{
struct ntb_queue_entry *entry;
mtx_lock_spin(lock);
if (STAILQ_EMPTY(from)) {
entry = NULL;
goto out;
}
entry = STAILQ_FIRST(from);
STAILQ_REMOVE_HEAD(from, entry);
STAILQ_INSERT_TAIL(to, entry, entry);
out:
mtx_unlock_spin(lock);
return (entry);
}
/**
* ntb_transport_qp_num - Query the qp number
* @qp: NTB transport layer queue to be queried
*
* Query qp number of the NTB transport queue
*
* RETURNS: a zero based number specifying the qp number
*/
unsigned char ntb_transport_qp_num(struct ntb_transport_qp *qp)
{
if (qp == NULL)
return 0;
return (qp->qp_num);
}
/**
* ntb_transport_max_size - Query the max payload size of a qp
* @qp: NTB transport layer queue to be queried
*
* Query the maximum payload size permissible on the given qp
*
* RETURNS: the max payload size of a qp
*/
unsigned int
ntb_transport_max_size(struct ntb_transport_qp *qp)
{
if (qp == NULL)
return (0);
return (qp->tx_max_frame - sizeof(struct ntb_payload_header));
}
unsigned int
ntb_transport_tx_free_entry(struct ntb_transport_qp *qp)
{
unsigned int head = qp->tx_index;
unsigned int tail = qp->remote_rx_info->entry;
return (tail >= head ? tail - head : qp->tx_max_entry + tail - head);
}
static device_method_t ntb_transport_methods[] = {
/* Device interface */
DEVMETHOD(device_probe, ntb_transport_probe),
DEVMETHOD(device_attach, ntb_transport_attach),
DEVMETHOD(device_detach, ntb_transport_detach),
DEVMETHOD_END
};
devclass_t ntb_transport_devclass;
static DEFINE_CLASS_0(ntb_transport, ntb_transport_driver,
ntb_transport_methods, sizeof(struct ntb_transport_ctx));
DRIVER_MODULE(ntb_transport, ntb_hw, ntb_transport_driver,
ntb_transport_devclass, NULL, NULL);
MODULE_DEPEND(ntb_transport, ntb, 1, 1, 1);
MODULE_VERSION(ntb_transport, 1);
Reference in New Issue View Git Blame Copy Permalink