nfp: bpf: rename nfp_prog->stack_depth as nfp_prog->stack_frame_depth

In preparation for support for BPF to BPF calls in offloaded programs,
rename the "stack_depth" field of the struct nfp_prog as

nfp: bpf: rename nfp_prog->stack_depth as nfp_prog->stack_frame_depth

In preparation for support for BPF to BPF calls in offloaded programs,
rename the "stack_depth" field of the struct nfp_prog as
"stack_frame_depth". This is to make it clear that the field refers to
the maximum size of the current stack frame (as opposed to the maximum
size of the whole stack memory).

Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

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nfp: bpf: xdp_adjust_tail support

Add support for adjust_tail. There are no FW changes needed but add
a FW capability just in case there would be any issue with previously
released FW, or we will h

nfp: bpf: xdp_adjust_tail support

Add support for adjust_tail. There are no FW changes needed but add
a FW capability just in case there would be any issue with previously
released FW, or we will have to change the ABI in the future.

The helper is trivial and shouldn't be used too often so just inline
the body of the function. We add the delta to locally maintained
packet length register and check for overflow, since add of negative
value must overflow if result is positive. Note that if delta of 0
would be allowed in the kernel this trick stops working and we need
one more instruction to compare lengths before and after the change.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

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nfp: bpf: remember maps by ID

Record perf maps by map ID, not raw kernel pointer. This helps
with debug messages, because printing pointers to logs is frowned
upon, and makes debug easier for the u

nfp: bpf: remember maps by ID

Record perf maps by map ID, not raw kernel pointer. This helps
with debug messages, because printing pointers to logs is frowned
upon, and makes debug easier for the users, as map ID is something
they should be more familiar with. Note that perf maps are offload
neutral, therefore IDs won't be orphaned.

While at it use a rate limited print helper for the error message.

Reported-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

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nfp: bpf: migrate to advanced reciprocal divide in reciprocal_div.h

As we are doing JIT, we would want to use the advanced version of the
reciprocal divide (reciprocal_value_adv) to trade performanc

nfp: bpf: migrate to advanced reciprocal divide in reciprocal_div.h

As we are doing JIT, we would want to use the advanced version of the
reciprocal divide (reciprocal_value_adv) to trade performance with host.

We could reduce the required ALU instructions from 4 to 2 or 1.

Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

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nfp: bpf: support u32 divide using reciprocal_div.h

NFP doesn't have integer divide instruction, this patch use reciprocal
algorithm (the basic one, reciprocal_div) to emulate it.

For each u32 divi

nfp: bpf: support u32 divide using reciprocal_div.h

NFP doesn't have integer divide instruction, this patch use reciprocal
algorithm (the basic one, reciprocal_div) to emulate it.

For each u32 divide, we would need 11 instructions to finish the operation.

7 (for multiplication) + 4 (various ALUs) = 11

Given NFP only supports multiplication no bigger than u32, we'd require
divisor and dividend no bigger than that as well.

Also eBPF doesn't support signed divide and has enforced this on C language
level by failing compilation. However LLVM assembler hasn't enforced this,
so it is possible for negative constant to leak in as a BPF_K operand
through assembly code, we reject such cases as well.

Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

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nfp: bpf: support u16 and u32 multiplications

NFP supports u16 and u32 multiplication. Multiplication is done 8-bits per
step, therefore we need 2 steps for u16 and 4 steps for u32.

We also need on

nfp: bpf: support u16 and u32 multiplications

NFP supports u16 and u32 multiplication. Multiplication is done 8-bits per
step, therefore we need 2 steps for u16 and 4 steps for u32.

We also need one start instruction to initialize the sequence and one or
two instructions to fetch the result depending on either you need the high
halve of u32 multiplication.

For ALU64, if either operand is beyond u32's value range, we reject it. One
thing to note, if the source operand is BPF_K, then we need to check "imm"
field directly, and we'd reject it if it is negative. Because for ALU64,
"imm" (with s32 type) is expected to be sign extended to s64 which NFP mul
doesn't support. For ALU32, it is fine for "imm" be negative though,
because the result is 32-bits and here is no difference on the low halve
of result for signed/unsigned mul, so we will get correct result.

Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

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nfp: bpf: rename umin/umax to umin_src/umax_src

The two fields are a copy of umin and umax info of bpf_insn->src_reg
generated by verifier.

Rename to make their meaning clear.

Signed-off-by: Jiong

nfp: bpf: rename umin/umax to umin_src/umax_src

The two fields are a copy of umin and umax info of bpf_insn->src_reg
generated by verifier.

Rename to make their meaning clear.

Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

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nfp: bpf: allow source ptr type be map ptr in memcpy optimization

Map read has been supported on NFP, this patch enables optimization
for memcpy from map to packet.

This patch also fixed one latent

nfp: bpf: allow source ptr type be map ptr in memcpy optimization

Map read has been supported on NFP, this patch enables optimization
for memcpy from map to packet.

This patch also fixed one latent bug which will cause copying from
unexpected address once memcpy for map pointer enabled. The fixed
code path was not exercised before.

Reported-by: Mary Pham <mary.pham@netronome.com>
Reported-by: David Beckett <david.beckett@netronome.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

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nfp: bpf: support arithmetic indirect right shift (BPF_ARSH | BPF_X)

Code logic is similar with arithmetic right shift by constant, and NFP
get indirect shift amount through source A operand of PREV

nfp: bpf: support arithmetic indirect right shift (BPF_ARSH | BPF_X)

Code logic is similar with arithmetic right shift by constant, and NFP
get indirect shift amount through source A operand of PREV_ALU.

It is possible to fall back to logic right shift if the MSB is known to be
zero from range info, however there is no benefit to do this given logic
indirect right shift use the same number and cycle of instruction sequence.

Suppose the MSB of regX is the bit we want to replicate to fill in all the
vacant positions, and regY contains the shift amount, then we could use
single instruction to set up both.

[alu, --, regY, OR, regX]

--
NOTE: the PREV_ALU result doesn't need to write to any destination
register.

Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

show more ...

nfp: bpf: support arithmetic right shift by constant (BPF_ARSH | BPF_K)

Code logic is similar with logic right shift except we also need to set
PREV_ALU result properly, the MSB of which is the bit

nfp: bpf: support arithmetic right shift by constant (BPF_ARSH | BPF_K)

Code logic is similar with logic right shift except we also need to set
PREV_ALU result properly, the MSB of which is the bit that will be
replicated to fill in all the vacant positions.

Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

show more ...

nfp: bpf: support logic indirect shifts (BPF_[L|R]SH | BPF_X)

For indirect shifts, shift amount is not specified as constant, NFP needs
to get the shift amount through the low 5 bits of source A ope

nfp: bpf: support logic indirect shifts (BPF_[L|R]SH | BPF_X)

For indirect shifts, shift amount is not specified as constant, NFP needs
to get the shift amount through the low 5 bits of source A operand in
PREV_ALU, therefore extra instructions are needed compared with shifts by
constants.

Because NFP is 32-bit, so we are using register pair for 64-bit shifts and
therefore would need different instruction sequences depending on whether
shift amount is less than 32 or not.

NFP branch-on-bit-test instruction emitter is added by this patch and is
used for efficient runtime check on shift amount. We'd think the shift
amount is less than 32 if bit 5 is clear and greater or equal than 32
otherwise. Shift amount is greater than or equal to 64 will result in
undefined behavior.

This patch also use range info to avoid generating unnecessary runtime code
if we are certain shift amount is less than 32 or not.

Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

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nfp: bpf: support setting the RX queue index

BPF has access to all internal FW datapath structures. Including
the structure containing RX queue selection. With little coordination
with the datapat

nfp: bpf: support setting the RX queue index

BPF has access to all internal FW datapath structures. Including
the structure containing RX queue selection. With little coordination
with the datapath we can let the offloaded BPF select the RX queue.
We just need a way to tell the datapath that queue selection has already
been done and it shouldn't overwrite it. Define a bit to tell datapath
BPF already selected a queue (QSEL_SET), if the selected queue is not
enabled (>= number of enabled queues) datapath will perform normal RSS.

BPF queue selection on the NIC can be used to replace standard
datapath RSS with fully programmable BPF/XDP RSS.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

show more ...

nfp: bpf: rewrite map pointers with NFP TIDs

Kernel will now replace map fds with actual pointer before
calling the offload prepare. We can identify those pointers
and replace them with NFP table I

nfp: bpf: rewrite map pointers with NFP TIDs

Kernel will now replace map fds with actual pointer before
calling the offload prepare. We can identify those pointers
and replace them with NFP table IDs instead of loading the
table ID in code generated for CALL instruction.

This allows us to support having the same CALL being used with
different maps.

Since we don't want to change the FW ABI we still need to
move the TID from R1 to portion of R0 before the jump.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

show more ...

nfp: bpf: perf event output helpers support

Add support for the perf_event_output family of helpers.

The implementation on the NFP will not match the host code exactly.
The state of the host map an

nfp: bpf: perf event output helpers support

Add support for the perf_event_output family of helpers.

The implementation on the NFP will not match the host code exactly.
The state of the host map and rings is unknown to the device, hence
device can't return errors when rings are not installed. The device
simply packs the data into a firmware notification message and sends
it over to the host, returning success to the program.

There is no notion of a host CPU on the device when packets are being
processed. Device will only offload programs which set BPF_F_CURRENT_CPU.
Still, if map index doesn't match CPU no error will be returned (see
above).

Dropped/lost firmware notification messages will not cause "lost
events" event on the perf ring, they are only visible via device
error counters.

Firmware notification messages may also get reordered in respect
to the packets which caused their generation.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

show more ...

nfp: bpf: optimize comparisons to negative constants

Comparison instruction requires a subtraction. If the constant
is negative we are more likely to fit it into a NFP instruction
directly if we ch

nfp: bpf: optimize comparisons to negative constants

Comparison instruction requires a subtraction. If the constant
is negative we are more likely to fit it into a NFP instruction
directly if we change the sign and use addition.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

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nfp: bpf: tabularize generations of compare operations

There are quite a few compare instructions now, use a table
to translate BPF instruction code to NFP instruction parameters
instead of paramete

nfp: bpf: tabularize generations of compare operations

There are quite a few compare instructions now, use a table
to translate BPF instruction code to NFP instruction parameters
instead of parameterizing helpers. This saves LOC and makes
future extensions easier.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

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nfp: bpf: optimize add/sub of a negative constant

NFP instruction set can fit small immediates into the instruction.
Negative integers, however, will never fit because they will have
highest bit set

nfp: bpf: optimize add/sub of a negative constant

NFP instruction set can fit small immediates into the instruction.
Negative integers, however, will never fit because they will have
highest bit set. If we swap the ALU op between ADD and SUB and
negate the constant we have a better chance of fitting small negative
integers into the instruction itself and saving one or two cycles.

immed[gprB_21, 0xfffffffc]
alu[gprA_4, gprA_4, +, gprB_21], gpr_wrboth
immed[gprB_21, 0xffffffff]
alu[gprA_5, gprA_5, +carry, gprB_21], gpr_wrboth

now becomes:

alu[gprA_4, gprA_4, -, 4], gpr_wrboth
alu[gprA_5, gprA_5, -carry, 0], gpr_wrboth

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

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nfp: bpf: remove double space

Whitespace cleanup - remove double space.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

nfp: bpf: add support for bpf_get_prandom_u32()

NFP has a prng register, which we can read to obtain a u32 worth
of pseudo random data. Generate code for it.

Signed-off-by: Jakub Kicinski <jakub.k

nfp: bpf: add support for bpf_get_prandom_u32()

NFP has a prng register, which we can read to obtain a u32 worth
of pseudo random data. Generate code for it.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

show more ...

nfp: bpf: add support for atomic add of unknown values

Allow atomic add to be used even when the value is not guaranteed
to fit into a 16 bit immediate. This requires the value to be pulled
as data

nfp: bpf: add support for atomic add of unknown values

Allow atomic add to be used even when the value is not guaranteed
to fit into a 16 bit immediate. This requires the value to be pulled
as data, and therefore use of a transfer register and a context swap.

Track the information about possible lengths of the value, if it's
guaranteed to be larger than 16bits don't generate the code for the
optimized case at all.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

show more ...

nfp: bpf: expose command delay slots

Allow callers to control the delay slots of commands, instead of
giving them just a wait/nowait choice.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.

nfp: bpf: expose command delay slots

Allow callers to control the delay slots of commands, instead of
giving them just a wait/nowait choice.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

show more ...

nfp: bpf: add basic support for atomic adds

Implement atomic add operation for 32 and 64 bit values. Depend
on the verifier to ensure alignment. Values have to be kept in
big endian and swapped up

nfp: bpf: add basic support for atomic adds

Implement atomic add operation for 32 and 64 bit values. Depend
on the verifier to ensure alignment. Values have to be kept in
big endian and swapped upon read/write. For now only support
atomic add of a constant.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

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nfp: bpf: add map deletes from the datapath

Support calling map_delete_elem() FW helper from the datapath
programs. For JIT checks and code are basically equivalent
to map lookups. Similarly to ot

nfp: bpf: add map deletes from the datapath

Support calling map_delete_elem() FW helper from the datapath
programs. For JIT checks and code are basically equivalent
to map lookups. Similarly to other map helper key must be on
the stack. Different pointer types are left for future extension.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

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nfp: bpf: add map updates from the datapath

Support calling map_update_elem() from the datapath programs
by calling into FW-provided helper. Value pointer is passed
in LM pointer #2. Keeping track

nfp: bpf: add map updates from the datapath

Support calling map_update_elem() from the datapath programs
by calling into FW-provided helper. Value pointer is passed
in LM pointer #2. Keeping track of old state for arg3 is not
necessary, since LM pointer #2 will be always loaded in this
case, the trivial optimization for value at the bottom of the
stack can't be done here.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

show more ...

nfp: bpf: add helper for validating stack pointers

Our implementation has restriction on stack pointers for function
calls. Move the common checks into a helper for reuse. The state
has to be enca

nfp: bpf: add helper for validating stack pointers

Our implementation has restriction on stack pointers for function
calls. Move the common checks into a helper for reuse. The state
has to be encapsulated into a structure to support parameters
other than BPF_REG_2.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

show more ...