Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  1) // SPDX-License-Identifier: GPL-2.0-or-later
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  2) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  3) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4)  * IBM ASM Service Processor Device Driver
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6)  * Copyright (C) IBM Corporation, 2004
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8)  * Author: Max Asböck <amax@us.ibm.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <linux/notifier.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include "ibmasm.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include "dot_command.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include "lowlevel.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) static int suspend_heartbeats = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19)  * Once the driver indicates to the service processor that it is running
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20)  * - see send_os_state() - the service processor sends periodic heartbeats
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21)  * to the driver. The driver must respond to the heartbeats or else the OS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22)  * will be rebooted.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23)  * In the case of a panic the interrupt handler continues to work and thus
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24)  * continues to respond to heartbeats, making the service processor believe
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25)  * the OS is still running and thus preventing a reboot.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26)  * To prevent this from happening a callback is added the panic_notifier_list.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27)  * Before responding to a heartbeat the driver checks if a panic has happened,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28)  * if yes it suspends heartbeat, causing the service processor to reboot as
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29)  * expected.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) static int panic_happened(struct notifier_block *n, unsigned long val, void *v)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) 	suspend_heartbeats = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) static struct notifier_block panic_notifier = { panic_happened, NULL, 1 };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) void ibmasm_register_panic_notifier(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) 	atomic_notifier_chain_register(&panic_notifier_list, &panic_notifier);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) void ibmasm_unregister_panic_notifier(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) 	atomic_notifier_chain_unregister(&panic_notifier_list,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) 			&panic_notifier);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) int ibmasm_heartbeat_init(struct service_processor *sp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) 	sp->heartbeat = ibmasm_new_command(sp, HEARTBEAT_BUFFER_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) 	if (sp->heartbeat == NULL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) 		return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) void ibmasm_heartbeat_exit(struct service_processor *sp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) 	char tsbuf[32];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) 	dbg("%s:%d at %s\n", __func__, __LINE__, get_timestamp(tsbuf));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) 	ibmasm_wait_for_response(sp->heartbeat, IBMASM_CMD_TIMEOUT_NORMAL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) 	dbg("%s:%d at %s\n", __func__, __LINE__, get_timestamp(tsbuf));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) 	suspend_heartbeats = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) 	command_put(sp->heartbeat);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) void ibmasm_receive_heartbeat(struct service_processor *sp,  void *message, size_t size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) 	struct command *cmd = sp->heartbeat;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) 	struct dot_command_header *header = (struct dot_command_header *)cmd->buffer;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) 	char tsbuf[32];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) 	dbg("%s:%d at %s\n", __func__, __LINE__, get_timestamp(tsbuf));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) 	if (suspend_heartbeats)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) 	/* return the received dot command to sender */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) 	cmd->status = IBMASM_CMD_PENDING;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) 	size = min(size, cmd->buffer_size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) 	memcpy_fromio(cmd->buffer, message, size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) 	header->type = sp_write;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) 	ibmasm_exec_command(sp, cmd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) }