xref: /linux/drivers/net/ethernet/alibaba/eea/eea_ring.c (revision 039ce329dfe6fb74f6394dcb59607425af8d0601)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Driver for Alibaba Elastic Ethernet Adapter.
4  *
5  * Copyright (C) 2025 Alibaba Inc.
6  */
7 
8 #include "eea_pci.h"
9 #include "eea_ring.h"
10 
11 void eea_ering_irq_active(struct eea_ring *ering, struct eea_ring *tx_ering)
12 {
13 	u64 value = 0, rx_idx, tx_idx;
14 
15 	tx_idx = (u64)tx_ering->cq.hw_idx;
16 	rx_idx = (u64)ering->cq.hw_idx;
17 
18 	value |= EEA_IRQ_UNMASK << EEA_DB_FLAGS_OFF;
19 	value |= tx_idx << EEA_DB_TX_CQ_HEAD_OFF;
20 	value |= rx_idx << EEA_DB_RX_CQ_HEAD_OFF;
21 
22 	writeq(value, ering->db);
23 }
24 
25 void *eea_ering_cq_get_desc(const struct eea_ring *ering)
26 {
27 	u8 phase;
28 	u8 *desc;
29 
30 	desc = ering->cq.desc + (ering->cq.head << ering->cq.desc_size_shift);
31 
32 	phase = READ_ONCE(*(u8 *)(desc + ering->cq.desc_size - 1));
33 
34 	if ((phase & EEA_RING_DESC_F_CQ_PHASE) == ering->cq.phase) {
35 		dma_rmb();
36 		return desc;
37 	}
38 
39 	return NULL;
40 }
41 
42 /* sq api */
43 void *eea_ering_sq_alloc_desc(struct eea_ring *ering, u16 id, bool is_last,
44 			      u16 flags)
45 {
46 	struct eea_ring_sq *sq = &ering->sq;
47 	struct eea_common_desc *desc;
48 
49 	if (!sq->shadow_num) {
50 		sq->shadow_idx = sq->head;
51 		sq->shadow_id = cpu_to_le16(id);
52 	}
53 
54 	if (!is_last)
55 		flags |= EEA_RING_DESC_F_MORE;
56 
57 	desc = sq->desc + (sq->shadow_idx << sq->desc_size_shift);
58 
59 	desc->flags = cpu_to_le16(flags);
60 	desc->id = sq->shadow_id;
61 
62 	if (unlikely(++sq->shadow_idx >= ering->num))
63 		sq->shadow_idx = 0;
64 
65 	++sq->shadow_num;
66 
67 	return desc;
68 }
69 
70 /* This is an allocation API for admin Q. For each call to admin Q, only one
71  * desc will be allocated.
72  */
73 void *eea_ering_aq_alloc_desc(struct eea_ring *ering)
74 {
75 	struct eea_ring_sq *sq = &ering->sq;
76 	struct eea_common_desc *desc;
77 
78 	if (!sq->shadow_num)
79 		sq->shadow_idx = sq->head;
80 
81 	desc = sq->desc + (sq->shadow_idx << sq->desc_size_shift);
82 
83 	if (unlikely(++sq->shadow_idx >= ering->num))
84 		sq->shadow_idx = 0;
85 
86 	++sq->shadow_num;
87 
88 	return desc;
89 }
90 
91 void eea_ering_sq_commit_desc(struct eea_ring *ering)
92 {
93 	struct eea_ring_sq *sq = &ering->sq;
94 	int num;
95 
96 	num = sq->shadow_num;
97 
98 	ering->num_free -= num;
99 
100 	sq->head       = sq->shadow_idx;
101 	sq->hw_idx     += num;
102 	sq->shadow_num = 0;
103 }
104 
105 void eea_ering_sq_cancel(struct eea_ring *ering)
106 {
107 	ering->sq.shadow_num = 0;
108 }
109 
110 /* cq api */
111 void eea_ering_cq_ack_desc(struct eea_ring *ering, u32 num)
112 {
113 	struct eea_ring_cq *cq = &ering->cq;
114 
115 	cq->head += num;
116 	cq->hw_idx += num;
117 
118 	if (unlikely(cq->head >= ering->num)) {
119 		cq->head -= ering->num;
120 		cq->phase ^= EEA_RING_DESC_F_CQ_PHASE;
121 	}
122 
123 	ering->num_free += num;
124 }
125 
126 /* notify */
127 void eea_ering_kick(struct eea_ring *ering)
128 {
129 	u64 value = 0, idx;
130 
131 	idx = (u64)ering->sq.hw_idx;
132 
133 	value |= EEA_IDX_PRESENT << EEA_DB_FLAGS_OFF;
134 	value |= idx << EEA_DB_IDX_OFF;
135 
136 	writeq(value, ering->db);
137 }
138 
139 /* ering alloc/free */
140 static void ering_free_queue(struct eea_device *edev, size_t size,
141 			     void *queue, dma_addr_t dma_handle)
142 {
143 	dma_free_coherent(edev->dma_dev, size, queue, dma_handle);
144 }
145 
146 static void *ering_alloc_queue(struct eea_device *edev, size_t size,
147 			       dma_addr_t *dma_handle)
148 {
149 	gfp_t flags = GFP_KERNEL | __GFP_NOWARN;
150 
151 	return dma_alloc_coherent(edev->dma_dev, size, dma_handle, flags);
152 }
153 
154 static int ering_alloc_queues(struct eea_ring *ering, struct eea_device *edev,
155 			      size_t num, u8 sq_desc_size, u8 cq_desc_size)
156 {
157 	dma_addr_t addr;
158 	size_t size;
159 	void *ring;
160 
161 	size = num * sq_desc_size;
162 
163 	ring = ering_alloc_queue(edev, size, &addr);
164 	if (!ring)
165 		return -ENOMEM;
166 
167 	ering->sq.desc     = ring;
168 	ering->sq.dma_addr = addr;
169 	ering->sq.dma_size = size;
170 	ering->sq.desc_size = sq_desc_size;
171 	ering->sq.desc_size_shift = fls(sq_desc_size) - 1;
172 
173 	size = num * cq_desc_size;
174 
175 	ring = ering_alloc_queue(edev, size, &addr);
176 	if (!ring)
177 		goto err_free_sq;
178 
179 	ering->cq.desc     = ring;
180 	ering->cq.dma_addr = addr;
181 	ering->cq.dma_size = size;
182 	ering->cq.desc_size = cq_desc_size;
183 	ering->cq.desc_size_shift = fls(cq_desc_size) - 1;
184 
185 	ering->num = num;
186 
187 	return 0;
188 
189 err_free_sq:
190 	ering_free_queue(ering->edev, ering->sq.dma_size,
191 			 ering->sq.desc, ering->sq.dma_addr);
192 	return -ENOMEM;
193 }
194 
195 static void ering_init(struct eea_ring *ering)
196 {
197 	ering->cq.phase = EEA_RING_DESC_F_CQ_PHASE;
198 	ering->num_free = ering->num;
199 }
200 
201 struct eea_ring *eea_ering_alloc(u32 index, u32 num, struct eea_device *edev,
202 				 u8 sq_desc_size, u8 cq_desc_size,
203 				 const char *name)
204 {
205 	struct eea_ring *ering;
206 
207 	if (num > EEA_NET_IO_HW_RING_DEPTH_MAX ||
208 	    num < EEA_NET_IO_RING_DEPTH_MIN)
209 		return NULL;
210 
211 	if (!is_power_of_2(num))
212 		return NULL;
213 
214 	if (!sq_desc_size || !is_power_of_2(sq_desc_size))
215 		return NULL;
216 
217 	if (!cq_desc_size || !is_power_of_2(cq_desc_size))
218 		return NULL;
219 
220 	ering = kzalloc(sizeof(*ering), GFP_KERNEL);
221 	if (!ering)
222 		return NULL;
223 
224 	ering->edev = edev;
225 	ering->name = name;
226 	ering->index = index;
227 
228 	if (ering_alloc_queues(ering, edev, num, sq_desc_size, cq_desc_size))
229 		goto err_free;
230 
231 	ering_init(ering);
232 
233 	return ering;
234 
235 err_free:
236 	kfree(ering);
237 	return NULL;
238 }
239 
240 void eea_ering_free(struct eea_ring *ering)
241 {
242 	ering_free_queue(ering->edev, ering->cq.dma_size,
243 			 ering->cq.desc, ering->cq.dma_addr);
244 
245 	ering_free_queue(ering->edev, ering->sq.dma_size,
246 			 ering->sq.desc, ering->sq.dma_addr);
247 
248 	kfree(ering);
249 }
250