mlxsw: Use refcount_t for reference counting

mlxsw driver uses 'unsigned int' for reference counters in several
structures. Instead, use refcount_t type which allows us to catch overflow
and underflow issues. Change the type of the counters and use the
appropriate API.

Signed-off-by: Amit Cohen <amcohen@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

mlxsw: core_acl_flex_keys: Fill blocks with high entropy first

The previous patches prepared the code to allow separating between
choosing blocks and filling blocks.

Do not add blocks as part of the loop that chooses them. When all the
required blocks are set in the bitmap 'chosen_blocks_bm', start filling
blocks. Iterate over the bitmap twice - first add only blocks that are
marked with 'high_entropy' flag. Then, fill the rest of the blocks.

The idea is to place key blocks with high entropy in blocks 0 to 5. See
more details in previous patches.

Signed-off-by: Amit Cohen <amcohen@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: core_acl_flex_keys: Save chosen elements in all blocks per search

Currently, mlxsw_afk_picker() chooses which blocks will be used for a
given list of elements, and fills the blocks during the searching - when a
key block is found with most hits, it adds it and removes the elements from
the count of hits. This should be changed as we want to be able to choose
which blocks will be placed in blocks 0 to 5.

To separate between choosing blocks and filling blocks, several pre-changes
are required. Currently, the indication of whether all elements were
found in the chosen blocks is by the structure 'key_info->elusage'. This
structure is updated when block is filled as part of
mlxsw_afk_picker_key_info_add(). A following patch will call this
function only after choosing all the blocks. Add a bitmap called
'elusage_chosen' to store which elements were chosen in the chosen blocks.
Change the condition in the loop to check elements that were chosen, not
elements that were already filled in the blocks.

Signed-off-by: Amit Cohen <amcohen@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: core_acl_flex_keys: Save chosen elements per block

Currently, mlxsw_afk_picker() chooses which blocks will be used for a
given list of elements, and fills the blocks during the searching - when a
key block is found with most hits, it adds it and removes the elements from
the count of hits. This should be changed as we want to be able to choose
which blocks will be placed in blocks 0 to 5.

To separate between choosing blocks and filling blocks, several pre-changes
are required. During the search, the structure 'mlxsw_afk_picker' is
used per block, it contains how many elements from the required list appear
in the block. When a block is chosen and filled, this bitmap of elements is
cleaned. To be able to fill the blocks at the end, add a bitmap called
'chosen_element' as part of picker. When a block is chosen, copy the
'element' bitmap to it. Use the new bitmap as part of
mlxsw_afk_picker_key_info_add(). So later, when filling the block will
be done at the end of the searching, we will use the copied bitmap that
contains the elements that should be used in the block.

Signed-off-by: Amit Cohen <amcohen@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: core_acl_flex_keys: Add a bitmap to save which blocks are chosen

Currently, mlxsw_afk_picker() chooses which blocks will be used for a
given list of elements, and fills the blocks during the searching - when a
key block is found with most hits, it adds it and removes the elements from
the count of hits. This should be changed as we want to be able to choose
which blocks will be placed in blocks 0 to 5.

To separate between choosing blocks and filling blocks, several pre-changes
are required. The indexes of the chosen blocks should be saved, so then
the relevant blocks will be filled at the end of search.

Allocate a bitmap for chosen blocks, when a block is found with most
hits, set the relevant bit in the bitmap. This bitmap will be used in a
following patch.

Signed-off-by: Amit Cohen <amcohen@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: Edit IPv6 key blocks to use one less block for multicast forwarding

Two ACL regions that are configured by the driver during initialization are
the ones used for IPv4 and IPv6 multicast forwarding. Entries residing
in these two regions match on the {SIP, DIP, VRID} key elements.

Currently for IPv6 region, 9 key blocks are used:
* 4 for SIP - 'ipv4_1', 'ipv6_{3,4,5}'
* 4 for DIP - 'ipv4_0', 'ipv6_{0,1,2/2b}'
* 1 for VRID - 'ipv4_4b'

This can be improved by reducing the amount key blocks needed for
the IPv6 region to 8. It is possible to use key blocks that mix subsets of
the VRID element with subsets of the DIP element.
The following key blocks can be used:
* 4 for SIP - 'ipv4_1', 'ipv6_{3,4,5}'
* 1 for subset of DIP - 'ipv4_0'
* 3 for the rest of DIP and subsets of VRID - 'ipv6_{0,1,2/2b}'

To make this happen, add VRID sub-elements as part of existing keys -
'ipv6_{0,1,2/2b}'. Note that one of the sub-elements is called
VRID_ROUTER_MSB and does not contain bit numbers like the rest, as for
Spectrum < 4 this element represents bits 8-10 and for Spectrum-4 it
represents bits 8-11.

Breaking VRID into 3 sub-elements makes the driver use one less block in
IPv6 region for multicast forwarding. The sub-elements can be filled in
blocks that are used for destination IP.

The algorithm in the driver that chooses which key blocks will be used is
lazy and not the optimal one. It searches the block that contains the most
elements that are required, chooses it, removes the elements that appear
in the chosen block and starts again searching the block that contains the
most elements.

When key block 'ipv4_4' is defined, the algorithm might choose it, as it
contains 2 sub-elements of VRID, then 8 blocks must be chosen for SIP and
DIP and we get 9 blocks to match on {SIP, DIP, VRID}. That is why we had to
remove key block 'ipv4_4' in a previous patch and use key block that
contains one field for VRID.

This improvement was tested and indeed 8 blocks are used instead of 9.

Signed-off-by: Amit Cohen <amcohen@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: Add 'ipv4_5' flex key

Currently virtual router ID element is broken to two sub-elements -
'VIRT_ROUTER_LSB' and 'VIRT_ROUTER_MSB'. It was broken as this field is
broken in 'ipv4_4' flex key which is used for IPv4 in Spectrum < 4.
For Spectrum-4, we use 'ipv4_4b' flex key which contains one field for
virtual router, this key is not supported in older ASICs.

Add 'ipv4_5' flex key which is supported in all ASICs and contains one
field for virtual router. Then there is no reason to use 'VIRT_ROUTER_LSB'
and 'VIRT_ROUTER_MSB', remove them and add one element 'VIRT_ROUTER' for
this field.

The motivation is to get rid of 'ipv4_4' flex key, as it might be chosen
for IPv6 multicast forwarding region. This will not allow the improvement
in a following patch. See more details in the cover letter and in a
following patch.

Signed-off-by: Amit Cohen <amcohen@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: spectrum_acl: Add port range key element

Add the port range key element to supported key blocks so that it could
be used to match on the output of the port range registers. Each bit in
the element can be used to match on the output of the port range
register with the corresponding index.

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Link: https://lore.kernel.org/r/f0423f6ee9e36c6b0a426bc9995f42223c48f2db.1689092769.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mlxsw: Fix the size of 'VIRT_ROUTER_MSB'

The field 'virtual router' was extended to 12 bits in Spectrum-4.
Therefore, the element 'MLXSW_AFK_ELEMENT_VIRT_ROUTER_MSB' needs 3 bits for
Spectrum < 4 and 4 bits for Spectrum >= 4.

The elements are stored in an internal storage scratchpad. Currently, the
MSB is defined there as 3 bits. It means that for Spectrum-4, only 2K VRFs
can be used for multicast routing, as the highest bit is not really used by
the driver. Fix the definition of 'VIRT_ROUTER_MSB' to use 4 bits. Adjust
the definitions of 'virtual router' field in the blocks accordingly - use
'_avoid_size_check' for Spectrum-2 instead of for Spectrum-4. Fix the mask
in parse function to use 4 bits.

Fixes: 6d5d8ebb881c ("mlxsw: Rename virtual router flex key element")
Signed-off-by: Amit Cohen <amcohen@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/79bed2b70f6b9ed58d4df02e9798a23da648015b.1692268427.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mlxsw: spectrum_flower: Add ability to match on layer 2 miss

Add the 'fdb_miss' key element to supported key blocks and make use of
it to match on layer 2 miss.

The key is only supported on Spectrum-{2,3,4}. An error is returned for
Spectrum-1 since the key element is not present in any of its key
blocks.

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mlxsw: Rename virtual router flex key element

In Spectrum-4, the size of the virtual router ACL key element increased
from 11 bits to 12 bits.

In order to reuse the existing virtual router ACL key element
enumerators for Spectrum-4, rename 'VIRT_ROUTER_8_10' and
'VIRT_ROUTER_0_7' to 'VIRT_ROUTER_MSB' and 'VIRT_ROUTER_LSB',
respectively.

No functional changes intended.

Signed-off-by: Amit Cohen <amcohen@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mlxsw: core_acl: Use an array instead of a struct with a zero-length array

Suppresses the following coccinelle warning:

drivers/net/ethernet/mellanox/mlxsw/core_acl_flex_keys.c:139:3-7:
WARNING use flexible-array member instead

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: core_acl: Avoid defining static variable in header file

The static array 'mlxsw_afk_element_infos' in 'core_acl_flex_keys.h' is
copied to each file that includes the header, but not all use it. This
results in the following warnings when compiling with W=1:

drivers/net/ethernet/mellanox/mlxsw//core_acl_flex_keys.h:76:44:
warning: ‘mlxsw_afk_element_infos’ defined but not used
[-Wunused-const-variable=]

One way to suppress the warning is to mark the array with
'__maybe_unused', but another option is to remove it from the header
file entirely.

Change 'struct mlxsw_afk_element_inst' to store the key to the array
('element') instead of the array value keyed by 'element'. Adjust the
different users accordingly.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: 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>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Tested-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: spectrum_acl: Avoid size check for RX_ACL_SYSTEM_PORT element

RX_ACL_SYSTEM_PORT is 8 bit but SRC_SYS_PORT is 16 bits. Internally,
SRC_SYS_PORT is used to carry the value. Relax the checker in case of
RX_ACL_SYSTEM_PORT and allow different size.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: spectrum_acl: Write RX_ACL_SYSTEM_PORT acl element correctly

RX_ACL_SYSTEM_PORT is equal to SRC_SYS_PORT - 1. So before write to
block we need to adjust the key value. Introduce new "EXT" helper to
implement this.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: spectrum: acl: Use struct_size() in kzalloc()

One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:

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

size = sizeof(struct foo) + count * sizeof(struct boo);
instance = kzalloc(size, GFP_KERNEL)

Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:

instance = kzalloc(struct_size(instance, entry, count), GFP_KERNEL)

Notice that, in this case, variable alloc_size is not necessary, hence
it is removed.

This code was detected with the help of Coccinelle.

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

mlxsw: spectrum: acl: Remove mlxsw_afk_encode() block range args and key/mask check

Since two remaining users of mlxsw_afk_encode() do not specify
block ranges to work on, remove the args. Also, key/mask is always
non-NULL now, so skip the checks.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: spectrum: acl: Don't encode the key again in mlxsw_sp_acl_atcam_12kb_lkey_id_get()

No need to do key encoding again in
mlxsw_sp_acl_atcam_12kb_lkey_id_get(). Instead of that, introduce
a new helper that would just clear unused blocks.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: core_acl: Change order of args of ops->encode_block()

Change order so it is aligned with the usual case where the "write_to"
buffer comes as the first arg.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: Replace license text with SPDX identifiers and adjust copyrights

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: spectrum_acl: Allow encoding a partial key

When working with 12 key blocks in the A-TCAM, rules are split into two
records, which constitute two lookups. The two records are linked using
a "large entry key ID". The ID is assigned to key blocks 6 to 11 and
resolved during the first lookup. The second lookup is performed using
the ID and the remaining key blocks.

Allow encoding a partial key so that it can be later used to check if an
ID can be reused.

This is done by adding two arguments to the existing encode function
that specify the range of the block indexes we would like to encode. The
key and mask arguments become optional, as we will not need to encode
both of them all the time.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: spectrum_acl: Prepare for Spectrum-2 block encoding

In Spectrum the key (and mask) block layout is very straight forward and
every block is 16 bytes aligned.

However, in Spectrum-2 the blocks are not even byte aligned, which makes
it difficult to encode them using current method.

Instead, first encode each block and then encode the block in the
general blocks layout.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: spectrum_acl: Move block items encoding into Spectrum op

Since Spectrum-2 encodes blocks into different HW layout, push this
code into Spectrum-specific op.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: spectrum_acl: Convert mlxsw_afk_create args to ops

Since the flex keys for Spectrum-2 differ not only in blocks definitions
but also in encoding layout, prepare for the implementation and pass
Spectrum/Spectrum-2 specific ops down to mlxsw_afk_create.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlxsw: core: Introduce flexible keys support

Hardware supports matching on so called "flexible keys". The idea is to
assemble an optimal key to use for matching according to the fields in
packet (elements) requested by user. Certain sets of elements are
combined into pre-defined blocks. There is a picker to find needed blocks.
Keys consist of 1..n blocks.

Alongside with that, an initial portion of elements is introduced in order
to be able to offload basic cls_flower rules.

Picked keys are cached so multiple rules could share them.

There is an encode function provided that takes care of encoding key and
mask values according to given key.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>