powerpc/powernv: Invoke opal call to handle hmi.

When we hit the HMI in Linux, invoke opal call to handle/recover from HMI
errors in real mode and then in virtual mode during check_irq_replay()
invoke opal_poll_events()/opal_do_notifier() to retrieve HMI event from
OPAL and act accordingly.

Now that we are ready to handle HMI interrupt directly in linux, remove
the HMI interrupt registration with firmware.

Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 188 insertions, 0 deletions

diff --git a/arch/powerpc/platforms/powernv/opal-hmi.c b/arch/powerpc/platforms/powernv/opal-hmi.c
new file mode 100644
index 000000000000..97ac8dc33667
--- /dev/null
+++ b/arch/powerpc/platforms/powernv/opal-hmi.c
@@ -0,0 +1,188 @@
+/*
+ * OPAL hypervisor Maintenance interrupt handling support in PowreNV.
+ *
+ * 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, see <http://www.gnu.org/licenses/>.
+ *
+ * Copyright 2014 IBM Corporation
+ * Author: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
+ */
+
+#undef DEBUG
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/of.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+
+#include <asm/opal.h>
+#include <asm/cputable.h>
+
+static int opal_hmi_handler_nb_init;
+struct OpalHmiEvtNode {
+	struct list_head list;
+	struct OpalHMIEvent hmi_evt;
+};
+static LIST_HEAD(opal_hmi_evt_list);
+static DEFINE_SPINLOCK(opal_hmi_evt_lock);
+
+static void print_hmi_event_info(struct OpalHMIEvent *hmi_evt)
+{
+	const char *level, *sevstr, *error_info;
+	static const char *hmi_error_types[] = {
+		"Malfunction Alert",
+		"Processor Recovery done",
+		"Processor recovery occurred again",
+		"Processor recovery occurred for masked error",
+		"Timer facility experienced an error",
+		"TFMR SPR is corrupted",
+		"UPS (Uniterrupted Power System) Overflow indication",
+		"An XSCOM operation failure",
+		"An XSCOM operation completed",
+		"SCOM has set a reserved FIR bit to cause recovery",
+		"Debug trigger has set a reserved FIR bit to cause recovery",
+		"A hypervisor resource error occurred"
+	};
+
+	/* Print things out */
+	if (hmi_evt->version != OpalHMIEvt_V1) {
+		pr_err("HMI Interrupt, Unknown event version %d !\n",
+			hmi_evt->version);
+		return;
+	}
+	switch (hmi_evt->severity) {
+	case OpalHMI_SEV_NO_ERROR:
+		level = KERN_INFO;
+		sevstr = "Harmless";
+		break;
+	case OpalHMI_SEV_WARNING:
+		level = KERN_WARNING;
+		sevstr = "";
+		break;
+	case OpalHMI_SEV_ERROR_SYNC:
+		level = KERN_ERR;
+		sevstr = "Severe";
+		break;
+	case OpalHMI_SEV_FATAL:
+	default:
+		level = KERN_ERR;
+		sevstr = "Fatal";
+		break;
+	}
+
+	printk("%s%s Hypervisor Maintenance interrupt [%s]\n",
+		level, sevstr,
+		hmi_evt->disposition == OpalHMI_DISPOSITION_RECOVERED ?
+		"Recovered" : "Not recovered");
+	error_info = hmi_evt->type < ARRAY_SIZE(hmi_error_types) ?
+			hmi_error_types[hmi_evt->type]
+			: "Unknown";
+	printk("%s Error detail: %s\n", level, error_info);
+	printk("%s	HMER: %016llx\n", level, be64_to_cpu(hmi_evt->hmer));
+	if ((hmi_evt->type == OpalHMI_ERROR_TFAC) ||
+		(hmi_evt->type == OpalHMI_ERROR_TFMR_PARITY))
+		printk("%s	TFMR: %016llx\n", level,
+						be64_to_cpu(hmi_evt->tfmr));
+}
+
+static void hmi_event_handler(struct work_struct *work)
+{
+	unsigned long flags;
+	struct OpalHMIEvent *hmi_evt;
+	struct OpalHmiEvtNode *msg_node;
+	uint8_t disposition;
+
+	spin_lock_irqsave(&opal_hmi_evt_lock, flags);
+	while (!list_empty(&opal_hmi_evt_list)) {
+		msg_node = list_entry(opal_hmi_evt_list.next,
+					   struct OpalHmiEvtNode, list);
+		list_del(&msg_node->list);
+		spin_unlock_irqrestore(&opal_hmi_evt_lock, flags);
+
+		hmi_evt = (struct OpalHMIEvent *) &msg_node->hmi_evt;
+		print_hmi_event_info(hmi_evt);
+		disposition = hmi_evt->disposition;
+		kfree(msg_node);
+
+		/*
+		 * Check if HMI event has been recovered or not. If not
+		 * then we can't continue, invoke panic.
+		 */
+		if (disposition != OpalHMI_DISPOSITION_RECOVERED)
+			panic("Unrecoverable HMI exception");
+
+		spin_lock_irqsave(&opal_hmi_evt_lock, flags);
+	}
+	spin_unlock_irqrestore(&opal_hmi_evt_lock, flags);
+}
+
+static DECLARE_WORK(hmi_event_work, hmi_event_handler);
+/*
+ * opal_handle_hmi_event - notifier handler that queues up HMI events
+ * to be preocessed later.
+ */
+static int opal_handle_hmi_event(struct notifier_block *nb,
+			  unsigned long msg_type, void *msg)
+{
+	unsigned long flags;
+	struct OpalHMIEvent *hmi_evt;
+	struct opal_msg *hmi_msg = msg;
+	struct OpalHmiEvtNode *msg_node;
+
+	/* Sanity Checks */
+	if (msg_type != OPAL_MSG_HMI_EVT)
+		return 0;
+
+	/* HMI event info starts from param[0] */
+	hmi_evt = (struct OpalHMIEvent *)&hmi_msg->params[0];
+
+	/* Delay the logging of HMI events to workqueue. */
+	msg_node = kzalloc(sizeof(*msg_node), GFP_ATOMIC);
+	if (!msg_node) {
+		pr_err("HMI: out of memory, Opal message event not handled\n");
+		return -ENOMEM;
+	}
+	memcpy(&msg_node->hmi_evt, hmi_evt, sizeof(struct OpalHMIEvent));
+
+	spin_lock_irqsave(&opal_hmi_evt_lock, flags);
+	list_add(&msg_node->list, &opal_hmi_evt_list);
+	spin_unlock_irqrestore(&opal_hmi_evt_lock, flags);
+
+	schedule_work(&hmi_event_work);
+	return 0;
+}
+
+static struct notifier_block opal_hmi_handler_nb = {
+	.notifier_call	= opal_handle_hmi_event,
+	.next		= NULL,
+	.priority	= 0,
+};
+
+static int __init opal_hmi_handler_init(void)
+{
+	int ret;
+
+	if (!opal_hmi_handler_nb_init) {
+		ret = opal_message_notifier_register(
+				OPAL_MSG_HMI_EVT, &opal_hmi_handler_nb);
+		if (ret) {
+			pr_err("%s: Can't register OPAL event notifier (%d)\n",
+			       __func__, ret);
+			return ret;
+		}
+		opal_hmi_handler_nb_init = 1;
+	}
+	return 0;
+}
+subsys_initcall(opal_hmi_handler_init);