Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3)  *   Channel report handling code
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5)  *    Copyright IBM Corp. 2000, 2009
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6)  *    Author(s): Ingo Adlung <adlung@de.ibm.com>,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7)  *		 Martin Schwidefsky <schwidefsky@de.ibm.com>,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8)  *		 Cornelia Huck <cornelia.huck@de.ibm.com>,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9)  *		 Heiko Carstens <heiko.carstens@de.ibm.com>,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12) #include <linux/mutex.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13) #include <linux/kthread.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14) #include <linux/init.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15) #include <linux/wait.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16) #include <asm/crw.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17) #include <asm/ctl_reg.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18) #include "ioasm.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) static DEFINE_MUTEX(crw_handler_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21) static crw_handler_t crw_handlers[NR_RSCS];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22) static atomic_t crw_nr_req = ATOMIC_INIT(0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23) static DECLARE_WAIT_QUEUE_HEAD(crw_handler_wait_q);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26)  * crw_register_handler() - register a channel report word handler
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27)  * @rsc: reporting source code to handle
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28)  * @handler: handler to be registered
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30)  * Returns %0 on success and a negative error value otherwise.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32) int crw_register_handler(int rsc, crw_handler_t handler)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34) 	int rc = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) 	if ((rsc < 0) || (rsc >= NR_RSCS))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) 		return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) 	mutex_lock(&crw_handler_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) 	if (crw_handlers[rsc])
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) 		rc = -EBUSY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) 	else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) 		crw_handlers[rsc] = handler;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) 	mutex_unlock(&crw_handler_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) 	return rc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48)  * crw_unregister_handler() - unregister a channel report word handler
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49)  * @rsc: reporting source code to handle
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) void crw_unregister_handler(int rsc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) 	if ((rsc < 0) || (rsc >= NR_RSCS))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) 	mutex_lock(&crw_handler_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) 	crw_handlers[rsc] = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) 	mutex_unlock(&crw_handler_mutex);
^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) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61)  * Retrieve CRWs and call function to handle event.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) static int crw_collect_info(void *unused)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) 	struct crw crw[2];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) 	int ccode, signal;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) 	unsigned int chain;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) repeat:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) 	signal = wait_event_interruptible(crw_handler_wait_q,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71) 					  atomic_read(&crw_nr_req) > 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) 	if (unlikely(signal))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) 		atomic_inc(&crw_nr_req);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) 	chain = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) 	while (1) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) 		crw_handler_t handler;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) 		if (unlikely(chain > 1)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) 			struct crw tmp_crw;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) 			printk(KERN_WARNING"%s: Code does not support more "
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) 			       "than two chained crws; please report to "
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) 			       "linux390@de.ibm.com!\n", __func__);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) 			ccode = stcrw(&tmp_crw);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) 			printk(KERN_WARNING"%s: crw reports slct=%d, oflw=%d, "
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) 			       "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) 			       __func__, tmp_crw.slct, tmp_crw.oflw,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 			       tmp_crw.chn, tmp_crw.rsc, tmp_crw.anc,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) 			       tmp_crw.erc, tmp_crw.rsid);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) 			printk(KERN_WARNING"%s: This was crw number %x in the "
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) 			       "chain\n", __func__, chain);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) 			if (ccode != 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) 				break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) 			chain = tmp_crw.chn ? chain + 1 : 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) 			continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) 		ccode = stcrw(&crw[chain]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) 		if (ccode != 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) 			break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) 		printk(KERN_DEBUG "crw_info : CRW reports slct=%d, oflw=%d, "
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) 		       "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) 		       crw[chain].slct, crw[chain].oflw, crw[chain].chn,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) 		       crw[chain].rsc, crw[chain].anc, crw[chain].erc,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) 		       crw[chain].rsid);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) 		/* Check for overflows. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) 		if (crw[chain].oflw) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) 			int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) 			pr_debug("%s: crw overflow detected!\n", __func__);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) 			mutex_lock(&crw_handler_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) 			for (i = 0; i < NR_RSCS; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) 				if (crw_handlers[i])
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) 					crw_handlers[i](NULL, NULL, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) 			}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) 			mutex_unlock(&crw_handler_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) 			chain = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) 			continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) 		if (crw[0].chn && !chain) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) 			chain++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) 			continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) 		mutex_lock(&crw_handler_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) 		handler = crw_handlers[crw[chain].rsc];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) 		if (handler)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) 			handler(&crw[0], chain ? &crw[1] : NULL, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) 		mutex_unlock(&crw_handler_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) 		/* chain is always 0 or 1 here. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) 		chain = crw[chain].chn ? chain + 1 : 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) 	if (atomic_dec_and_test(&crw_nr_req))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) 		wake_up(&crw_handler_wait_q);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) 	goto repeat;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) void crw_handle_channel_report(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) 	atomic_inc(&crw_nr_req);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) 	wake_up(&crw_handler_wait_q);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) void crw_wait_for_channel_report(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) 	crw_handle_channel_report();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) 	wait_event(crw_handler_wait_q, atomic_read(&crw_nr_req) == 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150)  * Machine checks for the channel subsystem must be enabled
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151)  * after the channel subsystem is initialized
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) static int __init crw_machine_check_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) 	struct task_struct *task;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) 	task = kthread_run(crw_collect_info, NULL, "kmcheck");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 	if (IS_ERR(task))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) 		return PTR_ERR(task);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) 	ctl_set_bit(14, 28);	/* enable channel report MCH */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) device_initcall(crw_machine_check_init);