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kernel-ark/drivers/ntb/ntb_transport.c
Dave Jiang 569410ca75 NTB: Use unique DMA channels for TX and RX 
Allocate two DMA channels, one for TX operation and one for RX
operation, instead of having one DMA channel for everything. This
provides slightly better performance, and also will make error handling
cleaner later on.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-09-07 15:17:09 -04:00

2095 lines
52 KiB
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/*
* 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"
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 struct dentry *nt_debugfs_dir;
struct ntb_queue_entry {
/* ntb_queue list reference */
struct list_head entry;
/* pointers to data to be transferred */
void *cb_data;
void *buf;
unsigned int len;
unsigned int flags;
struct ntb_transport_qp *qp;
union {
struct ntb_payload_header __iomem *tx_hdr;
struct ntb_payload_header *rx_hdr;
};
unsigned int index;
};
struct ntb_rx_info {
unsigned int entry;
};
struct ntb_transport_qp {
struct ntb_transport_ctx *transport;
struct ntb_dev *ndev;
void *cb_data;
struct dma_chan *tx_dma_chan;
struct dma_chan *rx_dma_chan;
bool client_ready;
bool link_is_up;
u8 qp_num; /* Only 64 QP's are allowed. 0-63 */
u64 qp_bit;
struct ntb_rx_info __iomem *rx_info;
struct ntb_rx_info *remote_rx_info;
void (*tx_handler)(struct ntb_transport_qp *qp, void *qp_data,
void *data, int len);
struct list_head tx_free_q;
spinlock_t ntb_tx_free_q_lock;
void __iomem *tx_mw;
dma_addr_t tx_mw_phys;
unsigned int tx_index;
unsigned int tx_max_entry;
unsigned int tx_max_frame;
void (*rx_handler)(struct ntb_transport_qp *qp, void *qp_data,
void *data, int len);
struct list_head rx_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;
dma_cookie_t last_cookie;
struct tasklet_struct rxc_db_work;
void (*event_handler)(void *data, int status);
struct delayed_work link_work;
struct work_struct link_cleanup;
struct dentry *debugfs_dir;
struct dentry *debugfs_stats;
/* Stats */
u64 rx_bytes;
u64 rx_pkts;
u64 rx_ring_empty;
u64 rx_err_no_buf;
u64 rx_err_oflow;
u64 rx_err_ver;
u64 rx_memcpy;
u64 rx_async;
u64 tx_bytes;
u64 tx_pkts;
u64 tx_ring_full;
u64 tx_err_no_buf;
u64 tx_memcpy;
u64 tx_async;
};
struct ntb_transport_mw {
phys_addr_t phys_addr;
resource_size_t phys_size;
resource_size_t xlat_align;
resource_size_t xlat_align_size;
void __iomem *vbase;
size_t xlat_size;
size_t buff_size;
void *virt_addr;
dma_addr_t dma_addr;
};
struct ntb_transport_client_dev {
struct list_head entry;
struct ntb_transport_ctx *nt;
struct device dev;
};
struct ntb_transport_ctx {
struct list_head entry;
struct list_head client_devs;
struct ntb_dev *ndev;
struct ntb_transport_mw *mw_vec;
struct ntb_transport_qp *qp_vec;
unsigned int mw_count;
unsigned int qp_count;
u64 qp_bitmap;
u64 qp_bitmap_free;
bool link_is_up;
struct delayed_work link_work;
struct work_struct link_cleanup;
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,
MW1_SZ_HIGH,
MW1_SZ_LOW,
MAX_SPAD,
};
#define dev_client_dev(__dev) \
container_of((__dev), struct ntb_transport_client_dev, dev)
#define drv_client(__drv) \
container_of((__drv), struct ntb_transport_client, driver)
#define QP_TO_MW(nt, qp) ((qp) % nt->mw_count)
#define NTB_QP_DEF_NUM_ENTRIES 100
#define NTB_LINK_DOWN_TIMEOUT 10
static void ntb_transport_rxc_db(unsigned long data);
static const struct ntb_ctx_ops ntb_transport_ops;
static struct ntb_client ntb_transport_client;
static int ntb_transport_bus_match(struct device *dev,
struct device_driver *drv)
{
return !strncmp(dev_name(dev), drv->name, strlen(drv->name));
}
static int ntb_transport_bus_probe(struct device *dev)
{
const struct ntb_transport_client *client;
int rc = -EINVAL;
get_device(dev);
client = drv_client(dev->driver);
rc = client->probe(dev);
if (rc)
put_device(dev);
return rc;
}
static int ntb_transport_bus_remove(struct device *dev)
{
const struct ntb_transport_client *client;
client = drv_client(dev->driver);
client->remove(dev);
put_device(dev);
return 0;
}
static struct bus_type ntb_transport_bus = {
.name = "ntb_transport",
.match = ntb_transport_bus_match,
.probe = ntb_transport_bus_probe,
.remove = ntb_transport_bus_remove,
};
static LIST_HEAD(ntb_transport_list);
static int ntb_bus_init(struct ntb_transport_ctx *nt)
{
list_add_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) {
kfree(client_dev);
goto err;
}
list_add_tail(&client_dev->entry, &nt->client_devs);
i++;
}
return 0;
err:
ntb_transport_unregister_client_dev(device_name);
return rc;
}
EXPORT_SYMBOL_GPL(ntb_transport_register_client_dev);
/**
* ntb_transport_register_client - Register NTB client driver
* @drv: NTB client driver to be registered
*
* Register an NTB client driver with the NTB transport layer
*
* RETURNS: An appropriate -ERRNO error value on error, or zero for success.
*/
int ntb_transport_register_client(struct ntb_transport_client *drv)
{
drv->driver.bus = &ntb_transport_bus;
if (list_empty(&ntb_transport_list))
return -ENODEV;
return driver_register(&drv->driver);
}
EXPORT_SYMBOL_GPL(ntb_transport_register_client);
/**
* ntb_transport_unregister_client - Unregister NTB client driver
* @drv: NTB client driver to be unregistered
*
* Unregister an NTB client driver with the NTB transport layer
*
* RETURNS: An appropriate -ERRNO error value on error, or zero for success.
*/
void ntb_transport_unregister_client(struct ntb_transport_client *drv)
{
driver_unregister(&drv->driver);
}
EXPORT_SYMBOL_GPL(ntb_transport_unregister_client);
static ssize_t debugfs_read(struct file *filp, char __user *ubuf, size_t count,
loff_t *offp)
{
struct ntb_transport_qp *qp;
char *buf;
ssize_t ret, out_offset, out_count;
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 += snprintf(buf + out_offset, out_count - out_offset,
"\nNTB QP stats:\n\n");
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"rx_bytes - \t%llu\n", qp->rx_bytes);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"rx_pkts - \t%llu\n", qp->rx_pkts);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"rx_memcpy - \t%llu\n", qp->rx_memcpy);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"rx_async - \t%llu\n", qp->rx_async);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"rx_ring_empty - %llu\n", qp->rx_ring_empty);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"rx_err_no_buf - %llu\n", qp->rx_err_no_buf);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"rx_err_oflow - \t%llu\n", qp->rx_err_oflow);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"rx_err_ver - \t%llu\n", qp->rx_err_ver);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"rx_buff - \t0x%p\n", qp->rx_buff);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"rx_index - \t%u\n", qp->rx_index);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"rx_max_entry - \t%u\n\n", qp->rx_max_entry);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"tx_bytes - \t%llu\n", qp->tx_bytes);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"tx_pkts - \t%llu\n", qp->tx_pkts);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"tx_memcpy - \t%llu\n", qp->tx_memcpy);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"tx_async - \t%llu\n", qp->tx_async);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"tx_ring_full - \t%llu\n", qp->tx_ring_full);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"tx_err_no_buf - %llu\n", qp->tx_err_no_buf);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"tx_mw - \t0x%p\n", qp->tx_mw);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"tx_index (H) - \t%u\n", qp->tx_index);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"RRI (T) - \t%u\n",
qp->remote_rx_info->entry);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"tx_max_entry - \t%u\n", qp->tx_max_entry);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"free tx - \t%u\n",
ntb_transport_tx_free_entry(qp));
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"\n");
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"Using TX DMA - \t%s\n",
qp->tx_dma_chan ? "Yes" : "No");
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"Using RX DMA - \t%s\n",
qp->rx_dma_chan ? "Yes" : "No");
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"QP Link - \t%s\n",
qp->link_is_up ? "Up" : "Down");
out_offset += snprintf(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;
unsigned int rx_size, num_qps_mw;
unsigned int mw_num, mw_count, qp_count;
unsigned int i;
mw_count = nt->mw_count;
qp_count = nt->qp_count;
mw_num = QP_TO_MW(nt, qp_num);
mw = &nt->mw_vec[mw_num];
if (!mw->virt_addr)
return -ENOMEM;
if (qp_count % mw_count && mw_num + 1 < qp_count / mw_count)
num_qps_mw = qp_count / mw_count + 1;
else
num_qps_mw = qp_count / mw_count;
rx_size = (unsigned int)mw->xlat_size / num_qps_mw;
qp->rx_buff = mw->virt_addr + rx_size * qp_num / mw_count;
rx_size -= sizeof(struct ntb_rx_info);
qp->remote_rx_info = qp->rx_buff + rx_size;
/* Due to housekeeping, there must be atleast 2 buffs */
qp->rx_max_frame = min(transport_mtu, rx_size / 2);
qp->rx_max_entry = rx_size / qp->rx_max_frame;
qp->rx_index = 0;
qp->remote_rx_info->entry = qp->rx_max_entry - 1;
/* setup the hdr offsets with 0's */
for (i = 0; i < qp->rx_max_entry; i++) {
void *offset = (qp->rx_buff + qp->rx_max_frame * (i + 1) -
sizeof(struct ntb_payload_header));
memset(offset, 0, sizeof(struct ntb_payload_header));
}
qp->rx_pkts = 0;
qp->tx_pkts = 0;
qp->tx_index = 0;
return 0;
}
static void ntb_free_mw(struct ntb_transport_ctx *nt, int num_mw)
{
struct ntb_transport_mw *mw = &nt->mw_vec[num_mw];
struct pci_dev *pdev = nt->ndev->pdev;
if (!mw->virt_addr)
return;
ntb_mw_clear_trans(nt->ndev, num_mw);
dma_free_coherent(&pdev->dev, mw->buff_size,
mw->virt_addr, mw->dma_addr);
mw->xlat_size = 0;
mw->buff_size = 0;
mw->virt_addr = NULL;
}
static int ntb_set_mw(struct ntb_transport_ctx *nt, int num_mw,
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;
int rc;
if (!size)
return -EINVAL;
xlat_size = round_up(size, mw->xlat_align_size);
buff_size = round_up(size, mw->xlat_align);
/* No need to re-setup */
if (mw->xlat_size == xlat_size)
return 0;
if (mw->buff_size)
ntb_free_mw(nt, num_mw);
/* Alloc memory for receiving data. Must be aligned */
mw->xlat_size = xlat_size;
mw->buff_size = buff_size;
mw->virt_addr = dma_alloc_coherent(&pdev->dev, buff_size,
&mw->dma_addr, GFP_KERNEL);
if (!mw->virt_addr) {
mw->xlat_size = 0;
mw->buff_size = 0;
dev_err(&pdev->dev, "Unable to alloc MW buff of size %zu\n",
buff_size);
return -ENOMEM;
}
/*
* we must ensure that the memory address allocated is BAR size
* aligned in order for the XLAT register to take the value. This
* is a requirement of the hardware. It is recommended to setup CMA
* for BAR sizes equal or greater than 4MB.
*/
if (!IS_ALIGNED(mw->dma_addr, mw->xlat_align)) {
dev_err(&pdev->dev, "DMA memory %pad is not aligned\n",
&mw->dma_addr);
ntb_free_mw(nt, num_mw);
return -ENOMEM;
}
/* Notify HW the memory location of the receive buffer */
rc = ntb_mw_set_trans(nt->ndev, num_mw, mw->dma_addr, mw->xlat_size);
if (rc) {
dev_err(&pdev->dev, "Unable to set mw%d translation", num_mw);
ntb_free_mw(nt, num_mw);
return -EIO;
}
return 0;
}
static void ntb_qp_link_down_reset(struct ntb_transport_qp *qp)
{
qp->link_is_up = 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_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;
int i;
qp_bitmap_alloc = nt->qp_bitmap & ~nt->qp_bitmap_free;
/* Pass along the info to any clients */
for (i = 0; i < nt->qp_count; i++)
if (qp_bitmap_alloc & BIT_ULL(i)) {
qp = &nt->qp_vec[i];
ntb_qp_link_cleanup(qp);
cancel_work_sync(&qp->link_cleanup);
cancel_delayed_work_sync(&qp->link_work);
}
if (!nt->link_is_up)
cancel_delayed_work_sync(&nt->link_work);
/* The scratchpad registers keep the values if the remote side
* goes down, blast them now to give them a sane value the next
* time they are accessed
*/
for (i = 0; i < MAX_SPAD; i++)
ntb_spad_write(nt->ndev, i, 0);
}
static void ntb_transport_link_cleanup_work(struct work_struct *work)
{
struct ntb_transport_ctx *nt =
container_of(work, struct ntb_transport_ctx, link_cleanup);
ntb_transport_link_cleanup(nt);
}
static void ntb_transport_event_callback(void *data)
{
struct ntb_transport_ctx *nt = data;
if (ntb_link_is_up(nt->ndev, NULL, NULL) == 1)
schedule_delayed_work(&nt->link_work, 0);
else
schedule_work(&nt->link_cleanup);
}
static void ntb_transport_link_work(struct work_struct *work)
{
struct ntb_transport_ctx *nt =
container_of(work, struct ntb_transport_ctx, link_work.work);
struct ntb_dev *ndev = nt->ndev;
struct pci_dev *pdev = ndev->pdev;
resource_size_t size;
u32 val;
int rc, i, spad;
/* send the local info, in the opposite order of the way we read it */
for (i = 0; i < nt->mw_count; i++) {
size = nt->mw_vec[i].phys_size;
if (max_mw_size && size > max_mw_size)
size = max_mw_size;
spad = MW0_SZ_HIGH + (i * 2);
ntb_peer_spad_write(ndev, spad, (u32)(size >> 32));
spad = MW0_SZ_LOW + (i * 2);
ntb_peer_spad_write(ndev, spad, (u32)size);
}
ntb_peer_spad_write(ndev, NUM_MWS, nt->mw_count);
ntb_peer_spad_write(ndev, NUM_QPS, nt->qp_count);
ntb_peer_spad_write(ndev, VERSION, NTB_TRANSPORT_VERSION);
/* Query the remote side for its info */
val = ntb_spad_read(ndev, VERSION);
dev_dbg(&pdev->dev, "Remote version = %d\n", val);
if (val != NTB_TRANSPORT_VERSION)
goto out;
val = ntb_spad_read(ndev, NUM_QPS);
dev_dbg(&pdev->dev, "Remote max number of qps = %d\n", val);
if (val != nt->qp_count)
goto out;
val = ntb_spad_read(ndev, NUM_MWS);
dev_dbg(&pdev->dev, "Remote number of mws = %d\n", val);
if (val != nt->mw_count)
goto out;
for (i = 0; i < nt->mw_count; i++) {
u64 val64;
val = ntb_spad_read(ndev, MW0_SZ_HIGH + (i * 2));
val64 = (u64)val << 32;
val = ntb_spad_read(ndev, MW0_SZ_LOW + (i * 2));
val64 |= val;
dev_dbg(&pdev->dev, "Remote MW%d size = %#llx\n", i, val64);
rc = ntb_set_mw(nt, i, val64);
if (rc)
goto out1;
}
nt->link_is_up = true;
for (i = 0; i < nt->qp_count; i++) {
struct ntb_transport_qp *qp = &nt->qp_vec[i];
ntb_transport_setup_qp_mw(nt, i);
if (qp->client_ready)
schedule_delayed_work(&qp->link_work, 0);
}
return;
out1:
for (i = 0; i < nt->mw_count; i++)
ntb_free_mw(nt, i);
out:
if (ntb_link_is_up(ndev, NULL, NULL) == 1)
schedule_delayed_work(&nt->link_work,
msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
}
static void ntb_qp_link_work(struct work_struct *work)
{
struct ntb_transport_qp *qp = container_of(work,
struct ntb_transport_qp,
link_work.work);
struct pci_dev *pdev = qp->ndev->pdev;
struct ntb_transport_ctx *nt = qp->transport;
int val;
WARN_ON(!nt->link_is_up);
val = ntb_spad_read(nt->ndev, QP_LINKS);
ntb_peer_spad_write(nt->ndev, QP_LINKS, val | BIT(qp->qp_num));
/* query remote spad for qp ready bits */
ntb_peer_spad_read(nt->ndev, QP_LINKS);
dev_dbg_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;
if (qp->event_handler)
qp->event_handler(qp->cb_data, qp->link_is_up);
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;
struct ntb_transport_mw *mw;
phys_addr_t mw_base;
resource_size_t mw_size;
unsigned int num_qps_mw, tx_size;
unsigned int mw_num, mw_count, qp_count;
u64 qp_offset;
mw_count = nt->mw_count;
qp_count = nt->qp_count;
mw_num = QP_TO_MW(nt, qp_num);
mw = &nt->mw_vec[mw_num];
qp = &nt->qp_vec[qp_num];
qp->qp_num = qp_num;
qp->transport = nt;
qp->ndev = nt->ndev;
qp->client_ready = false;
qp->event_handler = NULL;
ntb_qp_link_down_reset(qp);
if (qp_count % mw_count && mw_num + 1 < qp_count / mw_count)
num_qps_mw = qp_count / mw_count + 1;
else
num_qps_mw = qp_count / mw_count;
mw_base = nt->mw_vec[mw_num].phys_addr;
mw_size = nt->mw_vec[mw_num].phys_size;
tx_size = (unsigned int)mw_size / num_qps_mw;
qp_offset = tx_size * qp_num / mw_count;
qp->tx_mw = nt->mw_vec[mw_num].vbase + qp_offset;
if (!qp->tx_mw)
return -EINVAL;
qp->tx_mw_phys = mw_base + qp_offset;
if (!qp->tx_mw_phys)
return -EINVAL;
tx_size -= sizeof(struct ntb_rx_info);
qp->rx_info = qp->tx_mw + tx_size;
/* Due to housekeeping, there must be atleast 2 buffs */
qp->tx_max_frame = min(transport_mtu, tx_size / 2);
qp->tx_max_entry = tx_size / qp->tx_max_frame;
if (nt->debugfs_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;
u64 qp_bitmap;
int node;
int rc, i;
if (ntb_db_is_unsafe(ndev))
dev_dbg(&ndev->dev,
"doorbell is unsafe, proceed anyway...\n");
if (ntb_spad_is_unsafe(ndev))
dev_dbg(&ndev->dev,
"scratchpad is unsafe, proceed anyway...\n");
node = dev_to_node(&ndev->dev);
nt = kzalloc_node(sizeof(*nt), GFP_KERNEL, node);
if (!nt)
return -ENOMEM;
nt->ndev = ndev;
mw_count = ntb_mw_count(ndev);
nt->mw_count = mw_count;
nt->mw_vec = kzalloc_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_mw_get_range(ndev, i, &mw->phys_addr, &mw->phys_size,
&mw->xlat_align, &mw->xlat_align_size);
if (rc)
goto err1;
mw->vbase = ioremap_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 (max_num_clients && max_num_clients < qp_count)
qp_count = max_num_clients;
else if (mw_count < qp_count)
qp_count = mw_count;
qp_bitmap &= BIT_ULL(qp_count) - 1;
nt->qp_count = qp_count;
nt->qp_bitmap = qp_bitmap;
nt->qp_bitmap_free = qp_bitmap;
nt->qp_vec = kzalloc_node(qp_count * sizeof(*nt->qp_vec),
GFP_KERNEL, node);
if (!nt->qp_vec) {
rc = -ENOMEM;
goto err2;
}
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 err3;
}
INIT_DELAYED_WORK(&nt->link_work, ntb_transport_link_work);
INIT_WORK(&nt->link_cleanup, ntb_transport_link_cleanup_work);
rc = ntb_set_ctx(ndev, nt, &ntb_transport_ops);
if (rc)
goto err3;
INIT_LIST_HEAD(&nt->client_devs);
rc = ntb_bus_init(nt);
if (rc)
goto err4;
nt->link_is_up = false;
ntb_link_enable(ndev, NTB_SPEED_AUTO, NTB_WIDTH_AUTO);
ntb_link_event(ndev);
return 0;
err4:
ntb_clear_ctx(ndev);
err3:
kfree(nt->qp_vec);
err2:
kfree(nt->mw_vec);
err1:
while (i--) {
mw = &nt->mw_vec[i];
iounmap(mw->vbase);
}
err:
kfree(nt);
return rc;
}
static void ntb_transport_free(struct ntb_client *self, struct ntb_dev *ndev)
{
struct ntb_transport_ctx *nt = ndev->ctx;
struct ntb_transport_qp *qp;
u64 qp_bitmap_alloc;
int i;
ntb_transport_link_cleanup(nt);
cancel_work_sync(&nt->link_cleanup);
cancel_delayed_work_sync(&nt->link_work);
qp_bitmap_alloc = nt->qp_bitmap & ~nt->qp_bitmap_free;
/* verify that all the qp's are freed */
for (i = 0; i < nt->qp_count; i++) {
qp = &nt->qp_vec[i];
if (qp_bitmap_alloc & BIT_ULL(i))
ntb_transport_free_queue(qp);
debugfs_remove_recursive(qp->debugfs_dir);
}
ntb_link_disable(ndev);
ntb_clear_ctx(ndev);
ntb_bus_remove(nt);
for (i = nt->mw_count; i--; ) {
ntb_free_mw(nt, i);
iounmap(nt->mw_vec[i].vbase);
}
kfree(nt->qp_vec);
kfree(nt->mw_vec);
kfree(nt);
}
static void ntb_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->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)
{
struct ntb_queue_entry *entry = data;
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);
}
static void ntb_async_rx(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;
if (!chan)
goto err;
if (len < copy_bytes)
goto err;
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 = ntb_rx_copy_callback;
txd->callback_param = entry;
dma_set_unmap(txd, unmap);
cookie = dmaengine_submit(txd);
if (dma_submit_error(cookie))
goto err_set_unmap;
dmaengine_unmap_put(unmap);
qp->last_cookie = cookie;
qp->rx_async++;
return;
err_set_unmap:
dmaengine_unmap_put(unmap);
err_get_unmap:
dmaengine_unmap_put(unmap);
err:
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->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 */
tasklet_schedule(&qp->rxc_db_work);
} else if (ntb_db_read(qp->ndev) & BIT_ULL(qp->qp_num)) {
/* the doorbell bit is set: clear it */
ntb_db_clear(qp->ndev, BIT_ULL(qp->qp_num));
/* ntb_db_read ensures ntb_db_clear write is committed */
ntb_db_read(qp->ndev);
/* an interrupt may have arrived between finishing
* ntb_process_rxc and clearing the doorbell bit:
* there might be some more work to do.
*/
tasklet_schedule(&qp->rxc_db_work);
}
}
static void ntb_tx_copy_callback(void *data)
{
struct ntb_queue_entry *entry = data;
struct ntb_transport_qp *qp = entry->qp;
struct ntb_payload_header __iomem *hdr = entry->tx_hdr;
iowrite32(entry->flags | DESC_DONE_FLAG, &hdr->flags);
ntb_peer_db_set(qp->ndev, BIT_ULL(qp->qp_num));
/* The entry length can only be zero if the packet is intended to be a
* "link down" or similar. Since no payload is being sent in these
* cases, there is nothing to add to the completion queue.
*/
if (entry->len > 0) {
qp->tx_bytes += entry->len;
if (qp->tx_handler)
qp->tx_handler(qp, qp->cb_data, entry->cb_data,
entry->len);
}
ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry, &qp->tx_free_q);
}
static void ntb_memcpy_tx(struct ntb_queue_entry *entry, void __iomem *offset)
{
#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);
}
static void ntb_async_tx(struct ntb_transport_qp *qp,
struct ntb_queue_entry *entry)
{
struct ntb_payload_header __iomem *hdr;
struct dma_async_tx_descriptor *txd;
struct dma_chan *chan = qp->tx_dma_chan;
struct dma_device *device;
size_t dest_off, buff_off;
struct dmaengine_unmap_data *unmap;
dma_addr_t dest;
dma_cookie_t cookie;
void __iomem *offset;
size_t len = entry->len;
void *buf = entry->buf;
offset = qp->tx_mw + qp->tx_max_frame * qp->tx_index;
hdr = offset + qp->tx_max_frame - sizeof(struct ntb_payload_header);
entry->tx_hdr = hdr;
iowrite32(entry->len, &hdr->len);
iowrite32((u32)qp->tx_pkts, &hdr->ver);
if (!chan)
goto err;
if (len < copy_bytes)
goto err;
device = chan->device;
dest = qp->tx_mw_phys + qp->tx_max_frame * qp->tx_index;
buff_off = (size_t)buf & ~PAGE_MASK;
dest_off = (size_t)dest & ~PAGE_MASK;
if (!is_dma_copy_aligned(device, buff_off, dest_off, len))
goto err;
unmap = dmaengine_get_unmap_data(device->dev, 1, GFP_NOWAIT);
if (!unmap)
goto err;
unmap->len = len;
unmap->addr[0] = dma_map_page(device->dev, virt_to_page(buf),
buff_off, len, DMA_TO_DEVICE);
if (dma_mapping_error(device->dev, unmap->addr[0]))
goto err_get_unmap;
unmap->to_cnt = 1;
txd = device->device_prep_dma_memcpy(chan, dest, unmap->addr[0], len,
DMA_PREP_INTERRUPT);
if (!txd)
goto err_get_unmap;
txd->callback = ntb_tx_copy_callback;
txd->callback_param = entry;
dma_set_unmap(txd, unmap);
cookie = dmaengine_submit(txd);
if (dma_submit_error(cookie))
goto err_set_unmap;
dmaengine_unmap_put(unmap);
dma_async_issue_pending(chan);
qp->tx_async++;
return;
err_set_unmap:
dmaengine_unmap_put(unmap);
err_get_unmap:
dmaengine_unmap_put(unmap);
err:
ntb_memcpy_tx(entry, offset);
qp->tx_memcpy++;
}
static int ntb_process_tx(struct ntb_transport_qp *qp,
struct ntb_queue_entry *entry)
{
if (qp->tx_index == qp->remote_rx_info->entry) {
qp->tx_ring_full++;
return -EAGAIN;
}
if (entry->len > qp->tx_max_frame - sizeof(struct ntb_payload_header)) {
if (qp->tx_handler)
qp->tx_handler(qp->cb_data, qp, NULL, -EIO);
ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
&qp->tx_free_q);
return 0;
}
ntb_async_tx(qp, entry);
qp->tx_index++;
qp->tx_index %= qp->tx_max_entry;
qp->tx_pkts++;
return 0;
}
static void ntb_send_link_down(struct ntb_transport_qp *qp)
{
struct pci_dev *pdev = qp->ndev->pdev;
struct ntb_queue_entry *entry;
int i, rc;
if (!qp->link_is_up)
return;
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);
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;
}
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_ATOMIC, node);
if (!entry)
goto err1;
entry->qp = qp;
ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry,
&qp->rx_free_q);
}
for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {
entry = kzalloc_node(sizeof(*entry), GFP_ATOMIC, 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:
while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q)))
kfree(entry);
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;
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_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_disable(&qp->rxc_db_work);
cancel_delayed_work_sync(&qp->link_work);
qp->cb_data = NULL;
qp->rx_handler = NULL;
qp->tx_handler = NULL;
qp->event_handler = NULL;
while ((entry = ntb_list_rm(&qp->ntb_rx_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;
ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry, &qp->rx_pend_q);
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 || !qp->link_is_up || !len)
return -EINVAL;
entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
if (!entry) {
qp->tx_err_no_buf++;
return -EBUSY;
}
entry->cb_data = cb;
entry->buf = data;
entry->len = len;
entry->flags = 0;
rc = ntb_process_tx(qp, entry);
if (rc)
ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
&qp->tx_free_q);
return rc;
}
EXPORT_SYMBOL_GPL(ntb_transport_tx_enqueue);
/**
* ntb_transport_link_up - Notify NTB transport of client readiness to use queue
* @qp: NTB transport layer queue to be enabled
*
* Notify NTB transport layer of client readiness to use queue
*/
void ntb_transport_link_up(struct ntb_transport_qp *qp)
{
if (!qp)
return;
qp->client_ready = true;
if (qp->transport->link_is_up)
schedule_delayed_work(&qp->link_work, 0);
}
EXPORT_SYMBOL_GPL(ntb_transport_link_up);
/**
* ntb_transport_link_down - Notify NTB transport to no longer enqueue data
* @qp: NTB transport layer queue to be disabled
*
* Notify NTB transport layer of client's desire to no longer receive data on
* transport queue specified. It is the client's responsibility to ensure all
* entries on queue are purged or otherwise handled appropriately.
*/
void ntb_transport_link_down(struct ntb_transport_qp *qp)
{
struct pci_dev *pdev;
int val;
if (!qp)
return;
pdev = qp->ndev->pdev;
qp->client_ready = false;
val = ntb_spad_read(qp->ndev, QP_LINKS);
ntb_peer_spad_write(qp->ndev, QP_LINKS,
val & ~BIT(qp->qp_num));
if (qp->link_is_up)
ntb_send_link_down(qp);
else
cancel_delayed_work_sync(&qp->link_work);
}
EXPORT_SYMBOL_GPL(ntb_transport_link_down);
/**
* ntb_transport_link_query - Query transport link state
* @qp: NTB transport layer queue to be queried
*
* Query connectivity to the remote system of the NTB transport queue
*
* RETURNS: true for link up or false for link down
*/
bool ntb_transport_link_query(struct ntb_transport_qp *qp)
{
if (!qp)
return false;
return qp->link_is_up;
}
EXPORT_SYMBOL_GPL(ntb_transport_link_query);
/**
* ntb_transport_qp_num - Query the qp number
* @qp: NTB transport layer queue to be queried
*
* Query qp number of the NTB transport queue
*
* RETURNS: a zero based number specifying the qp number
*/
unsigned char ntb_transport_qp_num(struct ntb_transport_qp *qp)
{
if (!qp)
return 0;
return qp->qp_num;
}
EXPORT_SYMBOL_GPL(ntb_transport_qp_num);
/**
* ntb_transport_max_size - Query the max payload size of a qp
* @qp: NTB transport layer queue to be queried
*
* Query the maximum payload size permissible on the given qp
*
* RETURNS: the max payload size of a qp
*/
unsigned int ntb_transport_max_size(struct ntb_transport_qp *qp)
{
unsigned int max;
unsigned int copy_align;
if (!qp)
return 0;
if (!qp->tx_dma_chan && !qp->rx_dma_chan)
return qp->tx_max_frame - sizeof(struct ntb_payload_header);
copy_align = max(qp->tx_dma_chan->device->copy_align,
qp->rx_dma_chan->device->copy_align);
/* If DMA engine usage is possible, try to find the max size for that */
max = qp->tx_max_frame - sizeof(struct ntb_payload_header);
max -= max % (1 << copy_align);
return max;
}
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;
db_bits = (nt->qp_bitmap & ~nt->qp_bitmap_free &
ntb_db_vector_mask(nt->ndev, vector));
while (db_bits) {
qp_num = __ffs(db_bits);
qp = &nt->qp_vec[qp_num];
tasklet_schedule(&qp->rxc_db_work);
db_bits &= ~BIT_ULL(qp_num);
}
}
static const struct ntb_ctx_ops ntb_transport_ops = {
.link_event = ntb_transport_event_callback,
.db_event = ntb_transport_doorbell_callback,
};
static struct ntb_client ntb_transport_client = {
.ops = {
.probe = ntb_transport_probe,
.remove = ntb_transport_free,
},
};
static int __init ntb_transport_init(void)
{
int rc;
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)
{
debugfs_remove_recursive(nt_debugfs_dir);
ntb_unregister_client(&ntb_transport_client);
bus_unregister(&ntb_transport_bus);
}
module_exit(ntb_transport_exit);
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