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Date: Thu, 10 May 2012 16:30:22 +0200
From: Borislav Petkov <bp@...64.org>
To: LKML <linux-kernel@...r.kernel.org>
Cc: X86-ML <x86@...nel.org>, EDAC devel <linux-edac@...r.kernel.org>,
Borislav Petkov <borislav.petkov@....com>
Subject: [PATCH 2/9] x86, MCE, AMD: Remove shared banks sysfs linking
From: Borislav Petkov <borislav.petkov@....com>
The code used to create a symlink on all non-BSP cores of a node when
the MCi_MISCj bank is present once per node. (This is generally the
case with bank 4 on AMD). However, these sysfs links cause a bunch
of problems with cpu off-/onlining testing and are, as such, a bit
overengineered. IOW, there's nothing wrong with having normal sysfs
files for the shared banks since the corresponding MSRs are replicated
across each core anyway.
Signed-off-by: Borislav Petkov <borislav.petkov@....com>
---
arch/x86/kernel/cpu/mcheck/mce_amd.c | 105 +++-------------------------------
1 file changed, 7 insertions(+), 98 deletions(-)
diff --git a/arch/x86/kernel/cpu/mcheck/mce_amd.c b/arch/x86/kernel/cpu/mcheck/mce_amd.c
index f4873a64f46d..2a5dd30f9969 100644
--- a/arch/x86/kernel/cpu/mcheck/mce_amd.c
+++ b/arch/x86/kernel/cpu/mcheck/mce_amd.c
@@ -60,7 +60,6 @@ struct threshold_block {
struct threshold_bank {
struct kobject *kobj;
struct threshold_block *blocks;
- cpumask_var_t cpus;
};
static DEFINE_PER_CPU(struct threshold_bank * [NR_BANKS], threshold_banks);
@@ -224,8 +223,6 @@ void mce_amd_feature_init(struct cpuinfo_x86 *c)
if (!block)
per_cpu(bank_map, cpu) |= (1 << bank);
- if (shared_bank[bank] && c->cpu_core_id)
- break;
memset(&b, 0, sizeof(b));
b.cpu = cpu;
@@ -555,89 +552,35 @@ local_allocate_threshold_blocks(int cpu, unsigned int bank)
MSR_IA32_MC0_MISC + bank * 4);
}
-/* symlinks sibling shared banks to first core. first core owns dir/files. */
static __cpuinit int threshold_create_bank(unsigned int cpu, unsigned int bank)
{
- int i, err = 0;
- struct threshold_bank *b = NULL;
struct device *dev = per_cpu(mce_device, cpu);
+ struct threshold_bank *b = NULL;
char name[32];
+ int err = 0;
sprintf(name, "threshold_bank%i", bank);
-#ifdef CONFIG_SMP
- if (cpu_data(cpu).cpu_core_id && shared_bank[bank]) { /* symlink */
- i = cpumask_first(cpu_llc_shared_mask(cpu));
-
- /* first core not up yet */
- if (cpu_data(i).cpu_core_id)
- goto out;
-
- /* already linked */
- if (per_cpu(threshold_banks, cpu)[bank])
- goto out;
-
- b = per_cpu(threshold_banks, i)[bank];
-
- if (!b)
- goto out;
-
- err = sysfs_create_link(&dev->kobj, b->kobj, name);
- if (err)
- goto out;
-
- cpumask_copy(b->cpus, cpu_llc_shared_mask(cpu));
- per_cpu(threshold_banks, cpu)[bank] = b;
-
- goto out;
- }
-#endif
-
b = kzalloc(sizeof(struct threshold_bank), GFP_KERNEL);
if (!b) {
err = -ENOMEM;
goto out;
}
- if (!zalloc_cpumask_var(&b->cpus, GFP_KERNEL)) {
- kfree(b);
- err = -ENOMEM;
- goto out;
- }
b->kobj = kobject_create_and_add(name, &dev->kobj);
- if (!b->kobj)
+ if (!b->kobj) {
+ err = -EINVAL;
goto out_free;
-
-#ifndef CONFIG_SMP
- cpumask_setall(b->cpus);
-#else
- cpumask_set_cpu(cpu, b->cpus);
-#endif
+ }
per_cpu(threshold_banks, cpu)[bank] = b;
err = local_allocate_threshold_blocks(cpu, bank);
- if (err)
- goto out_free;
-
- for_each_cpu(i, b->cpus) {
- if (i == cpu)
- continue;
-
- dev = per_cpu(mce_device, i);
- if (dev)
- err = sysfs_create_link(&dev->kobj,b->kobj, name);
- if (err)
- goto out;
-
- per_cpu(threshold_banks, i)[bank] = b;
- }
-
- goto out;
+ if (!err)
+ goto out;
out_free:
per_cpu(threshold_banks, cpu)[bank] = NULL;
- free_cpumask_var(b->cpus);
kfree(b);
out:
return err;
@@ -660,12 +603,6 @@ static __cpuinit int threshold_create_device(unsigned int cpu)
return err;
}
-/*
- * let's be hotplug friendly.
- * in case of multiple core processors, the first core always takes ownership
- * of shared sysfs dir/files, and rest of the cores will be symlinked to it.
- */
-
static void deallocate_threshold_block(unsigned int cpu,
unsigned int bank)
{
@@ -689,9 +626,6 @@ static void deallocate_threshold_block(unsigned int cpu,
static void threshold_remove_bank(unsigned int cpu, int bank)
{
struct threshold_bank *b;
- struct device *dev;
- char name[32];
- int i = 0;
b = per_cpu(threshold_banks, cpu)[bank];
if (!b)
@@ -699,36 +633,11 @@ static void threshold_remove_bank(unsigned int cpu, int bank)
if (!b->blocks)
goto free_out;
- sprintf(name, "threshold_bank%i", bank);
-
-#ifdef CONFIG_SMP
- /* sibling symlink */
- if (shared_bank[bank] && b->blocks->cpu != cpu) {
- dev = per_cpu(mce_device, cpu);
- sysfs_remove_link(&dev->kobj, name);
- per_cpu(threshold_banks, cpu)[bank] = NULL;
-
- return;
- }
-#endif
-
- /* remove all sibling symlinks before unregistering */
- for_each_cpu(i, b->cpus) {
- if (i == cpu)
- continue;
-
- dev = per_cpu(mce_device, i);
- if (dev)
- sysfs_remove_link(&dev->kobj, name);
- per_cpu(threshold_banks, i)[bank] = NULL;
- }
-
deallocate_threshold_block(cpu, bank);
free_out:
kobject_del(b->kobj);
kobject_put(b->kobj);
- free_cpumask_var(b->cpus);
kfree(b);
per_cpu(threshold_banks, cpu)[bank] = NULL;
}
--
1.7.9.3.362.g71319
--
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