1 // SPDX-License-Identifier: (GPL-2.0 OR MIT)
2 /* Google virtual Ethernet (gve) driver
3  *
4  * Copyright (C) 2015-2021 Google, Inc.
5  */
6 
7 #include "gve.h"
8 #include "gve_adminq.h"
9 #include "gve_utils.h"
10 
gve_tx_remove_from_block(struct gve_priv * priv,int queue_idx)11 void gve_tx_remove_from_block(struct gve_priv *priv, int queue_idx)
12 {
13 	struct gve_notify_block *block =
14 			&priv->ntfy_blocks[gve_tx_idx_to_ntfy(priv, queue_idx)];
15 
16 	block->tx = NULL;
17 }
18 
gve_tx_add_to_block(struct gve_priv * priv,int queue_idx)19 void gve_tx_add_to_block(struct gve_priv *priv, int queue_idx)
20 {
21 	unsigned int active_cpus = min_t(int, priv->num_ntfy_blks / 2,
22 					 num_online_cpus());
23 	int ntfy_idx = gve_tx_idx_to_ntfy(priv, queue_idx);
24 	struct gve_notify_block *block = &priv->ntfy_blocks[ntfy_idx];
25 	struct gve_tx_ring *tx = &priv->tx[queue_idx];
26 
27 	block->tx = tx;
28 	tx->ntfy_id = ntfy_idx;
29 	netif_set_xps_queue(priv->dev, get_cpu_mask(ntfy_idx % active_cpus),
30 			    queue_idx);
31 }
32 
gve_rx_remove_from_block(struct gve_priv * priv,int queue_idx)33 void gve_rx_remove_from_block(struct gve_priv *priv, int queue_idx)
34 {
35 	struct gve_notify_block *block =
36 			&priv->ntfy_blocks[gve_rx_idx_to_ntfy(priv, queue_idx)];
37 
38 	block->rx = NULL;
39 }
40 
gve_rx_add_to_block(struct gve_priv * priv,int queue_idx)41 void gve_rx_add_to_block(struct gve_priv *priv, int queue_idx)
42 {
43 	u32 ntfy_idx = gve_rx_idx_to_ntfy(priv, queue_idx);
44 	struct gve_notify_block *block = &priv->ntfy_blocks[ntfy_idx];
45 	struct gve_rx_ring *rx = &priv->rx[queue_idx];
46 
47 	block->rx = rx;
48 	rx->ntfy_id = ntfy_idx;
49 }
50 
gve_rx_copy(struct net_device * dev,struct napi_struct * napi,struct gve_rx_slot_page_info * page_info,u16 len,u16 padding,struct gve_rx_ctx * ctx)51 struct sk_buff *gve_rx_copy(struct net_device *dev, struct napi_struct *napi,
52 			    struct gve_rx_slot_page_info *page_info, u16 len,
53 			    u16 padding, struct gve_rx_ctx *ctx)
54 {
55 	void *va = page_info->page_address + padding + page_info->page_offset;
56 	int skb_linear_offset = 0;
57 	bool set_protocol = false;
58 	struct sk_buff *skb;
59 
60 	if (ctx) {
61 		if (!ctx->skb_head)
62 			ctx->skb_head = napi_alloc_skb(napi, ctx->total_expected_size);
63 
64 		if (unlikely(!ctx->skb_head))
65 			return NULL;
66 		skb = ctx->skb_head;
67 		skb_linear_offset = skb->len;
68 		set_protocol = ctx->curr_frag_cnt == ctx->expected_frag_cnt - 1;
69 	} else {
70 		skb = napi_alloc_skb(napi, len);
71 
72 		if (unlikely(!skb))
73 			return NULL;
74 		set_protocol = true;
75 	}
76 	__skb_put(skb, len);
77 	skb_copy_to_linear_data_offset(skb, skb_linear_offset, va, len);
78 
79 	if (set_protocol)
80 		skb->protocol = eth_type_trans(skb, dev);
81 
82 	return skb;
83 }
84 
gve_dec_pagecnt_bias(struct gve_rx_slot_page_info * page_info)85 void gve_dec_pagecnt_bias(struct gve_rx_slot_page_info *page_info)
86 {
87 	page_info->pagecnt_bias--;
88 	if (page_info->pagecnt_bias == 0) {
89 		int pagecount = page_count(page_info->page);
90 
91 		/* If we have run out of bias - set it back up to INT_MAX
92 		 * minus the existing refs.
93 		 */
94 		page_info->pagecnt_bias = INT_MAX - pagecount;
95 
96 		/* Set pagecount back up to max. */
97 		page_ref_add(page_info->page, INT_MAX - pagecount);
98 	}
99 }
100