From 92e26e2a1a7d5fe6538e4a676f9c383966f894a7 Mon Sep 17 00:00:00 2001 From: Borislav Petkov Date: Wed, 2 May 2012 16:20:49 +0200 Subject: [PATCH] x86, MCE, AMD: Remove shared banks sysfs linking 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 --- 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 f4873a64f46..2a5dd30f996 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; } -- 2.20.1