NTB: ntb_tool: Switch to memdup_user_nul() helper

Use memdup_user_nul() helper instead of open-coding to simplify the code.

Signed-off-by: Ruan Jinjie <ruanjinjie@huawei.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Serge Semin <fancer.lancer@gmail.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

ntb: Remove error checking for debugfs_create_dir()

It is expected that most callers should _ignore_ the errors
return by debugfs_create_dir() in tool_setup_dbgfs()

Signed-off-by: Wang Ming <machel@vivo.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Serge Semin <fancer.lancer@gmail.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

NTB: ntb_tool: Add check for devm_kcalloc

As the devm_kcalloc may return NULL pointer,
it should be better to add check for the return
value, as same as the others.

Fixes: 7f46c8b3a552 ("NTB: ntb_tool: Add full multi-port NTB API support")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Reviewed-by: Serge Semin <fancer.lancer@gmail.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

NTB: ntb_tool: uninitialized heap data in tool_fn_write()

The call to:

ret = simple_write_to_buffer(buf, size, offp, ubuf, size);

will return success if it is able to write even one byte to "buf".
The value of "*offp" controls which byte. This could result in
reading uninitialized data when we do the sscanf() on the next line.

This code is not really desigined to handle partial writes where
*offp is non-zero and the "buf" is preserved and re-used between writes.
Just ban partial writes and replace the simple_write_to_buffer() with
copy_from_user().

Fixes: 578b881ba9c4 ("NTB: Add tool test client")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

NTB: ntb_tool: reading the link file should not end in a NULL byte

When running ntb_test this warning is issued:

./ntb_test.sh: line 200: warning: command substitution: ignored null
byte in input

This is caused by the kernel returning one more byte than is necessary
when reading the link file.

Reduce the number of bytes read back to 2 as it was before the
commit that regressed this.

Fixes: 7f46c8b3a552 ("NTB: ntb_tool: Add full multi-port NTB API support")
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Acked-by: Allen Hubbe <allenbh@gmail.com>
Tested-by: Alexander Fomichev <fomichev.ru@gmail.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

ntb_tool: pass correct struct device to dma_alloc_coherent

Currently, ntb->dev is passed to dma_alloc_coherent
and dma_free_coherent calls. The returned dma_addr_t
is the CPU physical address. This works fine as long
as IOMMU is disabled. But when IOMMU is enabled, we
need to make sure that IOVA is returned for dma_addr_t.
So the correct way to achieve this is by changing the
first parameter of dma_alloc_coherent() as ntb->pdev->dev
instead.

Fixes: 5648e56d03fa ("NTB: ntb_perf: Add full multi-port NTB API support")
Signed-off-by: Sanjay R Mehta <sanju.mehta@amd.com>
Signed-off-by: Arindam Nath <arindam.nath@amd.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

ntb_tool: Fix printk format

The correct printk format is %pa or %pap, but not %pa[p].

Fixes: 7f46c8b3a5523 ("NTB: ntb_tool: Add full multi-port NTB API support")
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

NTB: ntb_tool: fix memory leak on 'buf' on error exit path

Currently there is a memory leak on buf when the call to ntb_mw_get_align
fails. Add an exit err label and jump to this so that kfree on buf frees
the memory.

Detected by CoverityScan, CID#1464286 ("Resource leak")

Fixes: d637628ce00c ("NTB: ntb_tool: Add full multi-port NTB API support")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Serge Semin <fancer.lancer@gmail.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

NTB: ntb_tool: Add full multi-port NTB API support

Former NTB Debugging tool driver supported only the limited
functionality of the recently updated NTB API, which is now available
to work with the truly NTB multi-port devices and devices, which
got NTB Message registers instead of Scratchpads. This patch
fully rewrites the driver so one would fully expose all the new
NTB API interfaces. Particularly it concerns the Message registers,
peer ports API, NTB link settings. Additional cleanups are also added
here.

Signed-off-by: Serge Semin <fancer.lancer@gmail.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

ntb: remove unneeded DRIVER_LICENSE #defines

There is no need to #define the license of the driver, just put it in
the MODULE_LICENSE() line directly as a text string.

This allows tools that check that the module license matches the source
code license to work properly, as there is no need to unwind the
unneeded dereference, especially when the string is defined just a few
lines above the usage of it.

Reported-and-reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Allen Hubbe <Allen.Hubbe@emc.com>
Cc: Gary R Hook <gary.hook@amd.com>
Cc: Serge Semin <fancer.lancer@gmail.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

NTB: Ensure ntb_mw_get_align() is only called when the link is up

With Switchtec hardware it's impossible to get the alignment parameters
for a peer's memory window until the peer's driver has configured its
windows. Strictly speaking, the link doesn't have to be up for this,
but the link being up is the only way the client can tell that
the other side has been configured.

This patch converts ntb_transport and ntb_perf to use this function after
the link goes up. This simplifies these clients slightly because they
no longer have to store the alignment parameters. It also tweaks
ntb_tool so that peer_mw_trans will print zero if it is run before
the link goes up.

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

ntb: use correct mw_count function in ntb_tool and ntb_transport

After converting to the new API, both ntb_tool and ntb_transport are
using ntb_mw_count to iterate through ntb_peer_get_addr when they
should be using ntb_peer_mw_count.

This probably isn't an issue with the Intel and AMD drivers but
this will matter for any future driver with asymetric memory window
counts.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Acked-by: Allen Hubbe <Allen.Hubbe@emc.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
Fixes: 443b9a14ecbe ("NTB: Alter MW API to support multi-ports devices")

NTB: Alter Scratchpads API to support multi-ports devices

Even though there is no any real NTB hardware, which would have both more
than two ports and Scratchpad registers, it is logically correct to have
Scratchpad API accepting a peer port index as well. Intel/AMD drivers utilize
Primary and Secondary topology to split Scratchpad between connected root
devices. Since port-index API introduced, Intel/AMD NTB hardware drivers can
use device port to determine which Scratchpad registers actually belong to
local and peer devices. The same approach can be used if some potential
hardware in future will be multi-port and have some set of Scratchpads.
Here are the brief of changes in the API:
ntb_spad_count() - return number of Scratchpads per each port
ntb_peer_spad_addr(pidx, sidx) - address of Scratchpad register of the
peer device with pidx-index
ntb_peer_spad_read(pidx, sidx) - read specified Scratchpad register of the
peer with pidx-index
ntb_peer_spad_write(pidx, sidx) - write data to Scratchpad register of the
peer with pidx-index

Since there is hardware which doesn't support Scratchpad registers, the
corresponding API methods are now made optional.

Signed-off-by: Serge Semin <fancer.lancer@gmail.com>
Acked-by: Allen Hubbe <Allen.Hubbe@dell.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

NTB: Alter MW API to support multi-ports devices

Multi-port NTB devices permit to share a memory between all accessible peers.
Memory Windows API is altered to correspondingly initialize and map memory
windows for such devices:
ntb_mw_count(pidx); - number of inbound memory windows, which can be allocated
for shared buffer with specified peer device.
ntb_mw_get_align(pidx, widx); - get alignment and size restriction parameters
to properly allocate inbound memory region.
ntb_peer_mw_count(); - get number of outbound memory windows.
ntb_peer_mw_get_addr(widx); - get mapping address of an outbound memory window

If hardware supports inbound translation configured on the local ntb port:
ntb_mw_set_trans(pidx, widx); - set translation address of allocated inbound
memory window so a peer device could access it.
ntb_mw_clear_trans(pidx, widx); - clear the translation address of an inbound
memory window.

If hardware supports outbound translation configured on the peer ntb port:
ntb_peer_mw_set_trans(pidx, widx); - set translation address of a memory
window retrieved from a peer device
ntb_peer_mw_clear_trans(pidx, widx); - clear the translation address of an
outbound memory window

Signed-off-by: Serge Semin <fancer.lancer@gmail.com>
Acked-by: Allen Hubbe <Allen.Hubbe@dell.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

NTB: Add indexed ports NTB API

There is some NTB hardware, which can combine more than just two domains
over NTB. For instance, some IDT PCIe-switches can have NTB-functions
activated on more than two-ports. The different domains are distinguished
by ports they are connected to. So the new port-related methods are added to
the NTB API:
ntb_port_number() - return local port
ntb_peer_port_count() - return number of peers local port can connect to
ntb_peer_port_number(pdix) - return port number by it index
ntb_peer_port_idx(port) - return port index by it number

Current test-drivers aren't changed much. They still support two-ports devices
for the time being while multi-ports hardware drivers aren't added.

By default port-related API is declared for two-ports hardware.
So corresponding hardware drivers won't need to implement it.

Signed-off-by: Serge Semin <fancer.lancer@gmail.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

ntb_tool: Add link status and files to debugfs

In order to more successfully script with ntb_tool it's useful to
have a link file to check the link status so that the script
doesn't use the other files until the link is up.

This commit adds a 'link' file to the debugfs directory which reads
boolean (Y or N) depending on the link status. Writing to the file
change the link state using ntb_link_enable or ntb_link_disable.

A 'link_event' file is also provided so an application can block until
the link changes to the desired state. If the user writes a 1, it will
block until the link is up. If the user writes a 0, it will block until
the link is down.

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

ntb_tool: Postpone memory window initialization for the user

In order to make the interface closer to the raw NTB API, this commit
changes memory windows so they are not initialized on link up.
Instead, the 'peer_trans*' debugfs files are introduced. When read,
they return information provided by ntb_mw_get_range. When written,
they create a buffer and initialize the memory window. The
value written is taken as the requested size of the buffer (which
is then rounded for alignment). Writing a value of zero frees the buffer
and tears down the memory window translation. The 'peer_mw*' file is
only created once the memory window translation is setup by the user.

Additionally, it was noticed that the read and write functions for the
'peer_mw*' files should have checked for a NULL pointer.

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

ntb_tool: Add memory window debug support

We allocate some memory window buffers when the link comes up, then we
provide debugfs files to read/write each side of the link.

This is useful for debugging the mapping when writing new drivers.

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

ntb_tool: BUG: Ensure the buffer size is large enough to return all spads

On hardware with 32 scratchpad registers the spad field in ntb tool
could chop off the end. The maximum buffer size is increased from
256 to 15 times the number or scratchpads.

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

ntb_tool: Fix infinite loop bug when writing spad/peer_spad file

If you tried to write two spads in one line, as per the example:

root@peer# echo '0 0x01010101 1 0x7f7f7f7f' > $DBG_DIR/peer_spad

then the CPU would freeze in an infinite loop.

This wasn't immediately obvious but 'pos' was not incrementing the
buffer, so after reading the second pair of values, 'pos' would once
again be 3 and it would re-read the second pair of values ad infinitum.

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

NTB: Add tool test client

This is a simple debugging driver that enables the doorbell and
scratch pad registers to be read and written from the debugfs. This
tool enables more complicated debugging to be scripted from user space.
This driver may be used to test that your ntb hardware and drivers are
functioning at a basic level.

Signed-off-by: Allen Hubbe <Allen.Hubbe@emc.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>