The mapping from priorities to buffers determines which buffers should be
configured. Lossiness of these priorities combined with the mapping
determines whether a given buffer should be lossy.

Currently this configuration is stored implicitly in DCB ETS, PFC and
ethtool PAUSE configuration. Keeping it together with the rest of the
headroom configuration and deriving it as needed from PFC / ETS / PAUSE
will make things clearer. To that end, add a field "prios" to struct
mlxsw_sp_hdroom.

Previously, __mlxsw_sp_port_headroom_set() took prio_tc as an argument, and
assumed that the same mapping as we use on the egress should be used on
ingress as well. Instead, track this configuration at each priority, so
that it can be adjusted flexibly.

In the following patches, as dcbnl_setbuffer is implemented, it will need
to store its own mapping, and it will also be sometimes necessary to revert
back to the original ETS mapping. Therefore track two buffer indices: the
one for chip configuration (buf_idx), and the source one (ets_buf_idx).
Introduce a function to configure the chip-level buffer index, and for now
have it simply copy the ETS mapping over to the chip mapping.

Update the ETS handler to project prio_tc to the ets_buf_idx and invoke the
buf_idx recomputation.

Now that there is a canonical place to look for this configuration,
mlxsw_sp_port_headroom_set() does not need to invent def_prio_tc to use if
DCB is compiled out.
Signed-off-by: NPetr Machata <petrm@nvidia.com>
Reviewed-by: NJiri Pirko <jiri@nvidia.com>
Signed-off-by: NIdo Schimmel <idosch@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

MTU influences sizes of auto-allocated buffers. Make it a part of port
buffer configuration and have __mlxsw_sp_port_headroom_set() take it from
there, instead of as an argument.
Signed-off-by: NPetr Machata <petrm@nvidia.com>
Reviewed-by: NJiri Pirko <jiri@nvidia.com>
Signed-off-by: NIdo Schimmel <idosch@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The port headroom handling is currently strewn across several modules and
tricky to follow: MTU, DCB PFC, DCB ETS and ethtool pause all influence the
settings, and then there is the completely separate initial configuraion in
spectrum_buffers. A following patch will implement the dcbnl_setbuffer
callback, which is going to further complicate the landscape.

In order to simplify work with port buffers, the following patches are
going to centralize all port-buffer handling in spectrum_buffers. As a
first step, introduce a (currently empty) struct mlxsw_sp_hdroom that will
keep the configuration parameters, and allocate and free it in appropriate
places.
Signed-off-by: NPetr Machata <petrm@nvidia.com>
Reviewed-by: NJiri Pirko <jiri@nvidia.com>
Signed-off-by: NIdo Schimmel <idosch@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The second commit cited below performed a cast of 'u32 buffsize' to
'(u16 *)' when calling mlxsw_sp_port_headroom_8x_adjust():

mlxsw_sp_port_headroom_8x_adjust(mlxsw_sp_port, (u16 *) &buffsize);

Colin noted that this will behave differently on big endian
architectures compared to little endian architectures.

Fix this by following Colin's suggestion and have the function accept
and return 'u32' instead of passing the current size by reference.

Fixes: da382875 ("mlxsw: spectrum: Extend to support Spectrum-3 ASIC")
Fixes: 60833d54 ("mlxsw: spectrum: Adjust headroom buffers for 8x ports")
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Reported-by: NColin Ian King <colin.king@canonical.com>
Suggested-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The port's headroom buffers are used to store packets while they
traverse the device's pipeline and also to store packets that are egress
mirrored.

On Spectrum-3, ports with eight lanes use two headroom buffers between
which the configured headroom size is split.

In order to prevent packet loss, multiply the calculated headroom size
by two for 8x ports.

Fixes: da382875 ("mlxsw: spectrum: Extend to support Spectrum-3 ASIC")
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Reviewed-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As explained in commit 9ffcc372 ("mlxsw: spectrum: Allow packets to
be trapped from any PG"), incoming packets can be admitted to the shared
buffer and forwarded / trapped, if:

(Ingress{Port}.Usage < Thres && Ingress{Port,PG}.Usage < Thres &&
 Egress{Port}.Usage < Thres && Egress{Port,TC}.Usage < Thres)
||
(Ingress{Port}.Usage < Min || Ingress{Port,PG} < Min ||
 Egress{Port}.Usage < Min || Egress{Port,TC}.Usage < Min)

Trapped packets are scheduled to transmission through the CPU port.
Currently, the minimum and maximum quotas of traffic class (TC) 0 of the
CPU port are 0, which means it is not usable.

Assign non-zero quotas to TC 0 of the CPU port, so that it could be
utilized by subsequent patches.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Reviewed-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When building for 32-bit ARM, there is a link time error because of a
64-bit division:

ld.lld: error: undefined symbol: __aeabi_uldivmod
>>> referenced by spectrum_buffers.c
>>>               net/ethernet/mellanox/mlxsw/spectrum_buffers.o:(mlxsw_sp_buffers_init) in archive drivers/built-in.a
>>> did you mean: __aeabi_uidivmod
>>> defined in: arch/arm/lib/lib.a(lib1funcs.o

Avoid this by using div_u64, which is designed to avoid this problem.

Fixes: bc9f6e94 ("mlxsw: spectrum_buffers: Calculate the size of the main pool")
Signed-off-by: NNathan Chancellor <natechancellor@gmail.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Tested-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Remove excess semicolon after closing parenthesis.
Signed-off-by: NYueHaibing <yuehaibing@huawei.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Instead of hard-coding the size of the largest pool, calculate it from the
reported guaranteed shared buffer size and sizes of other pools (currently
only the CPU port pool).
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There are two resources associated with shared buffer size:
cap_total_buffer_size, and cap_guaranteed_shared_buffer. So far, mlxsw has
been using the former as a limit to determine how large a pool size is
allowed to be. However, the total size also includes headrooms and reserved
space, which really cannot be used for shared buffer pools.

Therefore convert mlxsw to use the latter resource as a limit. Adjust
hard-coded pool sizes to be the guaranteed size minus 256000 bytes for CPU
port pool. On Spectrum-1 that actually leads to an increase. A follow-up
patch will have this size calculated automatically.
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

While debugging packet loss towards the CPU, it is useful to be able to
query the CPU port's shared buffer quotas and occupancy.

Since the CPU port has no ingress buffers, all the shared buffers ingress
information will be cleared.
Signed-off-by: NShalom Toledo <shalomt@mellanox.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Next patch is going to register the CPU port with devlink, but only so
that the CPU port's shared buffer configuration and occupancy could be
queried.

Prevent changing CPU port's shared buffer threshold and binding
configuration.
Signed-off-by: NShalom Toledo <shalomt@mellanox.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In commit e891ce1d ("mlxsw: spectrum_buffers: Reduce pool size on
Spectrum-2"), pool size was reduced to mitigate a problem in port buffer
usage of ports split four ways. It turns out that this work around does not
solve the issue, and a further reduction is required.

Thus reduce the size of pool 0 by another 2.7 MiB, and round down to the
whole number of cells.

Fixes: e891ce1d ("mlxsw: spectrum_buffers: Reduce pool size on Spectrum-2")
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Due to an issue on Spectrum-2, in front-panel ports split four ways, 2 out
of 32 port buffers cannot be used. To work around this, the next FW release
will mark them as unused, and will report correspondingly lower total
shared buffer size. mlxsw will pick up the new value through a query to
cap_total_buffer_size resource. However the initial size for shared buffer
pool 0 is hard-coded and therefore needs to be updated.

Thus reduce the pool size by 2.7 MiB (which corresponds to 2/32 of the
total size of 42 MiB), and round down to the whole number of cells.

Fixes: fe099bf6 ("mlxsw: spectrum_buffers: Add Spectrum-2 shared buffer configuration")
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Switch the CPU port to use the new dedicated egress pool instead the
previously used egress pool which was shared with normal front panel
ports.

Add per-port quotas for the amount of traffic that can be buffered for
the CPU port and also adjust the per-{port, TC} quotas.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Reviewed-by: NPetr Machata <petrm@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The CPU port is used to transmit traffic that is trapped to the host
CPU. It is therefore irrelevant to define ingress quota for it.

Add a 'skip_ingress' argument to the function tasked with configuring
per-port quotas, so that ingress quotas could be skipped in case the
passed local port is the CPU port.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Reviewed-by: NPetr Machata <petrm@mellanox.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The function is used to set the per-port shared buffer quotas.
Currently, these quotas are only set for front panel ports, but a
subsequent patch will configure these quotas for the CPU port as well.

The configuration required for the CPU port is a bit different than that
of the front panel ports, so split the business logic into a separate
function which will be called with different parameters for the CPU
port.

No functional changes intended.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Reviewed-by: NPetr Machata <petrm@mellanox.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use the new ingress pool that was added in the previous patch for
control packets (e.g., STP, LACP) that are trapped to the CPU.

The previous management pool is no longer necessary and therefore its
size is set to 0.

The maximum quota for traffic towards the CPU is increased to 50% of the
free space in the new ingress pool and therefore the reserved space is
reduced by half, to 10KB - in both the shared and headroom buffer. This
allows for more efficient utilization of the shared buffer as reserved
space cannot be used for other purposes.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Reviewed-by: NPetr Machata <petrm@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Packets that are trapped to the CPU are transmitted through the CPU port
to the attached host. The CPU port is therefore like any other port and
needs to have shared buffer configuration.

The maximum quotas configured for the CPU are provided using dynamic
threshold and cannot be changed by the user. In order to make sure that
these thresholds are always valid, the configuration of the threshold
type of these pools is forbidden.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Reviewed-by: NPetr Machata <petrm@mellanox.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The code currently assumes that ingress pools have lower indices than
egress pools. This makes it impossible to add more ingress pools
without breaking user configuration that relies on a certain pool index
to correspond to an egress pool.

Remove such assumptions from the code, so that more ingress pools could
be added by subsequent patches.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Reviewed-by: NPetr Machata <petrm@mellanox.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit e83c045e ("mlxsw: spectrum_buffers: Configure MC pool")
configured the threshold of the multicast TCs as infinite so that the
admission of multicast packets is only depended on per-switch priority
threshold.

Forbid the user from changing the thresholds of these multicast TCs and
their binding to a different pool.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Reviewed-by: NPetr Machata <petrm@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Multicast packets have three egress quotas:
* Per egress port
* Per egress port and traffic class
* Per switch priority

The limits on the switch priority are not exposed to the user and
specified as dynamic threshold on the first egress pool.

Forbid changing the threshold type of the first egress pool so that
these limits are always valid.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Reviewed-by: NPetr Machata <petrm@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit e83c045e ("mlxsw: spectrum_buffers: Configure MC pool") added
a dedicated pool for multicast traffic. The pool is visible to the user
so that it would be possible to monitor its occupancy, but its
configuration should be forbidden in order to maintain its intended
operation.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Reviewed-by: NPetr Machata <petrm@mellanox.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Subsequent patches are going to need to veto changes in certain TCs'
binding and threshold configurations.

Add fields to the TC's struct that indicate if the TC can be bound to a
different pool and whether its threshold can change and enforce that.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Reviewed-by: NPetr Machata <petrm@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Subsequent patches are going to need to veto changes in certain pools'
size and / or threshold type (mode).

Add two fields to the pool's struct that indicate if either of these
attributes is allowed to change and enforce that.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Reviewed-by: NPetr Machata <petrm@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The pool indices are currently hard coded throughout the code, which
makes the code hard to follow and extend.

Overcome this by using defines for the pool indices.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Reviewed-by: NPetr Machata <petrm@mellanox.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add extack messages to better communicate invalid configuration to the
user.

Example:

# devlink sb pool set pci/0000:01:00.0 pool 0 size 104857600 thtype dynamic
Error: mlxsw_spectrum: Exceeded shared buffer size.
devlink answers: Invalid argument
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Reviewed-by: NPetr Machata <petrm@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In Spectrum-1, when a multicast packet is admitted to the shared buffer
it increases the quotas of all the ports and {port, TC} to which it is
forwarded to.

The above means that multicast packets are accounted multiple times in
the shared buffer and can therefore cause the associated shared buffer
pool to fill up very quickly.

To work around this issue, commit e83c045e ("mlxsw:
spectrum_buffers: Configure MC pool") added a dedicated multicast pool
in which multicast packets are accounted.

The issue is not present in Spectrum-2, but in order to be backward
compatible with Spectrum-1, its default behavior is to allow a multicast
packet to increase multiple egress quotas instead of one.

Until the new (non-backward compatible) mode is supported, configure a
dedicated multicast pool as in Spectrum-1.

Fixes: fe099bf6 ("mlxsw: spectrum_buffers: Add Spectrum-2 shared buffer configuration")
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Reviewed-by: NPetr Machata <petrm@mellanox.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

cap_max_headroom_size holds maximum headroom size supported.
Overstepping that limit might under certain conditions lead to ASIC
freeze.

Query and store the value, and add mlxsw_sp_sb_max_headroom_cells() for
obtaining the stored value. In __mlxsw_sp_port_headroom_set(), reject
requests where the total port buffer is larger than the advertised
maximum.
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The recommendation for headroom size for 100Gbps port and 100m cable is
101.6KB, reduced accordingly for split ports. The closest higher number
evenly divisible by cell size for both Spectrum-1 and Spectrum-2, and
such that the number of cells can be further divided by maximum split
factor of 4, is 102528 bytes, or 25632 bytes per lane.

Update mlxsw_sp_port_pb_init() to compute the headroom taking into
account this recommended per-lane value and number of lanes actually
dedicated to a given port.
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Customize the tables related to shared buffer configuration to match the
current recommendation for Spectrum-2 systems.
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The SBMM register configures the shared buffer quota for MC packets
according to Switch-Priority. The default configuration depends on the
chip type. Therefore keep the table and length in struct
mlxsw_sp_sb_vals. Redirect the references from the global definitions to
the fields.
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The SBCM register configures shared buffer quota according to
port-priority resp. port-TC. The default configuration depends on the
chip type. Therefore keep the tables and their lengths in struct
mlxsw_sp_sb_vals. Redirect the references from the global definitions to
the fields.
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The SBPR register configures shared buffer pools. The default
configuration depends on the chip type. Therefore keep it in struct
mlxsw_sp_sb_vals. Redirect the one reference from the global array to
the field.

Because the pool descriptor ID is implicit in the ordering of array
members, both this array and the pool descriptor array have the same
length. Therefore reuse mlxsw_sp_sb.pool_dess_len for the purpose of
determining the length of SBPR array.

Drop the now useless MLXSW_SP_SB_PRS_LEN.
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The SBPM register can be used to configure quotas for packets ingressing
from a certain pool to a certain port, and egressing from a certain pool
to a certain port. The default configuration depends on the chip type.
Therefore keep it in struct mlxsw_sp_sb_vals. Redirect the one reference
from the global array to the field.

Because the pool descriptor ID is implicit in the ordering of array
members, both this array and the pool descriptor array have the same
length. Therefore reuse mlxsw_sp_sb.pool_dess_len for the purpose of
determining the length of SBPM array.

Drop the now useless MLXSW_SP_SB_PMS_LEN.
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Keep the table of pool descriptors and its length in struct
mlxsw_sp_sb_vals so that it can be specialized per chip type. Redirect
all users from the global definitions to the mlxsw_sp_sb fields.

Give mlxsw_sp_pool_count() an extra mlxsw_sp parameter so that it can
access the descriptor table.

Drop the now unnecessary MLXSW_SP_SB_POOL_DESS_LEN.
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Spectrum-2 will be configured with a different set of pools than
Spectrum-1. The size of prs and pms buffers will therefore depend on the
chip type of the device.

Therefore, instead of reserving an array directly in a structure
definition, allocate the buffer in mlxsw_sp_sb_port{,s}_init().
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Spectrum-2 will be configured with a different shared buffer
configuration than Spectrum-1. Therefore introduce a structure for
keeping the chip-specific default and immutable configuration.

Configuration mutable in runtime will still be kept in struct
mlxsw_sp_sb.
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Shared buffer allocation is usually done in cell increments.
Drivers will either round up the allocation or refuse the
configuration if it's not an exact multiple of cell size.
Drivers know exactly the cell size of shared buffer, so help
out users by providing this information in dumps.
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: NDirk van der Merwe <dirk.vandermerwe@netronome.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The SBMM register configures shared buffer allocation and settings for
MC packets according to switch priority. The recommended values are no
reserved buffer and alpha of 1/4, which corresponds to buf_max of 6.
Update mlxsw_sp_sb_mms accordingly.
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Reviewed-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>