1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * OPAL asynchronus Memory error handling support in PowerNV.
4 *
5 * Copyright 2013 IBM Corporation
6 * Author: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
7 */
8
9#undef DEBUG
10
11#include <linux/kernel.h>
12#include <linux/init.h>
13#include <linux/of.h>
14#include <linux/mm.h>
15#include <linux/slab.h>
16
17#include <asm/machdep.h>
18#include <asm/opal.h>
19#include <asm/cputable.h>
20
21static int opal_mem_err_nb_init;
22static LIST_HEAD(opal_memory_err_list);
23static DEFINE_SPINLOCK(opal_mem_err_lock);
24
25struct OpalMsgNode {
26	struct list_head list;
27	struct opal_msg msg;
28};
29
30static void handle_memory_error_event(struct OpalMemoryErrorData *merr_evt)
31{
32	uint64_t paddr_start, paddr_end;
33
34	pr_debug("%s: Retrieved memory error event, type: 0x%x\n",
35		  __func__, merr_evt->type);
36	switch (merr_evt->type) {
37	case OPAL_MEM_ERR_TYPE_RESILIENCE:
38		paddr_start = be64_to_cpu(merr_evt->u.resilience.physical_address_start);
39		paddr_end = be64_to_cpu(merr_evt->u.resilience.physical_address_end);
40		break;
41	case OPAL_MEM_ERR_TYPE_DYN_DALLOC:
42		paddr_start = be64_to_cpu(merr_evt->u.dyn_dealloc.physical_address_start);
43		paddr_end = be64_to_cpu(merr_evt->u.dyn_dealloc.physical_address_end);
44		break;
45	default:
46		return;
47	}
48
49	for (; paddr_start < paddr_end; paddr_start += PAGE_SIZE) {
50		memory_failure(paddr_start >> PAGE_SHIFT, 0);
51	}
52}
53
54static void handle_memory_error(void)
55{
56	unsigned long flags;
57	struct OpalMemoryErrorData *merr_evt;
58	struct OpalMsgNode *msg_node;
59
60	spin_lock_irqsave(&opal_mem_err_lock, flags);
61	while (!list_empty(&opal_memory_err_list)) {
62		 msg_node = list_entry(opal_memory_err_list.next,
63					   struct OpalMsgNode, list);
64		list_del(&msg_node->list);
65		spin_unlock_irqrestore(&opal_mem_err_lock, flags);
66
67		merr_evt = (struct OpalMemoryErrorData *)
68					&msg_node->msg.params[0];
69		handle_memory_error_event(merr_evt);
70		kfree(msg_node);
71		spin_lock_irqsave(&opal_mem_err_lock, flags);
72	}
73	spin_unlock_irqrestore(&opal_mem_err_lock, flags);
74}
75
76static void mem_error_handler(struct work_struct *work)
77{
78	handle_memory_error();
79}
80
81static DECLARE_WORK(mem_error_work, mem_error_handler);
82
83/*
84 * opal_memory_err_event - notifier handler that queues up the opal message
85 * to be processed later.
86 */
87static int opal_memory_err_event(struct notifier_block *nb,
88			  unsigned long msg_type, void *msg)
89{
90	unsigned long flags;
91	struct OpalMsgNode *msg_node;
92
93	if (msg_type != OPAL_MSG_MEM_ERR)
94		return 0;
95
96	msg_node = kzalloc(sizeof(*msg_node), GFP_ATOMIC);
97	if (!msg_node) {
98		pr_err("MEMORY_ERROR: out of memory, Opal message event not"
99		       "handled\n");
100		return -ENOMEM;
101	}
102	memcpy(&msg_node->msg, msg, sizeof(msg_node->msg));
103
104	spin_lock_irqsave(&opal_mem_err_lock, flags);
105	list_add(&msg_node->list, &opal_memory_err_list);
106	spin_unlock_irqrestore(&opal_mem_err_lock, flags);
107
108	schedule_work(&mem_error_work);
109	return 0;
110}
111
112static struct notifier_block opal_mem_err_nb = {
113	.notifier_call	= opal_memory_err_event,
114	.next		= NULL,
115	.priority	= 0,
116};
117
118static int __init opal_mem_err_init(void)
119{
120	int ret;
121
122	if (!opal_mem_err_nb_init) {
123		ret = opal_message_notifier_register(
124					OPAL_MSG_MEM_ERR, &opal_mem_err_nb);
125		if (ret) {
126			pr_err("%s: Can't register OPAL event notifier (%d)\n",
127			       __func__, ret);
128			return ret;
129		}
130		opal_mem_err_nb_init = 1;
131	}
132	return 0;
133}
134machine_device_initcall(powernv, opal_mem_err_init);
135