1 /*
2  * Copyright 2021 Google LLC
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #ifndef PLATFORMS_NEMORA_PORTABLE_NCSI_FSM_H_
18 #define PLATFORMS_NEMORA_PORTABLE_NCSI_FSM_H_
19 
20 /* Nemora NC-SI (Finite) State Machine implementation */
21 
22 #include <stdint.h>
23 #include <stdbool.h>
24 
25 #include "platforms/nemora/portable/ncsi.h"
26 #include "platforms/nemora/portable/net_types.h"
27 
28 /* TODO put this into config somewhere? */
29 #define NCSI_FSM_RESTART_DELAY_COUNT 100
30 #define NCSI_FSM_RETEST_DELAY_COUNT 100
31 
32 /* The network state is defined as a combination of the NC-SI connection state
33  * and the network configuration. However the two cannot be decoupled:
34  * - we cannot DHCP unless the NC-SI connection is up
35  * - we cannot do the OEM L3/L4 NC-SI configuration unless we have a valid
36  *   network configuration
37  *
38  * For additional complexity we cannot get DHCP/ARP responses after the host
39  * has loaded the Mellanox NIC driver but we want to be able to periodically
40  * test the NC-SI connection regardless of whether we have network configuration
41  * (so that flaky cables can be troubleshooted using the host interface).
42  *
43  * For this reason there are actually 3 NC-SI finite state machines:
44  * - L2 configuration (i.e. enabling all available NC-SI channel for passthrough
45  *   RX and TX, although only TX will work after the host loads the NIC driver)
46  * - L3/L4 configuration (i.e. configuring flow steering for RX traffic that
47  *   matches our IP address and dedicated Nemora port so that we can receive
48  *   Nemora requests even after the host loaded the NIC driver)
49  * - Connection test (i.e. periodically doing a ping test between the EC and the
50  *   NIC) and also ensuring that L3/L4 configuration parameters have not been
51  *   wiped out)
52  *
53  * For good karma, try to keep the state machines as linear as possible (one
54  * step after the other).
55  */
56 
57 typedef enum {
58   // First
59   NCSI_STATE_L2_CONFIG_BEGIN,
60   // Actual sequence
61   NCSI_STATE_RESTART = NCSI_STATE_L2_CONFIG_BEGIN,
62   NCSI_STATE_CLEAR_0,
63   NCSI_STATE_CLEAR_0_RESPONSE,
64   NCSI_STATE_GET_VERSION,
65   NCSI_STATE_GET_VERSION_RESPONSE,
66   NCSI_STATE_GET_CAPABILITIES,
67   NCSI_STATE_GET_CAPABILITIES_RESPONSE,
68   NCSI_STATE_CLEAR_1,
69   NCSI_STATE_CLEAR_1_RESPONSE,
70   NCSI_STATE_RESET_CHANNEL_0,
71   NCSI_STATE_RESET_CHANNEL_0_RESPONSE,
72   NCSI_STATE_RESET_CHANNEL_1,
73   NCSI_STATE_RESET_CHANNEL_1_RESPONSE,
74   NCSI_STATE_STOPPED,
75   NCSI_STATE_GET_MAC,
76   NCSI_STATE_GET_MAC_RESPONSE,
77   NCSI_STATE_SET_MAC_FILTER_0,
78   NCSI_STATE_SET_MAC_FILTER_0_RESPONSE,
79   NCSI_STATE_SET_MAC_FILTER_1,
80   NCSI_STATE_SET_MAC_FILTER_1_RESPONSE,
81   NCSI_STATE_ENABLE_CHANNEL_0,
82   NCSI_STATE_ENABLE_CHANNEL_0_RESPONSE,
83   NCSI_STATE_ENABLE_CHANNEL_1,
84   NCSI_STATE_ENABLE_CHANNEL_1_RESPONSE,
85   NCSI_STATE_ENABLE_TX,
86   NCSI_STATE_ENABLE_TX_RESPONSE,
87   // Last
88   NCSI_STATE_L2_CONFIG_END
89 } ncsi_l2_config_state_t;
90 
91 typedef enum {
92   // First
93   NCSI_STATE_L3L4_CONFIG_BEGIN,
94   // Actual sequence
95   NCSI_STATE_CONFIG_FILTERS,
96   // Last
97   NCSI_STATE_L3L4_CONFIG_END
98 } ncsi_l3l4_config_state_t;
99 
100 typedef enum {
101   // First
102   NCSI_STATE_TEST_BEGIN,
103   // Actual sequence
104   NCSI_STATE_TEST_PARAMS = NCSI_STATE_TEST_BEGIN,
105   NCSI_STATE_ECHO,
106   NCSI_STATE_ECHO_RESPONSE,
107   NCSI_STATE_CHECK_FILTERS,
108   NCSI_STATE_CHECK_FILTERS_RESPONSE,
109   NCSI_STATE_GET_PT_STATS,
110   NCSI_STATE_GET_PT_STATS_RESPONSE,
111   NCSI_STATE_GET_LINK_STATUS,
112   NCSI_STATE_GET_LINK_STATUS_RESPONSE,
113   // Last
114   NCSI_STATE_TEST_END
115 } ncsi_test_state_t;
116 
117 typedef struct {
118   ncsi_l2_config_state_t l2_config_state;
119   ncsi_l3l4_config_state_t l3l4_config_state;
120   ncsi_test_state_t test_state;
121   // Last (OEM) command that was sent. (L3L4 SM only)
122   // Valid only if l3l4_waiting_response is true.
123   uint8_t l3l4_command;
124   // Number of the channel we are currently operating on. (L3L4 SM only)
125   uint8_t l3l4_channel;
126   // If true, means the request was sent and we are waiting for response.
127   bool l3l4_waiting_response;
128   uint8_t channel_count;
129   // The re-start and re-test delays ensures that we can flush the DMA
130   // buffers of potential out-of-sequence NC-SI packets (e.g. from
131   // packet that may have been received shortly after we timed out on
132   // them). The re-test delays also reduce the effect of NC-SI
133   // testing on more useful traffic.
134   uint8_t restart_delay_count;
135   uint8_t retest_delay_count;
136   struct {
137     uint8_t flags;
138     uint8_t regid[8];
139   } flowsteering[2];
140 } ncsi_state_t;
141 
142 // Debug variables.
143 // TODO - Change name to something more meaningful since the NC-SI test
144 //   is not a debug-only feature.
145 typedef struct {
146   uint32_t task_count;
147   uint32_t host_ctrl_flags;
148   struct {
149     bool enabled;
150     bool pending_stop;
151     bool pending_restart;
152     bool oem_filter_disable;
153     bool loopback;
154     bool mlx_legacy;
155     uint32_t fail_count;
156     ncsi_state_t state_that_failed;
157     uint32_t tx_count;
158     uint32_t rx_count;
159     uint32_t tx_error_count;
160     struct {
161       uint32_t timeout_count;
162       uint32_t oversized_count;
163       uint32_t undersized_count;
164       uint32_t nack_count;
165       uint32_t unexpected_size_count;
166       uint32_t unexpected_type_count;
167     } rx_error;
168     struct {
169       uint32_t runs;
170       uint8_t ch_under_test;
171       uint8_t tries;
172       uint8_t max_tries;  // 0 = skip test, 1 = restart on failure, > 1 = retry
173       struct {
174         uint8_t tx[NCSI_OEM_ECHO_PATTERN_SIZE];
175         uint32_t tx_count;
176         uint32_t rx_count;
177         uint32_t bad_rx_count;
178         uint8_t last_bad_rx[NCSI_OEM_ECHO_PATTERN_SIZE];
179       } ping;
180     } test;
181     ncsi_passthrough_stats_t pt_stats_be[2];  // big-endian as received from NIC
182   } ncsi;
183 } network_debug_t;
184 
185 typedef struct {
186   uint8_t data[ETH_BUFFER_SIZE];
187   uint32_t len;  // Non-zero when there's a new NC-SI response.
188 } ncsi_buf_t;
189 
190 
191 #ifdef __cplusplus
192 extern "C" {
193 #endif
194 
195 ncsi_response_type_t ncsi_fsm_poll_l2_config(ncsi_state_t* ncsi_state,
196                                              network_debug_t* network_debug,
197                                              ncsi_buf_t* ncsi_buf,
198                                              mac_addr_t* mac);
199 
200 ncsi_response_type_t ncsi_fsm_poll_l3l4_config(ncsi_state_t* ncsi_state,
201                                                network_debug_t* network_debug,
202                                                ncsi_buf_t* ncsi_buf,
203                                                mac_addr_t* mac,
204                                                uint32_t ipv4_addr,
205                                                uint16_t rx_port);
206 
207 ncsi_response_type_t ncsi_fsm_poll_test(ncsi_state_t* ncsi_state,
208                                         network_debug_t* network_debug,
209                                         ncsi_buf_t* ncsi_buf, mac_addr_t* mac,
210                                         uint32_t ipv4_addr, uint16_t rx_port);
211 
212 /*
213  * Report a global state of the NC-SI connection as a function of the state
214  * of the 3 finite state machines.
215  * Note: Additionally for the case where the connection is down it reports
216  *   whether a loopback is inferred.
217  */
218 ncsi_connection_state_t ncsi_fsm_connection_state(
219     const ncsi_state_t* ncsi_state, const network_debug_t* network_debug);
220 
221 /*
222  * Returns true if we have executed an NC-SI Get OEM Filter command for all
223  * channels and the flags indicate that it is running in hostless mode.
224  * This means that we can DHCP/ARP if needed.
225  * Otherwise returns false.
226  *
227  * NOTE: We default to false, if we cannot complete the L2 config state
228  *   machine or the test sequence.
229  */
230 bool ncsi_fsm_is_nic_hostless(const ncsi_state_t* ncsi_state);
231 
232 #ifdef __cplusplus
233 }  /* extern "C" */
234 #endif
235 
236 #endif  // PLATFORMS_NEMORA_PORTABLE_NCSI_FSM_H_
237