x86/mce: Merge mce_amd_inj into mce-inject

Reuse mce_amd_inj's debugfs interface so that mce-inject can
benefit from it too. The old functionality is still preserved under
CONFIG_X86_MCELOG_LEGACY.

Tested-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Yazen Ghannam <yazen.ghannam@amd.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/20170613162835.30750-4-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 526 insertions, 16 deletions

diff --git a/arch/x86/kernel/cpu/mcheck/mce-inject.c b/arch/x86/kernel/cpu/mcheck/mce-inject.c
index 99165b2..7170186 100644
--- a/arch/x86/kernel/cpu/mcheck/mce-inject.c
+++ b/arch/x86/kernel/cpu/mcheck/mce-inject.c
@@ -10,23 +10,108 @@
  * Authors:
  * Andi Kleen
  * Ying Huang
+ *
+ * The AMD part (from mce_amd_inj.c): a simple MCE injection facility
+ * for testing different aspects of the RAS code. This driver should be
+ * built as module so that it can be loaded on production kernels for
+ * testing purposes.
+ *
+ * This file may be distributed under the terms of the GNU General Public
+ * License version 2.
+ *
+ * Copyright (c) 2010-17:  Borislav Petkov <bp@alien8.de>
+ *			   Advanced Micro Devices Inc.
  */
-#include <linux/uaccess.h>
-#include <linux/module.h>
-#include <linux/timer.h>
-#include <linux/kernel.h>
-#include <linux/string.h>
+
+#include <linux/cpu.h>
+#include <linux/debugfs.h>
+#include <linux/device.h>
 #include <linux/fs.h>
-#include <linux/preempt.h>
-#include <linux/smp.h>
-#include <linux/notifier.h>
+#include <linux/gfp.h>
 #include <linux/kdebug.h>
-#include <linux/cpu.h>
+#include <linux/kernel.h>
+#include <linux/kobject.h>
+#include <linux/module.h>
+#include <linux/notifier.h>
+#include <linux/pci.h>
+#include <linux/preempt.h>
 #include <linux/sched.h>
-#include <linux/gfp.h>
-#include <asm/mce.h>
+#include <linux/smp.h>
+#include <linux/string.h>
+#include <linux/timer.h>
+#include <linux/uaccess.h>
+
+#include <asm/amd_nb.h>
 #include <asm/apic.h>
+#include <asm/irq_vectors.h>
+#include <asm/mce.h>
 #include <asm/nmi.h>
+#include <asm/smp.h>
+
+#include "mce-internal.h"
+
+/*
+ * Collect all the MCi_XXX settings
+ */
+static struct mce i_mce;
+static struct dentry *dfs_inj;
+
+static u8 n_banks;
+
+#define MAX_FLAG_OPT_SIZE	3
+#define NBCFG			0x44
+
+enum injection_type {
+	SW_INJ = 0,	/* SW injection, simply decode the error */
+	HW_INJ,		/* Trigger a #MC */
+	DFR_INT_INJ,    /* Trigger Deferred error interrupt */
+	THR_INT_INJ,    /* Trigger threshold interrupt */
+	N_INJ_TYPES,
+};
+
+static const char * const flags_options[] = {
+	[SW_INJ] = "sw",
+	[HW_INJ] = "hw",
+	[DFR_INT_INJ] = "df",
+	[THR_INT_INJ] = "th",
+	NULL
+};
+
+/* Set default injection to SW_INJ */
+static enum injection_type inj_type = SW_INJ;
+
+#define MCE_INJECT_SET(reg)						\
+static int inj_##reg##_set(void *data, u64 val)				\
+{									\
+	struct mce *m = (struct mce *)data;				\
+									\
+	m->reg = val;							\
+	return 0;							\
+}
+
+MCE_INJECT_SET(status);
+MCE_INJECT_SET(misc);
+MCE_INJECT_SET(addr);
+MCE_INJECT_SET(synd);
+
+#define MCE_INJECT_GET(reg)						\
+static int inj_##reg##_get(void *data, u64 *val)			\
+{									\
+	struct mce *m = (struct mce *)data;				\
+									\
+	*val = m->reg;							\
+	return 0;							\
+}
+
+MCE_INJECT_GET(status);
+MCE_INJECT_GET(misc);
+MCE_INJECT_GET(addr);
+MCE_INJECT_GET(synd);
+
+DEFINE_SIMPLE_ATTRIBUTE(status_fops, inj_status_get, inj_status_set, "%llx\n");
+DEFINE_SIMPLE_ATTRIBUTE(misc_fops, inj_misc_get, inj_misc_set, "%llx\n");
+DEFINE_SIMPLE_ATTRIBUTE(addr_fops, inj_addr_get, inj_addr_set, "%llx\n");
+DEFINE_SIMPLE_ATTRIBUTE(synd_fops, inj_synd_get, inj_synd_set, "%llx\n");
 
 /* Update fake mce registers on current CPU. */
 static void inject_mce(struct mce *m)
@@ -143,7 +228,7 @@ static int raise_local(void)
 	return ret;
 }
 
-static void raise_mce(struct mce *m)
+static void __maybe_unused raise_mce(struct mce *m)
 {
 	int context = MCJ_CTX(m->inject_flags);
 
@@ -198,6 +283,7 @@ static void raise_mce(struct mce *m)
 	}
 }
 
+#ifdef CONFIG_X86_MCELOG_LEGACY
 /* Error injection interface */
 static ssize_t mce_write(struct file *filp, const char __user *ubuf,
 			 size_t usize, loff_t *off)
@@ -232,21 +318,445 @@ static ssize_t mce_write(struct file *filp, const char __user *ubuf,
 	mutex_unlock(&mce_inject_mutex);
 	return usize;
 }
+#endif /* CONFIG_X86_MCELOG_LEGACY */
+
+/*
+ * Caller needs to be make sure this cpu doesn't disappear
+ * from under us, i.e.: get_cpu/put_cpu.
+ */
+static int toggle_hw_mce_inject(unsigned int cpu, bool enable)
+{
+	u32 l, h;
+	int err;
+
+	err = rdmsr_on_cpu(cpu, MSR_K7_HWCR, &l, &h);
+	if (err) {
+		pr_err("%s: error reading HWCR\n", __func__);
+		return err;
+	}
+
+	enable ? (l |= BIT(18)) : (l &= ~BIT(18));
+
+	err = wrmsr_on_cpu(cpu, MSR_K7_HWCR, l, h);
+	if (err)
+		pr_err("%s: error writing HWCR\n", __func__);
+
+	return err;
+}
+
+static int __set_inj(const char *buf)
+{
+	int i;
+
+	for (i = 0; i < N_INJ_TYPES; i++) {
+		if (!strncmp(flags_options[i], buf, strlen(flags_options[i]))) {
+			inj_type = i;
+			return 0;
+		}
+	}
+	return -EINVAL;
+}
+
+static ssize_t flags_read(struct file *filp, char __user *ubuf,
+			  size_t cnt, loff_t *ppos)
+{
+	char buf[MAX_FLAG_OPT_SIZE];
+	int n;
+
+	n = sprintf(buf, "%s\n", flags_options[inj_type]);
+
+	return simple_read_from_buffer(ubuf, cnt, ppos, buf, n);
+}
+
+static ssize_t flags_write(struct file *filp, const char __user *ubuf,
+			   size_t cnt, loff_t *ppos)
+{
+	char buf[MAX_FLAG_OPT_SIZE], *__buf;
+	int err;
+
+	if (cnt > MAX_FLAG_OPT_SIZE)
+		return -EINVAL;
+
+	if (copy_from_user(&buf, ubuf, cnt))
+		return -EFAULT;
+
+	buf[cnt - 1] = 0;
+
+	/* strip whitespace */
+	__buf = strstrip(buf);
+
+	err = __set_inj(__buf);
+	if (err) {
+		pr_err("%s: Invalid flags value: %s\n", __func__, __buf);
+		return err;
+	}
+
+	*ppos += cnt;
+
+	return cnt;
+}
+
+static const struct file_operations flags_fops = {
+	.read           = flags_read,
+	.write          = flags_write,
+	.llseek         = generic_file_llseek,
+};
+
+/*
+ * On which CPU to inject?
+ */
+MCE_INJECT_GET(extcpu);
+
+static int inj_extcpu_set(void *data, u64 val)
+{
+	struct mce *m = (struct mce *)data;
+
+	if (val >= nr_cpu_ids || !cpu_online(val)) {
+		pr_err("%s: Invalid CPU: %llu\n", __func__, val);
+		return -EINVAL;
+	}
+	m->extcpu = val;
+	return 0;
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(extcpu_fops, inj_extcpu_get, inj_extcpu_set, "%llu\n");
+
+static void trigger_mce(void *info)
+{
+	asm volatile("int $18");
+}
+
+static void trigger_dfr_int(void *info)
+{
+	asm volatile("int %0" :: "i" (DEFERRED_ERROR_VECTOR));
+}
+
+static void trigger_thr_int(void *info)
+{
+	asm volatile("int %0" :: "i" (THRESHOLD_APIC_VECTOR));
+}
+
+static u32 get_nbc_for_node(int node_id)
+{
+	struct cpuinfo_x86 *c = &boot_cpu_data;
+	u32 cores_per_node;
+
+	cores_per_node = (c->x86_max_cores * smp_num_siblings) / amd_get_nodes_per_socket();
+
+	return cores_per_node * node_id;
+}
+
+static void toggle_nb_mca_mst_cpu(u16 nid)
+{
+	struct amd_northbridge *nb;
+	struct pci_dev *F3;
+	u32 val;
+	int err;
+
+	nb = node_to_amd_nb(nid);
+	if (!nb)
+		return;
+
+	F3 = nb->misc;
+	if (!F3)
+		return;
+
+	err = pci_read_config_dword(F3, NBCFG, &val);
+	if (err) {
+		pr_err("%s: Error reading F%dx%03x.\n",
+		       __func__, PCI_FUNC(F3->devfn), NBCFG);
+		return;
+	}
+
+	if (val & BIT(27))
+		return;
+
+	pr_err("%s: Set D18F3x44[NbMcaToMstCpuEn] which BIOS hasn't done.\n",
+	       __func__);
+
+	val |= BIT(27);
+	err = pci_write_config_dword(F3, NBCFG, val);
+	if (err)
+		pr_err("%s: Error writing F%dx%03x.\n",
+		       __func__, PCI_FUNC(F3->devfn), NBCFG);
+}
 
-static int inject_init(void)
+static void prepare_msrs(void *info)
 {
+	struct mce m = *(struct mce *)info;
+	u8 b = m.bank;
+
+	wrmsrl(MSR_IA32_MCG_STATUS, m.mcgstatus);
+
+	if (boot_cpu_has(X86_FEATURE_SMCA)) {
+		if (m.inject_flags == DFR_INT_INJ) {
+			wrmsrl(MSR_AMD64_SMCA_MCx_DESTAT(b), m.status);
+			wrmsrl(MSR_AMD64_SMCA_MCx_DEADDR(b), m.addr);
+		} else {
+			wrmsrl(MSR_AMD64_SMCA_MCx_STATUS(b), m.status);
+			wrmsrl(MSR_AMD64_SMCA_MCx_ADDR(b), m.addr);
+		}
+
+		wrmsrl(MSR_AMD64_SMCA_MCx_MISC(b), m.misc);
+		wrmsrl(MSR_AMD64_SMCA_MCx_SYND(b), m.synd);
+	} else {
+		wrmsrl(MSR_IA32_MCx_STATUS(b), m.status);
+		wrmsrl(MSR_IA32_MCx_ADDR(b), m.addr);
+		wrmsrl(MSR_IA32_MCx_MISC(b), m.misc);
+	}
+}
+
+static void do_inject(void)
+{
+	u64 mcg_status = 0;
+	unsigned int cpu = i_mce.extcpu;
+	u8 b = i_mce.bank;
+
+	rdtscll(i_mce.tsc);
+
+	if (i_mce.misc)
+		i_mce.status |= MCI_STATUS_MISCV;
+
+	if (i_mce.synd)
+		i_mce.status |= MCI_STATUS_SYNDV;
+
+	if (inj_type == SW_INJ) {
+		mce_inject_log(&i_mce);
+		return;
+	}
+
+	/* prep MCE global settings for the injection */
+	mcg_status = MCG_STATUS_MCIP | MCG_STATUS_EIPV;
+
+	if (!(i_mce.status & MCI_STATUS_PCC))
+		mcg_status |= MCG_STATUS_RIPV;
+
+	/*
+	 * Ensure necessary status bits for deferred errors:
+	 * - MCx_STATUS[Deferred]: make sure it is a deferred error
+	 * - MCx_STATUS[UC] cleared: deferred errors are _not_ UC
+	 */
+	if (inj_type == DFR_INT_INJ) {
+		i_mce.status |= MCI_STATUS_DEFERRED;
+		i_mce.status |= (i_mce.status & ~MCI_STATUS_UC);
+	}
+
+	/*
+	 * For multi node CPUs, logging and reporting of bank 4 errors happens
+	 * only on the node base core. Refer to D18F3x44[NbMcaToMstCpuEn] for
+	 * Fam10h and later BKDGs.
+	 */
+	if (static_cpu_has(X86_FEATURE_AMD_DCM) &&
+	    b == 4 &&
+	    boot_cpu_data.x86 < 0x17) {
+		toggle_nb_mca_mst_cpu(amd_get_nb_id(cpu));
+		cpu = get_nbc_for_node(amd_get_nb_id(cpu));
+	}
+
+	get_online_cpus();
+	if (!cpu_online(cpu))
+		goto err;
+
+	toggle_hw_mce_inject(cpu, true);
+
+	i_mce.mcgstatus = mcg_status;
+	i_mce.inject_flags = inj_type;
+	smp_call_function_single(cpu, prepare_msrs, &i_mce, 0);
+
+	toggle_hw_mce_inject(cpu, false);
+
+	switch (inj_type) {
+	case DFR_INT_INJ:
+		smp_call_function_single(cpu, trigger_dfr_int, NULL, 0);
+		break;
+	case THR_INT_INJ:
+		smp_call_function_single(cpu, trigger_thr_int, NULL, 0);
+		break;
+	default:
+		smp_call_function_single(cpu, trigger_mce, NULL, 0);
+	}
+
+err:
+	put_online_cpus();
+
+}
+
+/*
+ * This denotes into which bank we're injecting and triggers
+ * the injection, at the same time.
+ */
+static int inj_bank_set(void *data, u64 val)
+{
+	struct mce *m = (struct mce *)data;
+
+	if (val >= n_banks) {
+		pr_err("Non-existent MCE bank: %llu\n", val);
+		return -EINVAL;
+	}
+
+	m->bank = val;
+	do_inject();
+
+	return 0;
+}
+
+MCE_INJECT_GET(bank);
+
+DEFINE_SIMPLE_ATTRIBUTE(bank_fops, inj_bank_get, inj_bank_set, "%llu\n");
+
+static const char readme_msg[] =
+"Description of the files and their usages:\n"
+"\n"
+"Note1: i refers to the bank number below.\n"
+"Note2: See respective BKDGs for the exact bit definitions of the files below\n"
+"as they mirror the hardware registers.\n"
+"\n"
+"status:\t Set MCi_STATUS: the bits in that MSR control the error type and\n"
+"\t attributes of the error which caused the MCE.\n"
+"\n"
+"misc:\t Set MCi_MISC: provide auxiliary info about the error. It is mostly\n"
+"\t used for error thresholding purposes and its validity is indicated by\n"
+"\t MCi_STATUS[MiscV].\n"
+"\n"
+"synd:\t Set MCi_SYND: provide syndrome info about the error. Only valid on\n"
+"\t Scalable MCA systems, and its validity is indicated by MCi_STATUS[SyndV].\n"
+"\n"
+"addr:\t Error address value to be written to MCi_ADDR. Log address information\n"
+"\t associated with the error.\n"
+"\n"
+"cpu:\t The CPU to inject the error on.\n"
+"\n"
+"bank:\t Specify the bank you want to inject the error into: the number of\n"
+"\t banks in a processor varies and is family/model-specific, therefore, the\n"
+"\t supplied value is sanity-checked. Setting the bank value also triggers the\n"
+"\t injection.\n"
+"\n"
+"flags:\t Injection type to be performed. Writing to this file will trigger a\n"
+"\t real machine check, an APIC interrupt or invoke the error decoder routines\n"
+"\t for AMD processors.\n"
+"\n"
+"\t Allowed error injection types:\n"
+"\t  - \"sw\": Software error injection. Decode error to a human-readable \n"
+"\t    format only. Safe to use.\n"
+"\t  - \"hw\": Hardware error injection. Causes the #MC exception handler to \n"
+"\t    handle the error. Be warned: might cause system panic if MCi_STATUS[PCC] \n"
+"\t    is set. Therefore, consider setting (debugfs_mountpoint)/mce/fake_panic \n"
+"\t    before injecting.\n"
+"\t  - \"df\": Trigger APIC interrupt for Deferred error. Causes deferred \n"
+"\t    error APIC interrupt handler to handle the error if the feature is \n"
+"\t    is present in hardware. \n"
+"\t  - \"th\": Trigger APIC interrupt for Threshold errors. Causes threshold \n"
+"\t    APIC interrupt handler to handle the error. \n"
+"\n";
+
+static ssize_t
+inj_readme_read(struct file *filp, char __user *ubuf,
+		       size_t cnt, loff_t *ppos)
+{
+	return simple_read_from_buffer(ubuf, cnt, ppos,
+					readme_msg, strlen(readme_msg));
+}
+
+static const struct file_operations readme_fops = {
+	.read		= inj_readme_read,
+};
+
+static struct dfs_node {
+	char *name;
+	struct dentry *d;
+	const struct file_operations *fops;
+	umode_t perm;
+} dfs_fls[] = {
+	{ .name = "status",	.fops = &status_fops, .perm = S_IRUSR | S_IWUSR },
+	{ .name = "misc",	.fops = &misc_fops,   .perm = S_IRUSR | S_IWUSR },
+	{ .name = "addr",	.fops = &addr_fops,   .perm = S_IRUSR | S_IWUSR },
+	{ .name = "synd",	.fops = &synd_fops,   .perm = S_IRUSR | S_IWUSR },
+	{ .name = "bank",	.fops = &bank_fops,   .perm = S_IRUSR | S_IWUSR },
+	{ .name = "flags",	.fops = &flags_fops,  .perm = S_IRUSR | S_IWUSR },
+	{ .name = "cpu",	.fops = &extcpu_fops, .perm = S_IRUSR | S_IWUSR },
+	{ .name = "README",	.fops = &readme_fops, .perm = S_IRUSR | S_IRGRP | S_IROTH },
+};
+
+static int __init debugfs_init(void)
+{
+	unsigned int i;
+	u64 cap;
+
+	rdmsrl(MSR_IA32_MCG_CAP, cap);
+	n_banks = cap & MCG_BANKCNT_MASK;
+
+	dfs_inj = debugfs_create_dir("mce-inject", NULL);
+	if (!dfs_inj)
+		return -EINVAL;
+
+	for (i = 0; i < ARRAY_SIZE(dfs_fls); i++) {
+		dfs_fls[i].d = debugfs_create_file(dfs_fls[i].name,
+						    dfs_fls[i].perm,
+						    dfs_inj,
+						    &i_mce,
+						    dfs_fls[i].fops);
+
+		if (!dfs_fls[i].d)
+			goto err_dfs_add;
+	}
+
+	return 0;
+
+err_dfs_add:
+	while (i-- > 0)
+		debugfs_remove(dfs_fls[i].d);
+
+	debugfs_remove(dfs_inj);
+	dfs_inj = NULL;
+
+	return -ENODEV;
+}
+
+static int __init inject_init(void)
+{
+	int err;
+
 	if (!alloc_cpumask_var(&mce_inject_cpumask, GFP_KERNEL))
 		return -ENOMEM;
+
+#ifdef CONFIG_X86_MCELOG_LEGACY
+		register_mce_write_callback(mce_write);
+#endif
+
+	register_nmi_handler(NMI_LOCAL, mce_raise_notify, 0, "mce_notify");
+
+	err = debugfs_init();
+	if (err) {
+		free_cpumask_var(mce_inject_cpumask);
+		return err;
+	}
+
 	pr_info("Machine check injector initialized\n");
-	register_mce_write_callback(mce_write);
-	register_nmi_handler(NMI_LOCAL, mce_raise_notify, 0,
-				"mce_notify");
+
 	return 0;
 }
 
 module_init(inject_init);
+
 /*
  * Cannot tolerate unloading currently because we cannot
  * guarantee all openers of mce_chrdev will get a reference to us.
  */
+#ifndef CONFIG_X86_MCELOG_LEGACY
+static void __exit inject_exit(void)
+{
+
+	debugfs_remove_recursive(dfs_inj);
+	dfs_inj = NULL;
+
+	memset(&dfs_fls, 0, sizeof(dfs_fls));
+
+	unregister_nmi_handler(NMI_LOCAL, "mce_notify");
+
+	free_cpumask_var(mce_inject_cpumask);
+}
+
+module_exit(inject_exit);
+#endif
+
 MODULE_LICENSE("GPL");