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x86, MCE, AMD: Remove shared banks sysfs linking

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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@amd.com>
This commit is contained in:
Borislav Petkov 2012-05-02 16:20:49 +02:00
parent 24214449b0
commit 92e26e2a1a
1 changed files with 7 additions and 98 deletions
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105
arch/x86/kernel/cpu/mcheck/mce_amd.c
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@ -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;
}