[PATCH bpf-next 0/2] nfp: bpf: add programmable RSS support

@@ -627,7 +627,7 @@ bool bpf_offload_dev_match(struct bpf_prog *prog, struct bpf_map *map);
 #if defined(CONFIG_NET) && defined(CONFIG_BPF_SYSCALL)
 int bpf_prog_offload_init(struct bpf_prog *prog, union bpf_attr *attr);
 
-static inline bool bpf_prog_is_dev_bound(struct bpf_prog_aux *aux)
+static inline bool bpf_prog_is_dev_bound(const struct bpf_prog_aux *aux)
 {
 	return aux->offload_requested;
 }

@@ -5215,7 +5215,7 @@ static int convert_ctx_accesses(struct bpf_verifier_env *env)
 		}
 	}
 
-	if (!ops->convert_ctx_access)
+	if (!ops->convert_ctx_access || bpf_prog_is_dev_bound(env->prog->aux))
 		return 0;
 
 	insn = env->prog->insnsi + delta;

@@ -4911,8 +4911,15 @@ static bool xdp_is_valid_access(int off, int size,
 				const struct bpf_prog *prog,
 				struct bpf_insn_access_aux *info)
 {
-	if (type == BPF_WRITE)
+	if (type == BPF_WRITE) {
+		if (bpf_prog_is_dev_bound(prog->aux)) {
+			switch (off) {
+			case offsetof(struct xdp_md, rx_queue_index):
+				return __is_valid_xdp_access(off, size);
+			}
+		}
 		return false;
+	}
 
 	switch (off) {
 	case offsetof(struct xdp_md, data):

@@ -50,6 +50,7 @@ enum bpf_cap_tlv_type {
 	NFP_BPF_CAP_TYPE_ADJUST_HEAD	= 2,
 	NFP_BPF_CAP_TYPE_MAPS		= 3,
 	NFP_BPF_CAP_TYPE_RANDOM		= 4,
+	NFP_BPF_CAP_TYPE_QUEUE_SELECT	= 5,
 };
 
 struct nfp_bpf_cap_tlv_func {

@@ -42,6 +42,7 @@
 
 #include "main.h"
 #include "../nfp_asm.h"
+#include "../nfp_net_ctrl.h"
 
 /* --- NFP prog --- */
 /* Foreach "multiple" entries macros provide pos and next<n> pointers.

@@ -1470,6 +1471,38 @@ nfp_perf_event_output(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
 	return 0;
 }
 
+static int
+nfp_queue_select(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
+{
+	u32 jmp_tgt;
+
+	jmp_tgt = nfp_prog_current_offset(nfp_prog) + 5;
+
+	/* Make sure the queue id fits into FW field */
+	emit_alu(nfp_prog, reg_none(), reg_a(meta->insn.src_reg * 2),
+		 ALU_OP_AND_NOT_B, reg_imm(0xff));
+	emit_br(nfp_prog, BR_BEQ, jmp_tgt, 2);
+
+	/* Set the 'queue selected' bit and the queue value */
+	emit_shf(nfp_prog, pv_qsel_set(nfp_prog),
+		 pv_qsel_set(nfp_prog), SHF_OP_OR, reg_imm(1),
+		 SHF_SC_L_SHF, PKT_VEL_QSEL_SET_BIT);
+	emit_ld_field(nfp_prog,
+		      pv_qsel_val(nfp_prog), 0x1, reg_b(meta->insn.src_reg * 2),
+		      SHF_SC_NONE, 0);
+	/* Delay slots end here, we will jump over next instruction if queue
+	 * value fits into the field.
+	 */
+	emit_ld_field(nfp_prog,
+		      pv_qsel_val(nfp_prog), 0x1, reg_imm(NFP_NET_RXR_MAX),
+		      SHF_SC_NONE, 0);
+
+	if (!nfp_prog_confirm_current_offset(nfp_prog, jmp_tgt))
+		return -EINVAL;
+
+	return 0;
+}
+
 /* --- Callbacks --- */
 static int mov_reg64(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
 {

@@ -2160,6 +2193,17 @@ mem_stx_stack(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta,
 			    false, wrp_lmem_store);
 }
 
+static int mem_stx_xdp(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
+{
+	switch (meta->insn.off) {
+	case offsetof(struct xdp_md, rx_queue_index):
+		return nfp_queue_select(nfp_prog, meta);
+	}
+
+	WARN_ON_ONCE(1); /* verifier should have rejected bad accesses */
+	return -EOPNOTSUPP;
+}
+
 static int
 mem_stx(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta,
 	unsigned int size)

@@ -2186,6 +2230,9 @@ static int mem_stx2(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
 
 static int mem_stx4(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
 {
+	if (meta->ptr.type == PTR_TO_CTX)
+		if (nfp_prog->type == BPF_PROG_TYPE_XDP)
+			return mem_stx_xdp(nfp_prog, meta);
 	return mem_stx(nfp_prog, meta, 4);
 }
 

@@ -334,6 +334,13 @@ nfp_bpf_parse_cap_random(struct nfp_app_bpf *bpf, void __iomem *value,
 	return 0;
 }
 
+static int
+nfp_bpf_parse_cap_qsel(struct nfp_app_bpf *bpf, void __iomem *value, u32 length)
+{
+	bpf->queue_select = true;
+	return 0;
+}
+
 static int nfp_bpf_parse_capabilities(struct nfp_app *app)
 {
 	struct nfp_cpp *cpp = app->pf->cpp;

@@ -376,6 +383,10 @@ static int nfp_bpf_parse_capabilities(struct nfp_app *app)
 			if (nfp_bpf_parse_cap_random(app->priv, value, length))
 				goto err_release_free;
 			break;
+		case NFP_BPF_CAP_TYPE_QUEUE_SELECT:
+			if (nfp_bpf_parse_cap_qsel(app->priv, value, length))
+				goto err_release_free;
+			break;
 		default:
 			nfp_dbg(cpp, "unknown BPF capability: %d\n", type);
 			break;

@@ -82,10 +82,16 @@ enum static_regs {
 enum pkt_vec {
 	PKT_VEC_PKT_LEN		= 0,
 	PKT_VEC_PKT_PTR		= 2,
+	PKT_VEC_QSEL_SET	= 4,
+	PKT_VEC_QSEL_VAL	= 6,
 };
 
+#define PKT_VEL_QSEL_SET_BIT	4
+
 #define pv_len(np)	reg_lm(1, PKT_VEC_PKT_LEN)
 #define pv_ctm_ptr(np)	reg_lm(1, PKT_VEC_PKT_PTR)
+#define pv_qsel_set(np)	reg_lm(1, PKT_VEC_QSEL_SET)
+#define pv_qsel_val(np)	reg_lm(1, PKT_VEC_QSEL_VAL)
 
 #define stack_reg(np)	reg_a(STATIC_REG_STACK)
 #define stack_imm(np)	imm_b(np)

@@ -139,6 +145,7 @@ enum pkt_vec {
  * @helpers.perf_event_output:	output perf event to a ring buffer
  *
  * @pseudo_random:	FW initialized the pseudo-random machinery (CSRs)
+ * @queue_select:	BPF can set the RX queue ID in packet vector
  */
 struct nfp_app_bpf {
 	struct nfp_app *app;

@@ -181,6 +188,7 @@ struct nfp_app_bpf {
 	} helpers;
 
 	bool pseudo_random;
+	bool queue_select;
 };
 
 enum nfp_bpf_map_use {

@@ -467,6 +467,30 @@ nfp_bpf_check_ptr(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta,
 	return 0;
 }
 
+static int
+nfp_bpf_check_store(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta,
+		    struct bpf_verifier_env *env)
+{
+	const struct bpf_reg_state *reg = cur_regs(env) + meta->insn.dst_reg;
+
+	if (reg->type == PTR_TO_CTX) {
+		if (nfp_prog->type == BPF_PROG_TYPE_XDP) {
+			/* XDP ctx accesses must be 4B in size */
+			switch (meta->insn.off) {
+			case offsetof(struct xdp_md, rx_queue_index):
+				if (nfp_prog->bpf->queue_select)
+					goto exit_check_ptr;
+				pr_vlog(env, "queue selection not supported by FW\n");
+				return -EOPNOTSUPP;
+			}
+		}
+		pr_vlog(env, "unsupported store to context field\n");
+		return -EOPNOTSUPP;
+	}
+exit_check_ptr:
+	return nfp_bpf_check_ptr(nfp_prog, meta, env, meta->insn.dst_reg);
+}
+
 static int
 nfp_bpf_check_xadd(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta,
 		   struct bpf_verifier_env *env)

@@ -522,8 +546,8 @@ nfp_verify_insn(struct bpf_verifier_env *env, int insn_idx, int prev_insn_idx)
 		return nfp_bpf_check_ptr(nfp_prog, meta, env,
 					 meta->insn.src_reg);
 	if (is_mbpf_store(meta))
-		return nfp_bpf_check_ptr(nfp_prog, meta, env,
-					 meta->insn.dst_reg);
+		return nfp_bpf_check_store(nfp_prog, meta, env);
+
 	if (is_mbpf_xadd(meta))
 		return nfp_bpf_check_xadd(nfp_prog, meta, env);
 

@@ -183,16 +183,18 @@ enum shf_sc {
 #define OP_ALU_DST_LMEXTN	0x80000000000ULL
 
 enum alu_op {
-	ALU_OP_NONE	= 0x00,
-	ALU_OP_ADD	= 0x01,
-	ALU_OP_NOT	= 0x04,
-	ALU_OP_ADD_2B	= 0x05,
-	ALU_OP_AND	= 0x08,
-	ALU_OP_SUB_C	= 0x0d,
-	ALU_OP_ADD_C	= 0x11,
-	ALU_OP_OR	= 0x14,
-	ALU_OP_SUB	= 0x15,
-	ALU_OP_XOR	= 0x18,
+	ALU_OP_NONE		= 0x00,
+	ALU_OP_ADD		= 0x01,
+	ALU_OP_NOT		= 0x04,
+	ALU_OP_ADD_2B		= 0x05,
+	ALU_OP_AND		= 0x08,
+	ALU_OP_AND_NOT_A	= 0x0c,
+	ALU_OP_SUB_C		= 0x0d,
+	ALU_OP_AND_NOT_B	= 0x10,
+	ALU_OP_ADD_C		= 0x11,
+	ALU_OP_OR		= 0x14,
+	ALU_OP_SUB		= 0x15,
+	ALU_OP_XOR		= 0x18,
 };
 
 enum alu_dst_ab {