driver core: class: remove struct class_interface * from callbacks

The add_dev and remove_dev callbacks in struct class_interface currently
pass in a pointer back to the class_interface structure that is calling
them, but none of the callback implementations actually use this pointer
as it is pointless (the structure is known, the driver passed it in in
the first place if it is really needed again.)

So clean this up and just remove the pointer from the callbacks and fix
up all callback functions.

Cc: Jean Delvare <jdelvare@suse.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Kurt Schwemmer <kurt.schwemmer@microsemi.com>
Cc: Jon Mason <jdmason@kudzu.us>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Allen Hubbe <allenbh@gmail.com>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Alexandre Bounine <alex.bou9@gmail.com>
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Doug Gilbert <dgilbert@interlog.com>
Cc: John Stultz <jstultz@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Wang Weiyang <wangweiyang2@huawei.com>
Cc: Yang Yingliang <yangyingliang@huawei.com>
Cc: Jakob Koschel <jakobkoschel@gmail.com>
Cc: Cai Xinchen <caixinchen1@huawei.com>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Acked-by: Logan Gunthorpe <logang@deltatee.com>
Link: https://lore.kernel.org/r/2023040250-pushover-platter-509c@gregkh
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

ntb_hw_switchtec: Fix a minor issue in config_req_id_table()

The req_id_table_size field is 16-bit wide, use ioread16() to read the
value.

Signed-off-by: Kelvin Cao <kelvin.cao@microchip.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

ntb_hw_switchtec: Remove code for disabling ID protection

ID protection is a firmware setting for NT window access control. With
it enabled, only the posted requests with requester IDs in the requester
ID table will be allowed to access the NT windows. Otherwise all posted
requests are allowed. Normally user will configure it statically via the
Switchtec config file, and it will take effect when the firmware boots
up. The driver can also toggle the ID protection setting dynamically,
which will overwrite the static setting in the Switchtec config file as
a side effect.

Currently, the driver disables the ID protection. However, it's not
necessary to disable the ID protection at the driver level as the driver
has already configured the proper requester IDs in the requester ID
table to allow the corresponding posted requests to hit the NT windows.
Remove the code that disables the ID protection to make the static
setting prevail.

Note: ID protection is not applicable to non-posted requests.

Signed-off-by: Kelvin Cao <kelvin.cao@microchip.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

ntb_hw_switchtec: Update the way of getting VEP instance ID

Gen4 firmware adds DMA VEP and NVMe VEP support in VEP (virtual EP)
instance ID register in addtion to management EP. Update the way of
getting management VEP instance ID.

Signed-off-by: Kelvin Cao <kelvin.cao@microchip.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

ntb_hw_switchtec: AND with the part_map for a valid tpart_vec

Some firmware versions return 1 in the target partition vector for
undefined partitions. AND with the part_map to give a valid tpart_vec.

Signed-off-by: Jeremy Pallotta <jmpallotta@gmail.com>
Signed-off-by: Kelvin Cao <kelvin.cao@microchip.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

ntb_hw_switchtec: Fix bug with more than 32 partitions

Switchtec could support as mush as 48 partitions, but ffs & fls are
for 32 bit argument, in case of partition index larger than 31, the
current code could not parse the peer partition index correctly.
Change to the 64 bit version __ffs64 & fls64 accordingly to fix this
bug.

Fixes: 3df54c870f52 ("ntb_hw_switchtec: Allow using Switchtec NTB in multi-partition setups")
Signed-off-by: Wesley Sheng <wesley.sheng@microchip.com>
Signed-off-by: Kelvin Cao <kelvin.cao@microchip.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

ntb_hw_switchtec: Fix pff ioread to read into mmio_part_cfg_all

Array mmio_part_cfg_all holds the partition configuration of all
partitions, with partition number as index. Fix this by reading into
mmio_part_cfg_all for pff.

Fixes: 0ee28f26f378 ("NTB: switchtec_ntb: Add link management")
Signed-off-by: Jeremy Pallotta <jmpallotta@gmail.com>
Signed-off-by: Kelvin Cao <kelvin.cao@microchip.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

ntb_hw_switchtec: fix the spelling of "its"

Use the possessive "its" instead of the contraction "it's" (it is)
in user messages.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Kurt Schwemmer <kurt.schwemmer@microsemi.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

ntb_hw_switchtec: Fix ntb_mw_clear_trans error if size == 0

ntb_mw_set_trans() should work as ntb_mw_clear_trans() when size == 0 and/or
addr == 0. But error in xlate_pos checking condition prevents this.
Fix the condition to make ntb_mw_clear_trans() working.

Fixes: 87d11e645e31 (NTB: switchtec_ntb: Add memory window support)
Signed-off-by: Alexander Fomichev <fomichev.ru@gmail.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

ntb_hw_switchtec: make ntb_mw_set_trans() work when addr == 0

On switchtec_ntb_mw_set_trans() call, when (only) address == 0, it acts as
ntb_mw_clear_trans(). Fix this, since address == 0 and size != 0 is valid
combination for setting translation.

Signed-off-by: Alexander Fomichev <fomichev.ru@gmail.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

ntb_hw_switchtec: Fix setup MW with failure bug

Switchtec does not support setting multiple MWs simultaneously. The
driver takes a hardware lock to ensure that two peers are not doing this
simultaneously and it fails if someone else takes the lock. In most
cases, this is fine as clients only setup the MWs once on one side of
the link.

However, there's a race condition when a re-initialization is caused by
a link event. The driver will re-setup the shared memory window
asynchronously and this races with the client setting up it's memory
windows on the link up event.

To fix this we ensure do the entire initialization in a work queue and
signal the client once it's done.

Signed-off-by: Joey Zhang <joey.zhang@microchip.com>
Signed-off-by: Wesley Sheng <wesley.sheng@microchip.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

ntb_hw_switchtec: Skip unnecessary re-setup of shared memory window for crosslink case

In case of NTB crosslink topology, the setting of shared memory window in
the virtual partition doesn't reset on peer's reboot. So skip the
unnecessary re-setup of shared memory window for that case.

Signed-off-by: Wesley Sheng <wesley.sheng@microchip.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

ntb_hw_switchtec: Remove redundant steps of switchtec_ntb_reinit_peer() function

When a re-initialization is caused by a link event, the driver will
re-setup the shared memory window. But at that time, the shared memory
is still valid, and it's unnecessary to free, reallocate and then
initialize it again. We only need to reconfigure the hardware
registers. Remove the redundant steps from
switchtec_ntb_reinit_peer() function.

Signed-off-by: Joey Zhang <joey.zhang@microchip.com>
Signed-off-by: Wesley Sheng <wesley.sheng@microchip.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

ntb_hw_switchtec: potential shift wrapping bug in switchtec_ntb_init_sndev()

This code triggers a Smatch warning:

drivers/ntb/hw/mscc/ntb_hw_switchtec.c:884 switchtec_ntb_init_sndev()
warn: should '(1 << sndev->peer_partition)' be a 64 bit type?

The "part_map" and "tpart_vec" variables are u64 type so this seems like
a valid warning.

Fixes: 3df54c870f52 ("ntb_hw_switchtec: Allow using Switchtec NTB in multi-partition setups")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 288

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms and conditions of the gnu general public license
version 2 as published by the free software foundation this program
is distributed in the hope 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

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 263 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141901.208660670@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

NTB: add new parameter to peer_db_addr() db_bit and db_data

NTB door bell usage depends on NTB hardware.

ex: intel NTB gen1 has one peer door bell register which can be controlled
by the bitmap writen to it, while Intel NTB gen3 has a registers
per door bell and the data trigering the each door bell is always 1.

therefore exposing only peer door bell address forcing the user
to be aware of such low level details

Signed-off-by: Leonid Ravich <Leonid.Ravich@emc.com>
Acked-by: Logan Gunthorpe <logang@deltatee.com>
Acked-by: Dave Jiang <dave.jiang@intel.com>
Acked-by: Allen Hubbe <allenbh@gmail.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

ntb_hw_switchtec: Added support of >=4G memory windows

Current Switchtec's BAR setup registers are limited to 32bits,
corresponding to the maximum MW (memory window) size is <4G.

Increase the MW sizes with the addition of the BAR Setup Extension
Register for the upper 32bits of a 64bits MW size. This increases the MW
range to between 4K and 2^63.

Reported-by: Boris Glimcher <boris.glimcher@emc.com>
Signed-off-by: Paul Selles <paul.selles@microchip.com>
Signed-off-by: Wesley Sheng <wesley.sheng@microchip.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

ntb_hw_switchtec: debug print 64bit aligned crosslink BAR Numbers

Switchtec NTB crosslink BARs are 64bit addressed but they are printed as
32bit addressed BARs. Fix debug log to increment the BAR numbers by 2 to
reflect the 64bit address alignment.

Fixes: 017525018202 ("ntb_hw_switchtec: Add initialization code for crosslink")
Signed-off-by: Paul Selles <paul.selles@microchip.com>
Signed-off-by: Wesley Sheng <wesley.sheng@microchip.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

ntb: ntb_hw_switchtec: Cleanup 64bit IO defines to use the common header

Clean up the ifdefs which conditionally defined the io{read|write}64
functions in favour of the new common io-64-nonatomic-lo-hi header.

Per a nit from Andy Shevchenko, the include list is also made
alphabetical.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Jon Mason <jdmason@kudzu.us>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

cross-tree: phase out dma_zalloc_coherent()

We already need to zero out memory for dma_alloc_coherent(), as such
using dma_zalloc_coherent() is superflous. Phase it out.

This change was generated with the following Coccinelle SmPL patch:

@ replace_dma_zalloc_coherent @
expression dev, size, data, handle, flags;
@@

-dma_zalloc_coherent(dev, size, handle, flags)
+dma_alloc_coherent(dev, size, handle, flags)

Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
[hch: re-ran the script on the latest tree]
Signed-off-by: Christoph Hellwig <hch@lst.de>

switchtec: Use generic PCI Vendor ID and Class Code

Move the Microsemi Switchtec PCI Vendor ID (same as
PCI_VENDOR_ID_PMC_Sierra) to pci_ids.h. Also, replace Microsemi class
constants with the standard PCI definitions.

Signed-off-by: Doug Meyer <dmeyer@gigaio.com>
[bhelgaas: restore SPDX (I assume it was removed by mistake), remove
device ID definitions]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>

ntb_hw_switchtec: Make function switchtec_ntb_remove() static

Fixes the following sparse warnings:

drivers/ntb/hw/mscc/ntb_hw_switchtec.c:1552:6: warning:
symbol 'switchtec_ntb_remove' was not declared. Should it be static?

Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

ntb_hw_switchtec: fix logic error

Newer gcc (version 7 and 8 presumably) warn about a statement mixing
the << operator with logical and:

drivers/ntb/hw/mscc/ntb_hw_switchtec.c: In function 'switchtec_ntb_init_sndev':
drivers/ntb/hw/mscc/ntb_hw_switchtec.c:888:24: error: '<<' in boolean context, did you mean '<' ? [-Werror=int-in-bool-context]

My interpretation here is that the author must have intended a bitmask
rather than a comparison, so I'm changing the '&&' to '&', which makes
a lot more sense in the context.

Fixes: 1b249475275d ("ntb_hw_switchtec: Allow using Switchtec NTB in multi-partition setups")
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

ntb_hw_switchtec: Check for alignment of the buffer in mw_set_trans()

With Switchtec hardware, the buffer used for a memory window must be
aligned to its size (the hardware only replaces the lower bits). In
certain circumstances dma_alloc_coherent() will not provide a buffer
that adheres to this requirement like when using the CMA and
CONFIG_CMA_ALIGNMENT is set lower than the buffer size.

When we get an unaligned buffer mw_set_trans() should return an error.
We also log an error so we know the cause of the problem.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

ntb_hw_switchtec: Force down the link before initializing

If one host crashes and soft reboots, the other host may not see a
link down event. Then when the crashed host comes back up, the
surviving host may not know the link was reset and the NTB clients
may not work without being reset.

To solve this, we send a LINK_FORCE_DOWN message to each peer every
time we come up, before we register the NTB device. If a surviving
host still thinks the link is up it will take it down immediately.
In this way, once the crashed host comes up fully, it will send a
regular link up event as per usual and the link will be properly
restarted.

While we are in the area, this also fixes the MSG_LINK_UP message that
was in the link down function that was reported by Doug Meyers.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reported-by: ThanhTuThai <cruisethai@gmail.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

ntb_hw_switchtec: Crosslink doorbells and messages

In a crosslink configuration doorbells and messages largely work the
same but the NTB registers must be accessed through the reserved LUT
window. Also, as a bonus, seeing there are now two independent sets of
NTB links, both partitions can actually use all 60 doorbell registers
instead of them having to be split into two for each partition.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

ntb_hw_switchtec: Add initialization code for crosslink

Crosslink is a feature of the Switchtec switches that is similar to
the B2B mode of other NTB devices. It allows a system to be designed
that is perfectly symmetric with two identical switches that link
two hosts together.

In order for the system to be symmetric, there is an empty host-less
partition between the two switches which the host must enumerate and
assign BAR addresses to. The firmware in the switch manages this
specially so that the BAR addresses on both sides of the empty
partition will be identical despite being in the same partition with
the same address space.

The driver determines whether crosslink is enabled by a flag set in
the NTB partition info registers which are set by the switch's
configuration file.

When crosslink is enabled, a reserved LUT window is setup to point to
the peer's switch's NTB registers and the local MWs are set to forward
to the host-less partition's BARs. (Yes, this hurts my brain too.)
Once this is setup, largely the same NTB infrastructure is used to
communicate between the two hosts.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

ntb_hw_switchtec: Make switchtec_ntb_init_req_id_table() more general

This is a prep patch in order to support the crosslink feature which
will require the driver to setup the requester ID table in another
partition as well as it's own. To aid this, create a helper function
which sets up the requester IDs from an array.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

ntb_hw_switchtec: Create helper function to setup reserved LUT MWs

This is a prep patch in order to support the crosslink feature which
will require the driver to use another reserved LUT window. To
simplify this we move the code which sets up the reserved LUT window
into a helper function which will be used by the crosslink
initialization.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

ntb_hw_switchtec: Keep track of the number of LUT windows used by the driver

This is a prep patch in order to support the crosslink feature which will
require the driver to use another reserved LUT window. To simplify this,
we add some code to track the number of reserved LUT windows in use
instead of assuming this is always 1.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

ntb_hw_switchtec: Allow using Switchtec NTB in multi-partition setups

Allow using Switchtec NTB in setups that have more than two partitions.
Note: this does not enable having multi-host communication, it only
allows for a single NTB link between two hosts in a network that might
have more than two.

Use following logic to determine the NT peer partition:

1) If there are 2 partitions, and the target vector is set in
the Switchtec configuration, use the partition specified in target
vector.
2) If there are 2 partitions and target vector is unset
use the only other partition as specified in the NT EP map.
3) If there are more than 2 partitions and target vector is set
use the other partition specified in target vector.
4) If there are more than 2 partitions and target vector is unset,
this is invalid and report an error.

Signed-off-by: Kelvin Cao <kelvin.cao@microsemi.com>
[logang@deltatee.com: commit message fleshed out]
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

NTB: switchtec_ntb: Add new line on appropriate printks

Trivial addition of "\n" to the dev_* prints where necessary

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

NTB: switchtec_ntb: fix spelling mistake: "peforming" -> "performing"

Trivial fix to spelling mistake in dev_err error message

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-By: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

NTB: ntb_hw_switchtec: Fix peer BAR bug in switchtec_ntb_init_shared_mw

This resolves a bug which may incorrectly configure the peer host's
LUT for shared memory window access. The code was using the local
host's first BAR number, rather than the peer hosts's first BAR
number, to determine what peer NT control register to program.

The bug will cause the Switchtec NTB link to work only if both peers
have the same first NTB BAR configured. In all other configurations,
the link will not come up, failing silently.

When both hosts have the same first BAR, the configuration works only
because the first BAR numbers happent to be the same. When the hosts
do not have the same first BAR, then the LUT translation will not be
configured in the correct peer LUT and will not give the peer the
shared memory window access required for the link to operate.

Signed-off-by: Doug Meyer <dmeyer@gigaio.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Fixes: 678784a44ae8 ("NTB: switchtec_ntb: Initialize hardware for memory windows")
Signed-off-by: Jon Mason <jdmason@kudzu.us>

NTB: switchtec_ntb: Add memory window support

The Switchtec hardware has two types of memory windows: LUTs and Direct.
The first area in each BAR is for LUT windows and the remaining area is
for the direct region. The total number of LUT entries is set by a
configuration setting in hardware and they all must be the same
size. (This is fixed by switchtec_ntb to be 64K.)

switchtec_ntb enables the LUTs only for the first BAR and enables the
highest power of two possible. Seeing the LUTs are at the beginning of
the BAR, the direct memory window's alignment is affected. Therefore,
the maximum direct memory window size can not be greater than the number
of LUTs times 64K. The direct window in other BARs will not have this
restriction as the LUTs will not be enabled there. LUTs will only be
exposed through the NTB API if the use_lut_mw parameter is set.

Seeing the Switchtec hardware, by default, configures BARs to be 4G a
module parameter is given to limit the size of the advertised memory
windows. Higher layers tend to allocate the maximum BAR size and this
has a tendency to fail when they try to allocate 4GB of contiguous
memory.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Stephen Bates <sbates@raithlin.com>
Reviewed-by: Kurt Schwemmer <kurt.schwemmer@microsemi.com>
Acked-by: Allen Hubbe <Allen.Hubbe@dell.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

NTB: switchtec_ntb: Implement scratchpad registers

Seeing there is no dedicated hardware for this, we simply add
these as entries in the shared memory window. Thus, we could support
any number of them but 128 seems like enough, for now.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Stephen Bates <sbates@raithlin.com>
Reviewed-by: Kurt Schwemmer <kurt.schwemmer@microsemi.com>
Acked-by: Allen Hubbe <Allen.Hubbe@dell.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

NTB: switchtec_ntb: Implement doorbell registers

Pretty straightforward implementation of doorbell registers.
The shift and mask were setup in an earlier patch and this just hooks
up the appropriate portion of the IDB register as the local doorbells
and the opposite portion of ODB as the peer doorbells. The DB mask is
protected by a spinlock to avoid concurrent read-modify-write accesses.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Stephen Bates <sbates@raithlin.com>
Reviewed-by: Kurt Schwemmer <kurt.schwemmer@microsemi.com>
Acked-by: Allen Hubbe <Allen.Hubbe@dell.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

NTB: switchtec_ntb: Add link management

switchtec_ntb checks for a link by looking at the shared memory
window. If the magic number is correct and the other side indicates
their link is enabled then we take the link to be up.

Whenever we change our local link status we send a msg to the
other side to check whether it's up and change their status.

The current status is maintained in a flag so ntb_is_link_up
can return quickly.

We utilize Switchtec's link status notifier to also check link changes
when the switch notices a port changes state.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Stephen Bates <sbates@raithlin.com>
Reviewed-by: Kurt Schwemmer <kurt.schwemmer@microsemi.com>
Acked-by: Allen Hubbe <Allen.Hubbe@dell.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

NTB: switchtec_ntb: Add skeleton NTB driver

Add a skeleton NTB driver which will be filled out in subsequent patches.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Stephen Bates <sbates@raithlin.com>
Reviewed-by: Kurt Schwemmer <kurt.schwemmer@microsemi.com>
Acked-by: Allen Hubbe <Allen.Hubbe@dell.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

NTB: switchtec_ntb: Initialize hardware for doorbells and messages

Set up some hardware registers and creates interrupt service routines
for the doorbells and messages.

There are 64 doorbells in the switch that are shared between all
partitions. The upper 4 doorbells are also shared with the messages
and are therefore not used. Thus, this provides 28 doorbells for each
partition.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Stephen Bates <sbates@raithlin.com>
Reviewed-by: Kurt Schwemmer <kurt.schwemmer@microsemi.com>
Acked-by: Allen Hubbe <Allen.Hubbe@dell.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

NTB: switchtec_ntb: Initialize hardware for memory windows

Add the code to initialize the memory windows in the hardware.
This includes setting up the requester ID table, and figuring out
which BAR corresponds to which memory window. (Seeing the switch
can be configured with any number of BARs.)

Also, seeing the device doesn't have hardware for scratchpads or
determining the link status, we create a shared memory window that has
these features. A magic number with a version component will be used
to determine if the other side's driver is actually up.

The shared memory window also informs the other side of the
size and count of the local memory windows.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Stephen Bates <sbates@raithlin.com>
Reviewed-by: Kurt Schwemmer <kurt.schwemmer@microsemi.com>
Acked-by: Allen Hubbe <Allen.Hubbe@dell.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

NTB: switchtec_ntb: Introduce initial NTB driver

Seeing the Switchtec NTB hardware shares the same endpoint as the
management endpoint we utilize the class_interface API to register
an NTB driver for every Switchtec device in the system that has the
NTB class code.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Stephen Bates <sbates@raithlin.com>
Reviewed-by: Kurt Schwemmer <kurt.schwemmer@microsemi.com>
Acked-by: Allen Hubbe <Allen.Hubbe@dell.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>