x86, microcode: Make reload interface per system

The reload interface should be per-system so that a full system ucode
reload happens (on each core) when doing

echo 1 > /sys/devices/system/cpu/microcode/reload

Move it to the cpu subsys directory instead of it being per-cpu.

Cc: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Link: http://lkml.kernel.org/r/1340280437-7718-3-git-send-email-bp@amd64.org
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

diff --git a/arch/x86/kernel/microcode_core.c b/arch/x86/kernel/microcode_core.c
index 24b852b..947e4c6 100644 (file)
--- a/arch/x86/kernel/microcode_core.c
+++ b/arch/x86/kernel/microcode_core.c
@@ -301,10 +301,6 @@ static ssize_t reload_store(struct device *dev,
        int cpu;
        ssize_t ret = 0, tmp_ret;
 
-       /* allow reload only from the BSP */
-       if (boot_cpu_data.cpu_index != dev->id)
-               return -EINVAL;
-
        ret = kstrtoul(buf, 0, &val);
        if (ret)
                return ret;
@@ -351,7 +347,6 @@ static DEVICE_ATTR(version, 0400, version_show, NULL);
 static DEVICE_ATTR(processor_flags, 0400, pf_show, NULL);
 
 static struct attribute *mc_default_attrs[] = {
-       &dev_attr_reload.attr,
        &dev_attr_version.attr,
        &dev_attr_processor_flags.attr,
        NULL
@@ -528,6 +523,16 @@ static const struct x86_cpu_id microcode_id[] = {
 MODULE_DEVICE_TABLE(x86cpu, microcode_id);
 #endif
 
+static struct attribute *cpu_root_microcode_attrs[] = {
+       &dev_attr_reload.attr,
+       NULL
+};
+
+static struct attribute_group cpu_root_microcode_group = {
+       .name  = "microcode",
+       .attrs = cpu_root_microcode_attrs,
+};
+
 static int __init microcode_init(void)
 {
        struct cpuinfo_x86 *c = &cpu_data(0);
@@ -559,9 +564,17 @@ static int __init microcode_init(void)
        if (error)
                goto out_pdev;
 
+       error = sysfs_create_group(&cpu_subsys.dev_root->kobj,
+                                  &cpu_root_microcode_group);
+
+       if (error) {
+               pr_err("Error creating microcode group!\n");
+               goto out_driver;
+       }
+
        error = microcode_dev_init();
        if (error)
-               goto out_driver;
+               goto out_ucode_group;
 
        register_syscore_ops(&mc_syscore_ops);
        register_hotcpu_notifier(&mc_cpu_notifier);
@@ -571,7 +584,11 @@ static int __init microcode_init(void)
 
        return 0;
 
-out_driver:
+ out_ucode_group:
+       sysfs_remove_group(&cpu_subsys.dev_root->kobj,
+                          &cpu_root_microcode_group);
+
+ out_driver:
        get_online_cpus();
        mutex_lock(&microcode_mutex);
 
@@ -580,7 +597,7 @@ out_driver:
        mutex_unlock(&microcode_mutex);
        put_online_cpus();
 
-out_pdev:
+ out_pdev:
        platform_device_unregister(microcode_pdev);
        return error;
 
@@ -596,6 +613,9 @@ static void __exit microcode_exit(void)
        unregister_hotcpu_notifier(&mc_cpu_notifier);
        unregister_syscore_ops(&mc_syscore_ops);
 
+       sysfs_remove_group(&cpu_subsys.dev_root->kobj,
+                          &cpu_root_microcode_group);
+
        get_online_cpus();
        mutex_lock(&microcode_mutex);