powerpc/eeh: Move common part to kernel directory

The patch moves the common part of EEH core into arch/powerpc/kernel
directory so that we needn't PPC_PSERIES while compiling POWERNV
platform:

        * Move the EEH common part into arch/powerpc/kernel
        * Move the functions for PCI hotplug from pSeries platform to
          arch/powerpc/kernel/pci-hotplug.c
        * Move CONFIG_EEH from arch/powerpc/platforms/pseries/Kconfig to
          arch/powerpc/platforms/Kconfig
        * Adjust makefile accordingly

Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/kernel/eeh_event.c

@@ -0,0 +1,142 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ *
+ * Copyright (c) 2005 Linas Vepstas <linas@linas.org>
+ */
+
+#include <linux/delay.h>
+#include <linux/list.h>
+#include <linux/mutex.h>
+#include <linux/sched.h>
+#include <linux/pci.h>
+#include <linux/slab.h>
+#include <linux/workqueue.h>
+#include <linux/kthread.h>
+#include <asm/eeh_event.h>
+#include <asm/ppc-pci.h>
+
+/** Overview:
+ *  EEH error states may be detected within exception handlers;
+ *  however, the recovery processing needs to occur asynchronously
+ *  in a normal kernel context and not an interrupt context.
+ *  This pair of routines creates an event and queues it onto a
+ *  work-queue, where a worker thread can drive recovery.
+ */
+
+/* EEH event workqueue setup. */
+static DEFINE_SPINLOCK(eeh_eventlist_lock);
+LIST_HEAD(eeh_eventlist);
+static void eeh_thread_launcher(struct work_struct *);
+DECLARE_WORK(eeh_event_wq, eeh_thread_launcher);
+
+/* Serialize reset sequences for a given pci device */
+DEFINE_MUTEX(eeh_event_mutex);
+
+/**
+ * eeh_event_handler - Dispatch EEH events.
+ * @dummy - unused
+ *
+ * The detection of a frozen slot can occur inside an interrupt,
+ * where it can be hard to do anything about it.  The goal of this
+ * routine is to pull these detection events out of the context
+ * of the interrupt handler, and re-dispatch them for processing
+ * at a later time in a normal context.
+ */
+static int eeh_event_handler(void * dummy)
+{
+	unsigned long flags;
+	struct eeh_event *event;
+	struct eeh_pe *pe;
+
+	spin_lock_irqsave(&eeh_eventlist_lock, flags);
+	event = NULL;
+
+	/* Unqueue the event, get ready to process. */
+	if (!list_empty(&eeh_eventlist)) {
+		event = list_entry(eeh_eventlist.next, struct eeh_event, list);
+		list_del(&event->list);
+	}
+	spin_unlock_irqrestore(&eeh_eventlist_lock, flags);
+
+	if (event == NULL)
+		return 0;
+
+	/* Serialize processing of EEH events */
+	mutex_lock(&eeh_event_mutex);
+	pe = event->pe;
+	eeh_pe_state_mark(pe, EEH_PE_RECOVERING);
+	pr_info("EEH: Detected PCI bus error on PHB#%d-PE#%x\n",
+		pe->phb->global_number, pe->addr);
+
+	set_current_state(TASK_INTERRUPTIBLE);	/* Don't add to load average */
+	eeh_handle_event(pe);
+	eeh_pe_state_clear(pe, EEH_PE_RECOVERING);
+
+	kfree(event);
+	mutex_unlock(&eeh_event_mutex);
+
+	/* If there are no new errors after an hour, clear the counter. */
+	if (pe && pe->freeze_count > 0) {
+		msleep_interruptible(3600*1000);
+		if (pe->freeze_count > 0)
+			pe->freeze_count--;
+
+	}
+
+	return 0;
+}
+
+/**
+ * eeh_thread_launcher - Start kernel thread to handle EEH events
+ * @dummy - unused
+ *
+ * This routine is called to start the kernel thread for processing
+ * EEH event.
+ */
+static void eeh_thread_launcher(struct work_struct *dummy)
+{
+	if (IS_ERR(kthread_run(eeh_event_handler, NULL, "eehd")))
+		printk(KERN_ERR "Failed to start EEH daemon\n");
+}
+
+/**
+ * eeh_send_failure_event - Generate a PCI error event
+ * @pe: EEH PE
+ *
+ * This routine can be called within an interrupt context;
+ * the actual event will be delivered in a normal context
+ * (from a workqueue).
+ */
+int eeh_send_failure_event(struct eeh_pe *pe)
+{
+	unsigned long flags;
+	struct eeh_event *event;
+
+	event = kzalloc(sizeof(*event), GFP_ATOMIC);
+	if (!event) {
+		pr_err("EEH: out of memory, event not handled\n");
+		return -ENOMEM;
+	}
+	event->pe = pe;
+
+	/* We may or may not be called in an interrupt context */
+	spin_lock_irqsave(&eeh_eventlist_lock, flags);
+	list_add(&event->list, &eeh_eventlist);
+	spin_unlock_irqrestore(&eeh_eventlist_lock, flags);
+
+	schedule_work(&eeh_event_wq);
+
+	return 0;
+}