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-rw-r--r--drivers/ntb/ntb_transport.c2507
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 000000000..9532108d2
--- /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 (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, 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);