1 // SPDX-License-Identifier: GPL-2.0+
2 /* Microchip lan969x Switch driver
3 *
4 * Copyright (c) 2024 Microchip Technology Inc. and its subsidiaries.
5 */
6
7 #include "lan969x.h"
8
9 #define LAN969X_DSM_CAL_DEVS_PER_TAXI 10
10 #define LAN969X_DSM_CAL_TAXIS 5
11
12 enum lan969x_dsm_cal_dev {
13 DSM_CAL_DEV_2G5,
14 DSM_CAL_DEV_5G,
15 DSM_CAL_DEV_10G,
16 DSM_CAL_DEV_OTHER, /* 1G or less */
17 DSM_CAL_DEV_MAX
18 };
19
20 /* Each entry in the following struct defines properties for a given speed
21 * (10G, 5G, 2.5G, or 1G or less).
22 */
23 struct lan969x_dsm_cal_dev_speed {
24 /* Number of devices that requires this speed. */
25 u32 n_devs;
26
27 /* Array of devices that requires this speed. */
28 u32 devs[LAN969X_DSM_CAL_DEVS_PER_TAXI];
29
30 /* Number of slots required for one device running this speed. */
31 u32 n_slots;
32
33 /* Gap between two slots for one device running this speed. */
34 u32 gap;
35 };
36
37 static u32
38 lan969x_taxi_ports[LAN969X_DSM_CAL_TAXIS][LAN969X_DSM_CAL_DEVS_PER_TAXI] = {
39 { 0, 4, 1, 2, 3, 5, 6, 7, 28, 29 },
40 { 8, 12, 9, 13, 10, 11, 14, 15, 99, 99 },
41 { 16, 20, 17, 21, 18, 19, 22, 23, 99, 99 },
42 { 24, 25, 99, 99, 99, 99, 99, 99, 99, 99 },
43 { 26, 27, 99, 99, 99, 99, 99, 99, 99, 99 }
44 };
45
lan969x_dsm_cal_idx_get(u32 * calendar,u32 cal_len,u32 * cal_idx)46 static int lan969x_dsm_cal_idx_get(u32 *calendar, u32 cal_len, u32 *cal_idx)
47 {
48 if (*cal_idx >= cal_len)
49 return -EINVAL;
50
51 do {
52 if (calendar[*cal_idx] == SPX5_DSM_CAL_EMPTY)
53 return 0;
54
55 (*cal_idx)++;
56 } while (*cal_idx < cal_len);
57
58 return -ENOENT;
59 }
60
lan969x_dsm_cal_get_dev(int speed)61 static enum lan969x_dsm_cal_dev lan969x_dsm_cal_get_dev(int speed)
62 {
63 return (speed == 10000 ? DSM_CAL_DEV_10G :
64 speed == 5000 ? DSM_CAL_DEV_5G :
65 speed == 2500 ? DSM_CAL_DEV_2G5 :
66 DSM_CAL_DEV_OTHER);
67 }
68
lan969x_dsm_cal_get_speed(enum lan969x_dsm_cal_dev dev)69 static int lan969x_dsm_cal_get_speed(enum lan969x_dsm_cal_dev dev)
70 {
71 return (dev == DSM_CAL_DEV_10G ? 10000 :
72 dev == DSM_CAL_DEV_5G ? 5000 :
73 dev == DSM_CAL_DEV_2G5 ? 2500 :
74 1000);
75 }
76
lan969x_dsm_calendar_calc(struct sparx5 * sparx5,u32 taxi,struct sparx5_calendar_data * data)77 int lan969x_dsm_calendar_calc(struct sparx5 *sparx5, u32 taxi,
78 struct sparx5_calendar_data *data)
79 {
80 struct lan969x_dsm_cal_dev_speed dev_speeds[DSM_CAL_DEV_MAX] = {};
81 u32 cal_len, n_slots, taxi_bw, n_devs = 0, required_bw = 0;
82 struct lan969x_dsm_cal_dev_speed *speed;
83 int err;
84
85 /* Maximum bandwidth for this taxi */
86 taxi_bw = (128 * 1000000) / sparx5_clk_period(sparx5->coreclock);
87
88 memcpy(data->taxi_ports, &lan969x_taxi_ports[taxi],
89 LAN969X_DSM_CAL_DEVS_PER_TAXI * sizeof(u32));
90
91 for (int i = 0; i < LAN969X_DSM_CAL_DEVS_PER_TAXI; i++) {
92 u32 portno = data->taxi_ports[i];
93 enum sparx5_cal_bw bw;
94
95 bw = sparx5_get_port_cal_speed(sparx5, portno);
96
97 if (portno < sparx5->data->consts->n_ports_all)
98 data->taxi_speeds[i] = sparx5_cal_speed_to_value(bw);
99 else
100 data->taxi_speeds[i] = 0;
101 }
102
103 /* Determine the different port types (10G, 5G, 2.5G, <= 1G) in the
104 * this taxi map.
105 */
106 for (int i = 0; i < LAN969X_DSM_CAL_DEVS_PER_TAXI; i++) {
107 u32 taxi_speed = data->taxi_speeds[i];
108 enum lan969x_dsm_cal_dev dev;
109
110 if (taxi_speed == 0)
111 continue;
112
113 required_bw += taxi_speed;
114
115 dev = lan969x_dsm_cal_get_dev(taxi_speed);
116 speed = &dev_speeds[dev];
117 speed->devs[speed->n_devs++] = i;
118 n_devs++;
119 }
120
121 if (required_bw > taxi_bw) {
122 pr_err("Required bandwidth: %u is higher than total taxi bandwidth: %u",
123 required_bw, taxi_bw);
124 return -EINVAL;
125 }
126
127 if (n_devs == 0) {
128 data->schedule[0] = SPX5_DSM_CAL_EMPTY;
129 return 0;
130 }
131
132 cal_len = n_devs;
133
134 /* Search for a calendar length that fits all active devices. */
135 while (cal_len < SPX5_DSM_CAL_LEN) {
136 u32 bw_per_slot = taxi_bw / cal_len;
137
138 n_slots = 0;
139
140 for (int i = 0; i < DSM_CAL_DEV_MAX; i++) {
141 speed = &dev_speeds[i];
142
143 if (speed->n_devs == 0)
144 continue;
145
146 required_bw = lan969x_dsm_cal_get_speed(i);
147 speed->n_slots = DIV_ROUND_UP(required_bw, bw_per_slot);
148
149 if (speed->n_slots)
150 speed->gap = DIV_ROUND_UP(cal_len,
151 speed->n_slots);
152 else
153 speed->gap = 0;
154
155 n_slots += speed->n_slots * speed->n_devs;
156 }
157
158 if (n_slots <= cal_len)
159 break; /* Found a suitable calendar length. */
160
161 /* Not good enough yet. */
162 cal_len = n_slots;
163 }
164
165 if (cal_len > SPX5_DSM_CAL_LEN) {
166 pr_err("Invalid length: %u for taxi: %u", cal_len, taxi);
167 return -EINVAL;
168 }
169
170 for (u32 i = 0; i < SPX5_DSM_CAL_LEN; i++)
171 data->schedule[i] = SPX5_DSM_CAL_EMPTY;
172
173 /* Place the remaining devices */
174 for (u32 i = 0; i < DSM_CAL_DEV_MAX; i++) {
175 speed = &dev_speeds[i];
176 for (u32 dev = 0; dev < speed->n_devs; dev++) {
177 u32 idx = 0;
178
179 for (n_slots = 0; n_slots < speed->n_slots; n_slots++) {
180 err = lan969x_dsm_cal_idx_get(data->schedule,
181 cal_len, &idx);
182 if (err)
183 return err;
184 data->schedule[idx] = speed->devs[dev];
185 idx += speed->gap;
186 }
187 }
188 }
189
190 return 0;
191 }
192