xref: /linux/drivers/net/ethernet/microchip/sparx5/sparx5_pool.c (revision 336b78c655c84ce9ce47219185171b3912109c0a)
1 // SPDX-License-Identifier: GPL-2.0+
2 /* Microchip Sparx5 Switch driver
3  *
4  * Copyright (c) 2023 Microchip Technology Inc. and its subsidiaries.
5  */
6 
7 #include "sparx5_main_regs.h"
8 #include "sparx5_main.h"
9 
10 static u32 sparx5_pool_id_to_idx(u32 id)
11 {
12 	return --id;
13 }
14 
15 u32 sparx5_pool_idx_to_id(u32 idx)
16 {
17 	return ++idx;
18 }
19 
20 /* Release resource from pool.
21  * Return reference count on success, otherwise return error.
22  */
23 int sparx5_pool_put(struct sparx5_pool_entry *pool, int size, u32 id)
24 {
25 	struct sparx5_pool_entry *e_itr;
26 
27 	e_itr = (pool + sparx5_pool_id_to_idx(id));
28 	if (e_itr->ref_cnt == 0)
29 		return -EINVAL;
30 
31 	return --e_itr->ref_cnt;
32 }
33 
34 /* Get resource from pool.
35  * Return reference count on success, otherwise return error.
36  */
37 int sparx5_pool_get(struct sparx5_pool_entry *pool, int size, u32 *id)
38 {
39 	struct sparx5_pool_entry *e_itr;
40 	int i;
41 
42 	for (i = 0, e_itr = pool; i < size; i++, e_itr++) {
43 		if (e_itr->ref_cnt == 0) {
44 			*id = sparx5_pool_idx_to_id(i);
45 			return ++e_itr->ref_cnt;
46 		}
47 	}
48 
49 	return -ENOSPC;
50 }
51 
52 /* Get resource from pool that matches index.
53  * Return reference count on success, otherwise return error.
54  */
55 int sparx5_pool_get_with_idx(struct sparx5_pool_entry *pool, int size, u32 idx,
56 			     u32 *id)
57 {
58 	struct sparx5_pool_entry *e_itr;
59 	int i, ret = -ENOSPC;
60 
61 	for (i = 0, e_itr = pool; i < size; i++, e_itr++) {
62 		/* Pool index of first free entry */
63 		if (e_itr->ref_cnt == 0 && ret == -ENOSPC)
64 			ret = i;
65 		/* Tc index already in use ? */
66 		if (e_itr->idx == idx && e_itr->ref_cnt > 0) {
67 			ret = i;
68 			break;
69 		}
70 	}
71 
72 	/* Did we find a free entry? */
73 	if (ret >= 0) {
74 		*id = sparx5_pool_idx_to_id(ret);
75 		e_itr = (pool + ret);
76 		e_itr->idx = idx;
77 		return ++e_itr->ref_cnt;
78 	}
79 
80 	return ret;
81 }
82