nfp: replace deprecated strncpy with strscpy

strncpy() is deprecated for use on NUL-terminated destination strings
[1] and as such we should prefer more robust and less ambiguous string
interfaces.

We expect res->name to be NUL-terminated based on its usage with format
strings:
| dev_err(cpp->dev.parent, "Dangling area: %d:%d:%d:0x%0llx-0x%0llx%s%s\n",
| NFP_CPP_ID_TARGET_of(res->cpp_id),
| NFP_CPP_ID_ACTION_of(res->cpp_id),
| NFP_CPP_ID_TOKEN_of(res->cpp_id),
| res->start, res->end,
| res->name ? " " : "",
| res->name ? res->name : "");
... and with strcmp()
| if (!strcmp(res->name, NFP_RESOURCE_TBL_NAME)) {

Moreover, NUL-padding is not required as `res` is already
zero-allocated:
| res = kzalloc(sizeof(*res), GFP_KERNEL);

Considering the above, a suitable replacement is `strscpy` [2] due to
the fact that it guarantees NUL-termination on the destination buffer
without unnecessarily NUL-padding.

Let's also opt to use the more idiomatic strscpy() usage of (dest, src,
sizeof(dest)) rather than (dest, src, SOME_LEN).

Typically the pattern of 1) allocate memory for string, 2) copy string
into freshly-allocated memory is a candidate for kmemdup_nul() but in
this case we are allocating the entirety of the `res` struct and that
should stay as is. As mentioned above, simple 1:1 replacement of strncpy
-> strscpy :)

Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2]
Link: https://github.com/KSPP/linux/issues/90
Signed-off-by: Justin Stitt <justinstitt@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Louis Peens <louis.peens@corigine.com>
Link: https://lore.kernel.org/r/20231011-strncpy-drivers-net-ethernet-netronome-nfp-nfpcore-nfp_resource-c-v1-1-7d1c984f0eba@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

nfp: replace long license headers with SPDX

Replace the repeated license text with SDPX identifiers.
While at it bump the Copyright dates for files we touched
this year.

Signed-off-by: Edwin Peer <edwin.peer@netronome.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Nic Viljoen <nick.viljoen@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

nfp: don't pad strings in nfp_cpp_resource_find() to avoid gcc 8 warning

Once upon a time nfp_cpp_resource_find() took a name parameter,
which could be any user-chosen string. Resources are identified
by a CRC32 hash of a 8 byte string, so we had to pad user input
with zeros to make sure CRC32 gave the correct result.

Since then nfp_cpp_resource_find() was made to operate on allocated
resources only (struct nfp_resource). We kzalloc those so there is
no need to pad the strings and use memcmp.

This avoids a GCC 8 stringop-truncation warning:

In function ‘nfp_cpp_resource_find’,
inlined from ‘nfp_resource_try_acquire’ at .../nfpcore/nfp_resource.c:153:8,
inlined from ‘nfp_resource_acquire’ at .../nfpcore/nfp_resource.c:206:9:
.../nfpcore/nfp_resource.c:108:2: warning: strncpy’ output may be truncated copying 8 bytes from a string of length 8 [-Wstringop-truncation]
strncpy(name_pad, res->name, sizeof(name_pad));
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

nfp: reset local locks on init

NFP locks record the owner when held, for PCIe devices the owner
ID will be the PCIe link number. When driver loads it should scan
known locks and if they indicate that they are held by local
endpoint but the driver doesn't hold them - release them.

Locks can be left taken for instance when kernel gets kexec-ed or
after a crash. Management FW tries to clean up stale locks too,
but it currently depends on PCIe link going down which doesn't
always happen.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

nfp: fix kdoc warnings on nested structures

Commit 84ce5b987783 ("scripts: kernel-doc: improve nested logic to
handle multiple identifiers") improved the handling of nested structure
definitions in scripts/kernel-doc, and changed the expected format of
documentation. This causes new warnings to appear on W=1 builds.

Only comment changes.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

nfp: wait for the NSP resource to appear on boot

The control process (NSP) may take some time to complete its
initialization. This is not a problem on most servers, but
on very fast-booting machines it may not be ready for operation
when driver probes the device. There is also a version of the
flash in the wild where NSP tries to train the links as part
of init. To wait for NSP initialization we should make sure
its resource has already been added to the resource table.
NSP adds itself there as last step of init.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

nfp: don't wait for resources indefinitely

There is currently no timeout to the resource and lock acquiring
loops. We printed warnings and depended on user sending a signal
to the waiting process to stop the waiting. This doesn't work
very well when wait happens out of a work queue. The simplest
example of that is PCI probe. When user loads the module and card
is in a broken state modprobe will wait forever and signals sent
to it will not actually reach the probing thread.

Make sure all wait loops have a time out. Set the upper wait time
to 60 seconds to stay on the safe side.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

nfp: fail graciously when someone tries to grab global lock

The global device lock is acquired to search the resource table.
The lock is actually itself part of the table (entry 0).
Therefore if someone asks for resource 0 we would deadlock since
double locking is no longer allowed.

Currently the driver doesn't try to lock that resource so let's
simply make sure we fail graciously and not add special handling
of this case until really need. Hide the relevant defines in
the source file.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

nfp: add support for resources

Resource table is an array placed in a well defined location
in device's memory which describes device resources and contains
locks which have to be acquired to use them.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>