/* * This file is provided under a dual BSD/GPLv2 license. When using or * redistributing this file, you may do so under either license. * * GPL LICENSE SUMMARY * * Copyright(c) 2012 Intel Corporation. All rights reserved. * Copyright (C) 2015 EMC Corporation. All Rights Reserved. * * This program is free software; you can redistribute it and/or modify * it under the terms of version 2 of the GNU General Public License as * published by the Free Software Foundation. * * BSD LICENSE * * Copyright(c) 2012 Intel Corporation. All rights reserved. * 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: * * * Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above copy * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * * Neither the name of Intel Corporation nor the names of its * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT * OWNER 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. * * PCIe NTB Transport Linux driver * * Contact Information: * Jon Mason */ #include #include #include #include #include #include #include #include #include #include #include #include "linux/ntb.h" #include "linux/ntb_transport.h" #define NTB_TRANSPORT_VERSION 4 #define NTB_TRANSPORT_VER "4" #define NTB_TRANSPORT_NAME "ntb_transport" #define NTB_TRANSPORT_DESC "Software Queue-Pair Transport over NTB" MODULE_DESCRIPTION(NTB_TRANSPORT_DESC); MODULE_VERSION(NTB_TRANSPORT_VER); MODULE_LICENSE("Dual BSD/GPL"); MODULE_AUTHOR("Intel Corporation"); static unsigned long max_mw_size; module_param(max_mw_size, ulong, 0644); MODULE_PARM_DESC(max_mw_size, "Limit size of large memory windows"); static unsigned int transport_mtu = 0x401E; module_param(transport_mtu, uint, 0644); MODULE_PARM_DESC(transport_mtu, "Maximum size of NTB transport packets"); static unsigned char max_num_clients; module_param(max_num_clients, byte, 0644); MODULE_PARM_DESC(max_num_clients, "Maximum number of NTB transport clients"); static unsigned int copy_bytes = 1024; module_param(copy_bytes, uint, 0644); MODULE_PARM_DESC(copy_bytes, "Threshold under which NTB will use the CPU to copy instead of DMA"); static struct dentry *nt_debugfs_dir; struct ntb_queue_entry { /* ntb_queue list reference */ struct list_head entry; /* pointers to data to be transferred */ void *cb_data; void *buf; unsigned int len; unsigned int flags; struct ntb_transport_qp *qp; union { struct ntb_payload_header __iomem *tx_hdr; struct ntb_payload_header *rx_hdr; }; unsigned int index; }; struct ntb_rx_info { unsigned int entry; }; struct ntb_transport_qp { struct ntb_transport_ctx *transport; struct ntb_dev *ndev; void *cb_data; struct dma_chan *dma_chan; bool client_ready; bool link_is_up; u8 qp_num; /* Only 64 QP's are allowed. 0-63 */ u64 qp_bit; struct ntb_rx_info __iomem *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 list_head tx_free_q; spinlock_t ntb_tx_free_q_lock; void __iomem *tx_mw; dma_addr_t tx_mw_phys; unsigned int tx_index; unsigned int tx_max_entry; unsigned int tx_max_frame; void (*rx_handler)(struct ntb_transport_qp *qp, void *qp_data, void *data, int len); struct list_head rx_pend_q; struct list_head rx_free_q; spinlock_t ntb_rx_pend_q_lock; spinlock_t ntb_rx_free_q_lock; void *rx_buff; unsigned int rx_index; unsigned int rx_max_entry; unsigned int rx_max_frame; dma_cookie_t last_cookie; struct tasklet_struct rxc_db_work; void (*event_handler)(void *data, int status); struct delayed_work link_work; struct work_struct link_cleanup; struct dentry *debugfs_dir; struct dentry *debugfs_stats; /* Stats */ u64 rx_bytes; u64 rx_pkts; u64 rx_ring_empty; u64 rx_err_no_buf; u64 rx_err_oflow; u64 rx_err_ver; u64 rx_memcpy; u64 rx_async; u64 tx_bytes; u64 tx_pkts; u64 tx_ring_full; u64 tx_err_no_buf; u64 tx_memcpy; u64 tx_async; }; struct ntb_transport_mw { phys_addr_t phys_addr; resource_size_t phys_size; resource_size_t xlat_align; resource_size_t xlat_align_size; void __iomem *vbase; size_t xlat_size; size_t buff_size; void *virt_addr; dma_addr_t dma_addr; }; struct ntb_transport_client_dev { struct list_head entry; struct ntb_transport_ctx *nt; struct device dev; }; struct ntb_transport_ctx { struct list_head entry; struct list_head client_devs; struct ntb_dev *ndev; struct ntb_transport_mw *mw_vec; struct ntb_transport_qp *qp_vec; unsigned int mw_count; unsigned int qp_count; u64 qp_bitmap; u64 qp_bitmap_free; bool link_is_up; struct delayed_work link_work; struct work_struct link_cleanup; }; enum { DESC_DONE_FLAG = BIT(0), LINK_DOWN_FLAG = BIT(1), }; struct ntb_payload_header { unsigned int ver; unsigned int len; unsigned int flags; }; enum { VERSION = 0, QP_LINKS, NUM_QPS, NUM_MWS, MW0_SZ_HIGH, MW0_SZ_LOW, MW1_SZ_HIGH, MW1_SZ_LOW, MAX_SPAD, }; #define dev_client_dev(__dev) \ container_of((__dev), struct ntb_transport_client_dev, dev) #define drv_client(__drv) \ container_of((__drv), struct ntb_transport_client, driver) #define QP_TO_MW(nt, qp) ((qp) % nt->mw_count) #define NTB_QP_DEF_NUM_ENTRIES 100 #define NTB_LINK_DOWN_TIMEOUT 10 static void ntb_transport_rxc_db(unsigned long data); static const struct ntb_ctx_ops ntb_transport_ops; static struct ntb_client ntb_transport_client; static int ntb_transport_bus_match(struct device *dev, struct device_driver *drv) { return !strncmp(dev_name(dev), drv->name, strlen(drv->name)); } static int ntb_transport_bus_probe(struct device *dev) { const struct ntb_transport_client *client; int rc = -EINVAL; get_device(dev); client = drv_client(dev->driver); rc = client->probe(dev); if (rc) put_device(dev); return rc; } static int ntb_transport_bus_remove(struct device *dev) { const struct ntb_transport_client *client; client = drv_client(dev->driver); client->remove(dev); put_device(dev); return 0; } static struct bus_type ntb_transport_bus = { .name = "ntb_transport", .match = ntb_transport_bus_match, .probe = ntb_transport_bus_probe, .remove = ntb_transport_bus_remove, }; static LIST_HEAD(ntb_transport_list); static int ntb_bus_init(struct ntb_transport_ctx *nt) { list_add(&nt->entry, &ntb_transport_list); return 0; } static void ntb_bus_remove(struct ntb_transport_ctx *nt) { struct ntb_transport_client_dev *client_dev, *cd; list_for_each_entry_safe(client_dev, cd, &nt->client_devs, entry) { dev_err(client_dev->dev.parent, "%s still attached to bus, removing\n", dev_name(&client_dev->dev)); list_del(&client_dev->entry); device_unregister(&client_dev->dev); } list_del(&nt->entry); } static void ntb_transport_client_release(struct device *dev) { struct ntb_transport_client_dev *client_dev; client_dev = dev_client_dev(dev); kfree(client_dev); } /** * ntb_transport_unregister_client_dev - Unregister NTB client device * @device_name: Name of NTB client device * * Unregister an NTB client device with the NTB transport layer */ void ntb_transport_unregister_client_dev(char *device_name) { struct ntb_transport_client_dev *client, *cd; struct ntb_transport_ctx *nt; list_for_each_entry(nt, &ntb_transport_list, entry) list_for_each_entry_safe(client, cd, &nt->client_devs, entry) if (!strncmp(dev_name(&client->dev), device_name, strlen(device_name))) { list_del(&client->entry); device_unregister(&client->dev); } } EXPORT_SYMBOL_GPL(ntb_transport_unregister_client_dev); /** * ntb_transport_register_client_dev - Register NTB client device * @device_name: Name of NTB client device * * Register an NTB client device with the NTB transport layer */ int ntb_transport_register_client_dev(char *device_name) { struct ntb_transport_client_dev *client_dev; struct ntb_transport_ctx *nt; int rc, i = 0; if (list_empty(&ntb_transport_list)) return -ENODEV; list_for_each_entry(nt, &ntb_transport_list, entry) { struct device *dev; client_dev = kzalloc(sizeof(*client_dev), GFP_KERNEL); if (!client_dev) { rc = -ENOMEM; goto err; } dev = &client_dev->dev; /* setup and register client devices */ dev_set_name(dev, "%s%d", device_name, i); dev->bus = &ntb_transport_bus; dev->release = ntb_transport_client_release; dev->parent = &nt->ndev->dev; rc = device_register(dev); if (rc) { kfree(client_dev); goto err; } list_add_tail(&client_dev->entry, &nt->client_devs); i++; } return 0; err: ntb_transport_unregister_client_dev(device_name); return rc; } EXPORT_SYMBOL_GPL(ntb_transport_register_client_dev); /** * ntb_transport_register_client - Register NTB client driver * @drv: NTB client driver to be registered * * Register an NTB client driver with the NTB transport layer * * RETURNS: An appropriate -ERRNO error value on error, or zero for success. */ int ntb_transport_register_client(struct ntb_transport_client *drv) { drv->driver.bus = &ntb_transport_bus; if (list_empty(&ntb_transport_list)) return -ENODEV; return driver_register(&drv->driver); } EXPORT_SYMBOL_GPL(ntb_transport_register_client); /** * ntb_transport_unregister_client - Unregister NTB client driver * @drv: NTB client driver to be unregistered * * Unregister an NTB client driver with the NTB transport layer * * RETURNS: An appropriate -ERRNO error value on error, or zero for success. */ void ntb_transport_unregister_client(struct ntb_transport_client *drv) { driver_unregister(&drv->driver); } EXPORT_SYMBOL_GPL(ntb_transport_unregister_client); static ssize_t debugfs_read(struct file *filp, char __user *ubuf, size_t count, loff_t *offp) { struct ntb_transport_qp *qp; char *buf; ssize_t ret, out_offset, out_count; out_count = 1000; buf = kmalloc(out_count, GFP_KERNEL); if (!buf) return -ENOMEM; qp = filp->private_data; out_offset = 0; out_offset += snprintf(buf + out_offset, out_count - out_offset, "NTB QP stats\n"); out_offset += snprintf(buf + out_offset, out_count - out_offset, "rx_bytes - \t%llu\n", qp->rx_bytes); out_offset += snprintf(buf + out_offset, out_count - out_offset, "rx_pkts - \t%llu\n", qp->rx_pkts); out_offset += snprintf(buf + out_offset, out_count - out_offset, "rx_memcpy - \t%llu\n", qp->rx_memcpy); out_offset += snprintf(buf + out_offset, out_count - out_offset, "rx_async - \t%llu\n", qp->rx_async); out_offset += snprintf(buf + out_offset, out_count - out_offset, "rx_ring_empty - %llu\n", qp->rx_ring_empty); out_offset += snprintf(buf + out_offset, out_count - out_offset, "rx_err_no_buf - %llu\n", qp->rx_err_no_buf); out_offset += snprintf(buf + out_offset, out_count - out_offset, "rx_err_oflow - \t%llu\n", qp->rx_err_oflow); out_offset += snprintf(buf + out_offset, out_count - out_offset, "rx_err_ver - \t%llu\n", qp->rx_err_ver); out_offset += snprintf(buf + out_offset, out_count - out_offset, "rx_buff - \t%p\n", qp->rx_buff); out_offset += snprintf(buf + out_offset, out_count - out_offset, "rx_index - \t%u\n", qp->rx_index); out_offset += snprintf(buf + out_offset, out_count - out_offset, "rx_max_entry - \t%u\n", qp->rx_max_entry); out_offset += snprintf(buf + out_offset, out_count - out_offset, "tx_bytes - \t%llu\n", qp->tx_bytes); out_offset += snprintf(buf + out_offset, out_count - out_offset, "tx_pkts - \t%llu\n", qp->tx_pkts); out_offset += snprintf(buf + out_offset, out_count - out_offset, "tx_memcpy - \t%llu\n", qp->tx_memcpy); out_offset += snprintf(buf + out_offset, out_count - out_offset, "tx_async - \t%llu\n", qp->tx_async); out_offset += snprintf(buf + out_offset, out_count - out_offset, "tx_ring_full - \t%llu\n", qp->tx_ring_full); out_offset += snprintf(buf + out_offset, out_count - out_offset, "tx_err_no_buf - %llu\n", qp->tx_err_no_buf); out_offset += snprintf(buf + out_offset, out_count - out_offset, "tx_mw - \t%p\n", qp->tx_mw); out_offset += snprintf(buf + out_offset, out_count - out_offset, "tx_index - \t%u\n", qp->tx_index); out_offset += snprintf(buf + out_offset, out_count - out_offset, "tx_max_entry - \t%u\n", qp->tx_max_entry); out_offset += snprintf(buf + out_offset, out_count - out_offset, "\nQP Link %s\n", qp->link_is_up ? "Up" : "Down"); if (out_offset > out_count) out_offset = out_count; ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset); kfree(buf); return ret; } static const struct file_operations ntb_qp_debugfs_stats = { .owner = THIS_MODULE, .open = simple_open, .read = debugfs_read, }; static void ntb_list_add(spinlock_t *lock, struct list_head *entry, struct list_head *list) { unsigned long flags; spin_lock_irqsave(lock, flags); list_add_tail(entry, list); spin_unlock_irqrestore(lock, flags); } static struct ntb_queue_entry *ntb_list_rm(spinlock_t *lock, struct list_head *list) { struct ntb_queue_entry *entry; unsigned long flags; spin_lock_irqsave(lock, flags); if (list_empty(list)) { entry = NULL; goto out; } entry = list_first_entry(list, struct ntb_queue_entry, entry); list_del(&entry->entry); out: spin_unlock_irqrestore(lock, flags); return entry; } 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; unsigned int rx_size, num_qps_mw; unsigned int mw_num, mw_count, qp_count; unsigned int i; mw_count = nt->mw_count; qp_count = nt->qp_count; mw_num = QP_TO_MW(nt, qp_num); mw = &nt->mw_vec[mw_num]; if (!mw->virt_addr) return -ENOMEM; if (qp_count % mw_count && mw_num + 1 < qp_count / mw_count) num_qps_mw = qp_count / mw_count + 1; else num_qps_mw = qp_count / mw_count; rx_size = (unsigned int)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 = qp->rx_buff + rx_size; /* Due to housekeeping, there must be atleast 2 buffs */ qp->rx_max_frame = min(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; /* setup the hdr offsets with 0's */ for (i = 0; i < qp->rx_max_entry; i++) { void *offset = (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_free_mw(struct ntb_transport_ctx *nt, int num_mw) { struct ntb_transport_mw *mw = &nt->mw_vec[num_mw]; struct pci_dev *pdev = nt->ndev->pdev; if (!mw->virt_addr) return; ntb_mw_clear_trans(nt->ndev, num_mw); dma_free_coherent(&pdev->dev, mw->buff_size, mw->virt_addr, mw->dma_addr); mw->xlat_size = 0; mw->buff_size = 0; mw->virt_addr = NULL; } static int ntb_set_mw(struct ntb_transport_ctx *nt, int num_mw, unsigned int size) { struct ntb_transport_mw *mw = &nt->mw_vec[num_mw]; struct pci_dev *pdev = nt->ndev->pdev; unsigned int xlat_size, buff_size; int rc; xlat_size = round_up(size, mw->xlat_align_size); buff_size = round_up(size, mw->xlat_align); /* No need to re-setup */ if (mw->xlat_size == xlat_size) return 0; if (mw->buff_size) 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 = dma_alloc_coherent(&pdev->dev, buff_size, &mw->dma_addr, GFP_KERNEL); if (!mw->virt_addr) { mw->xlat_size = 0; mw->buff_size = 0; dev_err(&pdev->dev, "Unable to alloc MW buff of size %d\n", buff_size); return -ENOMEM; } /* * we must ensure that the memory address allocated is BAR size * aligned in order for the XLAT register to take the value. This * is a requirement of the hardware. It is recommended to setup CMA * for BAR sizes equal or greater than 4MB. */ if (!IS_ALIGNED(mw->dma_addr, mw->xlat_align)) { dev_err(&pdev->dev, "DMA memory %pad is not aligned\n", &mw->dma_addr); ntb_free_mw(nt, num_mw); return -ENOMEM; } /* Notify HW the memory location of the receive buffer */ rc = ntb_mw_set_trans(nt->ndev, num_mw, mw->dma_addr, mw->xlat_size); if (rc) { dev_err(&pdev->dev, "Unable to set mw%d translation", num_mw); ntb_free_mw(nt, num_mw); return -EIO; } return 0; } static void ntb_qp_link_cleanup(struct ntb_transport_qp *qp) { struct ntb_transport_ctx *nt = qp->transport; struct pci_dev *pdev = nt->ndev->pdev; if (qp->link_is_up) { cancel_delayed_work_sync(&qp->link_work); return; } dev_info(&pdev->dev, "qp %d: Link Cleanup\n", qp->qp_num); qp->link_is_up = false; if (qp->event_handler) qp->event_handler(qp->cb_data, qp->link_is_up); } static void ntb_qp_link_cleanup_work(struct work_struct *work) { struct ntb_transport_qp *qp = container_of(work, struct ntb_transport_qp, link_cleanup); struct ntb_transport_ctx *nt = qp->transport; ntb_qp_link_cleanup(qp); if (nt->link_is_up) schedule_delayed_work(&qp->link_work, msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT)); } static void ntb_qp_link_down(struct ntb_transport_qp *qp) { schedule_work(&qp->link_cleanup); } static void ntb_transport_link_cleanup(struct ntb_transport_ctx *nt) { struct ntb_transport_qp *qp; u64 qp_bitmap_alloc; int i; qp_bitmap_alloc = nt->qp_bitmap & ~nt->qp_bitmap_free; /* Pass along the info to any clients */ for (i = 0; i < nt->qp_count; i++) if (qp_bitmap_alloc & BIT_ULL(i)) { qp = &nt->qp_vec[i]; ntb_qp_link_cleanup(qp); cancel_work_sync(&qp->link_cleanup); cancel_delayed_work_sync(&qp->link_work); } if (!nt->link_is_up) cancel_delayed_work_sync(&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 < MAX_SPAD; i++) ntb_spad_write(nt->ndev, i, 0); } static void ntb_transport_link_cleanup_work(struct work_struct *work) { struct ntb_transport_ctx *nt = container_of(work, struct ntb_transport_ctx, link_cleanup); ntb_transport_link_cleanup(nt); } static void ntb_transport_event_callback(void *data) { struct ntb_transport_ctx *nt = data; if (ntb_link_is_up(nt->ndev, NULL, NULL) == 1) schedule_delayed_work(&nt->link_work, 0); else schedule_work(&nt->link_cleanup); } static void ntb_transport_link_work(struct work_struct *work) { struct ntb_transport_ctx *nt = container_of(work, struct ntb_transport_ctx, link_work.work); struct ntb_dev *ndev = nt->ndev; struct pci_dev *pdev = ndev->pdev; resource_size_t size; u32 val; int rc, i, spad; /* 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 && size > max_mw_size) size = max_mw_size; spad = MW0_SZ_HIGH + (i * 2); ntb_peer_spad_write(ndev, spad, (u32)(size >> 32)); spad = MW0_SZ_LOW + (i * 2); ntb_peer_spad_write(ndev, spad, (u32)size); } ntb_peer_spad_write(ndev, NUM_MWS, nt->mw_count); ntb_peer_spad_write(ndev, NUM_QPS, nt->qp_count); ntb_peer_spad_write(ndev, VERSION, NTB_TRANSPORT_VERSION); /* Query the remote side for its info */ val = ntb_spad_read(ndev, VERSION); dev_dbg(&pdev->dev, "Remote version = %d\n", val); if (val != NTB_TRANSPORT_VERSION) goto out; val = ntb_spad_read(ndev, NUM_QPS); dev_dbg(&pdev->dev, "Remote max number of qps = %d\n", val); if (val != nt->qp_count) goto out; val = ntb_spad_read(ndev, NUM_MWS); dev_dbg(&pdev->dev, "Remote number of mws = %d\n", val); if (val != nt->mw_count) goto out; for (i = 0; i < nt->mw_count; i++) { u64 val64; val = ntb_spad_read(ndev, MW0_SZ_HIGH + (i * 2)); val64 = (u64)val << 32; val = ntb_spad_read(ndev, MW0_SZ_LOW + (i * 2)); val64 |= val; dev_dbg(&pdev->dev, "Remote MW%d size = %#llx\n", i, val64); rc = ntb_set_mw(nt, i, val64); if (rc) goto out1; } nt->link_is_up = true; for (i = 0; i < nt->qp_count; i++) { struct ntb_transport_qp *qp = &nt->qp_vec[i]; ntb_transport_setup_qp_mw(nt, i); if (qp->client_ready) schedule_delayed_work(&qp->link_work, 0); } return; out1: for (i = 0; i < nt->mw_count; i++) ntb_free_mw(nt, i); out: if (ntb_link_is_up(ndev, NULL, NULL) == 1) schedule_delayed_work(&nt->link_work, msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT)); } static void ntb_qp_link_work(struct work_struct *work) { struct ntb_transport_qp *qp = container_of(work, struct ntb_transport_qp, link_work.work); struct pci_dev *pdev = qp->ndev->pdev; struct ntb_transport_ctx *nt = qp->transport; int val; WARN_ON(!nt->link_is_up); val = ntb_spad_read(nt->ndev, QP_LINKS); ntb_peer_spad_write(nt->ndev, QP_LINKS, val | BIT(qp->qp_num)); /* query remote spad for qp ready bits */ ntb_peer_spad_read(nt->ndev, QP_LINKS); dev_dbg(&pdev->dev, "Remote QP link status = %x\n", val); /* See if the remote side is up */ if (val & BIT(qp->qp_num)) { dev_info(&pdev->dev, "qp %d: Link Up\n", qp->qp_num); qp->link_is_up = true; if (qp->event_handler) qp->event_handler(qp->cb_data, qp->link_is_up); } else if (nt->link_is_up) schedule_delayed_work(&qp->link_work, msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT)); } static int ntb_transport_init_queue(struct ntb_transport_ctx *nt, unsigned int qp_num) { struct ntb_transport_qp *qp; struct ntb_transport_mw *mw; phys_addr_t mw_base; resource_size_t mw_size; unsigned int num_qps_mw, tx_size; unsigned int mw_num, mw_count, qp_count; u64 qp_offset; mw_count = nt->mw_count; qp_count = nt->qp_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->ndev = nt->ndev; qp->link_is_up = false; qp->client_ready = false; qp->event_handler = NULL; if (qp_count % mw_count && mw_num + 1 < qp_count / mw_count) num_qps_mw = qp_count / mw_count + 1; else num_qps_mw = qp_count / mw_count; mw_base = nt->mw_vec[mw_num].phys_addr; mw_size = nt->mw_vec[mw_num].phys_size; tx_size = (unsigned int)mw_size / num_qps_mw; qp_offset = tx_size * qp_num / mw_count; qp->tx_mw = nt->mw_vec[mw_num].vbase + qp_offset; if (!qp->tx_mw) return -EINVAL; qp->tx_mw_phys = mw_base + qp_offset; if (!qp->tx_mw_phys) return -EINVAL; tx_size -= sizeof(struct ntb_rx_info); qp->rx_info = qp->tx_mw + tx_size; /* Due to housekeeping, there must be atleast 2 buffs */ qp->tx_max_frame = min(transport_mtu, tx_size / 2); qp->tx_max_entry = tx_size / qp->tx_max_frame; if (nt_debugfs_dir) { char debugfs_name[4]; snprintf(debugfs_name, 4, "qp%d", qp_num); qp->debugfs_dir = debugfs_create_dir(debugfs_name, nt_debugfs_dir); qp->debugfs_stats = debugfs_create_file("stats", S_IRUSR, qp->debugfs_dir, qp, &ntb_qp_debugfs_stats); } else { qp->debugfs_dir = NULL; qp->debugfs_stats = NULL; } INIT_DELAYED_WORK(&qp->link_work, ntb_qp_link_work); INIT_WORK(&qp->link_cleanup, ntb_qp_link_cleanup_work); spin_lock_init(&qp->ntb_rx_pend_q_lock); spin_lock_init(&qp->ntb_rx_free_q_lock); spin_lock_init(&qp->ntb_tx_free_q_lock); INIT_LIST_HEAD(&qp->rx_pend_q); INIT_LIST_HEAD(&qp->rx_free_q); INIT_LIST_HEAD(&qp->tx_free_q); tasklet_init(&qp->rxc_db_work, ntb_transport_rxc_db, (unsigned long)qp); return 0; } static int ntb_transport_probe(struct ntb_client *self, struct ntb_dev *ndev) { struct ntb_transport_ctx *nt; struct ntb_transport_mw *mw; unsigned int mw_count, qp_count; u64 qp_bitmap; int rc, i; if (ntb_db_is_unsafe(ndev)) dev_dbg(&ndev->dev, "doorbell is unsafe, proceed anyway...\n"); if (ntb_spad_is_unsafe(ndev)) dev_dbg(&ndev->dev, "scratchpad is unsafe, proceed anyway...\n"); nt = kzalloc(sizeof(*nt), GFP_KERNEL); if (!nt) return -ENOMEM; nt->ndev = ndev; mw_count = ntb_mw_count(ndev); nt->mw_count = mw_count; nt->mw_vec = kcalloc(mw_count, sizeof(*nt->mw_vec), GFP_KERNEL); if (!nt->mw_vec) { rc = -ENOMEM; goto err; } for (i = 0; i < mw_count; i++) { mw = &nt->mw_vec[i]; rc = ntb_mw_get_range(ndev, i, &mw->phys_addr, &mw->phys_size, &mw->xlat_align, &mw->xlat_align_size); if (rc) goto err1; mw->vbase = ioremap(mw->phys_addr, mw->phys_size); if (!mw->vbase) { rc = -ENOMEM; goto err1; } mw->buff_size = 0; mw->xlat_size = 0; mw->virt_addr = NULL; mw->dma_addr = 0; } qp_bitmap = ntb_db_valid_mask(ndev); qp_count = ilog2(qp_bitmap); if (max_num_clients && max_num_clients < qp_count) qp_count = max_num_clients; else if (mw_count < qp_count) qp_count = mw_count; qp_bitmap &= BIT_ULL(qp_count) - 1; nt->qp_count = qp_count; nt->qp_bitmap = qp_bitmap; nt->qp_bitmap_free = qp_bitmap; nt->qp_vec = kcalloc(qp_count, sizeof(*nt->qp_vec), GFP_KERNEL); if (!nt->qp_vec) { rc = -ENOMEM; goto err2; } for (i = 0; i < qp_count; i++) { rc = ntb_transport_init_queue(nt, i); if (rc) goto err3; } INIT_DELAYED_WORK(&nt->link_work, ntb_transport_link_work); INIT_WORK(&nt->link_cleanup, ntb_transport_link_cleanup_work); rc = ntb_set_ctx(ndev, nt, &ntb_transport_ops); if (rc) goto err3; INIT_LIST_HEAD(&nt->client_devs); rc = ntb_bus_init(nt); if (rc) goto err4; nt->link_is_up = false; ntb_link_enable(ndev, NTB_SPEED_AUTO, NTB_WIDTH_AUTO); ntb_link_event(ndev); return 0; err4: ntb_clear_ctx(ndev); err3: kfree(nt->qp_vec); err2: kfree(nt->mw_vec); err1: while (i--) { mw = &nt->mw_vec[i]; iounmap(mw->vbase); } err: kfree(nt); return rc; } static void ntb_transport_free(struct ntb_client *self, struct ntb_dev *ndev) { struct ntb_transport_ctx *nt = ndev->ctx; struct ntb_transport_qp *qp; u64 qp_bitmap_alloc; int i; ntb_transport_link_cleanup(nt); cancel_work_sync(&nt->link_cleanup); cancel_delayed_work_sync(&nt->link_work); qp_bitmap_alloc = nt->qp_bitmap & ~nt->qp_bitmap_free; /* verify that all the qp's are freed */ for (i = 0; i < nt->qp_count; i++) { qp = &nt->qp_vec[i]; if (qp_bitmap_alloc & BIT_ULL(i)) ntb_transport_free_queue(qp); debugfs_remove_recursive(qp->debugfs_dir); } ntb_link_disable(ndev); ntb_clear_ctx(ndev); ntb_bus_remove(nt); for (i = nt->mw_count; i--; ) { ntb_free_mw(nt, i); iounmap(nt->mw_vec[i].vbase); } kfree(nt->qp_vec); kfree(nt->mw_vec); kfree(nt); } static void ntb_rx_copy_callback(void *data) { struct ntb_queue_entry *entry = data; struct ntb_transport_qp *qp = entry->qp; void *cb_data = entry->cb_data; unsigned int len = entry->len; struct ntb_payload_header *hdr = entry->rx_hdr; hdr->flags = 0; iowrite32(entry->index, &qp->rx_info->entry); ntb_list_add(&qp->ntb_rx_free_q_lock, &entry->entry, &qp->rx_free_q); if (qp->rx_handler && qp->client_ready) qp->rx_handler(qp, qp->cb_data, cb_data, len); } static void ntb_memcpy_rx(struct ntb_queue_entry *entry, void *offset) { void *buf = entry->buf; size_t len = entry->len; memcpy(buf, offset, len); /* Ensure that the data is fully copied out before clearing the flag */ wmb(); ntb_rx_copy_callback(entry); } static void ntb_async_rx(struct ntb_queue_entry *entry, void *offset, size_t len) { struct dma_async_tx_descriptor *txd; struct ntb_transport_qp *qp = entry->qp; struct dma_chan *chan = qp->dma_chan; struct dma_device *device; size_t pay_off, buff_off; struct dmaengine_unmap_data *unmap; dma_cookie_t cookie; void *buf = entry->buf; entry->len = len; if (!chan) goto err; if (len < copy_bytes) goto err_wait; device = chan->device; pay_off = (size_t)offset & ~PAGE_MASK; buff_off = (size_t)buf & ~PAGE_MASK; if (!is_dma_copy_aligned(device, pay_off, buff_off, len)) goto err_wait; unmap = dmaengine_get_unmap_data(device->dev, 2, GFP_NOWAIT); if (!unmap) goto err_wait; unmap->len = len; unmap->addr[0] = dma_map_page(device->dev, virt_to_page(offset), pay_off, len, DMA_TO_DEVICE); if (dma_mapping_error(device->dev, unmap->addr[0])) goto err_get_unmap; unmap->to_cnt = 1; unmap->addr[1] = dma_map_page(device->dev, virt_to_page(buf), buff_off, len, DMA_FROM_DEVICE); if (dma_mapping_error(device->dev, unmap->addr[1])) goto err_get_unmap; unmap->from_cnt = 1; txd = device->device_prep_dma_memcpy(chan, unmap->addr[1], unmap->addr[0], len, DMA_PREP_INTERRUPT); if (!txd) goto err_get_unmap; txd->callback = ntb_rx_copy_callback; txd->callback_param = entry; dma_set_unmap(txd, unmap); cookie = dmaengine_submit(txd); if (dma_submit_error(cookie)) goto err_set_unmap; dmaengine_unmap_put(unmap); qp->last_cookie = cookie; qp->rx_async++; return; err_set_unmap: dmaengine_unmap_put(unmap); err_get_unmap: dmaengine_unmap_put(unmap); err_wait: /* If the callbacks come out of order, the writing of the index to the * last completed will be out of order. This may result in the * receive stalling forever. */ dma_sync_wait(chan, qp->last_cookie); err: ntb_memcpy_rx(entry, offset); qp->rx_memcpy++; } static int ntb_process_rxc(struct ntb_transport_qp *qp) { struct ntb_payload_header *hdr; struct ntb_queue_entry *entry; void *offset; int rc; offset = qp->rx_buff + qp->rx_max_frame * qp->rx_index; hdr = offset + qp->rx_max_frame - sizeof(struct ntb_payload_header); dev_dbg(&qp->ndev->pdev->dev, "qp %d: RX ver %u len %d flags %x\n", qp->qp_num, hdr->ver, hdr->len, hdr->flags); if (!(hdr->flags & DESC_DONE_FLAG)) { dev_dbg(&qp->ndev->pdev->dev, "done flag not set\n"); qp->rx_ring_empty++; return -EAGAIN; } if (hdr->flags & LINK_DOWN_FLAG) { dev_dbg(&qp->ndev->pdev->dev, "link down flag set\n"); ntb_qp_link_down(qp); hdr->flags = 0; iowrite32(qp->rx_index, &qp->rx_info->entry); return 0; } if (hdr->ver != (u32)qp->rx_pkts) { dev_dbg(&qp->ndev->pdev->dev, "version mismatch, expected %llu - got %u\n", qp->rx_pkts, hdr->ver); qp->rx_err_ver++; return -EIO; } entry = ntb_list_rm(&qp->ntb_rx_pend_q_lock, &qp->rx_pend_q); if (!entry) { dev_dbg(&qp->ndev->pdev->dev, "no receive buffer\n"); qp->rx_err_no_buf++; rc = -ENOMEM; goto err; } if (hdr->len > entry->len) { dev_dbg(&qp->ndev->pdev->dev, "receive buffer overflow! Wanted %d got %d\n", hdr->len, entry->len); qp->rx_err_oflow++; rc = -EIO; goto err; } dev_dbg(&qp->ndev->pdev->dev, "RX OK index %u ver %u size %d into buf size %d\n", qp->rx_index, hdr->ver, hdr->len, entry->len); qp->rx_bytes += hdr->len; qp->rx_pkts++; entry->index = qp->rx_index; entry->rx_hdr = hdr; ntb_async_rx(entry, offset, hdr->len); qp->rx_index++; qp->rx_index %= qp->rx_max_entry; return 0; err: /* FIXME: if this syncrhonous update of the rx_index gets ahead of * asyncrhonous ntb_rx_copy_callback of previous entry, there are three * scenarios: * * 1) The peer might miss this update, but observe the update * from the memcpy completion callback. In this case, the buffer will * not be freed on the peer to be reused for a different packet. The * successful rx of a later packet would clear the condition, but the * condition could persist if several rx fail in a row. * * 2) The peer may observe this update before the asyncrhonous copy of * prior packets is completed. The peer may overwrite the buffers of * the prior packets before they are copied. * * 3) Both: the peer may observe the update, and then observe the index * decrement by the asynchronous completion callback. Who knows what * badness that will cause. */ hdr->flags = 0; iowrite32(qp->rx_index, &qp->rx_info->entry); return rc; } static void ntb_transport_rxc_db(unsigned long data) { struct ntb_transport_qp *qp = (void *)data; int rc, i; dev_dbg(&qp->ndev->pdev->dev, "%s: doorbell %d received\n", __func__, qp->qp_num); /* Limit the number of packets processed in a single interrupt to * provide fairness to others */ for (i = 0; i < qp->rx_max_entry; i++) { rc = ntb_process_rxc(qp); if (rc) break; } if (qp->dma_chan) dma_async_issue_pending(qp->dma_chan); if (i == qp->rx_max_entry) { /* there is more work to do */ tasklet_schedule(&qp->rxc_db_work); } else if (ntb_db_read(qp->ndev) & BIT_ULL(qp->qp_num)) { /* the doorbell bit is set: clear it */ ntb_db_clear(qp->ndev, BIT_ULL(qp->qp_num)); /* ntb_db_read ensures ntb_db_clear write is committed */ ntb_db_read(qp->ndev); /* an interrupt may have arrived between finishing * ntb_process_rxc and clearing the doorbell bit: * there might be some more work to do. */ tasklet_schedule(&qp->rxc_db_work); } } 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 __iomem *hdr = entry->tx_hdr; iowrite32(entry->flags | DESC_DONE_FLAG, &hdr->flags); ntb_peer_db_set(qp->ndev, BIT_ULL(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->cb_data, entry->len); } ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry, &qp->tx_free_q); } static void ntb_memcpy_tx(struct ntb_queue_entry *entry, void __iomem *offset) { memcpy_toio(offset, entry->buf, entry->len); /* Ensure that the data is fully copied out 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 __iomem *hdr; struct dma_async_tx_descriptor *txd; struct dma_chan *chan = qp->dma_chan; struct dma_device *device; size_t dest_off, buff_off; struct dmaengine_unmap_data *unmap; dma_addr_t dest; dma_cookie_t cookie; void __iomem *offset; size_t len = entry->len; void *buf = entry->buf; offset = qp->tx_mw + qp->tx_max_frame * qp->tx_index; hdr = offset + qp->tx_max_frame - sizeof(struct ntb_payload_header); entry->tx_hdr = hdr; iowrite32(entry->len, &hdr->len); iowrite32((u32)qp->tx_pkts, &hdr->ver); if (!chan) goto err; if (len < copy_bytes) goto err; device = chan->device; dest = qp->tx_mw_phys + qp->tx_max_frame * qp->tx_index; buff_off = (size_t)buf & ~PAGE_MASK; dest_off = (size_t)dest & ~PAGE_MASK; if (!is_dma_copy_aligned(device, buff_off, dest_off, len)) goto err; unmap = dmaengine_get_unmap_data(device->dev, 1, GFP_NOWAIT); if (!unmap) goto err; unmap->len = len; unmap->addr[0] = dma_map_page(device->dev, virt_to_page(buf), buff_off, len, DMA_TO_DEVICE); if (dma_mapping_error(device->dev, unmap->addr[0])) goto err_get_unmap; unmap->to_cnt = 1; txd = device->device_prep_dma_memcpy(chan, dest, unmap->addr[0], len, DMA_PREP_INTERRUPT); if (!txd) goto err_get_unmap; txd->callback = ntb_tx_copy_callback; txd->callback_param = entry; dma_set_unmap(txd, unmap); cookie = dmaengine_submit(txd); if (dma_submit_error(cookie)) goto err_set_unmap; dmaengine_unmap_put(unmap); dma_async_issue_pending(chan); qp->tx_async++; return; err_set_unmap: dmaengine_unmap_put(unmap); err_get_unmap: dmaengine_unmap_put(unmap); err: ntb_memcpy_tx(entry, offset); qp->tx_memcpy++; } static int ntb_process_tx(struct ntb_transport_qp *qp, struct ntb_queue_entry *entry) { if (qp->tx_index == qp->remote_rx_info->entry) { qp->tx_ring_full++; return -EAGAIN; } if (entry->len > qp->tx_max_frame - sizeof(struct ntb_payload_header)) { if (qp->tx_handler) qp->tx_handler(qp->cb_data, qp, NULL, -EIO); ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry, &qp->tx_free_q); return 0; } ntb_async_tx(qp, entry); qp->tx_index++; qp->tx_index %= qp->tx_max_entry; qp->tx_pkts++; return 0; } static void ntb_send_link_down(struct ntb_transport_qp *qp) { struct pci_dev *pdev = qp->ndev->pdev; struct ntb_queue_entry *entry; int i, rc; if (!qp->link_is_up) return; qp->link_is_up = false; dev_info(&pdev->dev, "qp %d: Send Link Down\n", qp->qp_num); 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) break; msleep(100); } if (!entry) return; entry->cb_data = NULL; entry->buf = NULL; entry->len = 0; entry->flags = LINK_DOWN_FLAG; rc = ntb_process_tx(qp, entry); if (rc) dev_err(&pdev->dev, "ntb: QP%d unable to send linkdown msg\n", 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(void *data, struct device *client_dev, const struct ntb_queue_handlers *handlers) { struct ntb_dev *ndev; struct pci_dev *pdev; struct ntb_transport_ctx *nt; struct ntb_queue_entry *entry; struct ntb_transport_qp *qp; u64 qp_bit; unsigned int free_queue; int i; ndev = dev_ntb(client_dev->parent); pdev = ndev->pdev; nt = ndev->ctx; free_queue = ffs(nt->qp_bitmap); if (!free_queue) goto err; /* decrement free_queue to make it zero based */ free_queue--; qp = &nt->qp_vec[free_queue]; qp_bit = BIT_ULL(qp->qp_num); nt->qp_bitmap_free &= ~qp_bit; qp->cb_data = data; qp->rx_handler = handlers->rx_handler; qp->tx_handler = handlers->tx_handler; qp->event_handler = handlers->event_handler; dmaengine_get(); qp->dma_chan = dma_find_channel(DMA_MEMCPY); if (!qp->dma_chan) { dmaengine_put(); dev_info(&pdev->dev, "Unable to allocate DMA channel, using CPU instead\n"); } for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) { entry = kzalloc(sizeof(*entry), GFP_ATOMIC); if (!entry) goto err1; entry->qp = qp; ntb_list_add(&qp->ntb_rx_free_q_lock, &entry->entry, &qp->rx_free_q); } for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) { entry = kzalloc(sizeof(*entry), GFP_ATOMIC); if (!entry) goto err2; entry->qp = qp; ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry, &qp->tx_free_q); } ntb_db_clear(qp->ndev, qp_bit); ntb_db_clear_mask(qp->ndev, qp_bit); dev_info(&pdev->dev, "NTB Transport QP %d created\n", qp->qp_num); return qp; err2: while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q))) kfree(entry); err1: while ((entry = ntb_list_rm(&qp->ntb_rx_free_q_lock, &qp->rx_free_q))) kfree(entry); if (qp->dma_chan) dmaengine_put(); nt->qp_bitmap_free |= qp_bit; err: return NULL; } EXPORT_SYMBOL_GPL(ntb_transport_create_queue); /** * ntb_transport_free_queue - Frees NTB transport queue * @qp: NTB queue to be freed * * Frees NTB transport queue */ void ntb_transport_free_queue(struct ntb_transport_qp *qp) { struct ntb_transport_ctx *nt = qp->transport; struct pci_dev *pdev; struct ntb_queue_entry *entry; u64 qp_bit; if (!qp) return; pdev = qp->ndev->pdev; if (qp->dma_chan) { struct dma_chan *chan = qp->dma_chan; /* Putting the dma_chan to NULL will force any new traffic to be * processed by the CPU instead of the DAM engine */ qp->dma_chan = NULL; /* Try to be nice and wait for any queued DMA engine * transactions to process before smashing it with a rock */ dma_sync_wait(chan, qp->last_cookie); dmaengine_terminate_all(chan); dmaengine_put(); } qp_bit = BIT_ULL(qp->qp_num); ntb_db_set_mask(qp->ndev, qp_bit); tasklet_disable(&qp->rxc_db_work); cancel_delayed_work_sync(&qp->link_work); qp->cb_data = NULL; qp->rx_handler = NULL; qp->tx_handler = NULL; qp->event_handler = NULL; while ((entry = ntb_list_rm(&qp->ntb_rx_free_q_lock, &qp->rx_free_q))) kfree(entry); while ((entry = ntb_list_rm(&qp->ntb_rx_pend_q_lock, &qp->rx_pend_q))) { dev_warn(&pdev->dev, "Freeing item from a non-empty queue\n"); kfree(entry); } while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q))) kfree(entry); nt->qp_bitmap_free |= qp_bit; dev_info(&pdev->dev, "NTB Transport QP %d freed\n", qp->qp_num); } EXPORT_SYMBOL_GPL(ntb_transport_free_queue); /** * ntb_transport_rx_remove - Dequeues enqueued rx packet * @qp: NTB queue to be freed * @len: pointer to variable to write enqueued buffers length * * Dequeues unused buffers from receive queue. Should only be used during * shutdown of qp. * * RETURNS: NULL error value on error, or void* for success. */ void *ntb_transport_rx_remove(struct ntb_transport_qp *qp, unsigned int *len) { struct ntb_queue_entry *entry; void *buf; if (!qp || qp->client_ready) return NULL; entry = ntb_list_rm(&qp->ntb_rx_pend_q_lock, &qp->rx_pend_q); if (!entry) return NULL; buf = entry->cb_data; *len = entry->len; ntb_list_add(&qp->ntb_rx_free_q_lock, &entry->entry, &qp->rx_free_q); return buf; } EXPORT_SYMBOL_GPL(ntb_transport_rx_remove); /** * ntb_transport_rx_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 incoming packets will be copied into * @len: length of the data buffer * * Enqueue a new receive buffer onto the transport queue into which a NTB * payload can be received into. * * RETURNS: An appropriate -ERRNO error value on error, or zero for success. */ int ntb_transport_rx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data, unsigned int len) { struct ntb_queue_entry *entry; if (!qp) return -EINVAL; entry = ntb_list_rm(&qp->ntb_rx_free_q_lock, &qp->rx_free_q); if (!entry) return -ENOMEM; entry->cb_data = cb; entry->buf = data; entry->len = len; ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry, &qp->rx_pend_q); return 0; } EXPORT_SYMBOL_GPL(ntb_transport_rx_enqueue); /** * 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 || !qp->link_is_up || !len) return -EINVAL; entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q); if (!entry) { qp->tx_err_no_buf++; return -ENOMEM; } entry->cb_data = cb; entry->buf = data; entry->len = len; entry->flags = 0; rc = ntb_process_tx(qp, entry); if (rc) ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry, &qp->tx_free_q); return rc; } EXPORT_SYMBOL_GPL(ntb_transport_tx_enqueue); /** * 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) { if (!qp) return; qp->client_ready = true; if (qp->transport->link_is_up) schedule_delayed_work(&qp->link_work, 0); } EXPORT_SYMBOL_GPL(ntb_transport_link_up); /** * 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 pci_dev *pdev; int val; if (!qp) return; pdev = qp->ndev->pdev; qp->client_ready = false; val = ntb_spad_read(qp->ndev, QP_LINKS); ntb_peer_spad_write(qp->ndev, QP_LINKS, val & ~BIT(qp->qp_num)); if (qp->link_is_up) ntb_send_link_down(qp); else cancel_delayed_work_sync(&qp->link_work); } EXPORT_SYMBOL_GPL(ntb_transport_link_down); /** * 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) return false; return qp->link_is_up; } EXPORT_SYMBOL_GPL(ntb_transport_link_query); /** * 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) return 0; return qp->qp_num; } EXPORT_SYMBOL_GPL(ntb_transport_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) { unsigned int max; if (!qp) return 0; if (!qp->dma_chan) return qp->tx_max_frame - sizeof(struct ntb_payload_header); /* If DMA engine usage is possible, try to find the max size for that */ max = qp->tx_max_frame - sizeof(struct ntb_payload_header); max -= max % (1 << qp->dma_chan->device->copy_align); return max; } EXPORT_SYMBOL_GPL(ntb_transport_max_size); static void ntb_transport_doorbell_callback(void *data, int vector) { struct ntb_transport_ctx *nt = data; struct ntb_transport_qp *qp; u64 db_bits; unsigned int qp_num; db_bits = (nt->qp_bitmap & ~nt->qp_bitmap_free & ntb_db_vector_mask(nt->ndev, vector)); while (db_bits) { qp_num = __ffs(db_bits); qp = &nt->qp_vec[qp_num]; tasklet_schedule(&qp->rxc_db_work); db_bits &= ~BIT_ULL(qp_num); } } static const struct ntb_ctx_ops ntb_transport_ops = { .link_event = ntb_transport_event_callback, .db_event = ntb_transport_doorbell_callback, }; static struct ntb_client ntb_transport_client = { .ops = { .probe = ntb_transport_probe, .remove = ntb_transport_free, }, }; static int __init ntb_transport_init(void) { int rc; if (debugfs_initialized()) nt_debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL); rc = bus_register(&ntb_transport_bus); if (rc) goto err_bus; rc = ntb_register_client(&ntb_transport_client); if (rc) goto err_client; return 0; err_client: bus_unregister(&ntb_transport_bus); err_bus: debugfs_remove_recursive(nt_debugfs_dir); return rc; } module_init(ntb_transport_init); static void __exit ntb_transport_exit(void) { debugfs_remove_recursive(nt_debugfs_dir); ntb_unregister_client(&ntb_transport_client); bus_unregister(&ntb_transport_bus); } module_exit(ntb_transport_exit);