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Commit e3b8baf0 authored by Jakub Kicinski's avatar Jakub Kicinski Committed by David S. Miller
Browse files

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: default avatarJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 2d18421d

drivers/net/ethernet/netronome/nfp/nfp_bpf.h

+1 −0
Original line number Diff line number Diff line
@@ -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 */

drivers/net/ethernet/netronome/nfp/nfp_bpf_jit.c

+66 −0
Original line number Diff line number Diff line
@@ -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);

drivers/net/ethernet/netronome/nfp/nfp_bpf_verifier.c

+10 −1
Original line number Diff line number Diff line
@@ -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;

drivers/net/ethernet/netronome/nfp/nfp_net_offload.c

+5 −1
Original line number Diff line number Diff line
@@ -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))