1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* Copyright (C) 2024 Intel Corporation */ 3 4 #ifndef __LIBETH_TX_H 5 #define __LIBETH_TX_H 6 7 #include <linux/skbuff.h> 8 9 #include <net/libeth/types.h> 10 11 /* Tx buffer completion */ 12 13 /** 14 * enum libeth_sqe_type - type of &libeth_sqe to act on Tx completion 15 * @LIBETH_SQE_EMPTY: unused/empty, no action required 16 * @LIBETH_SQE_CTX: context descriptor with empty SQE, no action required 17 * @LIBETH_SQE_SLAB: kmalloc-allocated buffer, unmap and kfree() 18 * @LIBETH_SQE_FRAG: mapped skb frag, only unmap DMA 19 * @LIBETH_SQE_SKB: &sk_buff, unmap and napi_consume_skb(), update stats 20 */ 21 enum libeth_sqe_type { 22 LIBETH_SQE_EMPTY = 0U, 23 LIBETH_SQE_CTX, 24 LIBETH_SQE_SLAB, 25 LIBETH_SQE_FRAG, 26 LIBETH_SQE_SKB, 27 }; 28 29 /** 30 * struct libeth_sqe - represents a Send Queue Element / Tx buffer 31 * @type: type of the buffer, see the enum above 32 * @rs_idx: index of the last buffer from the batch this one was sent in 33 * @raw: slab buffer to free via kfree() 34 * @skb: &sk_buff to consume 35 * @dma: DMA address to unmap 36 * @len: length of the mapped region to unmap 37 * @nr_frags: number of frags in the frame this buffer belongs to 38 * @packets: number of physical packets sent for this frame 39 * @bytes: number of physical bytes sent for this frame 40 * @priv: driver-private scratchpad 41 */ 42 struct libeth_sqe { 43 enum libeth_sqe_type type:32; 44 u32 rs_idx; 45 46 union { 47 void *raw; 48 struct sk_buff *skb; 49 }; 50 51 DEFINE_DMA_UNMAP_ADDR(dma); 52 DEFINE_DMA_UNMAP_LEN(len); 53 54 u32 nr_frags; 55 u32 packets; 56 u32 bytes; 57 58 unsigned long priv; 59 } __aligned_largest; 60 61 /** 62 * LIBETH_SQE_CHECK_PRIV - check the driver's private SQE data 63 * @p: type or name of the object the driver wants to fit into &libeth_sqe 64 * 65 * Make sure the driver's private data fits into libeth_sqe::priv. To be used 66 * right after its declaration. 67 */ 68 #define LIBETH_SQE_CHECK_PRIV(p) \ 69 static_assert(sizeof(p) <= sizeof_field(struct libeth_sqe, priv)) 70 71 /** 72 * struct libeth_cq_pp - completion queue poll params 73 * @dev: &device to perform DMA unmapping 74 * @ss: onstack NAPI stats to fill 75 * @napi: whether it's called from the NAPI context 76 * 77 * libeth uses this structure to access objects needed for performing full 78 * Tx complete operation without passing lots of arguments and change the 79 * prototypes each time a new one is added. 80 */ 81 struct libeth_cq_pp { 82 struct device *dev; 83 struct libeth_sq_napi_stats *ss; 84 85 bool napi; 86 }; 87 88 /** 89 * libeth_tx_complete - perform Tx completion for one SQE 90 * @sqe: SQE to complete 91 * @cp: poll params 92 * 93 * Do Tx complete for all the types of buffers, incl. freeing, unmapping, 94 * updating the stats etc. 95 */ 96 static inline void libeth_tx_complete(struct libeth_sqe *sqe, 97 const struct libeth_cq_pp *cp) 98 { 99 switch (sqe->type) { 100 case LIBETH_SQE_EMPTY: 101 return; 102 case LIBETH_SQE_SKB: 103 case LIBETH_SQE_FRAG: 104 case LIBETH_SQE_SLAB: 105 dma_unmap_page(cp->dev, dma_unmap_addr(sqe, dma), 106 dma_unmap_len(sqe, len), DMA_TO_DEVICE); 107 break; 108 default: 109 break; 110 } 111 112 switch (sqe->type) { 113 case LIBETH_SQE_SKB: 114 cp->ss->packets += sqe->packets; 115 cp->ss->bytes += sqe->bytes; 116 117 napi_consume_skb(sqe->skb, cp->napi); 118 break; 119 case LIBETH_SQE_SLAB: 120 kfree(sqe->raw); 121 break; 122 default: 123 break; 124 } 125 126 sqe->type = LIBETH_SQE_EMPTY; 127 } 128 129 #endif /* __LIBETH_TX_H */ 130