1 files changed, 287 insertions, 0 deletions
diff --git a/drivers/net/ethernet/netronome/nfp/bpf/offload.c b/drivers/net/ethernet/netronome/nfp/bpf/offload.c
new file mode 100644
index 000000000000..30372dc99517
--- /dev/null
+++ b/drivers/net/ethernet/netronome/nfp/bpf/offload.c
@@ -0,0 +1,287 @@
+/*
+ * Copyright (C) 2016 Netronome Systems, Inc.
+ *
+ * This software is dual licensed under the GNU General License Version 2,
+ * June 1991 as shown in the file COPYING in the top-level directory of this
+ * source tree or the BSD 2-Clause License provided below.  You have the
+ * option to license this software under the complete terms of either license.
+ *
+ * The BSD 2-Clause License:
+ *
+ *     Redistribution and use in source and binary forms, with or
+ *     without modification, are permitted provided that the following
+ *     conditions are met:
+ *
+ *      1. Redistributions of source code must retain the above
+ *         copyright notice, this list of conditions and the following
+ *         disclaimer.
+ *
+ *      2. Redistributions in binary form must reproduce the above
+ *         copyright notice, this list of conditions and the following
+ *         disclaimer in the documentation and/or other materials
+ *         provided with the distribution.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+/*
+ * nfp_net_offload.c
+ * Netronome network device driver: TC offload functions for PF and VF
+ */
+
+#include <linux/kernel.h>
+#include <linux/netdevice.h>
+#include <linux/pci.h>
+#include <linux/jiffies.h>
+#include <linux/timer.h>
+#include <linux/list.h>
+
+#include <net/pkt_cls.h>
+#include <net/tc_act/tc_gact.h>
+#include <net/tc_act/tc_mirred.h>
+
+#include "main.h"
+#include "../nfp_net_ctrl.h"
+#include "../nfp_net.h"
+
+void nfp_net_filter_stats_timer(unsigned long data)
+{
+	struct nfp_net *nn = (void *)data;
+	struct nfp_stat_pair latest;
+
+	spin_lock_bh(&nn->rx_filter_lock);
+
+	if (nn->dp.ctrl & NFP_NET_CFG_CTRL_BPF)
+		mod_timer(&nn->rx_filter_stats_timer,
+			  jiffies + NFP_NET_STAT_POLL_IVL);
+
+	spin_unlock_bh(&nn->rx_filter_lock);
+
+	latest.pkts = nn_readq(nn, NFP_NET_CFG_STATS_APP1_FRAMES);
+	latest.bytes = nn_readq(nn, NFP_NET_CFG_STATS_APP1_BYTES);
+
+	if (latest.pkts != nn->rx_filter.pkts)
+		nn->rx_filter_change = jiffies;
+
+	nn->rx_filter = latest;
+}
+
+static void nfp_net_bpf_stats_reset(struct nfp_net *nn)
+{
+	nn->rx_filter.pkts = nn_readq(nn, NFP_NET_CFG_STATS_APP1_FRAMES);
+	nn->rx_filter.bytes = nn_readq(nn, NFP_NET_CFG_STATS_APP1_BYTES);
+	nn->rx_filter_prev = nn->rx_filter;
+	nn->rx_filter_change = jiffies;
+}
+
+static int
+nfp_net_bpf_stats_update(struct nfp_net *nn, struct tc_cls_bpf_offload *cls_bpf)
+{
+	u64 bytes, pkts;
+
+	pkts = nn->rx_filter.pkts - nn->rx_filter_prev.pkts;
+	bytes = nn->rx_filter.bytes - nn->rx_filter_prev.bytes;
+	bytes -= pkts * ETH_HLEN;
+
+	nn->rx_filter_prev = nn->rx_filter;
+
+	tcf_exts_stats_update(cls_bpf->exts,
+			      bytes, pkts, nn->rx_filter_change);
+
+	return 0;
+}
+
+static int
+nfp_net_bpf_get_act(struct nfp_net *nn, struct tc_cls_bpf_offload *cls_bpf)
+{
+	const struct tc_action *a;
+	LIST_HEAD(actions);
+
+	if (!cls_bpf->exts)
+		return NN_ACT_XDP;
+
+	/* TC direct action */
+	if (cls_bpf->exts_integrated) {
+		if (tc_no_actions(cls_bpf->exts))
+			return NN_ACT_DIRECT;
+
+		return -EOPNOTSUPP;
+	}
+
+	/* TC legacy mode */
+	if (!tc_single_action(cls_bpf->exts))
+		return -EOPNOTSUPP;
+
+	tcf_exts_to_list(cls_bpf->exts, &actions);
+	list_for_each_entry(a, &actions, list) {
+		if (is_tcf_gact_shot(a))
+			return NN_ACT_TC_DROP;
+
+		if (is_tcf_mirred_egress_redirect(a) &&
+		    tcf_mirred_ifindex(a) == nn->dp.netdev->ifindex)
+			return NN_ACT_TC_REDIR;
+	}
+
+	return -EOPNOTSUPP;
+}
+
+static int
+nfp_net_bpf_offload_prepare(struct nfp_net *nn,
+			    struct tc_cls_bpf_offload *cls_bpf,
+			    struct nfp_bpf_result *res,
+			    void **code, dma_addr_t *dma_addr, u16 max_instr)
+{
+	unsigned int code_sz = max_instr * sizeof(u64);
+	enum nfp_bpf_action_type act;
+	u16 start_off, done_off;
+	unsigned int max_mtu;
+	int ret;
+
+	if (!IS_ENABLED(CONFIG_BPF_SYSCALL))
+		return -EOPNOTSUPP;
+
+	ret = nfp_net_bpf_get_act(nn, cls_bpf);
+	if (ret < 0)
+		return ret;
+	act = ret;
+
+	max_mtu = nn_readb(nn, NFP_NET_CFG_BPF_INL_MTU) * 64 - 32;
+	if (max_mtu < nn->dp.netdev->mtu) {
+		nn_info(nn, "BPF offload not supported with MTU larger than HW packet split boundary\n");
+		return -EOPNOTSUPP;
+	}
+
+	start_off = nn_readw(nn, NFP_NET_CFG_BPF_START);
+	done_off = nn_readw(nn, NFP_NET_CFG_BPF_DONE);
+
+	*code = dma_zalloc_coherent(nn->dp.dev, code_sz, dma_addr, GFP_KERNEL);
+	if (!*code)
+		return -ENOMEM;
+
+	ret = nfp_bpf_jit(cls_bpf->prog, *code, act, start_off, done_off,
+			  max_instr, res);
+	if (ret)
+		goto out;
+
+	return 0;
+
+out:
+	dma_free_coherent(nn->dp.dev, code_sz, *code, *dma_addr);
+	return ret;
+}
+
+static void
+nfp_net_bpf_load_and_start(struct nfp_net *nn, u32 tc_flags,
+			   void *code, dma_addr_t dma_addr,
+			   unsigned int code_sz, unsigned int n_instr,
+			   bool dense_mode)
+{
+	u64 bpf_addr = dma_addr;
+	int err;
+
+	nn->dp.bpf_offload_skip_sw = !!(tc_flags & TCA_CLS_FLAGS_SKIP_SW);
+
+	if (dense_mode)
+		bpf_addr |= NFP_NET_CFG_BPF_CFG_8CTX;
+
+	nn_writew(nn, NFP_NET_CFG_BPF_SIZE, n_instr);
+	nn_writeq(nn, NFP_NET_CFG_BPF_ADDR, bpf_addr);
+
+	/* Load up the JITed code */
+	err = nfp_net_reconfig(nn, NFP_NET_CFG_UPDATE_BPF);
+	if (err)
+		nn_err(nn, "FW command error while loading BPF: %d\n", err);
+
+	/* Enable passing packets through BPF function */
+	nn->dp.ctrl |= NFP_NET_CFG_CTRL_BPF;
+	nn_writel(nn, NFP_NET_CFG_CTRL, nn->dp.ctrl);
+	err = nfp_net_reconfig(nn, NFP_NET_CFG_UPDATE_GEN);
+	if (err)
+		nn_err(nn, "FW command error while enabling BPF: %d\n", err);
+
+	dma_free_coherent(nn->dp.dev, code_sz, code, dma_addr);
+
+	nfp_net_bpf_stats_reset(nn);
+	mod_timer(&nn->rx_filter_stats_timer, jiffies + NFP_NET_STAT_POLL_IVL);
+}
+
+static int nfp_net_bpf_stop(struct nfp_net *nn)
+{
+	if (!(nn->dp.ctrl & NFP_NET_CFG_CTRL_BPF))
+		return 0;
+
+	spin_lock_bh(&nn->rx_filter_lock);
+	nn->dp.ctrl &= ~NFP_NET_CFG_CTRL_BPF;
+	spin_unlock_bh(&nn->rx_filter_lock);
+	nn_writel(nn, NFP_NET_CFG_CTRL, nn->dp.ctrl);
+
+	del_timer_sync(&nn->rx_filter_stats_timer);
+	nn->dp.bpf_offload_skip_sw = 0;
+
+	return nfp_net_reconfig(nn, NFP_NET_CFG_UPDATE_GEN);
+}
+
+int nfp_net_bpf_offload(struct nfp_net *nn, struct tc_cls_bpf_offload *cls_bpf)
+{
+	struct nfp_bpf_result res;
+	dma_addr_t dma_addr;
+	u16 max_instr;
+	void *code;
+	int err;
+
+	max_instr = nn_readw(nn, NFP_NET_CFG_BPF_MAX_LEN);
+
+	switch (cls_bpf->command) {
+	case TC_CLSBPF_REPLACE:
+		/* There is nothing stopping us from implementing seamless
+		 * replace but the simple method of loading I adopted in
+		 * the firmware does not handle atomic replace (i.e. we have to
+		 * stop the BPF offload and re-enable it).  Leaking-in a few
+		 * frames which didn't have BPF applied in the hardware should
+		 * be fine if software fallback is available, though.
+		 */
+		if (nn->dp.bpf_offload_skip_sw)
+			return -EBUSY;
+
+		err = nfp_net_bpf_offload_prepare(nn, cls_bpf, &res, &code,
+						  &dma_addr, max_instr);
+		if (err)
+			return err;
+
+		nfp_net_bpf_stop(nn);
+		nfp_net_bpf_load_and_start(nn, cls_bpf->gen_flags, code,
+					   dma_addr, max_instr * sizeof(u64),
+					   res.n_instr, res.dense_mode);
+		return 0;
+
+	case TC_CLSBPF_ADD:
+		if (nn->dp.ctrl & NFP_NET_CFG_CTRL_BPF)
+			return -EBUSY;
+
+		err = nfp_net_bpf_offload_prepare(nn, cls_bpf, &res, &code,
+						  &dma_addr, max_instr);
+		if (err)
+			return err;
+
+		nfp_net_bpf_load_and_start(nn, cls_bpf->gen_flags, code,
+					   dma_addr, max_instr * sizeof(u64),
+					   res.n_instr, res.dense_mode);
+		return 0;
+
+	case TC_CLSBPF_DESTROY:
+		return nfp_net_bpf_stop(nn);
+
+	case TC_CLSBPF_STATS:
+		return nfp_net_bpf_stats_update(nn, cls_bpf);
+
+	default:
+		return -EOPNOTSUPP;
+	}
+}