dev/ntb/ntb_if.m

#-
# Copyright (c) 2016 Alexander Motin <mav@FreeBSD.org>
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
#
# $FreeBSD: stable/10/sys/dev/ntb/ntb_if.m 304380 2016-08-18 10:39:00Z mav $
#

#include <sys/bus.h>
#include <machine/bus.h>

INTERFACE ntb;

HEADER {
	enum ntb_speed {
		NTB_SPEED_AUTO = -1,
		NTB_SPEED_NONE = 0,
		NTB_SPEED_GEN1 = 1,
		NTB_SPEED_GEN2 = 2,
		NTB_SPEED_GEN3 = 3,
	};

	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,
	};

	typedef void (*ntb_db_callback)(void *data, uint32_t vector);
	typedef void (*ntb_event_callback)(void *data);
	struct ntb_ctx_ops {
		ntb_event_callback	link_event;
		ntb_db_callback		db_event;
	};
};

#
# 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
#
# RETURNS: true or false based on the hardware link state
#
METHOD bool link_is_up {
	device_t	 ntb;
	enum ntb_speed	*speed;
	enum ntb_width	*width;
};

#
# ntb_link_enable() - enable the link on the secondary side of the ntb
# @ntb:        NTB device context
# @max_speed:  The maximum link speed expressed as PCIe generation number[0]
# @max_width:  The maximum link width expressed as the number of PCIe lanes[0]
#
# Enable the link on the secondary side of the ntb.  This can only be done
# from the primary side of the ntb in primary or b2b topology.  The ntb device
# should train the link to its maximum speed and width, or the requested speed
# and width, whichever is smaller, if supported.
#
# Return: Zero on success, otherwise an error number.
#
# [0]: Only NTB_SPEED_AUTO and NTB_WIDTH_AUTO are valid inputs; other speed
#      and width input will be ignored.
#/
METHOD int link_enable {
	device_t	 ntb;
	enum ntb_speed	 speed;
	enum ntb_width	 width;
};

#
# ntb_link_disable() - disable the link on the secondary side of the ntb
# @ntb:        NTB device context
#
# Disable the link on the secondary side of the ntb.  This can only be done
# from the primary side of the ntb in primary or b2b topology.  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.
#
METHOD int link_disable {
	device_t	 ntb;
};

#
# get enable status of the link on the secondary side of the ntb
#
METHOD bool link_enabled {
	device_t	 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.
#
METHOD int set_ctx {
	device_t	 ntb;
	void		*ctx;
	const struct ntb_ctx_ops *ctx_ops;
};

#
# ntb_set_ctx() - get a driver context associated with an ntb device
# @ntb:        NTB device context
# @ctx_ops:    Driver context operations
#
# Get a driver context and operations associated with a ntb device.
#
METHOD void * get_ctx {
	device_t	 ntb;
	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.
#
METHOD void clear_ctx {
	device_t	 ntb;
};

#
# ntb_mw_count() - Get the number of memory windows available for KPI
# consumers.
#
# (Excludes any MW wholly reserved for register access.)
#
METHOD uint8_t mw_count {
	device_t	 ntb;
};

#
# ntb_mw_get_range() - get the range of a memory window
# @ntb:        NTB device context
# @idx:        Memory window number
# @base:       OUT - the base address for mapping the memory window
# @size:       OUT - the size for mapping the memory window
# @align:      OUT - the base alignment for translating the memory window
# @align_size: OUT - the size alignment for translating the memory window
#
# Get the range of a memory window.  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.  The alignment and
# size may be used for translating the memory window, for the peer to access
# memory on the local system.
#
# Return: Zero on success, otherwise an error number.
#
METHOD int mw_get_range {
	device_t	 ntb;
	unsigned	 mw_idx;
	vm_paddr_t	*base;
	caddr_t		*vbase;
	size_t		*size;
	size_t		*align;
	size_t		*align_size;
	bus_addr_t	*plimit;
};

#
# ntb_mw_set_trans() - set the translation of a memory window
# @ntb:        NTB device context
# @idx:        Memory window number
# @addr:       The dma address 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
# must be aligned to the alignment specified by ntb_mw_get_range().  The size
# must be aligned to the size alignment specified by ntb_mw_get_range().  The
# address must be below the plimit specified by ntb_mw_get_range() (i.e. for
# 32-bit BARs).
#
# Return: Zero on success, otherwise an error number.
#
METHOD int mw_set_trans {
	device_t	 ntb;
	unsigned	 mw_idx;
	bus_addr_t	 addr;
	size_t		 size;
};

#
# ntb_mw_clear_trans() - clear the translation of a memory window
# @ntb:	NTB device context
# @idx:	Memory window number
#
# Clear the translation of a memory window.  The peer may no longer access
# local memory through the window.
#
# Return: Zero on success, otherwise an error number.
#
METHOD int mw_clear_trans {
	device_t	 ntb;
	unsigned	 mw_idx;
};

#
# ntb_mw_get_wc - Get the write-combine status of a memory window
#
# Returns:  Zero on success, setting *wc; otherwise an error number (e.g. if
# idx is an invalid memory window).
#
# Mode is a VM_MEMATTR_* type.
#
METHOD int mw_get_wc {
	device_t	 ntb;
	unsigned	 mw_idx;
	vm_memattr_t	*mode;
};

#
# ntb_mw_set_wc - Set the write-combine status of a memory window
#
# If 'mode' matches the current status, this does nothing and succeeds.  Mode
# is a VM_MEMATTR_* type.
#
# Returns:  Zero on success, setting the caching attribute on the virtual
# mapping of the BAR; otherwise an error number (e.g. if idx is an invalid
# memory window, or if changing the caching attribute fails).
#
METHOD int mw_set_wc {
	device_t	 ntb;
	unsigned	 mw_idx;
	vm_memattr_t	 mode;
};

#
# ntb_spad_count() - get the total scratch regs usable
# @ntb: pointer to ntb_softc instance
#
# This function returns the max 32bit scratchpad registers usable by the
# upper layer.
#
# RETURNS: total number of scratch pad registers available
#
METHOD uint8_t spad_count {
	device_t	 ntb;
};

#
# ntb_get_max_spads() - zero local scratch registers
# @ntb: pointer to ntb_softc instance
#
# This functions overwrites all local scratchpad registers with zeroes.
#
METHOD void spad_clear {
	device_t	 ntb;
};

#
# ntb_spad_write() - write to the secondary scratchpad register
# @ntb: pointer to ntb_softc instance
# @idx: index to the scratchpad register, 0 based
# @val: the data value to put into the register
#
# This function allows writing of a 32bit value to the indexed scratchpad
# register. The register resides on the secondary (external) side.
#
# RETURNS: An appropriate ERRNO error value on error, or zero for success.
#
METHOD int spad_write {
	device_t	 ntb;
	unsigned int	 idx;
	uint32_t	 val;
};

#
# ntb_spad_read() - read from the primary scratchpad register
# @ntb: pointer to ntb_softc instance
# @idx: index to scratchpad register, 0 based
# @val: pointer to 32bit integer for storing the register value
#
# This function allows reading of the 32bit scratchpad register on
# the primary (internal) side.
#
# RETURNS: An appropriate ERRNO error value on error, or zero for success.
#
METHOD int spad_read {
	device_t	 ntb;
	unsigned int	 idx;
	uint32_t	 *val;
};

#
# ntb_peer_spad_write() - write to the secondary scratchpad register
# @ntb: pointer to ntb_softc instance
# @idx: index to the scratchpad register, 0 based
# @val: the data value to put into the register
#
# This function allows writing of a 32bit value to the indexed scratchpad
# register. The register resides on the secondary (external) side.
#
# RETURNS: An appropriate ERRNO error value on error, or zero for success.
#
METHOD int peer_spad_write {
	device_t	 ntb;
	unsigned int	 idx;
	uint32_t	 val;
};

#
# ntb_peer_spad_read() - read from the primary scratchpad register
# @ntb: pointer to ntb_softc instance
# @idx: index to scratchpad register, 0 based
# @val: pointer to 32bit integer for storing the register value
#
# This function allows reading of the 32bit scratchpad register on
# the primary (internal) side.
#
# RETURNS: An appropriate ERRNO error value on error, or zero for success.
#
METHOD int peer_spad_read {
	device_t	 ntb;
	unsigned int	 idx;
	uint32_t	*val;
};

#
# 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.
#
METHOD uint64_t db_valid_mask {
	device_t	 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.
#
METHOD int db_vector_count {
	device_t	 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.
#
METHOD uint64_t db_vector_mask {
	device_t	 ntb;
	uint32_t	 vector;
};

#
# 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.
#
# 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.
#
# Note that writing the peer doorbell via a memory window will *not* generate
# an interrupt on the remote host; that must be done separately.
#
METHOD int peer_db_addr {
	device_t	 ntb;
	bus_addr_t	*db_addr;
	vm_size_t	*db_size;
};

#
# 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.
#
METHOD void db_clear {
	device_t	 ntb;
	uint64_t	 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.
#
METHOD void db_clear_mask {
	device_t	 ntb;
	uint64_t	 bits;
};

#
# 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.
#
METHOD uint64_t db_read {
	device_t	 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.
#
METHOD void db_set_mask {
	device_t	 ntb;
	uint64_t	 bits;
};

#
# ntb_peer_db_set() - Set the doorbell on the secondary/external side
# @ntb: pointer to ntb_softc instance
# @bit: doorbell bits to ring
#
# This function allows triggering of a doorbell on the secondary/external
# side that will initiate an interrupt on the remote host
#
METHOD void peer_db_set {
	device_t	 ntb;
	uint64_t	 bits;
};