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/* 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 */