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TOMOYO Linux Cross Reference
Linux/arch/powerpc/kernel/eeh_event.c

Version: ~ [ linux-5.2-rc6 ] ~ [ linux-5.1.15 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.56 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.130 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.183 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.183 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.69 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.39.4 ] ~ [ linux-2.6.38.8 ] ~ [ linux-2.6.37.6 ] ~ [ linux-2.6.36.4 ] ~ [ linux-2.6.35.14 ] ~ [ linux-2.6.34.15 ] ~ [ linux-2.6.33.20 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /*
  2  * This program is free software; you can redistribute it and/or modify
  3  * it under the terms of the GNU General Public License as published by
  4  * the Free Software Foundation; either version 2 of the License, or
  5  * (at your option) any later version.
  6  *
  7  * This program is distributed in the hope that it will be useful,
  8  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  9  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 10  * GNU General Public License for more details.
 11  *
 12  * You should have received a copy of the GNU General Public License
 13  * along with this program; if not, write to the Free Software
 14  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 15  *
 16  * Copyright (c) 2005 Linas Vepstas <linas@linas.org>
 17  */
 18 
 19 #include <linux/delay.h>
 20 #include <linux/list.h>
 21 #include <linux/sched.h>
 22 #include <linux/semaphore.h>
 23 #include <linux/pci.h>
 24 #include <linux/slab.h>
 25 #include <linux/kthread.h>
 26 #include <asm/eeh_event.h>
 27 #include <asm/ppc-pci.h>
 28 
 29 /** Overview:
 30  *  EEH error states may be detected within exception handlers;
 31  *  however, the recovery processing needs to occur asynchronously
 32  *  in a normal kernel context and not an interrupt context.
 33  *  This pair of routines creates an event and queues it onto a
 34  *  work-queue, where a worker thread can drive recovery.
 35  */
 36 
 37 static DEFINE_SPINLOCK(eeh_eventlist_lock);
 38 static struct semaphore eeh_eventlist_sem;
 39 static LIST_HEAD(eeh_eventlist);
 40 
 41 /**
 42  * eeh_event_handler - Dispatch EEH events.
 43  * @dummy - unused
 44  *
 45  * The detection of a frozen slot can occur inside an interrupt,
 46  * where it can be hard to do anything about it.  The goal of this
 47  * routine is to pull these detection events out of the context
 48  * of the interrupt handler, and re-dispatch them for processing
 49  * at a later time in a normal context.
 50  */
 51 static int eeh_event_handler(void * dummy)
 52 {
 53         unsigned long flags;
 54         struct eeh_event *event;
 55         struct eeh_pe *pe;
 56 
 57         while (!kthread_should_stop()) {
 58                 if (down_interruptible(&eeh_eventlist_sem))
 59                         break;
 60 
 61                 /* Fetch EEH event from the queue */
 62                 spin_lock_irqsave(&eeh_eventlist_lock, flags);
 63                 event = NULL;
 64                 if (!list_empty(&eeh_eventlist)) {
 65                         event = list_entry(eeh_eventlist.next,
 66                                            struct eeh_event, list);
 67                         list_del(&event->list);
 68                 }
 69                 spin_unlock_irqrestore(&eeh_eventlist_lock, flags);
 70                 if (!event)
 71                         continue;
 72 
 73                 /* We might have event without binding PE */
 74                 pe = event->pe;
 75                 if (pe) {
 76                         eeh_pe_state_mark(pe, EEH_PE_RECOVERING);
 77                         if (pe->type & EEH_PE_PHB)
 78                                 pr_info("EEH: Detected error on PHB#%x\n",
 79                                          pe->phb->global_number);
 80                         else
 81                                 pr_info("EEH: Detected PCI bus error on "
 82                                         "PHB#%x-PE#%x\n",
 83                                         pe->phb->global_number, pe->addr);
 84                         eeh_handle_event(pe);
 85                         eeh_pe_state_clear(pe, EEH_PE_RECOVERING);
 86                 } else {
 87                         eeh_handle_event(NULL);
 88                 }
 89 
 90                 kfree(event);
 91         }
 92 
 93         return 0;
 94 }
 95 
 96 /**
 97  * eeh_event_init - Start kernel thread to handle EEH events
 98  *
 99  * This routine is called to start the kernel thread for processing
100  * EEH event.
101  */
102 int eeh_event_init(void)
103 {
104         struct task_struct *t;
105         int ret = 0;
106 
107         /* Initialize semaphore */
108         sema_init(&eeh_eventlist_sem, 0);
109 
110         t = kthread_run(eeh_event_handler, NULL, "eehd");
111         if (IS_ERR(t)) {
112                 ret = PTR_ERR(t);
113                 pr_err("%s: Failed to start EEH daemon (%d)\n",
114                         __func__, ret);
115                 return ret;
116         }
117 
118         return 0;
119 }
120 
121 /**
122  * eeh_send_failure_event - Generate a PCI error event
123  * @pe: EEH PE
124  *
125  * This routine can be called within an interrupt context;
126  * the actual event will be delivered in a normal context
127  * (from a workqueue).
128  */
129 int eeh_send_failure_event(struct eeh_pe *pe)
130 {
131         unsigned long flags;
132         struct eeh_event *event;
133 
134         event = kzalloc(sizeof(*event), GFP_ATOMIC);
135         if (!event) {
136                 pr_err("EEH: out of memory, event not handled\n");
137                 return -ENOMEM;
138         }
139         event->pe = pe;
140 
141         /* We may or may not be called in an interrupt context */
142         spin_lock_irqsave(&eeh_eventlist_lock, flags);
143         list_add(&event->list, &eeh_eventlist);
144         spin_unlock_irqrestore(&eeh_eventlist_lock, flags);
145 
146         /* For EEH deamon to knick in */
147         up(&eeh_eventlist_sem);
148 
149         return 0;
150 }
151 
152 /**
153  * eeh_remove_event - Remove EEH event from the queue
154  * @pe: Event binding to the PE
155  * @force: Event will be removed unconditionally
156  *
157  * On PowerNV platform, we might have subsequent coming events
158  * is part of the former one. For that case, those subsequent
159  * coming events are totally duplicated and unnecessary, thus
160  * they should be removed.
161  */
162 void eeh_remove_event(struct eeh_pe *pe, bool force)
163 {
164         unsigned long flags;
165         struct eeh_event *event, *tmp;
166 
167         /*
168          * If we have NULL PE passed in, we have dead IOC
169          * or we're sure we can report all existing errors
170          * by the caller.
171          *
172          * With "force", the event with associated PE that
173          * have been isolated, the event won't be removed
174          * to avoid event lost.
175          */
176         spin_lock_irqsave(&eeh_eventlist_lock, flags);
177         list_for_each_entry_safe(event, tmp, &eeh_eventlist, list) {
178                 if (!force && event->pe &&
179                     (event->pe->state & EEH_PE_ISOLATED))
180                         continue;
181 
182                 if (!pe) {
183                         list_del(&event->list);
184                         kfree(event);
185                 } else if (pe->type & EEH_PE_PHB) {
186                         if (event->pe && event->pe->phb == pe->phb) {
187                                 list_del(&event->list);
188                                 kfree(event);
189                         }
190                 } else if (event->pe == pe) {
191                         list_del(&event->list);
192                         kfree(event);
193                 }
194         }
195         spin_unlock_irqrestore(&eeh_eventlist_lock, flags);
196 }
197 

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