Quelle ntb.h Sprache: C

/*
* 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) 2015 EMC Corporation. All Rights Reserved.
*   Copyright (C) 2016 T-Platforms. 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.
*
*   This program is distributed in the hope that it will be useful, but
*   WITHOUT ANY WARRANTY; without even the implied warranty of
*   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
*   General Public License for more details.
*
*   BSD LICENSE
*
*   Copyright (C) 2015 EMC Corporation. All Rights Reserved.
*   Copyright (C) 2016 T-Platforms. 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 Linux driver
*
* Contact Information:
* Allen Hubbe <Allen.Hubbe@emc.com>
*/

#ifndef _NTB_H_
#define _NTB_H_

#include <linux/completion.h>
#include <linux/device.h>
#include <linux/interrupt.h>

struct ntb_client;
struct ntb_dev;
struct ntb_msi;
struct pci_dev;

/**
* enum ntb_topo - NTB connection topology
* @NTB_TOPO_NONE: Topology is unknown or invalid.
* @NTB_TOPO_PRI: On primary side of local ntb.
* @NTB_TOPO_SEC: On secondary side of remote ntb.
* @NTB_TOPO_B2B_USD: On primary side of local ntb upstream of remote ntb.
* @NTB_TOPO_B2B_DSD: On primary side of local ntb downstream of remote ntb.
* @NTB_TOPO_SWITCH: Connected via a switch which supports ntb.
* @NTB_TOPO_CROSSLINK: Connected via two symmetric switchecs
*/
enum ntb_topo {
NTB_TOPO_NONE = -1,
NTB_TOPO_PRI,
NTB_TOPO_SEC,
NTB_TOPO_B2B_USD,
NTB_TOPO_B2B_DSD,
NTB_TOPO_SWITCH,
NTB_TOPO_CROSSLINK,
};

static inline int ntb_topo_is_b2b(enum ntb_topo topo)
{
switch ((int)topo) {
case NTB_TOPO_B2B_USD:
case NTB_TOPO_B2B_DSD:
  return 1;
}
return 0;
}

static inline char *ntb_topo_string(enum ntb_topo topo)
{
switch (topo) {
case NTB_TOPO_NONE:  return "NTB_TOPO_NONE";
case NTB_TOPO_PRI:  return "NTB_TOPO_PRI";
case NTB_TOPO_SEC:  return "NTB_TOPO_SEC";
case NTB_TOPO_B2B_USD:  return "NTB_TOPO_B2B_USD";
case NTB_TOPO_B2B_DSD:  return "NTB_TOPO_B2B_DSD";
case NTB_TOPO_SWITCH:  return "NTB_TOPO_SWITCH";
case NTB_TOPO_CROSSLINK: return "NTB_TOPO_CROSSLINK";
}
return "NTB_TOPO_INVALID";
}

/**
* enum ntb_speed - NTB link training speed
* @NTB_SPEED_AUTO: Request the max supported speed.
* @NTB_SPEED_NONE: Link is not trained to any speed.
* @NTB_SPEED_GEN1: Link is trained to gen1 speed.
* @NTB_SPEED_GEN2: Link is trained to gen2 speed.
* @NTB_SPEED_GEN3: Link is trained to gen3 speed.
* @NTB_SPEED_GEN4: Link is trained to gen4 speed.
*/
enum ntb_speed {
NTB_SPEED_AUTO = -1,
NTB_SPEED_NONE = 0,
NTB_SPEED_GEN1 = 1,
NTB_SPEED_GEN2 = 2,
NTB_SPEED_GEN3 = 3,
NTB_SPEED_GEN4 = 4
};

/**
* enum ntb_width - NTB link training width
* @NTB_WIDTH_AUTO: Request the max supported width.
* @NTB_WIDTH_NONE: Link is not trained to any width.
* @NTB_WIDTH_1: Link is trained to 1 lane width.
* @NTB_WIDTH_2: Link is trained to 2 lane width.
* @NTB_WIDTH_4: Link is trained to 4 lane width.
* @NTB_WIDTH_8: Link is trained to 8 lane width.
* @NTB_WIDTH_12: Link is trained to 12 lane width.
* @NTB_WIDTH_16: Link is trained to 16 lane width.
* @NTB_WIDTH_32: Link is trained to 32 lane width.
*/
enum ntb_width {
NTB_WIDTH_AUTO = -1,
NTB_WIDTH_NONE = 0,
NTB_WIDTH_1 = 1,
NTB_WIDTH_2 = 2,
NTB_WIDTH_4 = 4,
NTB_WIDTH_8 = 8,
NTB_WIDTH_12 = 12,
NTB_WIDTH_16 = 16,
NTB_WIDTH_32 = 32,
};

/**
* enum ntb_default_port - NTB default port number
* @NTB_PORT_PRI_USD: Default port of the NTB_TOPO_PRI/NTB_TOPO_B2B_USD
* topologies
* @NTB_PORT_SEC_DSD: Default port of the NTB_TOPO_SEC/NTB_TOPO_B2B_DSD
* topologies
*/
enum ntb_default_port {
NTB_PORT_PRI_USD,
NTB_PORT_SEC_DSD
};
#define NTB_DEF_PEER_CNT (1)
#define NTB_DEF_PEER_IDX (0)

/**
* struct ntb_client_ops - ntb client operations
* @probe: Notify client of a new device.
* @remove: Notify client to remove a device.
*/
struct ntb_client_ops {
int (*probe)(struct ntb_client *client, struct ntb_dev *ntb);
void (*remove)(struct ntb_client *client, struct ntb_dev *ntb);
};

static inline int ntb_client_ops_is_valid(const struct ntb_client_ops *ops)
{
/* commented callbacks are not required: */
return
  ops->probe   &&
  ops->remove   &&
  1;
}

/**
* struct ntb_ctx_ops - ntb driver context operations
* @link_event: See ntb_link_event().
* @db_event: See ntb_db_event().
* @msg_event: See ntb_msg_event().
*/
struct ntb_ctx_ops {
void (*link_event)(void *ctx);
void (*db_event)(void *ctx, int db_vector);
void (*msg_event)(void *ctx);
};

static inline int ntb_ctx_ops_is_valid(const struct ntb_ctx_ops *ops)
{
/* commented callbacks are not required: */
return
  /* ops->link_event && */
  /* ops->db_event && */
  /* ops->msg_event && */
  1;
}

/**
* struct ntb_dev_ops - ntb device operations
* @port_number: See ntb_port_number().
* @peer_port_count: See ntb_peer_port_count().
* @peer_port_number: See ntb_peer_port_number().
* @peer_port_idx: See ntb_peer_port_idx().
* @link_is_up: See ntb_link_is_up().
* @link_enable: See ntb_link_enable().
* @link_disable: See ntb_link_disable().
* @mw_count: See ntb_mw_count().
* @mw_get_align: See ntb_mw_get_align().
* @mw_set_trans: See ntb_mw_set_trans().
* @mw_clear_trans: See ntb_mw_clear_trans().
* @peer_mw_count: See ntb_peer_mw_count().
* @peer_mw_get_addr: See ntb_peer_mw_get_addr().
* @peer_mw_set_trans: See ntb_peer_mw_set_trans().
* @peer_mw_clear_trans:See ntb_peer_mw_clear_trans().
* @db_is_unsafe: See ntb_db_is_unsafe().
* @db_valid_mask: See ntb_db_valid_mask().
* @db_vector_count: See ntb_db_vector_count().
* @db_vector_mask: See ntb_db_vector_mask().
* @db_read: See ntb_db_read().
* @db_set: See ntb_db_set().
* @db_clear: See ntb_db_clear().
* @db_read_mask: See ntb_db_read_mask().
* @db_set_mask: See ntb_db_set_mask().
* @db_clear_mask: See ntb_db_clear_mask().
* @peer_db_addr: See ntb_peer_db_addr().
* @peer_db_read: See ntb_peer_db_read().
* @peer_db_set: See ntb_peer_db_set().
* @peer_db_clear: See ntb_peer_db_clear().
* @peer_db_read_mask: See ntb_peer_db_read_mask().
* @peer_db_set_mask: See ntb_peer_db_set_mask().
* @peer_db_clear_mask: See ntb_peer_db_clear_mask().
* @spad_is_unsafe: See ntb_spad_is_unsafe().
* @spad_count: See ntb_spad_count().
* @spad_read: See ntb_spad_read().
* @spad_write: See ntb_spad_write().
* @peer_spad_addr: See ntb_peer_spad_addr().
* @peer_spad_read: See ntb_peer_spad_read().
* @peer_spad_write: See ntb_peer_spad_write().
* @msg_count: See ntb_msg_count().
* @msg_inbits: See ntb_msg_inbits().
* @msg_outbits: See ntb_msg_outbits().
* @msg_read_sts: See ntb_msg_read_sts().
* @msg_clear_sts: See ntb_msg_clear_sts().
* @msg_set_mask: See ntb_msg_set_mask().
* @msg_clear_mask: See ntb_msg_clear_mask().
* @msg_read: See ntb_msg_read().
* @peer_msg_write: See ntb_peer_msg_write().
*/
struct ntb_dev_ops {
int (*port_number)(struct ntb_dev *ntb);
int (*peer_port_count)(struct ntb_dev *ntb);
int (*peer_port_number)(struct ntb_dev *ntb, int pidx);
int (*peer_port_idx)(struct ntb_dev *ntb, int port);

u64 (*link_is_up)(struct ntb_dev *ntb,
     enum ntb_speed *speed, enum ntb_width *width);
int (*link_enable)(struct ntb_dev *ntb,
      enum ntb_speed max_speed, enum ntb_width max_width);
int (*link_disable)(struct ntb_dev *ntb);

int (*mw_count)(struct ntb_dev *ntb, int pidx);
int (*mw_get_align)(struct ntb_dev *ntb, int pidx, int widx,
       resource_size_t *addr_align,
       resource_size_t *size_align,
       resource_size_t *size_max);
int (*mw_set_trans)(struct ntb_dev *ntb, int pidx, int widx,
       dma_addr_t addr, resource_size_t size);
int (*mw_clear_trans)(struct ntb_dev *ntb, int pidx, int widx);
int (*peer_mw_count)(struct ntb_dev *ntb);
int (*peer_mw_get_addr)(struct ntb_dev *ntb, int widx,
    phys_addr_t *base, resource_size_t *size);
int (*peer_mw_set_trans)(struct ntb_dev *ntb, int pidx, int widx,
     u64 addr, resource_size_t size);
int (*peer_mw_clear_trans)(struct ntb_dev *ntb, int pidx, int widx);

int (*db_is_unsafe)(struct ntb_dev *ntb);
u64 (*db_valid_mask)(struct ntb_dev *ntb);
int (*db_vector_count)(struct ntb_dev *ntb);
u64 (*db_vector_mask)(struct ntb_dev *ntb, int db_vector);

u64 (*db_read)(struct ntb_dev *ntb);
int (*db_set)(struct ntb_dev *ntb, u64 db_bits);
int (*db_clear)(struct ntb_dev *ntb, u64 db_bits);

u64 (*db_read_mask)(struct ntb_dev *ntb);
int (*db_set_mask)(struct ntb_dev *ntb, u64 db_bits);
int (*db_clear_mask)(struct ntb_dev *ntb, u64 db_bits);

int (*peer_db_addr)(struct ntb_dev *ntb,
       phys_addr_t *db_addr, resource_size_t *db_size,
    u64 *db_data, int db_bit);
u64 (*peer_db_read)(struct ntb_dev *ntb);
int (*peer_db_set)(struct ntb_dev *ntb, u64 db_bits);
int (*peer_db_clear)(struct ntb_dev *ntb, u64 db_bits);

u64 (*peer_db_read_mask)(struct ntb_dev *ntb);
int (*peer_db_set_mask)(struct ntb_dev *ntb, u64 db_bits);
int (*peer_db_clear_mask)(struct ntb_dev *ntb, u64 db_bits);

int (*spad_is_unsafe)(struct ntb_dev *ntb);
int (*spad_count)(struct ntb_dev *ntb);

u32 (*spad_read)(struct ntb_dev *ntb, int sidx);
int (*spad_write)(struct ntb_dev *ntb, int sidx, u32 val);

int (*peer_spad_addr)(struct ntb_dev *ntb, int pidx, int sidx,
         phys_addr_t *spad_addr);
u32 (*peer_spad_read)(struct ntb_dev *ntb, int pidx, int sidx);
int (*peer_spad_write)(struct ntb_dev *ntb, int pidx, int sidx,
          u32 val);

int (*msg_count)(struct ntb_dev *ntb);
u64 (*msg_inbits)(struct ntb_dev *ntb);
u64 (*msg_outbits)(struct ntb_dev *ntb);
u64 (*msg_read_sts)(struct ntb_dev *ntb);
int (*msg_clear_sts)(struct ntb_dev *ntb, u64 sts_bits);
int (*msg_set_mask)(struct ntb_dev *ntb, u64 mask_bits);
int (*msg_clear_mask)(struct ntb_dev *ntb, u64 mask_bits);
u32 (*msg_read)(struct ntb_dev *ntb, int *pidx, int midx);
int (*peer_msg_write)(struct ntb_dev *ntb, int pidx, int midx, u32 msg);
};

static inline int ntb_dev_ops_is_valid(const struct ntb_dev_ops *ops)
{
/* commented callbacks are not required: */
return
  /* Port operations are required for multiport devices */
  !ops->peer_port_count == !ops->port_number &&
  !ops->peer_port_number == !ops->port_number &&
  !ops->peer_port_idx == !ops->port_number &&

  /* Link operations are required */
  ops->link_is_up    &&
  ops->link_enable   &&
  ops->link_disable   &&

  /* One or both MW interfaces should be developed */
  ops->mw_count    &&
  ops->mw_get_align   &&
  (ops->mw_set_trans   ||
   ops->peer_mw_set_trans)  &&
  /* ops->mw_clear_trans && */
  ops->peer_mw_count   &&
  ops->peer_mw_get_addr   &&
  /* ops->peer_mw_clear_trans && */

  /* Doorbell operations are mostly required */
  /* ops->db_is_unsafe && */
  ops->db_valid_mask   &&
  /* both set, or both unset */
  (!ops->db_vector_count == !ops->db_vector_mask) &&
  ops->db_read    &&
  /* ops->db_set && */
  ops->db_clear    &&
  /* ops->db_read_mask && */
  ops->db_set_mask   &&
  ops->db_clear_mask   &&
  /* ops->peer_db_addr && */
  /* ops->peer_db_read && */
  ops->peer_db_set   &&
  /* ops->peer_db_clear && */
  /* ops->peer_db_read_mask && */
  /* ops->peer_db_set_mask && */
  /* ops->peer_db_clear_mask && */

  /* Scrachpads interface is optional */
  /* !ops->spad_is_unsafe == !ops->spad_count && */
  !ops->spad_read == !ops->spad_count  &&
  !ops->spad_write == !ops->spad_count  &&
  /* !ops->peer_spad_addr == !ops->spad_count && */
  /* !ops->peer_spad_read == !ops->spad_count && */
  !ops->peer_spad_write == !ops->spad_count &&

  /* Messaging interface is optional */
  !ops->msg_inbits == !ops->msg_count  &&
  !ops->msg_outbits == !ops->msg_count  &&
  !ops->msg_read_sts == !ops->msg_count  &&
  !ops->msg_clear_sts == !ops->msg_count  &&
  /* !ops->msg_set_mask == !ops->msg_count && */
  /* !ops->msg_clear_mask == !ops->msg_count && */
  !ops->msg_read == !ops->msg_count  &&
  !ops->peer_msg_write == !ops->msg_count  &&
  1;
}

/**
* struct ntb_client - client interested in ntb devices
* @drv: Linux driver object.
* @ops: See &ntb_client_ops.
*/
struct ntb_client {
struct device_driver  drv;
const struct ntb_client_ops ops;
};
#define drv_ntb_client(__drv) container_of((__drv), struct ntb_client, drv)

/**
* struct ntb_dev - ntb device
* @dev: Linux device object.
* @pdev: PCI device entry of the ntb.
* @topo: Detected topology of the ntb.
* @ops: See &ntb_dev_ops.
* @ctx: See &ntb_ctx_ops.
* @ctx_ops: See &ntb_ctx_ops.
*/
struct ntb_dev {
struct device   dev;
struct pci_dev   *pdev;
enum ntb_topo   topo;
const struct ntb_dev_ops *ops;
void    *ctx;
const struct ntb_ctx_ops *ctx_ops;

/* private: */

/* synchronize setting, clearing, and calling ctx_ops */
spinlock_t   ctx_lock;
/* block unregister until device is fully released */
struct completion  released;

#ifdef CONFIG_NTB_MSI
struct ntb_msi *msi;
#endif
};
#define dev_ntb(__dev) container_of((__dev), struct ntb_dev, dev)

/**
* ntb_register_client() - register a client for interest in ntb devices
* @client: Client context.
*
* The client will be added to the list of clients interested in ntb devices.
* The client will be notified of any ntb devices that are not already
* associated with a client, or if ntb devices are registered later.
*
* Return: Zero if the client is registered, otherwise an error number.
*/
#define ntb_register_client(client) \
__ntb_register_client((client), THIS_MODULE, KBUILD_MODNAME)

int __ntb_register_client(struct ntb_client *client, struct module *mod,
     const char *mod_name);

/**
* ntb_unregister_client() - unregister a client for interest in ntb devices
* @client: Client context.
*
* The client will be removed from the list of clients interested in ntb
* devices.  If any ntb devices are associated with the client, the client will
* be notified to remove those devices.
*/
void ntb_unregister_client(struct ntb_client *client);

#define module_ntb_client(__ntb_client) \
module_driver(__ntb_client, ntb_register_client, \
   ntb_unregister_client)

/**
* ntb_register_device() - register a ntb device
* @ntb: NTB device context.
*
* The device will be added to the list of ntb devices.  If any clients are
* interested in ntb devices, each client will be notified of the ntb device,
* until at most one client accepts the device.
*
* Return: Zero if the device is registered, otherwise an error number.
*/
int ntb_register_device(struct ntb_dev *ntb);

/**
* ntb_unregister_device() - unregister a ntb device
* @ntb: NTB device context.
*
* The device will be removed from the list of ntb devices.  If the ntb device
* is associated with a client, the client will be notified to remove the
* device.
*/
void ntb_unregister_device(struct ntb_dev *ntb);

/**
* ntb_set_ctx() - associate a driver context with an ntb device
* @ntb: NTB device context.
* @ctx: Driver context.
* @ctx_ops: Driver context operations.
*
* Associate a driver context and operations with a ntb device.  The context is
* provided by the client driver, and the driver may associate a different
* context with each ntb device.
*
* Return: Zero if the context is associated, otherwise an error number.
*/
int ntb_set_ctx(struct ntb_dev *ntb, void *ctx,
  const struct ntb_ctx_ops *ctx_ops);

/**
* ntb_clear_ctx() - disassociate any driver context from an ntb device
* @ntb: NTB device context.
*
* Clear any association that may exist between a driver context and the ntb
* device.
*/
void ntb_clear_ctx(struct ntb_dev *ntb);

/**
* ntb_link_event() - notify driver context of a change in link status
* @ntb: NTB device context.
*
* Notify the driver context that the link status may have changed.  The driver
* should call ntb_link_is_up() to get the current status.
*/
void ntb_link_event(struct ntb_dev *ntb);

/**
* ntb_db_event() - notify driver context of a doorbell event
* @ntb: NTB device context.
* @vector: Interrupt vector number.
*
* Notify the driver context of a doorbell event.  If hardware supports
* multiple interrupt vectors for doorbells, the vector number indicates which
* vector received the interrupt.  The vector number is relative to the first
* vector used for doorbells, starting at zero, and must be less than
* ntb_db_vector_count().  The driver may call ntb_db_read() to check which
* doorbell bits need service, and ntb_db_vector_mask() to determine which of
* those bits are associated with the vector number.
*/
void ntb_db_event(struct ntb_dev *ntb, int vector);

/**
* ntb_msg_event() - notify driver context of a message event
* @ntb: NTB device context.
*
* Notify the driver context of a message event.  If hardware supports
* message registers, this event indicates, that a new message arrived in
* some incoming message register or last sent message couldn't be delivered.
* The events can be masked/unmasked by the methods ntb_msg_set_mask() and
* ntb_msg_clear_mask().
*/
void ntb_msg_event(struct ntb_dev *ntb);

/**
* ntb_default_port_number() - get the default local port number
* @ntb: NTB device context.
*
* If hardware driver doesn't specify port_number() callback method, the NTB
* is considered with just two ports. So this method returns default local
* port number in compliance with topology.
*
* NOTE Don't call this method directly. The ntb_port_number() function should
* be used instead.
*
* Return: the default local port number
*/
int ntb_default_port_number(struct ntb_dev *ntb);

/**
* ntb_default_port_count() - get the default number of peer device ports
* @ntb: NTB device context.
*
* By default hardware driver supports just one peer device.
*
* NOTE Don't call this method directly. The ntb_peer_port_count() function
* should be used instead.
*
* Return: the default number of peer ports
*/
int ntb_default_peer_port_count(struct ntb_dev *ntb);

/**
* ntb_default_peer_port_number() - get the default peer port by given index
* @ntb: NTB device context.
* @idx: Peer port index (should not differ from zero).
*
* By default hardware driver supports just one peer device, so this method
* shall return the corresponding value from enum ntb_default_port.
*
* NOTE Don't call this method directly. The ntb_peer_port_number() function
* should be used instead.
*
* Return: the peer device port or negative value indicating an error
*/
int ntb_default_peer_port_number(struct ntb_dev *ntb, int pidx);

/**
* ntb_default_peer_port_idx() - get the default peer device port index by
* given port number
* @ntb: NTB device context.
* @port: Peer port number (should be one of enum ntb_default_port).
*
* By default hardware driver supports just one peer device, so while
* specified port-argument indicates peer port from enum ntb_default_port,
* the return value shall be zero.
*
* NOTE Don't call this method directly. The ntb_peer_port_idx() function
* should be used instead.
*
* Return: the peer port index or negative value indicating an error
*/
int ntb_default_peer_port_idx(struct ntb_dev *ntb, int port);

/**
* ntb_port_number() - get the local port number
* @ntb: NTB device context.
*
* Hardware must support at least simple two-ports ntb connection
*
* Return: the local port number
*/
static inline int ntb_port_number(struct ntb_dev *ntb)
{
if (!ntb->ops->port_number)
  return ntb_default_port_number(ntb);

return ntb->ops->port_number(ntb);
}
/**
* ntb_peer_port_count() - get the number of peer device ports
* @ntb: NTB device context.
*
* Hardware may support an access to memory of several remote domains
* over multi-port NTB devices. This method returns the number of peers,
* local device can have shared memory with.
*
* Return: the number of peer ports
*/
static inline int ntb_peer_port_count(struct ntb_dev *ntb)
{
if (!ntb->ops->peer_port_count)
  return ntb_default_peer_port_count(ntb);

return ntb->ops->peer_port_count(ntb);
}

/**
* ntb_peer_port_number() - get the peer port by given index
* @ntb: NTB device context.
* @pidx: Peer port index.
*
* Peer ports are continuously enumerated by NTB API logic, so this method
* lets to retrieve port real number by its index.
*
* Return: the peer device port or negative value indicating an error
*/
static inline int ntb_peer_port_number(struct ntb_dev *ntb, int pidx)
{
if (!ntb->ops->peer_port_number)
  return ntb_default_peer_port_number(ntb, pidx);

return ntb->ops->peer_port_number(ntb, pidx);
}

/**
* ntb_logical_port_number() - get the logical port number of the local port
* @ntb: NTB device context.
*
* The Logical Port Number is defined to be a unique number for each
* port starting from zero through to the number of ports minus one.
* This is in contrast to the Port Number where each port can be assigned
* any unique physical number by the hardware.
*
* The logical port number is useful for calculating the resource indexes
* used by peers.
*
* Return: the logical port number or negative value indicating an error
*/
static inline int ntb_logical_port_number(struct ntb_dev *ntb)
{
int lport = ntb_port_number(ntb);
int pidx;

if (lport < 0)
  return lport;

for (pidx = 0; pidx < ntb_peer_port_count(ntb); pidx++)
  if (lport <= ntb_peer_port_number(ntb, pidx))
   return pidx;

return pidx;
}

/**
* ntb_peer_logical_port_number() - get the logical peer port by given index
* @ntb: NTB device context.
* @pidx: Peer port index.
*
* The Logical Port Number is defined to be a unique number for each
* port starting from zero through to the number of ports minus one.
* This is in contrast to the Port Number where each port can be assigned
* any unique physical number by the hardware.
*
* The logical port number is useful for calculating the resource indexes
* used by peers.
*
* Return: the peer's logical port number or negative value indicating an error
*/
static inline int ntb_peer_logical_port_number(struct ntb_dev *ntb, int pidx)
{
if (ntb_peer_port_number(ntb, pidx) < ntb_port_number(ntb))
  return pidx;
else
  return pidx + 1;
}

/**
* ntb_peer_port_idx() - get the peer device port index by given port number
* @ntb: NTB device context.
* @port: Peer port number.
*
* Inverse operation of ntb_peer_port_number(), so one can get port index
* by specified port number.
*
* Return: the peer port index or negative value indicating an error
*/
static inline int ntb_peer_port_idx(struct ntb_dev *ntb, int port)
{
if (!ntb->ops->peer_port_idx)
  return ntb_default_peer_port_idx(ntb, port);

return ntb->ops->peer_port_idx(ntb, port);
}

/**
* ntb_link_is_up() - get the current ntb link state
* @ntb: NTB device context.
* @speed: OUT - The link speed expressed as PCIe generation number.
* @width: OUT - The link width expressed as the number of PCIe lanes.
*
* Get the current state of the ntb link.  It is recommended to query the link
* state once after every link event.  It is safe to query the link state in
* the context of the link event callback.
*
* Return: bitfield of indexed ports link state: bit is set/cleared if the
*         link is up/down respectively.
*/
static inline u64 ntb_link_is_up(struct ntb_dev *ntb,
     enum ntb_speed *speed, enum ntb_width *width)
{
return ntb->ops->link_is_up(ntb, speed, width);
}

/**
* ntb_link_enable() - enable the local port ntb connection
* @ntb: NTB device context.
* @max_speed: The maximum link speed expressed as PCIe generation number.
* @max_width: The maximum link width expressed as the number of PCIe lanes.
*
* Enable the NTB/PCIe link on the local or remote (for bridge-to-bridge
* topology) side of the bridge. If it's supported the ntb device should train
* the link to its maximum speed and width, or the requested speed and width,
* whichever is smaller. Some hardware doesn't support PCIe link training, so
* the last two arguments will be ignored then.
*
* Return: Zero on success, otherwise an error number.
*/
static inline int ntb_link_enable(struct ntb_dev *ntb,
      enum ntb_speed max_speed,
      enum ntb_width max_width)
{
return ntb->ops->link_enable(ntb, max_speed, max_width);
}

/**
* ntb_link_disable() - disable the local port ntb connection
* @ntb: NTB device context.
*
* Disable the link on the local or remote (for b2b topology) of the ntb.
* The ntb device should disable the link.  Returning from this call must
* indicate that a barrier has passed, though with no more writes may pass in
* either direction across the link, except if this call returns an error
* number.
*
* Return: Zero on success, otherwise an error number.
*/
static inline int ntb_link_disable(struct ntb_dev *ntb)
{
return ntb->ops->link_disable(ntb);
}

/**
* ntb_mw_count() - get the number of inbound memory windows, which could
*                  be created for a specified peer device
* @ntb: NTB device context.
* @pidx: Port index of peer device.
*
* Hardware and topology may support a different number of memory windows.
* Moreover different peer devices can support different number of memory
* windows. Simply speaking this method returns the number of possible inbound
* memory windows to share with specified peer device. Note: this may return
* zero if the link is not up yet.
*
* Return: the number of memory windows.
*/
static inline int ntb_mw_count(struct ntb_dev *ntb, int pidx)
{
return ntb->ops->mw_count(ntb, pidx);
}

/**
* ntb_mw_get_align() - get the restriction parameters of inbound memory window
* @ntb: NTB device context.
* @pidx: Port index of peer device.
* @widx: Memory window index.
* @addr_align: OUT - the base alignment for translating the memory window
* @size_align: OUT - the size alignment for translating the memory window
* @size_max: OUT - the maximum size of the memory window
*
* Get the alignments of an inbound memory window with specified index.
* NULL may be given for any output parameter if the value is not needed.
* The alignment and size parameters may be used for allocation of proper
* shared memory. Note: this must only be called when the link is up.
*
* Return: Zero on success, otherwise a negative error number.
*/
static inline int ntb_mw_get_align(struct ntb_dev *ntb, int pidx, int widx,
       resource_size_t *addr_align,
       resource_size_t *size_align,
       resource_size_t *size_max)
{
if (!(ntb_link_is_up(ntb, NULL, NULL) & BIT_ULL(pidx)))
  return -ENOTCONN;

return ntb->ops->mw_get_align(ntb, pidx, widx, addr_align, size_align,
          size_max);
}

/**
* ntb_mw_set_trans() - set the translation of an inbound memory window
* @ntb: NTB device context.
* @pidx: Port index of peer device.
* @widx: Memory window index.
* @addr: The dma address of local memory to expose to the peer.
* @size: The size of the local memory to expose to the peer.
*
* Set the translation of a memory window.  The peer may access local memory
* through the window starting at the address, up to the size.  The address
* and size must be aligned in compliance with restrictions of
* ntb_mw_get_align(). The region size should not exceed the size_max parameter
* of that method.
*
* This method may not be implemented due to the hardware specific memory
* windows interface.
*
* Return: Zero on success, otherwise an error number.
*/
static inline int ntb_mw_set_trans(struct ntb_dev *ntb, int pidx, int widx,
       dma_addr_t addr, resource_size_t size)
{
if (!ntb->ops->mw_set_trans)
  return 0;

return ntb->ops->mw_set_trans(ntb, pidx, widx, addr, size);
}

/**
* ntb_mw_clear_trans() - clear the translation address of an inbound memory
*                        window
* @ntb: NTB device context.
* @pidx: Port index of peer device.
* @widx: Memory window index.
*
* Clear the translation of an inbound memory window.  The peer may no longer
* access local memory through the window.
*
* Return: Zero on success, otherwise an error number.
*/
static inline int ntb_mw_clear_trans(struct ntb_dev *ntb, int pidx, int widx)
{
if (!ntb->ops->mw_clear_trans)
  return ntb_mw_set_trans(ntb, pidx, widx, 0, 0);

return ntb->ops->mw_clear_trans(ntb, pidx, widx);
}

/**
* ntb_peer_mw_count() - get the number of outbound memory windows, which could
*                       be mapped to access a shared memory
* @ntb: NTB device context.
*
* Hardware and topology may support a different number of memory windows.
* This method returns the number of outbound memory windows supported by
* local device.
*
* Return: the number of memory windows.
*/
static inline int ntb_peer_mw_count(struct ntb_dev *ntb)
{
return ntb->ops->peer_mw_count(ntb);
}

/**
* ntb_peer_mw_get_addr() - get map address of an outbound memory window
* @ntb: NTB device context.
* @widx: Memory window index (within ntb_peer_mw_count() return value).
* @base: OUT - the base address of mapping region.
* @size: OUT - the size of mapping region.
*
* Get base and size of memory region to map.  NULL may be given for any output
* parameter if the value is not needed.  The base and size may be used for
* mapping the memory window, to access the peer memory.
*
* Return: Zero on success, otherwise a negative error number.
*/
static inline int ntb_peer_mw_get_addr(struct ntb_dev *ntb, int widx,
          phys_addr_t *base, resource_size_t *size)
{
return ntb->ops->peer_mw_get_addr(ntb, widx, base, size);
}

/**
* ntb_peer_mw_set_trans() - set a translation address of a memory window
*                           retrieved from a peer device
* @ntb: NTB device context.
* @pidx: Port index of peer device the translation address received from.
* @widx: Memory window index.
* @addr: The dma address of the shared memory to access.
* @size: The size of the shared memory to access.
*
* Set the translation of an outbound memory window.  The local device may
* access shared memory allocated by a peer device sent the address.
*
* This method may not be implemented due to the hardware specific memory
* windows interface, so a translation address can be only set on the side,
* where shared memory (inbound memory windows) is allocated.
*
* Return: Zero on success, otherwise an error number.
*/
static inline int ntb_peer_mw_set_trans(struct ntb_dev *ntb, int pidx, int widx,
     u64 addr, resource_size_t size)
{
if (!ntb->ops->peer_mw_set_trans)
  return 0;

return ntb->ops->peer_mw_set_trans(ntb, pidx, widx, addr, size);
}

/**
* ntb_peer_mw_clear_trans() - clear the translation address of an outbound
*                             memory window
* @ntb: NTB device context.
* @pidx: Port index of peer device.
* @widx: Memory window index.
*
* Clear the translation of a outbound memory window.  The local device may no
* longer access a shared memory through the window.
*
* This method may not be implemented due to the hardware specific memory
* windows interface.
*
* Return: Zero on success, otherwise an error number.
*/
static inline int ntb_peer_mw_clear_trans(struct ntb_dev *ntb, int pidx,
       int widx)
{
if (!ntb->ops->peer_mw_clear_trans)
  return ntb_peer_mw_set_trans(ntb, pidx, widx, 0, 0);

return ntb->ops->peer_mw_clear_trans(ntb, pidx, widx);
}

/**
* ntb_db_is_unsafe() - check if it is safe to use hardware doorbell
* @ntb: NTB device context.
*
* It is possible for some ntb hardware to be affected by errata.  Hardware
* drivers can advise clients to avoid using doorbells.  Clients may ignore
* this advice, though caution is recommended.
*
* Return: Zero if it is safe to use doorbells, or One if it is not safe.
*/
static inline int ntb_db_is_unsafe(struct ntb_dev *ntb)
{
if (!ntb->ops->db_is_unsafe)
  return 0;

return ntb->ops->db_is_unsafe(ntb);
}

/**
* ntb_db_valid_mask() - get a mask of doorbell bits supported by the ntb
* @ntb: NTB device context.
*
* Hardware may support different number or arrangement of doorbell bits.
*
* Return: A mask of doorbell bits supported by the ntb.
*/
static inline u64 ntb_db_valid_mask(struct ntb_dev *ntb)
{
return ntb->ops->db_valid_mask(ntb);
}

/**
* ntb_db_vector_count() - get the number of doorbell interrupt vectors
* @ntb: NTB device context.
*
* Hardware may support different number of interrupt vectors.
*
* Return: The number of doorbell interrupt vectors.
*/
static inline int ntb_db_vector_count(struct ntb_dev *ntb)
{
if (!ntb->ops->db_vector_count)
  return 1;

return ntb->ops->db_vector_count(ntb);
}

/**
* ntb_db_vector_mask() - get a mask of doorbell bits serviced by a vector
* @ntb: NTB device context.
* @vector: Doorbell vector number.
*
* Each interrupt vector may have a different number or arrangement of bits.
*
* Return: A mask of doorbell bits serviced by a vector.
*/
static inline u64 ntb_db_vector_mask(struct ntb_dev *ntb, int vector)
{
if (!ntb->ops->db_vector_mask)
  return ntb_db_valid_mask(ntb);

return ntb->ops->db_vector_mask(ntb, vector);
}

/**
* ntb_db_read() - read the local doorbell register
* @ntb: NTB device context.
*
* Read the local doorbell register, and return the bits that are set.
*
* Return: The bits currently set in the local doorbell register.
*/
static inline u64 ntb_db_read(struct ntb_dev *ntb)
{
return ntb->ops->db_read(ntb);
}

/**
* ntb_db_set() - set bits in the local doorbell register
* @ntb: NTB device context.
* @db_bits: Doorbell bits to set.
*
* Set bits in the local doorbell register, which may generate a local doorbell
* interrupt.  Bits that were already set must remain set.
*
* This is unusual, and hardware may not support it.
*
* Return: Zero on success, otherwise an error number.
*/
static inline int ntb_db_set(struct ntb_dev *ntb, u64 db_bits)
{
if (!ntb->ops->db_set)
  return -EINVAL;

return ntb->ops->db_set(ntb, db_bits);
}

/**
* ntb_db_clear() - clear bits in the local doorbell register
* @ntb: NTB device context.
* @db_bits: Doorbell bits to clear.
*
* Clear bits in the local doorbell register, arming the bits for the next
* doorbell.
*
* Return: Zero on success, otherwise an error number.
*/
static inline int ntb_db_clear(struct ntb_dev *ntb, u64 db_bits)
{
return ntb->ops->db_clear(ntb, db_bits);
}

/**
* ntb_db_read_mask() - read the local doorbell mask
* @ntb: NTB device context.
*
* Read the local doorbell mask register, and return the bits that are set.
*
* This is unusual, though hardware is likely to support it.
*
* Return: The bits currently set in the local doorbell mask register.
*/
static inline u64 ntb_db_read_mask(struct ntb_dev *ntb)
{
if (!ntb->ops->db_read_mask)
  return 0;

return ntb->ops->db_read_mask(ntb);
}

/**
* ntb_db_set_mask() - set bits in the local doorbell mask
* @ntb: NTB device context.
* @db_bits: Doorbell mask bits to set.
*
* Set bits in the local doorbell mask register, preventing doorbell interrupts
* from being generated for those doorbell bits.  Bits that were already set
* must remain set.
*
* Return: Zero on success, otherwise an error number.
*/
static inline int ntb_db_set_mask(struct ntb_dev *ntb, u64 db_bits)
{
return ntb->ops->db_set_mask(ntb, db_bits);
}

/**
* ntb_db_clear_mask() - clear bits in the local doorbell mask
* @ntb: NTB device context.
* @db_bits: Doorbell bits to clear.
*
* Clear bits in the local doorbell mask register, allowing doorbell interrupts
* from being generated for those doorbell bits.  If a doorbell bit is already
* set at the time the mask is cleared, and the corresponding mask bit is
* changed from set to clear, then the ntb driver must ensure that
* ntb_db_event() is called.  If the hardware does not generate the interrupt
* on clearing the mask bit, then the driver must call ntb_db_event() anyway.
*
* Return: Zero on success, otherwise an error number.
*/
static inline int ntb_db_clear_mask(struct ntb_dev *ntb, u64 db_bits)
{
return ntb->ops->db_clear_mask(ntb, db_bits);
}

/**
* ntb_peer_db_addr() - address and size of the peer doorbell register
* @ntb: NTB device context.
* @db_addr: OUT - The address of the peer doorbell register.
* @db_size: OUT - The number of bytes to write the peer doorbell register.
* @db_data: OUT - The data of peer doorbell register
* @db_bit: door bell bit number
*
* Return the address of the peer doorbell register.  This may be used, for
* example, by drivers that offload memory copy operations to a dma engine.
* The drivers may wish to ring the peer doorbell at the completion of memory
* copy operations.  For efficiency, and to simplify ordering of operations
* between the dma memory copies and the ringing doorbell, the driver may
* append one additional dma memory copy with the doorbell register as the
* destination, after the memory copy operations.
*
* Return: Zero on success, otherwise an error number.
*/
static inline int ntb_peer_db_addr(struct ntb_dev *ntb,
       phys_addr_t *db_addr,
       resource_size_t *db_size,
       u64 *db_data, int db_bit)
{
if (!ntb->ops->peer_db_addr)
  return -EINVAL;

return ntb->ops->peer_db_addr(ntb, db_addr, db_size, db_data, db_bit);
}

/**
* ntb_peer_db_read() - read the peer doorbell register
* @ntb: NTB device context.
*
* Read the peer doorbell register, and return the bits that are set.
*
* This is unusual, and hardware may not support it.
*
* Return: The bits currently set in the peer doorbell register.
*/
static inline u64 ntb_peer_db_read(struct ntb_dev *ntb)
{
if (!ntb->ops->peer_db_read)
  return 0;

return ntb->ops->peer_db_read(ntb);
}

/**
* ntb_peer_db_set() - set bits in the peer doorbell register
* @ntb: NTB device context.
* @db_bits: Doorbell bits to set.
*
* Set bits in the peer doorbell register, which may generate a peer doorbell
* interrupt.  Bits that were already set must remain set.
*
* Return: Zero on success, otherwise an error number.
*/
static inline int ntb_peer_db_set(struct ntb_dev *ntb, u64 db_bits)
{
return ntb->ops->peer_db_set(ntb, db_bits);
}

/**
* ntb_peer_db_clear() - clear bits in the peer doorbell register
* @ntb: NTB device context.
* @db_bits: Doorbell bits to clear.
*
* Clear bits in the peer doorbell register, arming the bits for the next
* doorbell.
*
* This is unusual, and hardware may not support it.
*
* Return: Zero on success, otherwise an error number.
*/
static inline int ntb_peer_db_clear(struct ntb_dev *ntb, u64 db_bits)
{
if (!ntb->ops->db_clear)
  return -EINVAL;

return ntb->ops->peer_db_clear(ntb, db_bits);
}

/**
* ntb_peer_db_read_mask() - read the peer doorbell mask
* @ntb: NTB device context.
*
* Read the peer doorbell mask register, and return the bits that are set.
*
* This is unusual, and hardware may not support it.
*
* Return: The bits currently set in the peer doorbell mask register.
*/
static inline u64 ntb_peer_db_read_mask(struct ntb_dev *ntb)
{
if (!ntb->ops->db_read_mask)
  return 0;

return ntb->ops->peer_db_read_mask(ntb);
}

/**
* ntb_peer_db_set_mask() - set bits in the peer doorbell mask
* @ntb: NTB device context.
* @db_bits: Doorbell mask bits to set.
*
* Set bits in the peer doorbell mask register, preventing doorbell interrupts
* from being generated for those doorbell bits.  Bits that were already set
* must remain set.
*
* This is unusual, and hardware may not support it.
*
* Return: Zero on success, otherwise an error number.
*/
static inline int ntb_peer_db_set_mask(struct ntb_dev *ntb, u64 db_bits)
{
if (!ntb->ops->db_set_mask)
  return -EINVAL;

return ntb->ops->peer_db_set_mask(ntb, db_bits);
}

/**
* ntb_peer_db_clear_mask() - clear bits in the peer doorbell mask
* @ntb: NTB device context.
* @db_bits: Doorbell bits to clear.
*
* Clear bits in the peer doorbell mask register, allowing doorbell interrupts
* from being generated for those doorbell bits.  If the hardware does not
* generate the interrupt on clearing the mask bit, then the driver should not
* implement this function!
*
* This is unusual, and hardware may not support it.
*
* Return: Zero on success, otherwise an error number.
*/
static inline int ntb_peer_db_clear_mask(struct ntb_dev *ntb, u64 db_bits)
{
if (!ntb->ops->db_clear_mask)
  return -EINVAL;

return ntb->ops->peer_db_clear_mask(ntb, db_bits);
}

/**
* ntb_spad_is_unsafe() - check if it is safe to use the hardware scratchpads
* @ntb: NTB device context.
*
* It is possible for some ntb hardware to be affected by errata.  Hardware
* drivers can advise clients to avoid using scratchpads.  Clients may ignore
* this advice, though caution is recommended.
*
* Return: Zero if it is safe to use scratchpads, or One if it is not safe.
*/
static inline int ntb_spad_is_unsafe(struct ntb_dev *ntb)
{
if (!ntb->ops->spad_is_unsafe)
  return 0;

return ntb->ops->spad_is_unsafe(ntb);
}

/**
* ntb_spad_count() - get the number of scratchpads
* @ntb: NTB device context.
*
* Hardware and topology may support a different number of scratchpads.
* Although it must be the same for all ports per NTB device.
*
* Return: the number of scratchpads.
*/
static inline int ntb_spad_count(struct ntb_dev *ntb)
{
if (!ntb->ops->spad_count)
  return 0;

return ntb->ops->spad_count(ntb);
}

/**
* ntb_spad_read() - read the local scratchpad register
* @ntb: NTB device context.
* @sidx: Scratchpad index.
*
* Read the local scratchpad register, and return the value.
*
* Return: The value of the local scratchpad register.
*/
static inline u32 ntb_spad_read(struct ntb_dev *ntb, int sidx)
{
if (!ntb->ops->spad_read)
  return ~(u32)0;

return ntb->ops->spad_read(ntb, sidx);
}

/**
* ntb_spad_write() - write the local scratchpad register
* @ntb: NTB device context.
* @sidx: Scratchpad index.
* @val: Scratchpad value.
*
* Write the value to the local scratchpad register.
*
* Return: Zero on success, otherwise an error number.
*/
static inline int ntb_spad_write(struct ntb_dev *ntb, int sidx, u32 val)
{
if (!ntb->ops->spad_write)
  return -EINVAL;

return ntb->ops->spad_write(ntb, sidx, val);
}

/**
* ntb_peer_spad_addr() - address of the peer scratchpad register
* @ntb: NTB device context.
* @pidx: Port index of peer device.
* @sidx: Scratchpad index.
* @spad_addr: OUT - The address of the peer scratchpad register.
*
* Return the address of the peer scratchpad register.  This may be used, for
* example, by drivers that offload memory copy operations to a dma engine.
*
* Return: Zero on success, otherwise an error number.
*/
static inline int ntb_peer_spad_addr(struct ntb_dev *ntb, int pidx, int sidx,
         phys_addr_t *spad_addr)
{
if (!ntb->ops->peer_spad_addr)
  return -EINVAL;

return ntb->ops->peer_spad_addr(ntb, pidx, sidx, spad_addr);
}

/**
* ntb_peer_spad_read() - read the peer scratchpad register
* @ntb: NTB device context.
* @pidx: Port index of peer device.
* @sidx: Scratchpad index.
*
* Read the peer scratchpad register, and return the value.
*
* Return: The value of the peer scratchpad register.
*/
static inline u32 ntb_peer_spad_read(struct ntb_dev *ntb, int pidx, int sidx)
{
if (!ntb->ops->peer_spad_read)
  return ~(u32)0;

return ntb->ops->peer_spad_read(ntb, pidx, sidx);
}

/**
* ntb_peer_spad_write() - write the peer scratchpad register
* @ntb: NTB device context.
* @pidx: Port index of peer device.
* @sidx: Scratchpad index.
* @val: Scratchpad value.
*
* Write the value to the peer scratchpad register.
*
* Return: Zero on success, otherwise an error number.
*/
static inline int ntb_peer_spad_write(struct ntb_dev *ntb, int pidx, int sidx,
          u32 val)
{
if (!ntb->ops->peer_spad_write)
  return -EINVAL;

return ntb->ops->peer_spad_write(ntb, pidx, sidx, val);
}

/**
* ntb_msg_count() - get the number of message registers
* @ntb: NTB device context.
*
* Hardware may support a different number of message registers.
*
* Return: the number of message registers.
*/
static inline int ntb_msg_count(struct ntb_dev *ntb)
{
if (!ntb->ops->msg_count)
  return 0;

return ntb->ops->msg_count(ntb);
}

/**
* ntb_msg_inbits() - get a bitfield of inbound message registers status
* @ntb: NTB device context.
*
* The method returns the bitfield of status and mask registers, which related
* to inbound message registers.
*
* Return: bitfield of inbound message registers.
*/
static inline u64 ntb_msg_inbits(struct ntb_dev *ntb)
{
if (!ntb->ops->msg_inbits)
  return 0;

return ntb->ops->msg_inbits(ntb);
}

/**
* ntb_msg_outbits() - get a bitfield of outbound message registers status
* @ntb: NTB device context.
*
* The method returns the bitfield of status and mask registers, which related
* to outbound message registers.
*
* Return: bitfield of outbound message registers.
*/
static inline u64 ntb_msg_outbits(struct ntb_dev *ntb)
{
if (!ntb->ops->msg_outbits)
  return 0;

return ntb->ops->msg_outbits(ntb);
}

/**
* ntb_msg_read_sts() - read the message registers status
* @ntb: NTB device context.
*
* Read the status of message register. Inbound and outbound message registers
* related bits can be filtered by masks retrieved from ntb_msg_inbits() and
* ntb_msg_outbits().
*
* Return: status bits of message registers
*/
static inline u64 ntb_msg_read_sts(struct ntb_dev *ntb)
{
if (!ntb->ops->msg_read_sts)
  return 0;

return ntb->ops->msg_read_sts(ntb);
}

/**
* ntb_msg_clear_sts() - clear status bits of message registers
* @ntb: NTB device context.
* @sts_bits: Status bits to clear.
*
* Clear bits in the status register.
*
* Return: Zero on success, otherwise a negative error number.
*/
static inline int ntb_msg_clear_sts(struct ntb_dev *ntb, u64 sts_bits)
{
if (!ntb->ops->msg_clear_sts)
  return -EINVAL;

return ntb->ops->msg_clear_sts(ntb, sts_bits);
}

/**
* ntb_msg_set_mask() - set mask of message register status bits
* @ntb: NTB device context.
* @mask_bits: Mask bits.
*
* Mask the message registers status bits from raising the message event.
*
* Return: Zero on success, otherwise a negative error number.
*/
static inline int ntb_msg_set_mask(struct ntb_dev *ntb, u64 mask_bits)
{
if (!ntb->ops->msg_set_mask)
  return -EINVAL;

return ntb->ops->msg_set_mask(ntb, mask_bits);
}

/**
* ntb_msg_clear_mask() - clear message registers mask
* @ntb: NTB device context.
* @mask_bits: Mask bits to clear.
*
* Clear bits in the message events mask register.
*
* Return: Zero on success, otherwise a negative error number.
*/
static inline int ntb_msg_clear_mask(struct ntb_dev *ntb, u64 mask_bits)
{
if (!ntb->ops->msg_clear_mask)
  return -EINVAL;

return ntb->ops->msg_clear_mask(ntb, mask_bits);
}

/**
* ntb_msg_read() - read inbound message register with specified index
* @ntb: NTB device context.
* @pidx: OUT - Port index of peer device a message retrieved from
* @midx: Message register index
*
* Read data from the specified message register. Source port index of a
* message is retrieved as well.
*
* Return: The value of the inbound message register.
*/
static inline u32 ntb_msg_read(struct ntb_dev *ntb, int *pidx, int midx)
{
if (!ntb->ops->msg_read)
  return ~(u32)0;

return ntb->ops->msg_read(ntb, pidx, midx);
}

/**
* ntb_peer_msg_write() - write data to the specified peer message register
* @ntb: NTB device context.
* @pidx: Port index of peer device a message being sent to
* @midx: Message register index
* @msg: Data to send
*
* Send data to a specified peer device using the defined message register.
* Message event can be raised if the midx registers isn't empty while
* calling this method and the corresponding interrupt isn't masked.
*
* Return: Zero on success, otherwise a negative error number.
*/
static inline int ntb_peer_msg_write(struct ntb_dev *ntb, int pidx, int midx,
         u32 msg)
{
if (!ntb->ops->peer_msg_write)
  return -EINVAL;

return ntb->ops->peer_msg_write(ntb, pidx, midx, msg);
}

/**
* ntb_peer_resource_idx() - get a resource index for a given peer idx
* @ntb: NTB device context.
* @pidx: Peer port index.
*
* When constructing a graph of peers, each remote peer must use a different
* resource index (mw, doorbell, etc) to communicate with each other
* peer.
*
* In a two peer system, this function should always return 0 such that
* resource 0 points to the remote peer on both ports.
*
* In a 5 peer system, this function will return the following matrix
*
* pidx \ port    0    1    2    3    4
* 0              0    0    1    2    3
* 1              0    1    1    2    3
* 2              0    1    2    2    3
* 3              0    1    2    3    3
*
* For example, if this function is used to program peer's memory
* windows, port 0 will program MW 0 on all it's peers to point to itself.
* port 1 will program MW 0 in port 0 to point to itself and MW 1 on all
* other ports. etc.
*
* For the legacy two host case, ntb_port_number() and ntb_peer_port_number()
* both return zero and therefore this function will always return zero.
* So MW 0 on each host would be programmed to point to the other host.
*
* Return: the resource index to use for that peer.
*/
static inline int ntb_peer_resource_idx(struct ntb_dev *ntb, int pidx)
{
int local_port, peer_port;

if (pidx >= ntb_peer_port_count(ntb))
  return -EINVAL;

local_port = ntb_logical_port_number(ntb);
peer_port = ntb_peer_logical_port_number(ntb, pidx);

if (peer_port < local_port)
  return local_port - 1;
else
  return local_port;
}

/**
* ntb_peer_highest_mw_idx() - get a memory window index for a given peer idx
* using the highest index memory windows first
*
* @ntb: NTB device context.
* @pidx: Peer port index.
*
* Like ntb_peer_resource_idx(), except it returns indexes starting with
* last memory window index.
*
* Return: the resource index to use for that peer.
*/
static inline int ntb_peer_highest_mw_idx(struct ntb_dev *ntb, int pidx)
{
int ret;

ret = ntb_peer_resource_idx(ntb, pidx);
if (ret < 0)
  return ret;

return ntb_mw_count(ntb, pidx) - ret - 1;
}

struct ntb_msi_desc {
u32 addr_offset;
u32 data;
};

#ifdef CONFIG_NTB_MSI

int ntb_msi_init(struct ntb_dev *ntb, void (*desc_changed)(void *ctx));
int ntb_msi_setup_mws(struct ntb_dev *ntb);
void ntb_msi_clear_mws(struct ntb_dev *ntb);
int ntbm_msi_request_threaded_irq(struct ntb_dev *ntb, irq_handler_t handler,
      irq_handler_t thread_fn,
      const char *name, void *dev_id,
      struct ntb_msi_desc *msi_desc);
void ntbm_msi_free_irq(struct ntb_dev *ntb, unsigned int irq, void *dev_id);
int ntb_msi_peer_trigger(struct ntb_dev *ntb, int peer,
    struct ntb_msi_desc *desc);
int ntb_msi_peer_addr(struct ntb_dev *ntb, int peer,
        struct ntb_msi_desc *desc,
        phys_addr_t *msi_addr);

#else /* not CONFIG_NTB_MSI */

static inline int ntb_msi_init(struct ntb_dev *ntb,
          void (*desc_changed)(void *ctx))
{
return -EOPNOTSUPP;
}
static inline int ntb_msi_setup_mws(struct ntb_dev *ntb)
{
return -EOPNOTSUPP;
}
static inline void ntb_msi_clear_mws(struct ntb_dev *ntb) {}
static inline int ntbm_msi_request_threaded_irq(struct ntb_dev *ntb,
      irq_handler_t handler,
      irq_handler_t thread_fn,
      const char *name, void *dev_id,
      struct ntb_msi_desc *msi_desc)
{
return -EOPNOTSUPP;
}
static inline void ntbm_msi_free_irq(struct ntb_dev *ntb, unsigned int irq,
         void *dev_id) {}
static inline int ntb_msi_peer_trigger(struct ntb_dev *ntb, int peer,
           struct ntb_msi_desc *desc)
{
return -EOPNOTSUPP;
}
static inline int ntb_msi_peer_addr(struct ntb_dev *ntb, int peer,
        struct ntb_msi_desc *desc,
        phys_addr_t *msi_addr)
{
return -EOPNOTSUPP;

}

#endif /* CONFIG_NTB_MSI */

static inline int ntbm_msi_request_irq(struct ntb_dev *ntb,
           irq_handler_t handler,
           const char *name, void *dev_id,
           struct ntb_msi_desc *msi_desc)
{
return ntbm_msi_request_threaded_irq(ntb, handler, NULL, name,
          dev_id, msi_desc);
}

#endif

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