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path: root/drivers/net/ethernet/netronome/nfp/bpf/jit.c
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2018-05-18nfp: bpf: support arithmetic indirect right shift (BPF_ARSH | BPF_X)Jiong Wang
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>
2018-05-18nfp: bpf: support arithmetic right shift by constant (BPF_ARSH | BPF_K)Jiong Wang
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>
2018-05-18nfp: bpf: support logic indirect shifts (BPF_[L|R]SH | BPF_X)Jiong Wang
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>
2018-05-09nfp: bpf: support setting the RX queue indexJakub Kicinski
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>
2018-05-04nfp: bpf: rewrite map pointers with NFP TIDsJakub Kicinski
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>
2018-05-04nfp: bpf: perf event output helpers supportJakub Kicinski
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>
2018-04-25nfp: bpf: optimize comparisons to negative constantsJakub Kicinski
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>
2018-04-25nfp: bpf: tabularize generations of compare operationsJakub Kicinski
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>
2018-04-25nfp: bpf: optimize add/sub of a negative constantJakub Kicinski
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>
2018-04-25nfp: bpf: remove double spaceJakub Kicinski
Whitespace cleanup - remove double space. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-04-01Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Minor conflicts in drivers/net/ethernet/mellanox/mlx5/core/en_rep.c, we had some overlapping changes: 1) In 'net' MLX5E_PARAMS_LOG_{SQ,RQ}_SIZE --> MLX5E_REP_PARAMS_LOG_{SQ,RQ}_SIZE 2) In 'net-next' params->log_rq_size is renamed to be params->log_rq_mtu_frames. 3) In 'net-next' params->hard_mtu is added. Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-28nfp: bpf: add support for bpf_get_prandom_u32()Jakub Kicinski
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>
2018-03-28nfp: bpf: add support for atomic add of unknown valuesJakub Kicinski
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>
2018-03-28nfp: bpf: expose command delay slotsJakub Kicinski
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>
2018-03-28nfp: bpf: add basic support for atomic addsJakub Kicinski
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>
2018-03-28nfp: bpf: add map deletes from the datapathJakub Kicinski
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>
2018-03-28nfp: bpf: add map updates from the datapathJakub Kicinski
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>
2018-03-28nfp: bpf: add helper for validating stack pointersJakub Kicinski
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>
2018-03-28nfp: bpf: rename map_lookup_stack() to map_call_stack_common()Jakub Kicinski
We will reuse most of map call code gen for other map calls. Rename the lookup gen function and use meta->func_id instead of hard-coding lookup. 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>
2018-03-28nfp: bpf: detect packet reads could be cached, enable the optimisationJiong Wang
This patch is the front end of this optimisation, it detects and marks those packet reads that could be cached. Then the optimisation "backend" will be activated automatically. Signed-off-by: Jiong Wang <jiong.wang@netronome.com> Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-03-28nfp: bpf: support unaligned read offsetJiong Wang
This patch add the support for unaligned read offset, i.e. the read offset to the start of packet cache area is not aligned to REG_WIDTH. In this case, the read area might across maximum three transfer-in registers. Signed-off-by: Jiong Wang <jiong.wang@netronome.com> Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-03-28nfp: bpf: read from packet data cache for PTR_TO_PACKETJiong Wang
This patch assumes there is a packet data cache, and would try to read packet data from the cache instead of from memory. This patch only implements the optimisation "backend", it doesn't build the packet data cache, so this optimisation is not enabled. This patch has only enabled aligned packet data read, i.e. when the read offset to the start of cache is REG_WIDTH aligned. Signed-off-by: Jiong Wang <jiong.wang@netronome.com> Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-03-24nfp: bpf: fix check of program max insn countJakub Kicinski
NFP program allocation length is in bytes and NFP program length is in instructions, fix the comparison of the two. Fixes: 9314c442d7dd ("nfp: bpf: move translation prepare to offload.c") Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Jiong Wang <jiong.wang@netronome.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-01-17nfp: bpf: reject program on instructions unknown to the JIT compilerQuentin Monnet
If an eBPF instruction is unknown to the driver JIT compiler, we can reject the program at verification time. Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com> Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Jiong Wang <jiong.wang@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-01-14nfp: bpf: add support for reading map memoryJakub Kicinski
Map memory needs to use 40 bit addressing. Add handling of such accesses. Since 40 bit addresses are formed by using both 32 bit operands we need to pre-calculate the actual address instead of adding in the offset inside the instruction, like we did in 32 bit mode. 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>
2018-01-14nfp: bpf: add verification and codegen for map lookupsJakub Kicinski
Verify our current constraints on the location of the key are met and generate the code for calling map lookup on the datapath. New relocation types have to be added - for helpers and return addresses. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-01-10nfp: bpf: add signed jump insnsNic Viljoen
This patch adds signed jump instructions (jsgt, jsge, jslt, jsle) to the nfp jit. As well as adding the additional required raw assembler branch mask to nfp_asm.h Signed-off-by: Nic Viljoen <nick.viljoen@netronome.com> Reviewed-by: Jiong Wang <jiong.wang@netronome.com> Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-01-10nfp: bpf: use a large constant in unresolved branchesJakub Kicinski
To make absolute relocated branches (branches which will be completely rewritten with br_set_offset()) distinguishable in user space dumps from normal jumps add a large offset to them. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Jiong Wang <jiong.wang@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-01-10nfp: bpf: don't depend on high order allocations for program imageJakub Kicinski
The translator pre-allocates a buffer of maximal program size. Due to HW/FW limitations the program buffer can't currently be longer than 128Kb, so we used to kmalloc() it, and then map for DMA directly. Now that the late branch resolution is copying the program image anyway, we can just kvmalloc() the buffer. While at it, after translation reallocate the buffer to save space. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-01-10nfp: bpf: relocate jump targets just before the loadJakub Kicinski
Don't translate the program assuming it will be loaded at a given address. This will be required for sharing programs between ports of the same NIC, tail calls and subprograms. It will also make the jump targets easier to understand when dumping the program to user space. Translate the program as if it was going to be loaded at address zero. When load happens add the load offset in and set addresses of special branches. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Jiong Wang <jiong.wang@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-01-10nfp: bpf: add helpers for modifying branch addressesJakub Kicinski
In preparation for better handling of relocations move existing helper for setting branch offset to nfp_asm.c and add two more. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Jiong Wang <jiong.wang@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-01-10nfp: bpf: move jump resolution to jit.cJakub Kicinski
Jump target resolution should be in jit.c not offload.c. No functional changes. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Jiong Wang <jiong.wang@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-12-15nfp: bpf: optimize the adjust_head calls in trivial casesJakub Kicinski
If the program is simple and has only one adjust head call with constant parameters, we can check that the call will always succeed at translation time. We need to track the location of the call and make sure parameters are always the same. We also have to check the parameters against datapath constraints and ETH_HLEN. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-12-15nfp: bpf: add basic support for adjust head callJakub Kicinski
Support bpf_xdp_adjust_head(). We need to check whether the packet offset after adjustment is within datapath's limits. We also check if the frame is at least ETH_HLEN long (similar to the kernel implementation). Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-12-15nfp: bpf: prepare for call supportJakub Kicinski
Add skeleton of verifier checks and translation handler for call instructions. Make sure jump target resolution will not treat them as jumps. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-12-01nfp: bpf: detect load/store sequences lowered from memory copyJiong Wang
This patch add the optimization frontend, but adding a new eBPF IR scan pass "nfp_bpf_opt_ldst_gather". The pass will traverse the IR to recognize the load/store pairs sequences that come from lowering of memory copy builtins. The gathered memory copy information will be kept in the meta info structure of the first load instruction in the sequence and will be consumed by the optimization backend added in the previous patches. NOTE: a sequence with cross memory access doesn't qualify this optimization, i.e. if one load in the sequence will load from place that has been written by previous store. This is because when we turn the sequence into single CPP operation, we are reading all contents at once into NFP transfer registers, then write them out as a whole. This is not identical with what the original load/store sequence is doing. Detecting cross memory access for two random pointers will be difficult, fortunately under XDP/eBPF's restrictied runtime environment, the copy normally happen among map, packet data and stack, they do not overlap with each other. And for cases supported by NFP, cross memory access will only happen on PTR_TO_PACKET. Fortunately for this, there is ID information that we could do accurate memory alias check. 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>
2017-12-01nfp: bpf: implement memory bulk copy for length bigger than 32-bytesJiong Wang
When the gathered copy length is bigger than 32-bytes and within 128-bytes (the maximum length a single CPP Pull/Push request can finish), the strategy of read/write are changeed into: * Read. - use direct reference mode when length is within 32-bytes. - use indirect mode when length is bigger than 32-bytes. * Write. - length <= 8-bytes use write8 (direct_ref). - length <= 32-byte and 4-bytes aligned use write32 (direct_ref). - length <= 32-bytes but not 4-bytes aligned use write8 (indirect_ref). - length > 32-bytes and 4-bytes aligned use write32 (indirect_ref). - length > 32-bytes and not 4-bytes aligned and <= 40-bytes use write32 (direct_ref) to finish the first 32-bytes. use write8 (direct_ref) to finish all remaining hanging part. - length > 32-bytes and not 4-bytes aligned use write32 (indirect_ref) to finish those 4-byte aligned parts. use write8 (direct_ref) to finish all remaining hanging part. 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>
2017-12-01nfp: bpf: implement memory bulk copy for length within 32-bytesJiong Wang
For NFP, we want to re-group a sequence of load/store pairs lowered from memcpy/memmove into single memory bulk operation which then could be accelerated using NFP CPP bus. This patch extends the existing load/store auxiliary information by adding two new fields: struct bpf_insn *paired_st; s16 ldst_gather_len; Both fields are supposed to be carried by the the load instruction at the head of the sequence. "paired_st" is the corresponding store instruction at the head and "ldst_gather_len" is the gathered length. If "ldst_gather_len" is negative, then the sequence is doing memory load/store in descending order, otherwise it is in ascending order. We need this information to detect overlapped memory access. This patch then optimize memory bulk copy when the copy length is within 32-bytes. The strategy of read/write used is: * Read. Use read32 (direct_ref), always. * Write. - length <= 8-bytes write8 (direct_ref). - length <= 32-bytes and is 4-byte aligned write32 (direct_ref). - length <= 32-bytes but is not 4-byte aligned write8 (indirect_ref). NOTE: the optimization should not change program semantics. The destination register of the last load instruction should contain the same value before and after this optimization. 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>
2017-12-01nfp: bpf: encode indirect commandsJakub Kicinski
Add support for emitting commands with field overwrites. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Jiong Wang <jiong.wang@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-12-01nfp: bpf: correct the encoding for No-Dest immedJiong Wang
When immed is used with No-Dest, the emitter should use reg.dst instead of reg.areg for the destination, using the latter will actually encode register zero. 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>
2017-12-01nfp: bpf: don't do ld/shifts combination if shifts are jump destinationJiong Wang
If any of the shift insns in the ld/shift sequence is jump destination, don't do combination. 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>
2017-12-01nfp: bpf: don't do ld/mask combination if mask is jump destinationJiong Wang
If the mask insn in the ld/mask pair is jump destination, then don't do combination. 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>
2017-12-01nfp: bpf: record jump destination to simplify jump fixupJiong Wang
eBPF insns are internally organized as dual-list inside NFP offload JIT. Random access to an insn needs to be done by either forward or backward traversal along the list. One place we need to do such traversal is at nfp_fixup_branches where one traversal is needed for each jump insn to find the destination. Such traversals could be avoided if jump destinations are collected through a single travesal in a pre-scan pass, and such information could also be useful in other places where jump destination info are needed. This patch adds such jump destination collection in nfp_prog_prepare. Suggested-by: Jakub Kicinski <jakub.kicinski@netronome.com> 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>
2017-12-01nfp: bpf: support backward jumpJiong Wang
This patch adds support for backward jump on NFP. - restrictions on backward jump in various functions have been removed. - nfp_fixup_branches now supports backward jump. There is one thing to note, currently an input eBPF JMP insn may generate several NFP insns, for example, NFP imm move insn A \ NFP compare insn B --> 3 NFP insn jited from eBPF JMP insn M NFP branch insn C / --- NFP insn X --> 1 NFP insn jited from eBPF insn N --- ... therefore, we are doing sanity check to make sure the last jited insn from an eBPF JMP is a NFP branch instruction. Once backward jump is allowed, it is possible an eBPF JMP insn is at the end of the program. This is however causing trouble for the sanity check. Because the sanity check requires the end index of the NFP insns jited from one eBPF insn while only the start index is recorded before this patch that we can only get the end index by: start_index_of_the_next_eBPF_insn - 1 or for the above example: start_index_of_eBPF_insn_N (which is the index of NFP insn X) - 1 nfp_fixup_branches was using nfp_for_each_insn_walk2 to expose *next* insn to each iteration during the traversal so the last index could be calculated from which. Now, it needs some extra code to handle the last insn. Meanwhile, the use of walk2 is actually unnecessary, we could simply use generic single instruction walk to do this, the next insn could be easily calculated using list_next_entry. So, this patch migrates the jump fixup traversal method to *list_for_each_entry*, this simplifies the code logic a little bit. The other thing to note is a new state variable "last_bpf_off" is introduced to track the index of the last jited NFP insn. This is necessary because NFP is generating special purposes epilogue sequences, so the index of the last jited NFP insn is *not* always nfp_prog->prog_len - 1. Suggested-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Jiong Wang <jiong.wang@netronome.com> Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-11-05nfp: bpf: move to new BPF program offload infrastructureJakub Kicinski
Following steps are taken in the driver to offload an XDP program: XDP_SETUP_PROG: * prepare: - allocate program state; - run verifier (bpf_analyzer()); - run translation; * load: - stop old program if needed; - load program; - enable BPF if not enabled; * clean up: - free program image. With new infrastructure the flow will look like this: BPF_OFFLOAD_VERIFIER_PREP: - allocate program state; BPF_OFFLOAD_TRANSLATE: - run translation; XDP_SETUP_PROG: - stop old program if needed; - load program; - enable BPF if not enabled; BPF_OFFLOAD_DESTROY: - free program image. Take advantage of the new infrastructure. Allocation of driver metadata has to be moved from jit.c to offload.c since it's now done at a different stage. Since there is no separate driver private data for verification step, move temporary nfp_meta pointer into nfp_prog. We will now use user space context offsets. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-05nfp: bpf: move translation prepare to offload.cJakub Kicinski
struct nfp_prog is currently only used internally by the translator. This means there is a lot of parameter passing going on, between the translator and different stages of offload. Simplify things by allocating nfp_prog in offload.c already. We will now use kmalloc() to allocate the program area and only DMA map it for the time of loading (instead of allocating DMA coherent memory upfront). Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-05nfp: bpf: move program prepare and free into offload.cJakub Kicinski
Most of offload/translation prepare logic will be moved to offload.c. To help git generate more reasonable diffs move nfp_prog_prepare() and nfp_prog_free() functions there as a first step. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-05nfp: bpf: remove the register renumbering leftoversJakub Kicinski
The register renumbering was removed and will not be coming back in its old, naive form, given that it would be fundamentally incompatible with calling functions. Remove the leftovers. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-05nfp: bpf: drop support for cls_bpf with legacy actionsJakub Kicinski
Only support BPF_PROG_TYPE_SCHED_CLS programs in direct action mode. This simplifies preparing the offload since there will now be only one mode of operation for that type of program. We need to know the attachment mode type of cls_bpf programs, because exit codes are interpreted differently for legacy vs DA mode. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-02nfp: bpf: support [BPF_ALU | BPF_ALU64] | BPF_NEGJiong Wang
This patch supports BPF_NEG under both BPF_ALU64 and BPF_ALU. LLVM recently starts to generate it. NOTE: BPF_NEG takes single operand which is an register and serve as both input and output. Signed-off-by: Jiong Wang <jiong.wang@netronome.com> Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: David S. Miller <davem@davemloft.net>