summaryrefslogtreecommitdiff
path: root/include/net/libeth/tx.h
diff options
context:
space:
mode:
Diffstat (limited to 'include/net/libeth/tx.h')
-rw-r--r--include/net/libeth/tx.h129
1 files changed, 129 insertions, 0 deletions
diff --git a/include/net/libeth/tx.h b/include/net/libeth/tx.h
new file mode 100644
index 000000000000..35614f9523f6
--- /dev/null
+++ b/include/net/libeth/tx.h
@@ -0,0 +1,129 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* Copyright (C) 2024 Intel Corporation */
+
+#ifndef __LIBETH_TX_H
+#define __LIBETH_TX_H
+
+#include <linux/skbuff.h>
+
+#include <net/libeth/types.h>
+
+/* Tx buffer completion */
+
+/**
+ * enum libeth_sqe_type - type of &libeth_sqe to act on Tx completion
+ * @LIBETH_SQE_EMPTY: unused/empty, no action required
+ * @LIBETH_SQE_CTX: context descriptor with empty SQE, no action required
+ * @LIBETH_SQE_SLAB: kmalloc-allocated buffer, unmap and kfree()
+ * @LIBETH_SQE_FRAG: mapped skb frag, only unmap DMA
+ * @LIBETH_SQE_SKB: &sk_buff, unmap and napi_consume_skb(), update stats
+ */
+enum libeth_sqe_type {
+ LIBETH_SQE_EMPTY = 0U,
+ LIBETH_SQE_CTX,
+ LIBETH_SQE_SLAB,
+ LIBETH_SQE_FRAG,
+ LIBETH_SQE_SKB,
+};
+
+/**
+ * struct libeth_sqe - represents a Send Queue Element / Tx buffer
+ * @type: type of the buffer, see the enum above
+ * @rs_idx: index of the last buffer from the batch this one was sent in
+ * @raw: slab buffer to free via kfree()
+ * @skb: &sk_buff to consume
+ * @dma: DMA address to unmap
+ * @len: length of the mapped region to unmap
+ * @nr_frags: number of frags in the frame this buffer belongs to
+ * @packets: number of physical packets sent for this frame
+ * @bytes: number of physical bytes sent for this frame
+ * @priv: driver-private scratchpad
+ */
+struct libeth_sqe {
+ enum libeth_sqe_type type:32;
+ u32 rs_idx;
+
+ union {
+ void *raw;
+ struct sk_buff *skb;
+ };
+
+ DEFINE_DMA_UNMAP_ADDR(dma);
+ DEFINE_DMA_UNMAP_LEN(len);
+
+ u32 nr_frags;
+ u32 packets;
+ u32 bytes;
+
+ unsigned long priv;
+} __aligned_largest;
+
+/**
+ * LIBETH_SQE_CHECK_PRIV - check the driver's private SQE data
+ * @p: type or name of the object the driver wants to fit into &libeth_sqe
+ *
+ * Make sure the driver's private data fits into libeth_sqe::priv. To be used
+ * right after its declaration.
+ */
+#define LIBETH_SQE_CHECK_PRIV(p) \
+ static_assert(sizeof(p) <= sizeof_field(struct libeth_sqe, priv))
+
+/**
+ * struct libeth_cq_pp - completion queue poll params
+ * @dev: &device to perform DMA unmapping
+ * @ss: onstack NAPI stats to fill
+ * @napi: whether it's called from the NAPI context
+ *
+ * libeth uses this structure to access objects needed for performing full
+ * Tx complete operation without passing lots of arguments and change the
+ * prototypes each time a new one is added.
+ */
+struct libeth_cq_pp {
+ struct device *dev;
+ struct libeth_sq_napi_stats *ss;
+
+ bool napi;
+};
+
+/**
+ * libeth_tx_complete - perform Tx completion for one SQE
+ * @sqe: SQE to complete
+ * @cp: poll params
+ *
+ * Do Tx complete for all the types of buffers, incl. freeing, unmapping,
+ * updating the stats etc.
+ */
+static inline void libeth_tx_complete(struct libeth_sqe *sqe,
+ const struct libeth_cq_pp *cp)
+{
+ switch (sqe->type) {
+ case LIBETH_SQE_EMPTY:
+ return;
+ case LIBETH_SQE_SKB:
+ case LIBETH_SQE_FRAG:
+ case LIBETH_SQE_SLAB:
+ dma_unmap_page(cp->dev, dma_unmap_addr(sqe, dma),
+ dma_unmap_len(sqe, len), DMA_TO_DEVICE);
+ break;
+ default:
+ break;
+ }
+
+ switch (sqe->type) {
+ case LIBETH_SQE_SKB:
+ cp->ss->packets += sqe->packets;
+ cp->ss->bytes += sqe->bytes;
+
+ napi_consume_skb(sqe->skb, cp->napi);
+ break;
+ case LIBETH_SQE_SLAB:
+ kfree(sqe->raw);
+ break;
+ default:
+ break;
+ }
+
+ sqe->type = LIBETH_SQE_EMPTY;
+}
+
+#endif /* __LIBETH_TX_H */