diff options
Diffstat (limited to 'drivers/ntb/ntb_transport.c')
| -rw-r--r-- | drivers/ntb/ntb_transport.c | 2507 |
1 files changed, 2507 insertions, 0 deletions
diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c new file mode 100644 index 0000000000..f9e7847a37 --- /dev/null +++ b/drivers/ntb/ntb_transport.c @@ -0,0 +1,2507 @@ +/* + * 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 <jon.mason@intel.com> + */ +#include <linux/debugfs.h> +#include <linux/delay.h> +#include <linux/dmaengine.h> +#include <linux/dma-mapping.h> +#include <linux/errno.h> +#include <linux/export.h> +#include <linux/interrupt.h> +#include <linux/module.h> +#include <linux/pci.h> +#include <linux/slab.h> +#include <linux/types.h> +#include <linux/uaccess.h> +#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" +#define NTB_TRANSPORT_MIN_SPADS (MW0_SZ_HIGH + 2) + +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 = 0x10000; +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 bool use_dma; +module_param(use_dma, bool, 0644); +MODULE_PARM_DESC(use_dma, "Use DMA engine to perform large data copy"); + +static bool use_msi; +#ifdef CONFIG_NTB_MSI +module_param(use_msi, bool, 0644); +MODULE_PARM_DESC(use_msi, "Use MSI interrupts instead of doorbells"); +#endif + +static struct dentry *nt_debugfs_dir; + +/* Only two-ports NTB devices are supported */ +#define PIDX NTB_DEF_PEER_IDX + +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; + int retries; + int errors; + unsigned int tx_index; + unsigned int rx_index; + + struct ntb_transport_qp *qp; + union { + struct ntb_payload_header __iomem *tx_hdr; + struct ntb_payload_header *rx_hdr; + }; +}; + +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 *tx_dma_chan; + struct dma_chan *rx_dma_chan; + + bool client_ready; + bool link_is_up; + bool active; + + 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; + phys_addr_t tx_mw_phys; + size_t tx_mw_size; + dma_addr_t tx_mw_dma_addr; + 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_post_q; + struct list_head rx_pend_q; + struct list_head rx_free_q; + /* ntb_rx_q_lock: synchronize access to rx_XXXX_q */ + spinlock_t ntb_rx_q_lock; + void *rx_buff; + unsigned int rx_index; + unsigned int rx_max_entry; + unsigned int rx_max_frame; + unsigned int rx_alloc_entry; + 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; + + bool use_msi; + int msi_irq; + struct ntb_msi_desc msi_desc; + struct ntb_msi_desc peer_msi_desc; +}; + +struct ntb_transport_mw { + phys_addr_t phys_addr; + resource_size_t phys_size; + void __iomem *vbase; + size_t xlat_size; + size_t buff_size; + size_t alloc_size; + void *alloc_addr; + 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 use_msi; + unsigned int msi_spad_offset; + u64 msi_db_mask; + + bool link_is_up; + struct delayed_work link_work; + struct work_struct link_cleanup; + + struct dentry *debugfs_node_dir; +}; + +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, +}; + +#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_async_tx_submit(struct ntb_transport_qp *qp, + struct ntb_queue_entry *entry); +static void ntb_memcpy_tx(struct ntb_queue_entry *entry, void __iomem *offset); +static int ntb_async_rx_submit(struct ntb_queue_entry *entry, void *offset); +static void ntb_memcpy_rx(struct ntb_queue_entry *entry, void *offset); + + +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; + + get_device(dev); + + client = drv_client(dev->driver); + rc = client->probe(dev); + if (rc) + put_device(dev); + + return rc; +} + +static void ntb_transport_bus_remove(struct device *dev) +{ + const struct ntb_transport_client *client; + + client = drv_client(dev->driver); + client->remove(dev); + + put_device(dev); +} + +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_tail(&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 node; + int rc, i = 0; + + if (list_empty(&ntb_transport_list)) + return -ENODEV; + + list_for_each_entry(nt, &ntb_transport_list, entry) { + struct device *dev; + + node = dev_to_node(&nt->ndev->dev); + + client_dev = kzalloc_node(sizeof(*client_dev), + GFP_KERNEL, node); + 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) { + put_device(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; + + qp = filp->private_data; + + if (!qp || !qp->link_is_up) + return 0; + + out_count = 1000; + + buf = kmalloc(out_count, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + out_offset = 0; + out_offset += scnprintf(buf + out_offset, out_count - out_offset, + "\nNTB QP stats:\n\n"); + out_offset += scnprintf(buf + out_offset, out_count - out_offset, + "rx_bytes - \t%llu\n", qp->rx_bytes); + out_offset += scnprintf(buf + out_offset, out_count - out_offset, + "rx_pkts - \t%llu\n", qp->rx_pkts); + out_offset += scnprintf(buf + out_offset, out_count - out_offset, + "rx_memcpy - \t%llu\n", qp->rx_memcpy); + out_offset += scnprintf(buf + out_offset, out_count - out_offset, + "rx_async - \t%llu\n", qp->rx_async); + out_offset += scnprintf(buf + out_offset, out_count - out_offset, + "rx_ring_empty - %llu\n", qp->rx_ring_empty); + out_offset += scnprintf(buf + out_offset, out_count - out_offset, + "rx_err_no_buf - %llu\n", qp->rx_err_no_buf); + out_offset += scnprintf(buf + out_offset, out_count - out_offset, + "rx_err_oflow - \t%llu\n", qp->rx_err_oflow); + out_offset += scnprintf(buf + out_offset, out_count - out_offset, + "rx_err_ver - \t%llu\n", qp->rx_err_ver); + out_offset += scnprintf(buf + out_offset, out_count - out_offset, + "rx_buff - \t0x%p\n", qp->rx_buff); + out_offset += scnprintf(buf + out_offset, out_count - out_offset, + "rx_index - \t%u\n", qp->rx_index); + out_offset += scnprintf(buf + out_offset, out_count - out_offset, + "rx_max_entry - \t%u\n", qp->rx_max_entry); + out_offset += scnprintf(buf + out_offset, out_count - out_offset, + "rx_alloc_entry - \t%u\n\n", qp->rx_alloc_entry); + + out_offset += scnprintf(buf + out_offset, out_count - out_offset, + "tx_bytes - \t%llu\n", qp->tx_bytes); + out_offset += scnprintf(buf + out_offset, out_count - out_offset, + "tx_pkts - \t%llu\n", qp->tx_pkts); + out_offset += scnprintf(buf + out_offset, out_count - out_offset, + "tx_memcpy - \t%llu\n", qp->tx_memcpy); + out_offset += scnprintf(buf + out_offset, out_count - out_offset, + "tx_async - \t%llu\n", qp->tx_async); + out_offset += scnprintf(buf + out_offset, out_count - out_offset, + "tx_ring_full - \t%llu\n", qp->tx_ring_full); + out_offset += scnprintf(buf + out_offset, out_count - out_offset, + "tx_err_no_buf - %llu\n", qp->tx_err_no_buf); + out_offset += scnprintf(buf + out_offset, out_count - out_offset, + "tx_mw - \t0x%p\n", qp->tx_mw); + out_offset += scnprintf(buf + out_offset, out_count - out_offset, + "tx_index (H) - \t%u\n", qp->tx_index); + out_offset += scnprintf(buf + out_offset, out_count - out_offset, + "RRI (T) - \t%u\n", + qp->remote_rx_info->entry); + out_offset += scnprintf(buf + out_offset, out_count - out_offset, + "tx_max_entry - \t%u\n", qp->tx_max_entry); + out_offset += scnprintf(buf + out_offset, out_count - out_offset, + "free tx - \t%u\n", + ntb_transport_tx_free_entry(qp)); + + out_offset += scnprintf(buf + out_offset, out_count - out_offset, + "\n"); + out_offset += scnprintf(buf + out_offset, out_count - out_offset, + "Using TX DMA - \t%s\n", + qp->tx_dma_chan ? "Yes" : "No"); + out_offset += scnprintf(buf + out_offset, out_count - out_offset, + "Using RX DMA - \t%s\n", + qp->rx_dma_chan ? "Yes" : "No"); + out_offset += scnprintf(buf + out_offset, out_count - out_offset, + "QP Link - \t%s\n", + qp->link_is_up ? "Up" : "Down"); + out_offset += scnprintf(buf + out_offset, out_count - out_offset, + "\n"); + + 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 struct ntb_queue_entry *ntb_list_mv(spinlock_t *lock, + struct list_head *list, + struct list_head *to_list) +{ + struct ntb_queue_entry *entry; + unsigned long flags; + + spin_lock_irqsave(lock, flags); + + if (list_empty(list)) { + entry = NULL; + } else { + entry = list_first_entry(list, struct ntb_queue_entry, entry); + list_move_tail(&entry->entry, to_list); + } + + 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; + struct ntb_dev *ndev = nt->ndev; + struct ntb_queue_entry *entry; + unsigned int rx_size, num_qps_mw; + unsigned int mw_num, mw_count, qp_count; + unsigned int i; + int node; + + 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 (mw_num < 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; + + /* + * Checking to see if we have more entries than the default. + * We should add additional entries if that is the case so we + * can be in sync with the transport frames. + */ + node = dev_to_node(&ndev->dev); + for (i = qp->rx_alloc_entry; i < qp->rx_max_entry; i++) { + entry = kzalloc_node(sizeof(*entry), GFP_KERNEL, node); + if (!entry) + return -ENOMEM; + + entry->qp = qp; + ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry, + &qp->rx_free_q); + qp->rx_alloc_entry++; + } + + 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 irqreturn_t ntb_transport_isr(int irq, void *dev) +{ + struct ntb_transport_qp *qp = dev; + + tasklet_schedule(&qp->rxc_db_work); + + return IRQ_HANDLED; +} + +static void ntb_transport_setup_qp_peer_msi(struct ntb_transport_ctx *nt, + unsigned int qp_num) +{ + struct ntb_transport_qp *qp = &nt->qp_vec[qp_num]; + int spad = qp_num * 2 + nt->msi_spad_offset; + + if (!nt->use_msi) + return; + + if (spad >= ntb_spad_count(nt->ndev)) + return; + + qp->peer_msi_desc.addr_offset = + ntb_peer_spad_read(qp->ndev, PIDX, spad); + qp->peer_msi_desc.data = + ntb_peer_spad_read(qp->ndev, PIDX, spad + 1); + + dev_dbg(&qp->ndev->pdev->dev, "QP%d Peer MSI addr=%x data=%x\n", + qp_num, qp->peer_msi_desc.addr_offset, qp->peer_msi_desc.data); + + if (qp->peer_msi_desc.addr_offset) { + qp->use_msi = true; + dev_info(&qp->ndev->pdev->dev, + "Using MSI interrupts for QP%d\n", qp_num); + } +} + +static void ntb_transport_setup_qp_msi(struct ntb_transport_ctx *nt, + unsigned int qp_num) +{ + struct ntb_transport_qp *qp = &nt->qp_vec[qp_num]; + int spad = qp_num * 2 + nt->msi_spad_offset; + int rc; + + if (!nt->use_msi) + return; + + if (spad >= ntb_spad_count(nt->ndev)) { + dev_warn_once(&qp->ndev->pdev->dev, + "Not enough SPADS to use MSI interrupts\n"); + return; + } + + ntb_spad_write(qp->ndev, spad, 0); + ntb_spad_write(qp->ndev, spad + 1, 0); + + if (!qp->msi_irq) { + qp->msi_irq = ntbm_msi_request_irq(qp->ndev, ntb_transport_isr, + KBUILD_MODNAME, qp, + &qp->msi_desc); + if (qp->msi_irq < 0) { + dev_warn(&qp->ndev->pdev->dev, + "Unable to allocate MSI interrupt for qp%d\n", + qp_num); + return; + } + } + + rc = ntb_spad_write(qp->ndev, spad, qp->msi_desc.addr_offset); + if (rc) + goto err_free_interrupt; + + rc = ntb_spad_write(qp->ndev, spad + 1, qp->msi_desc.data); + if (rc) + goto err_free_interrupt; + + dev_dbg(&qp->ndev->pdev->dev, "QP%d MSI %d addr=%x data=%x\n", + qp_num, qp->msi_irq, qp->msi_desc.addr_offset, + qp->msi_desc.data); + + return; + +err_free_interrupt: + devm_free_irq(&nt->ndev->dev, qp->msi_irq, qp); +} + +static void ntb_transport_msi_peer_desc_changed(struct ntb_transport_ctx *nt) +{ + int i; + + dev_dbg(&nt->ndev->pdev->dev, "Peer MSI descriptors changed"); + + for (i = 0; i < nt->qp_count; i++) + ntb_transport_setup_qp_peer_msi(nt, i); +} + +static void ntb_transport_msi_desc_changed(void *data) +{ + struct ntb_transport_ctx *nt = data; + int i; + + dev_dbg(&nt->ndev->pdev->dev, "MSI descriptors changed"); + + for (i = 0; i < nt->qp_count; i++) + ntb_transport_setup_qp_msi(nt, i); + + ntb_peer_db_set(nt->ndev, nt->msi_db_mask); +} + +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, PIDX, num_mw); + dma_free_coherent(&pdev->dev, mw->alloc_size, + mw->alloc_addr, mw->dma_addr); + mw->xlat_size = 0; + mw->buff_size = 0; + mw->alloc_size = 0; + mw->alloc_addr = NULL; + mw->virt_addr = NULL; +} + +static int ntb_alloc_mw_buffer(struct ntb_transport_mw *mw, + struct device *dma_dev, size_t align) +{ + dma_addr_t dma_addr; + void *alloc_addr, *virt_addr; + int rc; + + alloc_addr = dma_alloc_coherent(dma_dev, mw->alloc_size, + &dma_addr, GFP_KERNEL); + if (!alloc_addr) { + dev_err(dma_dev, "Unable to alloc MW buff of size %zu\n", + mw->alloc_size); + return -ENOMEM; + } + virt_addr = alloc_addr; + + /* + * 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(dma_addr, align)) { + if (mw->alloc_size > mw->buff_size) { + virt_addr = PTR_ALIGN(alloc_addr, align); + dma_addr = ALIGN(dma_addr, align); + } else { + rc = -ENOMEM; + goto err; + } + } + + mw->alloc_addr = alloc_addr; + mw->virt_addr = virt_addr; + mw->dma_addr = dma_addr; + + return 0; + +err: + dma_free_coherent(dma_dev, mw->alloc_size, alloc_addr, dma_addr); + + return rc; +} + +static int ntb_set_mw(struct ntb_transport_ctx *nt, int num_mw, + resource_size_t size) +{ + struct ntb_transport_mw *mw = &nt->mw_vec[num_mw]; + struct pci_dev *pdev = nt->ndev->pdev; + size_t xlat_size, buff_size; + resource_size_t xlat_align; + resource_size_t xlat_align_size; + int rc; + + if (!size) + return -EINVAL; + + rc = ntb_mw_get_align(nt->ndev, PIDX, num_mw, &xlat_align, + &xlat_align_size, NULL); + if (rc) + return rc; + + xlat_size = round_up(size, xlat_align_size); + buff_size = round_up(size, 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->alloc_size = buff_size; + + rc = ntb_alloc_mw_buffer(mw, &pdev->dev, xlat_align); + if (rc) { + mw->alloc_size *= 2; + rc = ntb_alloc_mw_buffer(mw, &pdev->dev, xlat_align); + if (rc) { + dev_err(&pdev->dev, + "Unable to alloc aligned MW buff\n"); + mw->xlat_size = 0; + mw->buff_size = 0; + mw->alloc_size = 0; + return rc; + } + } + + /* Notify HW the memory location of the receive buffer */ + rc = ntb_mw_set_trans(nt->ndev, PIDX, 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_context_reset(struct ntb_transport_qp *qp) +{ + qp->link_is_up = false; + qp->active = false; + + qp->tx_index = 0; + qp->rx_index = 0; + qp->rx_bytes = 0; + qp->rx_pkts = 0; + qp->rx_ring_empty = 0; + qp->rx_err_no_buf = 0; + qp->rx_err_oflow = 0; + qp->rx_err_ver = 0; + qp->rx_memcpy = 0; + qp->rx_async = 0; + qp->tx_bytes = 0; + qp->tx_pkts = 0; + qp->tx_ring_full = 0; + qp->tx_err_no_buf = 0; + qp->tx_memcpy = 0; + qp->tx_async = 0; +} + +static void ntb_qp_link_down_reset(struct ntb_transport_qp *qp) +{ + ntb_qp_link_context_reset(qp); + if (qp->remote_rx_info) + qp->remote_rx_info->entry = qp->rx_max_entry - 1; +} + +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; + + dev_info(&pdev->dev, "qp %d: Link Cleanup\n", qp->qp_num); + + cancel_delayed_work_sync(&qp->link_work); + ntb_qp_link_down_reset(qp); + + 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; + unsigned int i, count; + + 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); + + for (i = 0; i < nt->mw_count; i++) + ntb_free_mw(nt, i); + + /* 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 + */ + count = ntb_spad_count(nt->ndev); + for (i = 0; i < count; 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 = 0, i, spad; + + /* send the local info, in the opposite order of the way we read it */ + + if (nt->use_msi) { + rc = ntb_msi_setup_mws(ndev); + if (rc) { + dev_warn(&pdev->dev, + "Failed to register MSI memory window: %d\n", + rc); + nt->use_msi = false; + } + } + + for (i = 0; i < nt->qp_count; i++) + ntb_transport_setup_qp_msi(nt, i); + + 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, PIDX, spad, upper_32_bits(size)); + + spad = MW0_SZ_LOW + (i * 2); + ntb_peer_spad_write(ndev, PIDX, spad, lower_32_bits(size)); + } + + ntb_peer_spad_write(ndev, PIDX, NUM_MWS, nt->mw_count); + + ntb_peer_spad_write(ndev, PIDX, NUM_QPS, nt->qp_count); + + ntb_peer_spad_write(ndev, PIDX, 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); + ntb_transport_setup_qp_peer_msi(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); + + /* if there's an actual failure, we should just bail */ + if (rc < 0) + return; + +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, PIDX, QP_LINKS, val | BIT(qp->qp_num)); + + /* query remote spad for qp ready bits */ + dev_dbg_ratelimited(&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; + qp->active = true; + + if (qp->event_handler) + qp->event_handler(qp->cb_data, qp->link_is_up); + + if (qp->active) + tasklet_schedule(&qp->rxc_db_work); + } 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; + 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); + + qp = &nt->qp_vec[qp_num]; + qp->qp_num = qp_num; + qp->transport = nt; + qp->ndev = nt->ndev; + qp->client_ready = false; + qp->event_handler = NULL; + ntb_qp_link_context_reset(qp); + + if (mw_num < 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; + + if (max_mw_size && mw_size > max_mw_size) + mw_size = max_mw_size; + + tx_size = (unsigned int)mw_size / num_qps_mw; + qp_offset = tx_size * (qp_num / mw_count); + + qp->tx_mw_size = tx_size; + 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_node_dir) { + char debugfs_name[4]; + + snprintf(debugfs_name, 4, "qp%d", qp_num); + qp->debugfs_dir = debugfs_create_dir(debugfs_name, + nt->debugfs_node_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_q_lock); + spin_lock_init(&qp->ntb_tx_free_q_lock); + + INIT_LIST_HEAD(&qp->rx_post_q); + 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, spad_count, max_mw_count_for_spads; + u64 qp_bitmap; + int node; + int rc, i; + + mw_count = ntb_peer_mw_count(ndev); + + if (!ndev->ops->mw_set_trans) { + dev_err(&ndev->dev, "Inbound MW based NTB API is required\n"); + return -EINVAL; + } + + 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"); + + if (ntb_peer_port_count(ndev) != NTB_DEF_PEER_CNT) + dev_warn(&ndev->dev, "Multi-port NTB devices unsupported\n"); + + node = dev_to_node(&ndev->dev); + + nt = kzalloc_node(sizeof(*nt), GFP_KERNEL, node); + if (!nt) + return -ENOMEM; + + nt->ndev = ndev; + + /* + * If we are using MSI, and have at least one extra memory window, + * we will reserve the last MW for the MSI window. + */ + if (use_msi && mw_count > 1) { + rc = ntb_msi_init(ndev, ntb_transport_msi_desc_changed); + if (!rc) { + mw_count -= 1; + nt->use_msi = true; + } + } + + spad_count = ntb_spad_count(ndev); + + /* Limit the MW's based on the availability of scratchpads */ + + if (spad_count < NTB_TRANSPORT_MIN_SPADS) { + nt->mw_count = 0; + rc = -EINVAL; + goto err; + } + + max_mw_count_for_spads = (spad_count - MW0_SZ_HIGH) / 2; + nt->mw_count = min(mw_count, max_mw_count_for_spads); + + nt->msi_spad_offset = nt->mw_count * 2 + MW0_SZ_HIGH; + + nt->mw_vec = kcalloc_node(mw_count, sizeof(*nt->mw_vec), + GFP_KERNEL, node); + if (!nt->mw_vec) { + rc = -ENOMEM; + goto err; + } + + for (i = 0; i < mw_count; i++) { + mw = &nt->mw_vec[i]; + + rc = ntb_peer_mw_get_addr(ndev, i, &mw->phys_addr, + &mw->phys_size); + if (rc) + goto err1; + + mw->vbase = ioremap_wc(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 (nt->use_msi) { + qp_count -= 1; + nt->msi_db_mask = 1 << qp_count; + ntb_db_clear_mask(ndev, nt->msi_db_mask); + } + + if (max_num_clients && max_num_clients < qp_count) + qp_count = max_num_clients; + else if (nt->mw_count < qp_count) + qp_count = nt->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_node(qp_count, sizeof(*nt->qp_vec), + GFP_KERNEL, node); + if (!nt->qp_vec) { + rc = -ENOMEM; + goto err1; + } + + if (nt_debugfs_dir) { + nt->debugfs_node_dir = + debugfs_create_dir(pci_name(ndev->pdev), + nt_debugfs_dir); + } + + for (i = 0; i < qp_count; i++) { + rc = ntb_transport_init_queue(nt, i); + if (rc) + goto err2; + } + + 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 err2; + + INIT_LIST_HEAD(&nt->client_devs); + rc = ntb_bus_init(nt); + if (rc) + goto err3; + + nt->link_is_up = false; + ntb_link_enable(ndev, NTB_SPEED_AUTO, NTB_WIDTH_AUTO); + ntb_link_event(ndev); + + return 0; + +err3: + ntb_clear_ctx(ndev); +err2: + kfree(nt->qp_vec); +err1: + while (i--) { + mw = &nt->mw_vec[i]; + iounmap(mw->vbase); + } + kfree(nt->mw_vec); +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_complete_rxc(struct ntb_transport_qp *qp) +{ + struct ntb_queue_entry *entry; + void *cb_data; + unsigned int len; + unsigned long irqflags; + + spin_lock_irqsave(&qp->ntb_rx_q_lock, irqflags); + + while (!list_empty(&qp->rx_post_q)) { + entry = list_first_entry(&qp->rx_post_q, + struct ntb_queue_entry, entry); + if (!(entry->flags & DESC_DONE_FLAG)) + break; + + entry->rx_hdr->flags = 0; + iowrite32(entry->rx_index, &qp->rx_info->entry); + + cb_data = entry->cb_data; + len = entry->len; + + list_move_tail(&entry->entry, &qp->rx_free_q); + + spin_unlock_irqrestore(&qp->ntb_rx_q_lock, irqflags); + + if (qp->rx_handler && qp->client_ready) + qp->rx_handler(qp, qp->cb_data, cb_data, len); + + spin_lock_irqsave(&qp->ntb_rx_q_lock, irqflags); + } + + spin_unlock_irqrestore(&qp->ntb_rx_q_lock, irqflags); +} + +static void ntb_rx_copy_callback(void *data, + const struct dmaengine_result *res) +{ + struct ntb_queue_entry *entry = data; + + /* we need to check DMA results if we are using DMA */ + if (res) { + enum dmaengine_tx_result dma_err = res->result; + + switch (dma_err) { + case DMA_TRANS_READ_FAILED: + case DMA_TRANS_WRITE_FAILED: + entry->errors++; + fallthrough; + case DMA_TRANS_ABORTED: + { + struct ntb_transport_qp *qp = entry->qp; + void *offset = qp->rx_buff + qp->rx_max_frame * + qp->rx_index; + + ntb_memcpy_rx(entry, offset); + qp->rx_memcpy++; + return; + } + + case DMA_TRANS_NOERROR: + default: + break; + } + } + + entry->flags |= DESC_DONE_FLAG; + + ntb_complete_rxc(entry->qp); +} + +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, NULL); +} + +static int ntb_async_rx_submit(struct ntb_queue_entry *entry, void *offset) +{ + struct dma_async_tx_descriptor *txd; + struct ntb_transport_qp *qp = entry->qp; + struct dma_chan *chan = qp->rx_dma_chan; + struct dma_device *device; + size_t pay_off, buff_off, len; + struct dmaengine_unmap_data *unmap; + dma_cookie_t cookie; + void *buf = entry->buf; + + len = entry->len; + 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; + + unmap = dmaengine_get_unmap_data(device->dev, 2, GFP_NOWAIT); + if (!unmap) + goto err; + + 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_result = 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 0; + +err_set_unmap: + dmaengine_unmap_put(unmap); +err_get_unmap: + dmaengine_unmap_put(unmap); +err: + return -ENXIO; +} + +static void ntb_async_rx(struct ntb_queue_entry *entry, void *offset) +{ + struct ntb_transport_qp *qp = entry->qp; + struct dma_chan *chan = qp->rx_dma_chan; + int res; + + if (!chan) + goto err; + + if (entry->len < copy_bytes) + goto err; + + res = ntb_async_rx_submit(entry, offset); + if (res < 0) + goto err; + + if (!entry->retries) + qp->rx_async++; + + return; + +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; + + 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; + return -EAGAIN; + } + + 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_mv(&qp->ntb_rx_q_lock, &qp->rx_pend_q, &qp->rx_post_q); + if (!entry) { + dev_dbg(&qp->ndev->pdev->dev, "no receive buffer\n"); + qp->rx_err_no_buf++; + return -EAGAIN; + } + + entry->rx_hdr = hdr; + entry->rx_index = qp->rx_index; + + 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++; + + entry->len = -EIO; + entry->flags |= DESC_DONE_FLAG; + + ntb_complete_rxc(qp); + } else { + 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->len = hdr->len; + + ntb_async_rx(entry, offset); + } + + qp->rx_index++; + qp->rx_index %= qp->rx_max_entry; + + return 0; +} + +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 (i && qp->rx_dma_chan) + dma_async_issue_pending(qp->rx_dma_chan); + + if (i == qp->rx_max_entry) { + /* there is more work to do */ + if (qp->active) + 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. + */ + if (qp->active) + tasklet_schedule(&qp->rxc_db_work); + } +} + +static void ntb_tx_copy_callback(void *data, + const struct dmaengine_result *res) +{ + struct ntb_queue_entry *entry = data; + struct ntb_transport_qp *qp = entry->qp; + struct ntb_payload_header __iomem *hdr = entry->tx_hdr; + + /* we need to check DMA results if we are using DMA */ + if (res) { + enum dmaengine_tx_result dma_err = res->result; + + switch (dma_err) { + case DMA_TRANS_READ_FAILED: + case DMA_TRANS_WRITE_FAILED: + entry->errors++; + fallthrough; + case DMA_TRANS_ABORTED: + { + void __iomem *offset = + qp->tx_mw + qp->tx_max_frame * + entry->tx_index; + + /* resubmit via CPU */ + ntb_memcpy_tx(entry, offset); + qp->tx_memcpy++; + return; + } + + case DMA_TRANS_NOERROR: + default: + break; + } + } + + iowrite32(entry->flags | DESC_DONE_FLAG, &hdr->flags); + + if (qp->use_msi) + ntb_msi_peer_trigger(qp->ndev, PIDX, &qp->peer_msi_desc); + else + 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) +{ +#ifdef ARCH_HAS_NOCACHE_UACCESS + /* + * Using non-temporal mov to improve performance on non-cached + * writes, even though we aren't actually copying from user space. + */ + __copy_from_user_inatomic_nocache(offset, entry->buf, entry->len); +#else + memcpy_toio(offset, entry->buf, entry->len); +#endif + + /* Ensure that the data is fully copied out before setting the flags */ + wmb(); + + ntb_tx_copy_callback(entry, NULL); +} + +static int ntb_async_tx_submit(struct ntb_transport_qp *qp, + struct ntb_queue_entry *entry) +{ + struct dma_async_tx_descriptor *txd; + struct dma_chan *chan = qp->tx_dma_chan; + struct dma_device *device; + size_t len = entry->len; + void *buf = entry->buf; + size_t dest_off, buff_off; + struct dmaengine_unmap_data *unmap; + dma_addr_t dest; + dma_cookie_t cookie; + + device = chan->device; + dest = qp->tx_mw_dma_addr + qp->tx_max_frame * entry->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_result = 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); + + return 0; +err_set_unmap: + dmaengine_unmap_put(unmap); +err_get_unmap: + dmaengine_unmap_put(unmap); +err: + return -ENXIO; +} + +static void ntb_async_tx(struct ntb_transport_qp *qp, + struct ntb_queue_entry *entry) +{ + struct ntb_payload_header __iomem *hdr; + struct dma_chan *chan = qp->tx_dma_chan; + void __iomem *offset; + int res; + + entry->tx_index = qp->tx_index; + offset = qp->tx_mw + qp->tx_max_frame * entry->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 (entry->len < copy_bytes) + goto err; + + res = ntb_async_tx_submit(qp, entry); + if (res < 0) + goto err; + + if (!entry->retries) + qp->tx_async++; + + return; + +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 (!ntb_transport_tx_free_entry(qp)) { + 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, qp->cb_data, 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; + + 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_qp_link_down_reset(qp); +} + +static bool ntb_dma_filter_fn(struct dma_chan *chan, void *node) +{ + return dev_to_node(&chan->dev->device) == (int)(unsigned long)node; +} + +/** + * 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; + dma_cap_mask_t dma_mask; + int node; + int i; + + ndev = dev_ntb(client_dev->parent); + pdev = ndev->pdev; + nt = ndev->ctx; + + node = dev_to_node(&ndev->dev); + + free_queue = ffs(nt->qp_bitmap_free); + 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; + + dma_cap_zero(dma_mask); + dma_cap_set(DMA_MEMCPY, dma_mask); + + if (use_dma) { + qp->tx_dma_chan = + dma_request_channel(dma_mask, ntb_dma_filter_fn, + (void *)(unsigned long)node); + if (!qp->tx_dma_chan) + dev_info(&pdev->dev, "Unable to allocate TX DMA channel\n"); + + qp->rx_dma_chan = + dma_request_channel(dma_mask, ntb_dma_filter_fn, + (void *)(unsigned long)node); + if (!qp->rx_dma_chan) + dev_info(&pdev->dev, "Unable to allocate RX DMA channel\n"); + } else { + qp->tx_dma_chan = NULL; + qp->rx_dma_chan = NULL; + } + + qp->tx_mw_dma_addr = 0; + if (qp->tx_dma_chan) { + qp->tx_mw_dma_addr = + dma_map_resource(qp->tx_dma_chan->device->dev, + qp->tx_mw_phys, qp->tx_mw_size, + DMA_FROM_DEVICE, 0); + if (dma_mapping_error(qp->tx_dma_chan->device->dev, + qp->tx_mw_dma_addr)) { + qp->tx_mw_dma_addr = 0; + goto err1; + } + } + + dev_dbg(&pdev->dev, "Using %s memcpy for TX\n", + qp->tx_dma_chan ? "DMA" : "CPU"); + + dev_dbg(&pdev->dev, "Using %s memcpy for RX\n", + qp->rx_dma_chan ? "DMA" : "CPU"); + + for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) { + entry = kzalloc_node(sizeof(*entry), GFP_KERNEL, node); + if (!entry) + goto err1; + + entry->qp = qp; + ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry, + &qp->rx_free_q); + } + qp->rx_alloc_entry = NTB_QP_DEF_NUM_ENTRIES; + + for (i = 0; i < qp->tx_max_entry; i++) { + entry = kzalloc_node(sizeof(*entry), GFP_KERNEL, node); + 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: + qp->rx_alloc_entry = 0; + while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q))) + kfree(entry); + if (qp->tx_mw_dma_addr) + dma_unmap_resource(qp->tx_dma_chan->device->dev, + qp->tx_mw_dma_addr, qp->tx_mw_size, + DMA_FROM_DEVICE, 0); + if (qp->tx_dma_chan) + dma_release_channel(qp->tx_dma_chan); + if (qp->rx_dma_chan) + dma_release_channel(qp->rx_dma_chan); + 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 pci_dev *pdev; + struct ntb_queue_entry *entry; + u64 qp_bit; + + if (!qp) + return; + + pdev = qp->ndev->pdev; + + qp->active = false; + + if (qp->tx_dma_chan) { + struct dma_chan *chan = qp->tx_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->tx_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); + + dma_unmap_resource(chan->device->dev, + qp->tx_mw_dma_addr, qp->tx_mw_size, + DMA_FROM_DEVICE, 0); + + dma_release_channel(chan); + } + + if (qp->rx_dma_chan) { + struct dma_chan *chan = qp->rx_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->rx_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); + dma_release_channel(chan); + } + + qp_bit = BIT_ULL(qp->qp_num); + + ntb_db_set_mask(qp->ndev, qp_bit); + tasklet_kill(&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_q_lock, &qp->rx_free_q))) + kfree(entry); + + while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_pend_q))) { + dev_warn(&pdev->dev, "Freeing item from non-empty rx_pend_q\n"); + kfree(entry); + } + + while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_post_q))) { + dev_warn(&pdev->dev, "Freeing item from non-empty rx_post_q\n"); + kfree(entry); + } + + while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q))) + kfree(entry); + + qp->transport->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_q_lock, &qp->rx_pend_q); + if (!entry) + return NULL; + + buf = entry->cb_data; + *len = entry->len; + + ntb_list_add(&qp->ntb_rx_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_q_lock, &qp->rx_free_q); + if (!entry) + return -ENOMEM; + + entry->cb_data = cb; + entry->buf = data; + entry->len = len; + entry->flags = 0; + entry->retries = 0; + entry->errors = 0; + entry->rx_index = 0; + + ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry, &qp->rx_pend_q); + + if (qp->active) + tasklet_schedule(&qp->rxc_db_work); + + 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 || !len) + return -EINVAL; + + /* If the qp link is down already, just ignore. */ + if (!qp->link_is_up) + return 0; + + entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q); + if (!entry) { + qp->tx_err_no_buf++; + return -EBUSY; + } + + entry->cb_data = cb; + entry->buf = data; + entry->len = len; + entry->flags = 0; + entry->errors = 0; + entry->retries = 0; + entry->tx_index = 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) +{ + int val; + + if (!qp) + return; + + qp->client_ready = false; + + val = ntb_spad_read(qp->ndev, QP_LINKS); + + ntb_peer_spad_write(qp->ndev, PIDX, 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_size; + unsigned int copy_align; + struct dma_chan *rx_chan, *tx_chan; + + if (!qp) + return 0; + + rx_chan = qp->rx_dma_chan; + tx_chan = qp->tx_dma_chan; + + copy_align = max(rx_chan ? rx_chan->device->copy_align : 0, + tx_chan ? tx_chan->device->copy_align : 0); + + /* If DMA engine usage is possible, try to find the max size for that */ + max_size = qp->tx_max_frame - sizeof(struct ntb_payload_header); + max_size = round_down(max_size, 1 << copy_align); + + return max_size; +} +EXPORT_SYMBOL_GPL(ntb_transport_max_size); + +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; +} +EXPORT_SYMBOL_GPL(ntb_transport_tx_free_entry); + +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; + + if (ntb_db_read(nt->ndev) & nt->msi_db_mask) { + ntb_transport_msi_peer_desc_changed(nt); + ntb_db_clear(nt->ndev, nt->msi_db_mask); + } + + 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]; + + if (qp->active) + 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; + + pr_info("%s, version %s\n", NTB_TRANSPORT_DESC, NTB_TRANSPORT_VER); + + 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) +{ + ntb_unregister_client(&ntb_transport_client); + bus_unregister(&ntb_transport_bus); + debugfs_remove_recursive(nt_debugfs_dir); +} +module_exit(ntb_transport_exit); |