netronome: Replace zero-length array with flexible-array member

The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
int stuff;
struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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: make RTsym users handle absolute symbols correctly

Make the RTsym users access the size via the helper, which
takes care of special handling of absolute symbols.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Francois H. Theron <francois.theron@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

nfp: convert all RTsym users to use new read/write helpers

Convert all users of RTsym to the new set of helpers which
handle all targets correctly.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Francois H. Theron <francois.theron@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

nfp: fix fw dump handling of absolute rtsym size

Fix bug that causes _absolute_ rtsym sizes of > 8 bytes (as per symbol
table) to result in incorrect space used during a TLV-based debug dump.

Detail: The size calculation stage calculates the correct size (size of
the rtsym address field == 8), while the dump uses the size in the table
to calculate the TLV size to reserve. Symbols with size <= 8 are handled
OK due to aligning sizes to 8, but including any absolute symbol with
listed size > 8 leads to an ENOSPC error during the dump.

Fixes: da762863edd9 ("nfp: fix absolute rtsym handling in debug dump")
Signed-off-by: Carl Heymann <carl.heymann@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

nfp: core: make scalar CPP helpers fail on short accesses

Currently the helpers for accessing 4 or 8 byte values over
the CPP bus return the length of IO on success. If the IO
was short caller has to deal with error handling. The short
IO for 4/8B values is completely impractical. Make the
helpers return an error if full access was not possible.
Fix the few places which are actually dealing with errors
correctly, most call sites already only deal with negative
return codes.

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 XPB register reads in debug dump

For XPB registers reads, some island IDs require special handling (e.g.
ARM island), which is already taken care of in nfp_xpb_readl(), so use
that instead of a straight CPP read.

Without this fix all "xpbm:ArmIsldXpbmMap.*" registers are reported as
0xffffffff. It has also been observed to cause a system reboot.

With this fix correct values are reported, none of which are 0xffffffff.

The values may be read using ethtool debug level 2.
# ethtool -W <netdev> 2
# ethtool -w <netdev> data dump.dat

Fixes: 0e6c4955e149 ("nfp: dump CPP, XPB and direct ME CSRs")
Signed-off-by: Carl Heymann <carl.heymann@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

nfp: fix absolute rtsym handling in debug dump

In TLV-based ethtool debug dumps, don't do a CPP read for absolute
rtsyms, use the addr field in the symbol table directly as the value.

Without this fix rtsym gro_release_ring_0 is 4 bytes of zeros.
With this fix the correct value, 0x0000004a 0x00000000 is reported.

The values may be read using ethtool debug level 2.
# ethtool -W <netdev> 2
# ethtool -w <netdev> data dump.dat

Fixes: e1e798e3fd93 ("nfp: dump rtsyms")
Signed-off-by: Carl Heymann <carl.heymann@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

nfp: debug dump - decrease endian conversions

Convert the requested dump level parameter to big-endian at the start of
nfp_net_dump_calculate_size() and nfp_net_dump_populate_buffer(), then
compare and assign it directly where needed in the traversal and prolog
code. This decreases the total number of conversions used.

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

nfp: dump indirect ME CSRs

- The spec defines CSR address ranges for indirect ME CSRs. For Each TLV
chunk in the spec, dump a chunk that includes the spec and the data
over the defined address range.
- Each indirect CSR has 8 contexts. To read one context, first write the
context to a specific derived address, read it back, and then read the
register value.
- For each address, read and dump all 8 contexts in this manner.

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

nfp: dump CPP, XPB and direct ME CSRs

- The spec defines CSR address ranges for these types.
- Dump each TLV chunk in the spec as a chunk that includes the spec and
the data over the defined address range.

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

nfp: dump firmware name

Dump FW name as TLV, based on dump specification.

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

nfp: dump single hwinfo field by key

- Add spec TLV for hwinfo field, containing key string as data.
- Add dump TLV for hwinfo field, with data being key and value as packed
zero-terminated strings.
- If specified hwinfo field is not found, dump the spec TLV as -ENOENT
error.

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

nfp: dump all hwinfo

- Dump hwinfo as separate TLV chunk, in a packed format containing
zero-separated key and value strings.
- This provides additional debug context, if requested by the dumpspec.

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

nfp: dump rtsyms

- Support rtsym TLVs.
- If specified rtsym is not found, dump the spec TLV as -ENOENT error.

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

nfp: dumpspec TLV traversal

- Perform dumpspec traversals for calculating size and populating the
dump.
- Initially, wrap all spec TLVs in dump error TLVs (changed by later
patches in the series).

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

nfp: dump prolog

- Use a TLV structure, with the typed chunks aligned to 8-byte sizes.
- Dump numeric fields as big-endian.
- Prolog contains the dump level.

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

nfp: load debug dump spec

Load the TLV-based binary specification of what needs to be included in
a dump, from the "_abi_dump_spec" rtsymbol. If the symbol is not defined,
then dumps for levels >= 1 are not supported.

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

nfp: debug dump ethtool ops

- Skeleton code to perform a binary debug dump via ethtoolops
"set_dump", "get_dump_flags" and "get_dump_data", i.e. the ethtool
-W/w mechanism.
- Skeleton functions for debugdump operations provided.
- An integer "dump level" can be specified, this is stored between
ethtool invocations. Dump level 0 is still the "arm.diag" resource for
backward compatibility. Other dump levels each define a set of state
information to include in the dump, driven by a spec from FW.

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