2 files changed, 14 insertions, 22 deletions

diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index e558ca77cfe8..c3498732ba28 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -1481,13 +1481,12 @@ EXPORT_SYMBOL_GPL(mce_notify_irq);
 static int __mcheck_cpu_mce_banks_init(void)
 {
         int i;
-        u8 num_banks = mca_cfg.banks;
 
-        mce_banks = kcalloc(num_banks, sizeof(struct mce_bank), GFP_KERNEL);
+        mce_banks = kcalloc(MAX_NR_BANKS, sizeof(struct mce_bank), GFP_KERNEL);
         if (!mce_banks)
                 return -ENOMEM;
 
-        for (i = 0; i < num_banks; i++) {
+        for (i = 0; i < MAX_NR_BANKS; i++) {
                 struct mce_bank *b = &mce_banks[i];
 
                 b->ctl = -1ULL;
@@ -1501,28 +1500,19 @@ static int __mcheck_cpu_mce_banks_init(void)
  */
 static int __mcheck_cpu_cap_init(void)
 {
-        unsigned b;
         u64 cap;
+        u8 b;
 
         rdmsrl(MSR_IA32_MCG_CAP, cap);
 
         b = cap & MCG_BANKCNT_MASK;
-        if (!mca_cfg.banks)
-                pr_info("CPU supports %d MCE banks\n", b);
-
-        if (b > MAX_NR_BANKS) {
-                pr_warn("Using only %u machine check banks out of %u\n",
-                        MAX_NR_BANKS, b);
+        if (WARN_ON_ONCE(b > MAX_NR_BANKS))
                 b = MAX_NR_BANKS;
-        }
 
-        /* Don't support asymmetric configurations today */
-        WARN_ON(mca_cfg.banks != 0 && b != mca_cfg.banks);
-        mca_cfg.banks = b;
+        mca_cfg.banks = max(mca_cfg.banks, b);
 
         if (!mce_banks) {
                 int err = __mcheck_cpu_mce_banks_init();
-
                 if (err)
                         return err;
         }
@@ -2481,6 +2471,8 @@ EXPORT_SYMBOL_GPL(mcsafe_key);
 
 static int __init mcheck_late_init(void)
 {
+        pr_info("Using %d MCE banks\n", mca_cfg.banks);
+
         if (mca_cfg.recovery)
                 static_branch_inc(&mcsafe_key);
 
diff --git a/arch/x86/kernel/cpu/mce/inject.c b/arch/x86/kernel/cpu/mce/inject.c
index 8492ef7d9015..3f82afd0f46f 100644
--- a/arch/x86/kernel/cpu/mce/inject.c
+++ b/arch/x86/kernel/cpu/mce/inject.c
@@ -46,8 +46,6 @@
 static struct mce i_mce;
 static struct dentry *dfs_inj;
 
-static u8 n_banks;
-
 #define MAX_FLAG_OPT_SIZE       4
 #define NBCFG                   0x44
 
@@ -570,9 +568,15 @@ err:
 static int inj_bank_set(void *data, u64 val)
 {
         struct mce *m = (struct mce *)data;
+        u8 n_banks;
+        u64 cap;
+
+        /* Get bank count on target CPU so we can handle non-uniform values. */
+        rdmsrl_on_cpu(m->extcpu, MSR_IA32_MCG_CAP, &cap);
+        n_banks = cap & MCG_BANKCNT_MASK;
 
         if (val >= n_banks) {
-                pr_err("Non-existent MCE bank: %llu\n", val);
+                pr_err("MCA bank %llu non-existent on CPU%d\n", val, m->extcpu);
                 return -EINVAL;
         }
 
@@ -665,10 +669,6 @@ static struct dfs_node {
 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)