powerpc/powernv: Get FSP memory errors and plumb into memory poison infrastructure.

Get the memory errors reported by opal and plumb it into memory poison
infrastructure. This patch uses new messaging channel infrastructure to
pull the fsp memory errors to linux.

Signed-off-by: Mahesh Salgaonkar <[e-mail]>
Signed-off-by: Benjamin Herrenschmidt <[e-mail]>

arch/powerpc/include/asm/opal.h

···
 	} u;
 };
 
+/* FSP memory errors handling */
+enum OpalMemErr_Version {
+	OpalMemErr_V1 = 1,
+};
+
+enum OpalMemErrType {
+	OPAL_MEM_ERR_TYPE_RESILIENCE	= 0,
+	OPAL_MEM_ERR_TYPE_DYN_DALLOC,
+	OPAL_MEM_ERR_TYPE_SCRUB,
+};
+
+/* Memory Reilience error type */
+enum OpalMemErr_ResilErrType {
+	OPAL_MEM_RESILIENCE_CE		= 0,
+	OPAL_MEM_RESILIENCE_UE,
+	OPAL_MEM_RESILIENCE_UE_SCRUB,
+};
+
+/* Dynamic Memory Deallocation type */
+enum OpalMemErr_DynErrType {
+	OPAL_MEM_DYNAMIC_DEALLOC	= 0,
+};
+
+/* OpalMemoryErrorData->flags */
+#define OPAL_MEM_CORRECTED_ERROR	0x0001
+#define OPAL_MEM_THRESHOLD_EXCEEDED	0x0002
+#define OPAL_MEM_ACK_REQUIRED		0x8000
+
+struct OpalMemoryErrorData {
+	enum OpalMemErr_Version	version:8;	/* 0x00 */
+	enum OpalMemErrType	type:8;		/* 0x01 */
+	uint16_t		flags;		/* 0x02 */
+	uint8_t			reserved_1[4];	/* 0x04 */
+
+	union {
+		/* Memory Resilience corrected/uncorrected error info */
+		struct {
+			enum OpalMemErr_ResilErrType resil_err_type:8;
+			uint8_t		reserved_1[7];
+			uint64_t	physical_address_start;
+			uint64_t	physical_address_end;
+		} resilience;
+		/* Dynamic memory deallocation error info */
+		struct {
+			enum OpalMemErr_DynErrType dyn_err_type:8;
+			uint8_t		reserved_1[7];
+			uint64_t	physical_address_start;
+			uint64_t	physical_address_end;
+		} dyn_dealloc;
+	} u;
+};
+
 enum {
 	OPAL_P7IOC_DIAG_TYPE_NONE	= 0,
 	OPAL_P7IOC_DIAG_TYPE_RGC	= 1,

arch/powerpc/platforms/powernv/Makefile

···
 obj-$(CONFIG_PCI)	+= pci.o pci-p5ioc2.o pci-ioda.o
 obj-$(CONFIG_EEH)	+= eeh-ioda.o eeh-powernv.o
 obj-$(CONFIG_PPC_SCOM)	+= opal-xscom.o
+obj-$(CONFIG_MEMORY_FAILURE)	+= opal-memory-errors.o

arch/powerpc/platforms/powernv/opal-memory-errors.c

···
+/*
+ * OPAL asynchronus Memory error 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, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ * Copyright 2013 IBM Corporation
+ * Author: Mahesh Salgaonkar <[e-mail]>
+ */
+
+#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_mem_err_nb_init;
+static LIST_HEAD(opal_memory_err_list);
+static DEFINE_SPINLOCK(opal_mem_err_lock);
+
+struct OpalMsgNode {
+	struct list_head list;
+	struct opal_msg msg;
+};
+
+static void handle_memory_error_event(struct OpalMemoryErrorData *merr_evt)
+{
+	uint64_t paddr_start, paddr_end;
+
+	pr_debug("%s: Retrived memory error event, type: 0x%x\n",
+		  __func__, merr_evt->type);
+	switch (merr_evt->type) {
+	case OPAL_MEM_ERR_TYPE_RESILIENCE:
+		paddr_start = merr_evt->u.resilience.physical_address_start;
+		paddr_end = merr_evt->u.resilience.physical_address_end;
+		break;
+	case OPAL_MEM_ERR_TYPE_DYN_DALLOC:
+		paddr_start = merr_evt->u.dyn_dealloc.physical_address_start;
+		paddr_end = merr_evt->u.dyn_dealloc.physical_address_end;
+		break;
+	default:
+		return;
+	}
+
+	for (; paddr_start < paddr_end; paddr_start += PAGE_SIZE) {
+		memory_failure(paddr_start >> PAGE_SHIFT, 0, 0);
+	}
+}
+
+static void handle_memory_error(void)
+{
+	unsigned long flags;
+	struct OpalMemoryErrorData *merr_evt;
+	struct OpalMsgNode *msg_node;
+
+	spin_lock_irqsave(&opal_mem_err_lock, flags);
+	while (!list_empty(&opal_memory_err_list)) {
+		 msg_node = list_entry(opal_memory_err_list.next,
+					   struct OpalMsgNode, list);
+		list_del(&msg_node->list);
+		spin_unlock_irqrestore(&opal_mem_err_lock, flags);
+
+		merr_evt = (struct OpalMemoryErrorData *)
+					&msg_node->msg.params[0];
+		handle_memory_error_event(merr_evt);
+		kfree(msg_node);
+		spin_lock_irqsave(&opal_mem_err_lock, flags);
+	}
+	spin_unlock_irqrestore(&opal_mem_err_lock, flags);
+}
+
+static void mem_error_handler(struct work_struct *work)
+{
+	handle_memory_error();
+}
+
+static DECLARE_WORK(mem_error_work, mem_error_handler);
+
+/*
+ * opal_memory_err_event - notifier handler that queues up the opal message
+ * to be preocessed later.
+ */
+static int opal_memory_err_event(struct notifier_block *nb,
+			  unsigned long msg_type, void *msg)
+{
+	unsigned long flags;
+	struct OpalMsgNode *msg_node;
+
+	if (msg_type != OPAL_MSG_MEM_ERR)
+		return 0;
+
+	msg_node = kzalloc(sizeof(*msg_node), GFP_ATOMIC);
+	if (!msg_node) {
+		pr_err("MEMORY_ERROR: out of memory, Opal message event not"
+		       "handled\n");
+		return -ENOMEM;
+	}
+	memcpy(&msg_node->msg, msg, sizeof(struct opal_msg));
+
+	spin_lock_irqsave(&opal_mem_err_lock, flags);
+	list_add(&msg_node->list, &opal_memory_err_list);
+	spin_unlock_irqrestore(&opal_mem_err_lock, flags);
+
+	schedule_work(&mem_error_work);
+	return 0;
+}
+
+static struct notifier_block opal_mem_err_nb = {
+	.notifier_call	= opal_memory_err_event,
+	.next		= NULL,
+	.priority	= 0,
+};
+
+static int __init opal_mem_err_init(void)
+{
+	int ret;
+
+	if (!opal_mem_err_nb_init) {
+		ret = opal_message_notifier_register(
+					OPAL_MSG_MEM_ERR, &opal_mem_err_nb);
+		if (ret) {
+			pr_err("%s: Can't register OPAL event notifier (%d)\n",
+			       __func__, ret);
+			return ret;
+		}
+		opal_mem_err_nb_init = 1;
+	}
+	return 0;
+}
+subsys_initcall(opal_mem_err_init);