1 files changed, 267 insertions, 0 deletions
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/xsk/umem.c b/drivers/net/ethernet/mellanox/mlx5/core/en/xsk/umem.c
new file mode 100644
index 000000000000..4baaa5788320
--- /dev/null
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/xsk/umem.c
@@ -0,0 +1,267 @@
+// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
+/* Copyright (c) 2019 Mellanox Technologies. */
+
+#include <net/xdp_sock.h>
+#include "umem.h"
+#include "setup.h"
+#include "en/params.h"
+
+static int mlx5e_xsk_map_umem(struct mlx5e_priv *priv,
+			      struct xdp_umem *umem)
+{
+	struct device *dev = priv->mdev->device;
+	u32 i;
+
+	for (i = 0; i < umem->npgs; i++) {
+		dma_addr_t dma = dma_map_page(dev, umem->pgs[i], 0, PAGE_SIZE,
+					      DMA_BIDIRECTIONAL);
+
+		if (unlikely(dma_mapping_error(dev, dma)))
+			goto err_unmap;
+		umem->pages[i].dma = dma;
+	}
+
+	return 0;
+
+err_unmap:
+	while (i--) {
+		dma_unmap_page(dev, umem->pages[i].dma, PAGE_SIZE,
+			       DMA_BIDIRECTIONAL);
+		umem->pages[i].dma = 0;
+	}
+
+	return -ENOMEM;
+}
+
+static void mlx5e_xsk_unmap_umem(struct mlx5e_priv *priv,
+				 struct xdp_umem *umem)
+{
+	struct device *dev = priv->mdev->device;
+	u32 i;
+
+	for (i = 0; i < umem->npgs; i++) {
+		dma_unmap_page(dev, umem->pages[i].dma, PAGE_SIZE,
+			       DMA_BIDIRECTIONAL);
+		umem->pages[i].dma = 0;
+	}
+}
+
+static int mlx5e_xsk_get_umems(struct mlx5e_xsk *xsk)
+{
+	if (!xsk->umems) {
+		xsk->umems = kcalloc(MLX5E_MAX_NUM_CHANNELS,
+				     sizeof(*xsk->umems), GFP_KERNEL);
+		if (unlikely(!xsk->umems))
+			return -ENOMEM;
+	}
+
+	xsk->refcnt++;
+	xsk->ever_used = true;
+
+	return 0;
+}
+
+static void mlx5e_xsk_put_umems(struct mlx5e_xsk *xsk)
+{
+	if (!--xsk->refcnt) {
+		kfree(xsk->umems);
+		xsk->umems = NULL;
+	}
+}
+
+static int mlx5e_xsk_add_umem(struct mlx5e_xsk *xsk, struct xdp_umem *umem, u16 ix)
+{
+	int err;
+
+	err = mlx5e_xsk_get_umems(xsk);
+	if (unlikely(err))
+		return err;
+
+	xsk->umems[ix] = umem;
+	return 0;
+}
+
+static void mlx5e_xsk_remove_umem(struct mlx5e_xsk *xsk, u16 ix)
+{
+	xsk->umems[ix] = NULL;
+
+	mlx5e_xsk_put_umems(xsk);
+}
+
+static bool mlx5e_xsk_is_umem_sane(struct xdp_umem *umem)
+{
+	return umem->headroom <= 0xffff && umem->chunk_size_nohr <= 0xffff;
+}
+
+void mlx5e_build_xsk_param(struct xdp_umem *umem, struct mlx5e_xsk_param *xsk)
+{
+	xsk->headroom = umem->headroom;
+	xsk->chunk_size = umem->chunk_size_nohr + umem->headroom;
+}
+
+static int mlx5e_xsk_enable_locked(struct mlx5e_priv *priv,
+				   struct xdp_umem *umem, u16 ix)
+{
+	struct mlx5e_params *params = &priv->channels.params;
+	struct mlx5e_xsk_param xsk;
+	struct mlx5e_channel *c;
+	int err;
+
+	if (unlikely(mlx5e_xsk_get_umem(&priv->channels.params, &priv->xsk, ix)))
+		return -EBUSY;
+
+	if (unlikely(!mlx5e_xsk_is_umem_sane(umem)))
+		return -EINVAL;
+
+	err = mlx5e_xsk_map_umem(priv, umem);
+	if (unlikely(err))
+		return err;
+
+	err = mlx5e_xsk_add_umem(&priv->xsk, umem, ix);
+	if (unlikely(err))
+		goto err_unmap_umem;
+
+	mlx5e_build_xsk_param(umem, &xsk);
+
+	if (!test_bit(MLX5E_STATE_OPENED, &priv->state)) {
+		/* XSK objects will be created on open. */
+		goto validate_closed;
+	}
+
+	if (!params->xdp_prog) {
+		/* XSK objects will be created when an XDP program is set,
+		 * and the channels are reopened.
+		 */
+		goto validate_closed;
+	}
+
+	c = priv->channels.c[ix];
+
+	err = mlx5e_open_xsk(priv, params, &xsk, umem, c);
+	if (unlikely(err))
+		goto err_remove_umem;
+
+	mlx5e_activate_xsk(c);
+
+	/* Don't wait for WQEs, because the newer xdpsock sample doesn't provide
+	 * any Fill Ring entries at the setup stage.
+	 */
+
+	err = mlx5e_xsk_redirect_rqt_to_channel(priv, priv->channels.c[ix]);
+	if (unlikely(err))
+		goto err_deactivate;
+
+	return 0;
+
+err_deactivate:
+	mlx5e_deactivate_xsk(c);
+	mlx5e_close_xsk(c);
+
+err_remove_umem:
+	mlx5e_xsk_remove_umem(&priv->xsk, ix);
+
+err_unmap_umem:
+	mlx5e_xsk_unmap_umem(priv, umem);
+
+	return err;
+
+validate_closed:
+	/* Check the configuration in advance, rather than fail at a later stage
+	 * (in mlx5e_xdp_set or on open) and end up with no channels.
+	 */
+	if (!mlx5e_validate_xsk_param(params, &xsk, priv->mdev)) {
+		err = -EINVAL;
+		goto err_remove_umem;
+	}
+
+	return 0;
+}
+
+static int mlx5e_xsk_disable_locked(struct mlx5e_priv *priv, u16 ix)
+{
+	struct xdp_umem *umem = mlx5e_xsk_get_umem(&priv->channels.params,
+						   &priv->xsk, ix);
+	struct mlx5e_channel *c;
+
+	if (unlikely(!umem))
+		return -EINVAL;
+
+	if (!test_bit(MLX5E_STATE_OPENED, &priv->state))
+		goto remove_umem;
+
+	/* XSK RQ and SQ are only created if XDP program is set. */
+	if (!priv->channels.params.xdp_prog)
+		goto remove_umem;
+
+	c = priv->channels.c[ix];
+	mlx5e_xsk_redirect_rqt_to_drop(priv, ix);
+	mlx5e_deactivate_xsk(c);
+	mlx5e_close_xsk(c);
+
+remove_umem:
+	mlx5e_xsk_remove_umem(&priv->xsk, ix);
+	mlx5e_xsk_unmap_umem(priv, umem);
+
+	return 0;
+}
+
+static int mlx5e_xsk_enable_umem(struct mlx5e_priv *priv, struct xdp_umem *umem,
+				 u16 ix)
+{
+	int err;
+
+	mutex_lock(&priv->state_lock);
+	err = mlx5e_xsk_enable_locked(priv, umem, ix);
+	mutex_unlock(&priv->state_lock);
+
+	return err;
+}
+
+static int mlx5e_xsk_disable_umem(struct mlx5e_priv *priv, u16 ix)
+{
+	int err;
+
+	mutex_lock(&priv->state_lock);
+	err = mlx5e_xsk_disable_locked(priv, ix);
+	mutex_unlock(&priv->state_lock);
+
+	return err;
+}
+
+int mlx5e_xsk_setup_umem(struct net_device *dev, struct xdp_umem *umem, u16 qid)
+{
+	struct mlx5e_priv *priv = netdev_priv(dev);
+	struct mlx5e_params *params = &priv->channels.params;
+	u16 ix;
+
+	if (unlikely(!mlx5e_qid_get_ch_if_in_group(params, qid, MLX5E_RQ_GROUP_XSK, &ix)))
+		return -EINVAL;
+
+	return umem ? mlx5e_xsk_enable_umem(priv, umem, ix) :
+		      mlx5e_xsk_disable_umem(priv, ix);
+}
+
+int mlx5e_xsk_resize_reuseq(struct xdp_umem *umem, u32 nentries)
+{
+	struct xdp_umem_fq_reuse *reuseq;
+
+	reuseq = xsk_reuseq_prepare(nentries);
+	if (unlikely(!reuseq))
+		return -ENOMEM;
+	xsk_reuseq_free(xsk_reuseq_swap(umem, reuseq));
+
+	return 0;
+}
+
+u16 mlx5e_xsk_first_unused_channel(struct mlx5e_params *params, struct mlx5e_xsk *xsk)
+{
+	u16 res = xsk->refcnt ? params->num_channels : 0;
+
+	while (res) {
+		if (mlx5e_xsk_get_umem(params, xsk, res - 1))
+			break;
+		--res;
+	}
+
+	return res;
+}