nfp: bpf: add offload of TC direct action mode

Add offload of TC in direct action mode.  We just need
to provide appropriate checks in the verifier and
a new outro block to translate the exit codes to what
data path expects

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jakub Kicinski 2016-09-21 11:44:07 +01:00 committed by David S. Miller
parent 2d18421deb
commit e3b8baf0ca
4 changed files with 82 additions and 2 deletions

View file

@ -61,6 +61,7 @@ enum static_regs {
enum nfp_bpf_action_type {
NN_ACT_TC_DROP,
NN_ACT_TC_REDIR,
NN_ACT_DIRECT,
};
/* Software register representation, hardware encoding in asm.h */

View file

@ -321,6 +321,16 @@ __emit_br(struct nfp_prog *nfp_prog, enum br_mask mask, enum br_ev_pip ev_pip,
nfp_prog_push(nfp_prog, insn);
}
static void emit_br_def(struct nfp_prog *nfp_prog, u16 addr, u8 defer)
{
if (defer > 2) {
pr_err("BUG: branch defer out of bounds %d\n", defer);
nfp_prog->error = -EFAULT;
return;
}
__emit_br(nfp_prog, BR_UNC, BR_EV_PIP_UNCOND, BR_CSS_NONE, addr, defer);
}
static void
emit_br(struct nfp_prog *nfp_prog, enum br_mask mask, u16 addr, u8 defer)
{
@ -1465,9 +1475,65 @@ static void nfp_outro_tc_legacy(struct nfp_prog *nfp_prog)
SHF_SC_L_SHF, 16);
}
static void nfp_outro_tc_da(struct nfp_prog *nfp_prog)
{
/* TC direct-action mode:
* 0,1 ok NOT SUPPORTED[1]
* 2 drop 0x22 -> drop, count as stat1
* 4,5 nuke 0x02 -> drop
* 7 redir 0x44 -> redir, count as stat2
* * unspec 0x11 -> pass, count as stat0
*
* [1] We can't support OK and RECLASSIFY because we can't tell TC
* the exact decision made. We are forced to support UNSPEC
* to handle aborts so that's the only one we handle for passing
* packets up the stack.
*/
/* Target for aborts */
nfp_prog->tgt_abort = nfp_prog_current_offset(nfp_prog);
emit_br_def(nfp_prog, nfp_prog->tgt_done, 2);
emit_alu(nfp_prog, reg_a(0),
reg_none(), ALU_OP_NONE, NFP_BPF_ABI_FLAGS);
emit_ld_field(nfp_prog, reg_a(0), 0xc, reg_imm(0x11), SHF_SC_L_SHF, 16);
/* Target for normal exits */
nfp_prog->tgt_out = nfp_prog_current_offset(nfp_prog);
/* if R0 > 7 jump to abort */
emit_alu(nfp_prog, reg_none(), reg_imm(7), ALU_OP_SUB, reg_b(0));
emit_br(nfp_prog, BR_BLO, nfp_prog->tgt_abort, 0);
emit_alu(nfp_prog, reg_a(0),
reg_none(), ALU_OP_NONE, NFP_BPF_ABI_FLAGS);
wrp_immed(nfp_prog, reg_b(2), 0x41221211);
wrp_immed(nfp_prog, reg_b(3), 0x41001211);
emit_shf(nfp_prog, reg_a(1),
reg_none(), SHF_OP_NONE, reg_b(0), SHF_SC_L_SHF, 2);
emit_alu(nfp_prog, reg_none(), reg_a(1), ALU_OP_OR, reg_imm(0));
emit_shf(nfp_prog, reg_a(2),
reg_imm(0xf), SHF_OP_AND, reg_b(2), SHF_SC_R_SHF, 0);
emit_alu(nfp_prog, reg_none(), reg_a(1), ALU_OP_OR, reg_imm(0));
emit_shf(nfp_prog, reg_b(2),
reg_imm(0xf), SHF_OP_AND, reg_b(3), SHF_SC_R_SHF, 0);
emit_br_def(nfp_prog, nfp_prog->tgt_done, 2);
emit_shf(nfp_prog, reg_b(2),
reg_a(2), SHF_OP_OR, reg_b(2), SHF_SC_L_SHF, 4);
emit_ld_field(nfp_prog, reg_a(0), 0xc, reg_b(2), SHF_SC_L_SHF, 16);
}
static void nfp_outro(struct nfp_prog *nfp_prog)
{
switch (nfp_prog->act) {
case NN_ACT_DIRECT:
nfp_outro_tc_da(nfp_prog);
break;
case NN_ACT_TC_DROP:
case NN_ACT_TC_REDIR:
nfp_outro_tc_legacy(nfp_prog);

View file

@ -86,7 +86,16 @@ nfp_bpf_check_exit(struct nfp_prog *nfp_prog,
return -EINVAL;
}
if (reg0->imm != 0 && (reg0->imm & ~0U) != ~0U) {
if (nfp_prog->act != NN_ACT_DIRECT &&
reg0->imm != 0 && (reg0->imm & ~0U) != ~0U) {
pr_info("unsupported exit state: %d, imm: %llx\n",
reg0->type, reg0->imm);
return -EINVAL;
}
if (nfp_prog->act == NN_ACT_DIRECT && reg0->imm <= TC_ACT_REDIRECT &&
reg0->imm != TC_ACT_SHOT && reg0->imm != TC_ACT_STOLEN &&
reg0->imm != TC_ACT_QUEUED) {
pr_info("unsupported exit state: %d, imm: %llx\n",
reg0->type, reg0->imm);
return -EINVAL;

View file

@ -112,8 +112,12 @@ nfp_net_bpf_get_act(struct nfp_net *nn, struct tc_cls_bpf_offload *cls_bpf)
LIST_HEAD(actions);
/* TC direct action */
if (cls_bpf->exts_integrated)
if (cls_bpf->exts_integrated) {
if (tc_no_actions(cls_bpf->exts))
return NN_ACT_DIRECT;
return -ENOTSUPP;
}
/* TC legacy mode */
if (!tc_single_action(cls_bpf->exts))