nfp: bpf: parse function call and map capabilities

Parse helper function and supported map FW TLV capabilities.
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>

drivers/net/ethernet/netronome/nfp/bpf/fw.h

@@ -38,7 +38,14 @@
 #include <linux/types.h>
 
 enum bpf_cap_tlv_type {
+	NFP_BPF_CAP_TYPE_FUNC		= 1,
 	NFP_BPF_CAP_TYPE_ADJUST_HEAD	= 2,
+	NFP_BPF_CAP_TYPE_MAPS		= 3,
+};
+
+struct nfp_bpf_cap_tlv_func {
+	__le32 func_id;
+	__le32 func_addr;
 };
 
 struct nfp_bpf_cap_tlv_adjust_head {
@@ -51,6 +58,15 @@ struct nfp_bpf_cap_tlv_adjust_head {
 
 #define NFP_BPF_ADJUST_HEAD_NO_META	BIT(0)
 
+struct nfp_bpf_cap_tlv_maps {
+	__le32 types;
+	__le32 max_maps;
+	__le32 max_elems;
+	__le32 max_key_sz;
+	__le32 max_val_sz;
+	__le32 max_elem_sz;
+};
+
 /*
  * Types defined for map related control messages
  */

drivers/net/ethernet/netronome/nfp/bpf/main.c

@@ -251,6 +251,45 @@ nfp_bpf_parse_cap_adjust_head(struct nfp_app_bpf *bpf, void __iomem *value,
 	return 0;
 }
 
+static int
+nfp_bpf_parse_cap_func(struct nfp_app_bpf *bpf, void __iomem *value, u32 length)
+{
+	struct nfp_bpf_cap_tlv_func __iomem *cap = value;
+
+	if (length < sizeof(*cap)) {
+		nfp_err(bpf->app->cpp, "truncated function TLV: %d\n", length);
+		return -EINVAL;
+	}
+
+	switch (readl(&cap->func_id)) {
+	case BPF_FUNC_map_lookup_elem:
+		bpf->helpers.map_lookup = readl(&cap->func_addr);
+		break;
+	}
+
+	return 0;
+}
+
+static int
+nfp_bpf_parse_cap_maps(struct nfp_app_bpf *bpf, void __iomem *value, u32 length)
+{
+	struct nfp_bpf_cap_tlv_maps __iomem *cap = value;
+
+	if (length < sizeof(*cap)) {
+		nfp_err(bpf->app->cpp, "truncated maps TLV: %d\n", length);
+		return -EINVAL;
+	}
+
+	bpf->maps.types = readl(&cap->types);
+	bpf->maps.max_maps = readl(&cap->max_maps);
+	bpf->maps.max_elems = readl(&cap->max_elems);
+	bpf->maps.max_key_sz = readl(&cap->max_key_sz);
+	bpf->maps.max_val_sz = readl(&cap->max_val_sz);
+	bpf->maps.max_elem_sz = readl(&cap->max_elem_sz);
+
+	return 0;
+}
+
 static int nfp_bpf_parse_capabilities(struct nfp_app *app)
 {
 	struct nfp_cpp *cpp = app->pf->cpp;
@@ -276,11 +315,19 @@ static int nfp_bpf_parse_capabilities(struct nfp_app *app)
 			goto err_release_free;
 
 		switch (type) {
+		case NFP_BPF_CAP_TYPE_FUNC:
+			if (nfp_bpf_parse_cap_func(app->priv, value, length))
+				goto err_release_free;
+			break;
 		case NFP_BPF_CAP_TYPE_ADJUST_HEAD:
 			if (nfp_bpf_parse_cap_adjust_head(app->priv, value,
 							  length))
 				goto err_release_free;
 			break;
+		case NFP_BPF_CAP_TYPE_MAPS:
+			if (nfp_bpf_parse_cap_maps(app->priv, value, length))
+				goto err_release_free;
+			break;
 		default:
 			nfp_dbg(cpp, "unknown BPF capability: %d\n", type);
 			break;

drivers/net/ethernet/netronome/nfp/bpf/main.h

@@ -112,6 +112,17 @@ enum pkt_vec {
  * @off_max:		maximum packet offset within buffer required
  * @guaranteed_sub:	amount of negative adjustment guaranteed possible
  * @guaranteed_add:	amount of positive adjustment guaranteed possible
+ *
+ * @maps:		map capability
+ * @types:		supported map types
+ * @max_maps:		max number of maps supported
+ * @max_elems:		max number of entries in each map
+ * @max_key_sz:		max size of map key
+ * @max_val_sz:		max size of map value
+ * @max_elem_sz:	max size of map entry (key + value)
+ *
+ * @helpers:		helper addressess for various calls
+ * @map_lookup:		map lookup helper address
  */
 struct nfp_app_bpf {
 	struct nfp_app *app;
@@ -132,6 +143,19 @@ struct nfp_app_bpf {
 		int guaranteed_sub;
 		int guaranteed_add;
 	} adjust_head;
+
+	struct {
+		u32 types;
+		u32 max_maps;
+		u32 max_elems;
+		u32 max_key_sz;
+		u32 max_val_sz;
+		u32 max_elem_sz;
+	} maps;
+
+	struct {
+		u32 map_lookup;
+	} helpers;
 };
 
 /**