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Date: Thu, 3 Nov 2016 15:50:18 +0100
From: Sebastian Andrzej Siewior <bigeasy@...utronix.de>
To: linux-kernel@...r.kernel.org
Cc: rt@...utronix.de,
Sebastian Andrzej Siewior <bigeasy@...utronix.de>,
Tony Luck <tony.luck@...el.com>,
Borislav Petkov <bp@...en8.de>, linux-edac@...r.kernel.org,
x86@...nel.org, Thomas Gleixner <tglx@...utronix.de>
Subject: [PATCH 22/25] x86/mcheck: Do the init in one place
Part of the init (memory allocation and so on) is done
in mcheck_cpu_init(). While moving the the allocation to
mcheck_init_device() (where the hotplug calls are initialized) it
becomes necessary to move the callback (mcheck_cpu_init()), too.
The callback is now removed from identify_cpu() and registered as a
hotplug event which is invoked as the very first one which is shortly
after the original point of invocation (look at smp_store_cpu_info() and
notify_cpu_starting() in smp_callin()).
One "visible" difference is that MCE for the boot CPU is not enabled at
identify_boot_cpu() time but at device_initcall_sync() time. Either way,
both times we had no userland around.
Cc: Tony Luck <tony.luck@...el.com>
Cc: Borislav Petkov <bp@...en8.de>
Cc: linux-edac@...r.kernel.org
Cc: x86@...nel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@...utronix.de>
Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
---
arch/x86/include/asm/mce.h | 2 --
arch/x86/kernel/cpu/common.c | 4 ---
arch/x86/kernel/cpu/mcheck/mce.c | 77 ++++++++++++++++++++++++----------------
include/linux/cpuhotplug.h | 1 +
4 files changed, 48 insertions(+), 36 deletions(-)
diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h
index 978be74a12c1..ba8108166aec 100644
--- a/arch/x86/include/asm/mce.h
+++ b/arch/x86/include/asm/mce.h
@@ -203,12 +203,10 @@ extern int mce_p5_enabled;
#ifdef CONFIG_X86_MCE
int mcheck_init(void);
-void mcheck_cpu_init(struct cpuinfo_x86 *c);
void mcheck_cpu_clear(struct cpuinfo_x86 *c);
void mcheck_vendor_init_severity(void);
#else
static inline int mcheck_init(void) { return 0; }
-static inline void mcheck_cpu_init(struct cpuinfo_x86 *c) {}
static inline void mcheck_cpu_clear(struct cpuinfo_x86 *c) {}
static inline void mcheck_vendor_init_severity(void) {}
#endif
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 9bd910a7dd0a..283b1fa64e69 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -39,7 +39,6 @@
#include <asm/asm.h>
#include <asm/bugs.h>
#include <asm/cpu.h>
-#include <asm/mce.h>
#include <asm/msr.h>
#include <asm/pat.h>
#include <asm/microcode.h>
@@ -1095,9 +1094,6 @@ static void identify_cpu(struct cpuinfo_x86 *c)
c->x86_capability[i] |= boot_cpu_data.x86_capability[i];
}
- /* Init Machine Check Exception if available. */
- mcheck_cpu_init(c);
-
select_idle_routine(c);
#ifdef CONFIG_NUMA
diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index 79b5ad9570ca..72af9db8526d 100644
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -1436,11 +1436,24 @@ EXPORT_SYMBOL_GPL(mce_notify_irq);
static int __mcheck_cpu_mce_banks_init(void)
{
int i;
- u8 num_banks = mca_cfg.banks;
+ u64 cap;
+ unsigned int num_banks;
+
+ rdmsrl(MSR_IA32_MCG_CAP, cap);
+
+ num_banks = cap & MCG_BANKCNT_MASK;
+ pr_info("CPU supports %d MCE banks\n", num_banks);
+
+ if (num_banks > MAX_NR_BANKS) {
+ pr_warn("Using only %u machine check banks out of %u\n",
+ MAX_NR_BANKS, num_banks);
+ num_banks = MAX_NR_BANKS;
+ }
mce_banks = kzalloc(num_banks * sizeof(struct mce_bank), GFP_KERNEL);
if (!mce_banks)
return -ENOMEM;
+ mca_cfg.banks = num_banks;
for (i = 0; i < num_banks; i++) {
struct mce_bank *b = &mce_banks[i];
@@ -1462,25 +1475,11 @@ static int __mcheck_cpu_cap_init(void)
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 (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;
-
- if (!mce_banks) {
- int err = __mcheck_cpu_mce_banks_init();
-
- if (err)
- return err;
- }
+ WARN_ON(b != mca_cfg.banks);
/* Use accurate RIP reporting if available. */
if ((cap & MCG_EXT_P) && MCG_EXT_CNT(cap) >= 9)
@@ -1769,26 +1768,22 @@ void (*machine_check_vector)(struct pt_regs *, long error_code) =
* Called for each booted CPU to set up machine checks.
* Must be called with preempt off:
*/
-void mcheck_cpu_init(struct cpuinfo_x86 *c)
+static int mcheck_cpu_starting(unsigned int cpu)
{
+ struct cpuinfo_x86 *c = &cpu_data(cpu);
+
if (mca_cfg.disabled)
- return;
+ return 0;
if (__mcheck_cpu_ancient_init(c))
- return;
+ return 0;
if (!mce_available(c))
- return;
+ return 0;
if (__mcheck_cpu_cap_init() < 0 || __mcheck_cpu_apply_quirks(c) < 0) {
mca_cfg.disabled = true;
- return;
- }
-
- if (mce_gen_pool_init()) {
- mca_cfg.disabled = true;
- pr_emerg("Couldn't allocate MCE records pool!\n");
- return;
+ return 0;
}
machine_check_vector = do_machine_check;
@@ -1797,6 +1792,7 @@ void mcheck_cpu_init(struct cpuinfo_x86 *c)
__mcheck_cpu_init_vendor(c);
__mcheck_cpu_init_clear_banks();
__mcheck_cpu_init_timer();
+ return 0;
}
/*
@@ -2584,11 +2580,26 @@ static __init int mcheck_init_device(void)
goto err_out;
}
+ err = __mcheck_cpu_mce_banks_init();
+ if (err)
+ goto err_out_mem;
+
mce_init_banks();
+ err = mce_gen_pool_init();
+ if (err) {
+ pr_emerg("Couldn't allocate MCE records pool!\n");
+ goto err_init_pool;
+ }
+
err = subsys_system_register(&mce_subsys, NULL);
if (err)
- goto err_out_mem;
+ goto err_init_pool;
+
+ err = cpuhp_setup_state(CPUHP_AP_X86_MCE_STARTING, "x86/mce:starting",
+ mcheck_cpu_starting, NULL);
+ if (err)
+ goto err_init_pool;
cpu_notifier_register_begin();
for_each_online_cpu(i) {
@@ -2630,12 +2641,18 @@ static __init int mcheck_init_device(void)
for_each_possible_cpu(i)
mce_device_remove(i);
+ cpuhp_remove_state(CPUHP_AP_X86_MCE_STARTING);
+
+err_init_pool:
+ mca_cfg.banks = 0;
+ kfree(mce_banks);
+ mce_banks = NULL;
+
err_out_mem:
free_cpumask_var(mce_device_initialized);
err_out:
pr_err("Unable to init device /dev/mcelog (rc: %d)\n", err);
-
return err;
}
device_initcall_sync(mcheck_init_device);
diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index 3410d83cc2e2..4fe2ba418471 100644
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -64,6 +64,7 @@ enum cpuhp_state {
CPUHP_BRINGUP_CPU,
CPUHP_AP_IDLE_DEAD,
CPUHP_AP_OFFLINE,
+ CPUHP_AP_X86_MCE_STARTING,
CPUHP_AP_SCHED_STARTING,
CPUHP_AP_RCUTREE_DYING,
CPUHP_AP_IRQ_GIC_STARTING,
--
2.10.2
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