diff mbox series

[net-next,v3,1/6] libeth: add Tx buffer completion helpers

Message ID 20240909205323.3110312-2-anthony.l.nguyen@intel.com (mailing list archive)
State Accepted
Commit 080d72f471c86f8906845bc822051f5790d0a90d
Delegated to: Netdev Maintainers
Headers show
Series idpf: XDP chapter II: convert Tx completion to libeth | expand

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Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next, async
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 16 this patch: 16
netdev/build_tools success Errors and warnings before: 0 this patch: 0
netdev/cc_maintainers success CCed 4 of 4 maintainers
netdev/build_clang success Errors and warnings before: 17 this patch: 17
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 22 this patch: 22
netdev/checkpatch warning WARNING: added, moved or deleted file(s), does MAINTAINERS need updating?
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2024-09-12--00-00 (tests: 764)

Commit Message

Tony Nguyen Sept. 9, 2024, 8:53 p.m. UTC
From: Alexander Lobakin <aleksander.lobakin@intel.com>

Software-side Tx buffers for storing DMA, frame size, skb pointers etc.
are pretty much generic and every driver defines them the same way. The
same can be said for software Tx completions -- same napi_consume_skb()s
and all that...
Add a couple simple wrappers for doing that to stop repeating the old
tale at least within the Intel code. Drivers are free to use 'priv'
member at the end of the structure.

Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
 include/net/libeth/tx.h    | 129 +++++++++++++++++++++++++++++++++++++
 include/net/libeth/types.h |  25 +++++++
 2 files changed, 154 insertions(+)
 create mode 100644 include/net/libeth/tx.h
 create mode 100644 include/net/libeth/types.h
diff mbox series

Patch

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 */
diff --git a/include/net/libeth/types.h b/include/net/libeth/types.h
new file mode 100644
index 000000000000..603825e45133
--- /dev/null
+++ b/include/net/libeth/types.h
@@ -0,0 +1,25 @@ 
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* Copyright (C) 2024 Intel Corporation */
+
+#ifndef __LIBETH_TYPES_H
+#define __LIBETH_TYPES_H
+
+#include <linux/types.h>
+
+/**
+ * struct libeth_sq_napi_stats - "hot" counters to update in Tx completion loop
+ * @packets: completed frames counter
+ * @bytes: sum of bytes of completed frames above
+ * @raw: alias to access all the fields as an array
+ */
+struct libeth_sq_napi_stats {
+	union {
+		struct {
+							u32 packets;
+							u32 bytes;
+		};
+		DECLARE_FLEX_ARRAY(u32, raw);
+	};
+};
+
+#endif /* __LIBETH_TYPES_H */