nfp: bpf: implement bpf map offload

Plug in to the stack's map offload callbacks for BPF map offload.
Get next call needs some special handling on the FW side, since
we can't send a NULL pointer to the FW there is a get first entry
FW command.

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>

1 files changed, 104 insertions, 0 deletions

diff --git a/drivers/net/ethernet/netronome/nfp/bpf/offload.c b/drivers/net/ethernet/netronome/nfp/bpf/offload.c
index 6590228d3755..e2859b2e9c6a 100644
--- a/drivers/net/ethernet/netronome/nfp/bpf/offload.c
+++ b/drivers/net/ethernet/netronome/nfp/bpf/offload.c
@@ -36,6 +36,9 @@
  * Netronome network device driver: TC offload functions for PF and VF
  */
 
+#define pr_fmt(fmt)	"NFP net bpf: " fmt
+
+#include <linux/bpf.h>
 #include <linux/kernel.h>
 #include <linux/netdevice.h>
 #include <linux/pci.h>
@@ -153,6 +156,103 @@ static int nfp_bpf_destroy(struct nfp_net *nn, struct bpf_prog *prog)
 	return 0;
 }
 
+static int
+nfp_bpf_map_get_next_key(struct bpf_offloaded_map *offmap,
+			 void *key, void *next_key)
+{
+	if (!key)
+		return nfp_bpf_ctrl_getfirst_entry(offmap, next_key);
+	return nfp_bpf_ctrl_getnext_entry(offmap, key, next_key);
+}
+
+static int
+nfp_bpf_map_delete_elem(struct bpf_offloaded_map *offmap, void *key)
+{
+	return nfp_bpf_ctrl_del_entry(offmap, key);
+}
+
+static const struct bpf_map_dev_ops nfp_bpf_map_ops = {
+	.map_get_next_key	= nfp_bpf_map_get_next_key,
+	.map_lookup_elem	= nfp_bpf_ctrl_lookup_entry,
+	.map_update_elem	= nfp_bpf_ctrl_update_entry,
+	.map_delete_elem	= nfp_bpf_map_delete_elem,
+};
+
+static int
+nfp_bpf_map_alloc(struct nfp_app_bpf *bpf, struct bpf_offloaded_map *offmap)
+{
+	struct nfp_bpf_map *nfp_map;
+	long long int res;
+
+	if (!bpf->maps.types)
+		return -EOPNOTSUPP;
+
+	if (offmap->map.map_flags ||
+	    offmap->map.numa_node != NUMA_NO_NODE) {
+		pr_info("map flags are not supported\n");
+		return -EINVAL;
+	}
+
+	if (!(bpf->maps.types & 1 << offmap->map.map_type)) {
+		pr_info("map type not supported\n");
+		return -EOPNOTSUPP;
+	}
+	if (bpf->maps.max_maps == bpf->maps_in_use) {
+		pr_info("too many maps for a device\n");
+		return -ENOMEM;
+	}
+	if (bpf->maps.max_elems - bpf->map_elems_in_use <
+	    offmap->map.max_entries) {
+		pr_info("map with too many elements: %u, left: %u\n",
+			offmap->map.max_entries,
+			bpf->maps.max_elems - bpf->map_elems_in_use);
+		return -ENOMEM;
+	}
+	if (offmap->map.key_size > bpf->maps.max_key_sz ||
+	    offmap->map.value_size > bpf->maps.max_val_sz ||
+	    round_up(offmap->map.key_size, 8) +
+	    round_up(offmap->map.value_size, 8) > bpf->maps.max_elem_sz) {
+		pr_info("elements don't fit in device constraints\n");
+		return -ENOMEM;
+	}
+
+	nfp_map = kzalloc(sizeof(*nfp_map), GFP_USER);
+	if (!nfp_map)
+		return -ENOMEM;
+
+	offmap->dev_priv = nfp_map;
+	nfp_map->offmap = offmap;
+	nfp_map->bpf = bpf;
+
+	res = nfp_bpf_ctrl_alloc_map(bpf, &offmap->map);
+	if (res < 0) {
+		kfree(nfp_map);
+		return res;
+	}
+
+	nfp_map->tid = res;
+	offmap->dev_ops = &nfp_bpf_map_ops;
+	bpf->maps_in_use++;
+	bpf->map_elems_in_use += offmap->map.max_entries;
+	list_add_tail(&nfp_map->l, &bpf->map_list);
+
+	return 0;
+}
+
+static int
+nfp_bpf_map_free(struct nfp_app_bpf *bpf, struct bpf_offloaded_map *offmap)
+{
+	struct nfp_bpf_map *nfp_map = offmap->dev_priv;
+
+	nfp_bpf_ctrl_free_map(bpf, nfp_map);
+	list_del_init(&nfp_map->l);
+	bpf->map_elems_in_use -= offmap->map.max_entries;
+	bpf->maps_in_use--;
+	kfree(nfp_map);
+
+	return 0;
+}
+
 int nfp_ndo_bpf(struct nfp_app *app, struct nfp_net *nn, struct netdev_bpf *bpf)
 {
 	switch (bpf->command) {
@@ -162,6 +262,10 @@ int nfp_ndo_bpf(struct nfp_app *app, struct nfp_net *nn, struct netdev_bpf *bpf)
 		return nfp_bpf_translate(nn, bpf->offload.prog);
 	case BPF_OFFLOAD_DESTROY:
 		return nfp_bpf_destroy(nn, bpf->offload.prog);
+	case BPF_OFFLOAD_MAP_ALLOC:
+		return nfp_bpf_map_alloc(app->priv, bpf->offmap);
+	case BPF_OFFLOAD_MAP_FREE:
+		return nfp_bpf_map_free(app->priv, bpf->offmap);
 	default:
 		return -EINVAL;
 	}