[IA64] Itanium MC Error Injection Tool: Driver sysfs interface

This kernel driver patch provides sysfs interface for user application to
call pal_mc_error_inject() procedure.
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

arch/ia64/kernel/err_inject.c

+/*
+ * err_inject.c -
+ *	1.) Inject errors to a processor.
+ *	2.) Query error injection capabilities.
+ * This driver along with user space code can be acting as an error
+ * injection tool.
+ *
+ * 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, GOOD TITLE or
+ * NON INFRINGEMENT.  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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ * Written by: Fenghua Yu <fenghua.yu@intel.com>, Intel Corporation
+ * Copyright (C) 2006, Intel Corp.  All rights reserved.
+ *
+ */
+#include <linux/sysdev.h>
+#include <linux/init.h>
+#include <linux/mm.h>
+#include <linux/cpu.h>
+#include <linux/module.h>
+
+#define ERR_INJ_DEBUG
+
+#define ERR_DATA_BUFFER_SIZE 3 		// Three 8-byte;
+
+#define define_one_ro(name) 						\
+static SYSDEV_ATTR(name, 0444, show_##name, NULL)
+
+#define define_one_rw(name) 						\
+static SYSDEV_ATTR(name, 0644, show_##name, store_##name)
+
+static u64 call_start[NR_CPUS];
+static u64 phys_addr[NR_CPUS];
+static u64 err_type_info[NR_CPUS];
+static u64 err_struct_info[NR_CPUS];
+static struct {
+	u64 data1;
+	u64 data2;
+	u64 data3;
+} __attribute__((__aligned__(16))) err_data_buffer[NR_CPUS];
+static s64 status[NR_CPUS];
+static u64 capabilities[NR_CPUS];
+static u64 resources[NR_CPUS];
+
+#define show(name) 							\
+static ssize_t 								\
+show_##name(struct sys_device *dev, char *buf)				\
+{									\
+	u32 cpu=dev->id;						\
+	return sprintf(buf, "%lx\n", name[cpu]);			\
+}
+
+#define store(name)							\
+static ssize_t 								\
+store_##name(struct sys_device *dev, const char *buf, size_t size)	\
+{									\
+	unsigned int cpu=dev->id;					\
+	name[cpu] = simple_strtoull(buf, NULL, 16);			\
+	return size;							\
+}
+
+show(call_start)
+
+/* It's user's responsibility to call the PAL procedure on a specific
+ * processor. The cpu number in driver is only used for storing data.
+ */
+static ssize_t
+store_call_start(struct sys_device *dev, const char *buf, size_t size)
+{
+	unsigned int cpu=dev->id;
+	unsigned long call_start = simple_strtoull(buf, NULL, 16);
+
+#ifdef ERR_INJ_DEBUG
+	printk(KERN_DEBUG "pal_mc_err_inject for cpu%d:\n", cpu);
+	printk(KERN_DEBUG "err_type_info=%lx,\n", err_type_info[cpu]);
+	printk(KERN_DEBUG "err_struct_info=%lx,\n", err_struct_info[cpu]);
+	printk(KERN_DEBUG "err_data_buffer=%lx, %lx, %lx.\n",
+			  err_data_buffer[cpu].data1,
+			  err_data_buffer[cpu].data2,
+			  err_data_buffer[cpu].data3);
+#endif
+	switch (call_start) {
+	    case 0: /* Do nothing. */
+		break;
+	    case 1: /* Call pal_mc_error_inject in physical mode. */
+		status[cpu]=ia64_pal_mc_error_inject_phys(err_type_info[cpu],
+					err_struct_info[cpu],
+					ia64_tpa(&err_data_buffer[cpu]),
+					&capabilities[cpu],
+			 		&resources[cpu]);
+		break;
+	    case 2: /* Call pal_mc_error_inject in virtual mode. */
+		status[cpu]=ia64_pal_mc_error_inject_virt(err_type_info[cpu],
+					err_struct_info[cpu],
+					ia64_tpa(&err_data_buffer[cpu]),
+					&capabilities[cpu],
+			 		&resources[cpu]);
+		break;
+	    default:
+		status[cpu] = -EINVAL;
+		break;
+	}
+
+#ifdef ERR_INJ_DEBUG
+	printk(KERN_DEBUG "Returns: status=%d,\n", (int)status[cpu]);
+	printk(KERN_DEBUG "capapbilities=%lx,\n", capabilities[cpu]);
+	printk(KERN_DEBUG "resources=%lx\n", resources[cpu]);
+#endif
+	return size;
+}
+
+show(err_type_info)
+store(err_type_info)
+
+static ssize_t
+show_virtual_to_phys(struct sys_device *dev, char *buf)
+{
+	unsigned int cpu=dev->id;
+	return sprintf(buf, "%lx\n", phys_addr[cpu]);
+}
+
+static ssize_t
+store_virtual_to_phys(struct sys_device *dev, const char *buf, size_t size)
+{
+	unsigned int cpu=dev->id;
+	u64 virt_addr=simple_strtoull(buf, NULL, 16);
+	int ret;
+
+        ret = get_user_pages(current, current->mm, virt_addr,
+                        1, VM_READ, 0, NULL, NULL);
+	if (ret<=0) {
+#ifdef ERR_INJ_DEBUG
+		printk("Virtual address %lx is not existing.\n",virt_addr);
+#endif
+		return -EINVAL;
+	}
+
+	phys_addr[cpu] = ia64_tpa(virt_addr);
+	return size;
+}
+
+show(err_struct_info)
+store(err_struct_info)
+
+static ssize_t
+show_err_data_buffer(struct sys_device *dev, char *buf)
+{
+	unsigned int cpu=dev->id;
+
+	return sprintf(buf, "%lx, %lx, %lx\n",
+			err_data_buffer[cpu].data1,
+			err_data_buffer[cpu].data2,
+			err_data_buffer[cpu].data3);
+}
+
+static ssize_t
+store_err_data_buffer(struct sys_device *dev, const char *buf, size_t size)
+{
+	unsigned int cpu=dev->id;
+	int ret;
+
+#ifdef ERR_INJ_DEBUG
+	printk("write err_data_buffer=[%lx,%lx,%lx] on cpu%d\n",
+		 err_data_buffer[cpu].data1,
+		 err_data_buffer[cpu].data2,
+		 err_data_buffer[cpu].data3,
+		 cpu);
+#endif
+	ret=sscanf(buf, "%lx, %lx, %lx",
+			&err_data_buffer[cpu].data1,
+			&err_data_buffer[cpu].data2,
+			&err_data_buffer[cpu].data3);
+	if (ret!=ERR_DATA_BUFFER_SIZE)
+		return -EINVAL;
+
+	return size;
+}
+
+show(status)
+show(capabilities)
+show(resources)
+
+define_one_rw(call_start);
+define_one_rw(err_type_info);
+define_one_rw(err_struct_info);
+define_one_rw(err_data_buffer);
+define_one_rw(virtual_to_phys);
+define_one_ro(status);
+define_one_ro(capabilities);
+define_one_ro(resources);
+
+static struct attribute *default_attrs[] = {
+	&attr_call_start.attr,
+	&attr_virtual_to_phys.attr,
+	&attr_err_type_info.attr,
+	&attr_err_struct_info.attr,
+	&attr_err_data_buffer.attr,
+	&attr_status.attr,
+	&attr_capabilities.attr,
+	&attr_resources.attr,
+	NULL
+};
+
+static struct attribute_group err_inject_attr_group = {
+	.attrs = default_attrs,
+	.name = "err_inject"
+};
+/* Add/Remove err_inject interface for CPU device */
+static int __cpuinit err_inject_add_dev(struct sys_device * sys_dev)
+{
+	return sysfs_create_group(&sys_dev->kobj, &err_inject_attr_group);
+}
+
+static int __cpuinit err_inject_remove_dev(struct sys_device * sys_dev)
+{
+	sysfs_remove_group(&sys_dev->kobj, &err_inject_attr_group);
+	return 0;
+}
+static int __cpuinit err_inject_cpu_callback(struct notifier_block *nfb,
+		unsigned long action, void *hcpu)
+{
+	unsigned int cpu = (unsigned long)hcpu;
+	struct sys_device *sys_dev;
+
+	sys_dev = get_cpu_sysdev(cpu);
+	switch (action) {
+	case CPU_ONLINE:
+		err_inject_add_dev(sys_dev);
+		break;
+	case CPU_DEAD:
+		err_inject_remove_dev(sys_dev);
+		break;
+	}
+
+	return NOTIFY_OK;
+}
+
+static struct notifier_block __cpuinitdata err_inject_cpu_notifier =
+{
+	.notifier_call = err_inject_cpu_callback,
+};
+
+static int __init
+err_inject_init(void)
+{
+	int i;
+
+#ifdef ERR_INJ_DEBUG
+	printk(KERN_INFO "Enter error injection driver.\n");
+#endif
+	for_each_online_cpu(i) {
+		err_inject_cpu_callback(&err_inject_cpu_notifier, CPU_ONLINE,
+				(void *)(long)i);
+	}
+
+	register_hotcpu_notifier(&err_inject_cpu_notifier);
+
+	return 0;
+}
+
+static void __exit
+err_inject_exit(void)
+{
+	int i;
+	struct sys_device *sys_dev;
+
+#ifdef ERR_INJ_DEBUG
+	printk(KERN_INFO "Exit error injection driver.\n");
+#endif
+	for_each_online_cpu(i) {
+		sys_dev = get_cpu_sysdev(i);
+		sysfs_remove_group(&sys_dev->kobj, &err_inject_attr_group);
+	}
+	unregister_hotcpu_notifier(&err_inject_cpu_notifier);
+}
+
+module_init(err_inject_init);
+module_exit(err_inject_exit);
+
+MODULE_AUTHOR("Fenghua Yu <fenghua.yu@intel.com>");
+MODULE_DESCRIPTION("MC error injection kenrel sysfs interface");
+MODULE_LICENSE("GPL");