diff options
Diffstat (limited to 'sys/dev/ntb/ntb_transport.c')
| -rw-r--r-- | sys/dev/ntb/ntb_transport.c | 1518 |
1 files changed, 1518 insertions, 0 deletions
diff --git a/sys/dev/ntb/ntb_transport.c b/sys/dev/ntb/ntb_transport.c new file mode 100644 index 0000000..c7bc4da --- /dev/null +++ b/sys/dev/ntb/ntb_transport.c @@ -0,0 +1,1518 @@ +/*- + * 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/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 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 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 dev; + + 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_child { + device_t dev; + int qpoff; + int qpcnt; + struct ntb_transport_child *next; +}; + +struct ntb_transport_ctx { + device_t dev; + struct ntb_transport_child *child; + struct ntb_transport_mw *mw_vec; + struct ntb_transport_qp *qp_vec; + unsigned mw_count; + unsigned qp_count; + uint64_t qp_bitmap; + 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, + + /* + * 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->dev, 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); + struct ntb_transport_child **cpp = &nt->child; + struct ntb_transport_child *nc; + struct ntb_transport_mw *mw; + uint64_t db_bitmap; + int rc, i, db_count, spad_count, qp, qpu, qpo, qpt; + char cfg[128] = ""; + char buf[32]; + char *n, *np, *c, *name; + + nt->dev = dev; + nt->mw_count = ntb_mw_count(dev); + spad_count = ntb_spad_count(dev); + db_bitmap = ntb_db_valid_mask(dev); + db_count = flsll(db_bitmap); + KASSERT(db_bitmap == (1 << db_count) - 1, + ("Doorbells are not sequential (%jx).\n", db_bitmap)); + + device_printf(dev, "%d memory windows, %d scratchpads, " + "%d doorbells\n", nt->mw_count, spad_count, db_count); + + if (nt->mw_count == 0) { + device_printf(dev, "At least 1 memory window required.\n"); + return (ENXIO); + } + if (spad_count < 6) { + device_printf(dev, "At least 6 scratchpads required.\n"); + return (ENXIO); + } + if (spad_count < 4 + 2 * nt->mw_count) { + nt->mw_count = (spad_count - 4) / 2; + device_printf(dev, "Scratchpads enough only for %d " + "memory windows.\n", nt->mw_count); + } + if (db_bitmap == 0) { + device_printf(dev, "At least one doorbell required.\n"); + return (ENXIO); + } + + 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(dev, 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(dev, i, VM_MEMATTR_WRITE_COMBINING); + if (rc) + ntb_printf(0, "Unable to set mw%d caching\n", i); + } + + qpu = 0; + qpo = imin(db_count, nt->mw_count); + qpt = db_count; + + snprintf(buf, sizeof(buf), "hint.%s.%d.config", device_get_name(dev), + device_get_unit(dev)); + TUNABLE_STR_FETCH(buf, cfg, sizeof(cfg)); + n = cfg; + i = 0; + while ((c = strsep(&n, ",")) != NULL) { + np = c; + name = strsep(&np, ":"); + if (name != NULL && name[0] == 0) + name = NULL; + qp = (np && np[0] != 0) ? strtol(np, NULL, 10) : qpo - qpu; + if (qp <= 0) + qp = 1; + + if (qp > qpt - qpu) { + device_printf(dev, "Not enough resources for config\n"); + break; + } + + nc = malloc(sizeof(*nc), M_DEVBUF, M_WAITOK | M_ZERO); + nc->qpoff = qpu; + nc->qpcnt = qp; + nc->dev = device_add_child(dev, name, -1); + if (nc->dev == NULL) { + device_printf(dev, "Can not add child.\n"); + break; + } + device_set_ivars(nc->dev, nc); + *cpp = nc; + cpp = &nc->next; + + if (bootverbose) { + device_printf(dev, "%d \"%s\": queues %d", + i, name, qpu); + if (qp > 1) + printf("-%d", qpu + qp - 1); + printf("\n"); + } + + qpu += qp; + i++; + } + nt->qp_count = qpu; + + 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++) + 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(dev, nt, &ntb_transport_ops); + if (rc != 0) + goto err; + + nt->link_is_up = false; + ntb_link_enable(dev, NTB_SPEED_AUTO, NTB_WIDTH_AUTO); + + if (enable_xeon_watchdog != 0) + callout_reset(&nt->link_watchdog, 0, xeon_link_watchdog_hb, nt); + + 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); + struct ntb_transport_child **cpp = &nt->child; + struct ntb_transport_child *nc; + int error = 0, i; + + while ((nc = *cpp) != NULL) { + *cpp = (*cpp)->next; + error = device_delete_child(dev, nc->dev); + if (error) + break; + free(nc, M_DEVBUF); + } + KASSERT(nt->qp_bitmap == 0, + ("Some queues not freed on detach (%jx)", nt->qp_bitmap)); + + ntb_transport_link_cleanup(nt); + taskqueue_drain(taskqueue_swi, &nt->link_cleanup); + callout_drain(&nt->link_work); + callout_drain(&nt->link_watchdog); + + ntb_link_disable(dev); + ntb_clear_ctx(dev); + + 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); +} + +int +ntb_transport_queue_count(device_t dev) +{ + struct ntb_transport_child *nc = device_get_ivars(dev); + + return (nc->qpcnt); +} + +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->dev = nt->dev; + 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(transport_mtu, tx_size / 2); + 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); +} + +void +ntb_transport_free_queue(struct ntb_transport_qp *qp) +{ + struct ntb_transport_ctx *nt = qp->transport; + struct ntb_queue_entry *entry; + + callout_drain(&qp->link_work); + + ntb_db_set_mask(qp->dev, 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); + + nt->qp_bitmap &= ~(1 << qp->qp_num); +} + +/** + * 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(device_t dev, int q, + const struct ntb_queue_handlers *handlers, void *data) +{ + struct ntb_transport_child *nc = device_get_ivars(dev); + struct ntb_transport_ctx *nt = device_get_softc(device_get_parent(dev)); + struct ntb_queue_entry *entry; + struct ntb_transport_qp *qp; + int i; + + if (q < 0 || q >= nc->qpcnt) + return (NULL); + + qp = &nt->qp_vec[nc->qpoff + q]; + nt->qp_bitmap |= (1 << qp->qp_num); + 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(dev, 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->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->dev, 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->dev) & (1ull << qp->qp_num)) != 0) { + /* If db is set, clear it and check queue once more. */ + ntb_db_clear(qp->dev, 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); + if (entry->buf == NULL) + entry->len = -ENOMEM; + + /* Ensure that the data is globally visible before clearing the flag */ + wmb(); + + CTR2(KTR_NTB, "RX: copied entry %p to mbuf %p.", entry, entry->buf); + 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; + uint64_t vec_mask; + unsigned qp_num; + + vec_mask = ntb_db_vector_mask(nt->dev, vector); + vec_mask &= nt->qp_bitmap; + if ((vec_mask & (vec_mask - 1)) != 0) + vec_mask &= ntb_db_read(nt->dev); + while (vec_mask != 0) { + qp_num = ffsll(vec_mask) - 1; + + qp = &nt->qp_vec[qp_num]; + if (qp->link_is_up) + 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->dev, 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 dev = nt->dev; + 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(dev, NTBT_MW0_SZ_HIGH + (i * 2), + size >> 32); + ntb_peer_spad_write(dev, NTBT_MW0_SZ_LOW + (i * 2), size); + } + ntb_peer_spad_write(dev, NTBT_NUM_MWS, nt->mw_count); + ntb_peer_spad_write(dev, NTBT_NUM_QPS, nt->qp_count); + ntb_peer_spad_write(dev, NTBT_QP_LINKS, 0); + ntb_peer_spad_write(dev, NTBT_VERSION, NTB_TRANSPORT_VERSION); + + /* Query the remote side for its info */ + val = 0; + ntb_spad_read(dev, NTBT_VERSION, &val); + if (val != NTB_TRANSPORT_VERSION) + goto out; + + ntb_spad_read(dev, NTBT_NUM_QPS, &val); + if (val != nt->qp_count) + goto out; + + ntb_spad_read(dev, NTBT_NUM_MWS, &val); + if (val != nt->mw_count) + goto out; + + for (i = 0; i < nt->mw_count; i++) { + ntb_spad_read(dev, NTBT_MW0_SZ_HIGH + (i * 2), &val); + val64 = (uint64_t)val << 32; + + ntb_spad_read(dev, 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(dev, 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->dev, 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->dev, 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(transport_mtu, rx_size / 2); + 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 dev = qp->dev; + struct ntb_transport_ctx *nt = qp->transport; + int i; + uint32_t val; + + /* Report queues that are up on our side */ + for (i = 0, val = 0; i < nt->qp_count; i++) { + if (nt->qp_vec[i].client_ready) + val |= (1 << i); + } + ntb_peer_spad_write(dev, NTBT_QP_LINKS, val); + + /* See if the remote side is up */ + ntb_spad_read(dev, NTBT_QP_LINKS, &val); + 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); + + ntb_db_clear_mask(dev, 1ull << qp->qp_num); + } 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; + int i; + + /* Pass along the info to any clients */ + for (i = 0; i < nt->qp_count; i++) { + if ((nt->qp_bitmap & (1 << i)) != 0) { + 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 + */ + ntb_spad_clear(nt->dev); +} + +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; + ntb_db_set_mask(qp->dev, 1ull << qp->qp_num); + + 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) +{ + + 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); +} + +/* 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) +{ + struct ntb_transport_ctx *nt = qp->transport; + int i; + uint32_t val; + + qp->client_ready = false; + for (i = 0, val = 0; i < nt->qp_count; i++) { + if (nt->qp_vec[i].client_ready) + val |= (1 << i); + } + ntb_peer_spad_write(qp->dev, NTBT_QP_LINKS, val); + + 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) +{ + + 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) +{ + + 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) +{ + + 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); |
