1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | |
3 | /* |
4 | * |
5 | * Copyright (C) IBM Corporation, 2004 |
6 | * |
7 | * Author: Max Asböck <amax@us.ibm.com> |
8 | */ |
9 | |
10 | #include <linux/sched/signal.h> |
11 | #include "ibmasm.h" |
12 | #include "dot_command.h" |
13 | |
14 | /* |
15 | * Reverse Heartbeat, i.e. heartbeats sent from the driver to the |
16 | * service processor. |
17 | * These heartbeats are initiated by user level programs. |
18 | */ |
19 | |
20 | /* the reverse heartbeat dot command */ |
21 | #pragma pack(1) |
22 | static struct { |
23 | struct dot_command_header ; |
24 | unsigned char command[3]; |
25 | } rhb_dot_cmd = { |
26 | .header = { |
27 | .type = sp_read, |
28 | .command_size = 3, |
29 | .data_size = 0, |
30 | .status = 0 |
31 | }, |
32 | .command = { 4, 3, 6 } |
33 | }; |
34 | #pragma pack() |
35 | |
36 | void ibmasm_init_reverse_heartbeat(struct service_processor *sp, struct reverse_heartbeat *rhb) |
37 | { |
38 | init_waitqueue_head(&rhb->wait); |
39 | rhb->stopped = 0; |
40 | } |
41 | |
42 | /* |
43 | * start_reverse_heartbeat |
44 | * Loop forever, sending a reverse heartbeat dot command to the service |
45 | * processor, then sleeping. The loop comes to an end if the service |
46 | * processor fails to respond 3 times or we were interrupted. |
47 | */ |
48 | int ibmasm_start_reverse_heartbeat(struct service_processor *sp, struct reverse_heartbeat *rhb) |
49 | { |
50 | struct command *cmd; |
51 | int times_failed = 0; |
52 | int result = 1; |
53 | |
54 | cmd = ibmasm_new_command(sp, buffer_size: sizeof rhb_dot_cmd); |
55 | if (!cmd) |
56 | return -ENOMEM; |
57 | |
58 | while (times_failed < 3) { |
59 | memcpy(cmd->buffer, (void *)&rhb_dot_cmd, sizeof rhb_dot_cmd); |
60 | cmd->status = IBMASM_CMD_PENDING; |
61 | ibmasm_exec_command(sp, cmd); |
62 | ibmasm_wait_for_response(cmd, IBMASM_CMD_TIMEOUT_NORMAL); |
63 | |
64 | if (cmd->status != IBMASM_CMD_COMPLETE) |
65 | times_failed++; |
66 | |
67 | wait_event_interruptible_timeout(rhb->wait, |
68 | rhb->stopped, |
69 | REVERSE_HEARTBEAT_TIMEOUT * HZ); |
70 | |
71 | if (signal_pending(current) || rhb->stopped) { |
72 | result = -EINTR; |
73 | break; |
74 | } |
75 | } |
76 | command_put(cmd); |
77 | rhb->stopped = 0; |
78 | |
79 | return result; |
80 | } |
81 | |
82 | void ibmasm_stop_reverse_heartbeat(struct reverse_heartbeat *rhb) |
83 | { |
84 | rhb->stopped = 1; |
85 | wake_up_interruptible(&rhb->wait); |
86 | } |
87 | |