microcode: use suspend-related CPU hotplug notifications

Make the microcode driver use the suspend-related CPU hotplug notifications
to handle the CPU hotplug events occuring during system-wide suspend and
resume transitions.  Remove the global variable suspend_cpu_hotplug
previously used for this purpose.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Gautham R Shenoy <ego@in.ibm.com>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/arch/i386/kernel/microcode.c b/arch/i386/kernel/microcode.c
index 7d934e4..83f825f 100644 (file)
--- a/arch/i386/kernel/microcode.c
+++ b/arch/i386/kernel/microcode.c
@@ -567,7 +567,7 @@ static int cpu_request_microcode(int cpu)
        return error;
 }
 
-static int apply_microcode_on_cpu(int cpu)
+static int apply_microcode_check_cpu(int cpu)
 {
        struct cpuinfo_x86 *c = cpu_data + cpu;
        struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
@@ -575,8 +575,9 @@ static int apply_microcode_on_cpu(int cpu)
        unsigned int val[2];
        int err = 0;
 
+       /* Check if the microcode is available */
        if (!uci->mc)
-               return -EINVAL;
+               return 0;
 
        old = current->cpus_allowed;
        set_cpus_allowed(current, cpumask_of_cpu(cpu));
@@ -614,7 +615,7 @@ static int apply_microcode_on_cpu(int cpu)
        return err;
 }
 
-static void microcode_init_cpu(int cpu)
+static void microcode_init_cpu(int cpu, int resume)
 {
        cpumask_t old;
        struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
@@ -624,8 +625,7 @@ static void microcode_init_cpu(int cpu)
        set_cpus_allowed(current, cpumask_of_cpu(cpu));
        mutex_lock(&microcode_mutex);
        collect_cpu_info(cpu);
-       if (uci->valid && system_state == SYSTEM_RUNNING &&
-           !suspend_cpu_hotplug)
+       if (uci->valid && system_state == SYSTEM_RUNNING && !resume)
                cpu_request_microcode(cpu);
        mutex_unlock(&microcode_mutex);
        set_cpus_allowed(current, old);
@@ -702,7 +702,7 @@ static struct attribute_group mc_attr_group = {
        .name = "microcode",
 };
 
-static int mc_sysdev_add(struct sys_device *sys_dev)
+static int __mc_sysdev_add(struct sys_device *sys_dev, int resume)
 {
        int err, cpu = sys_dev->id;
        struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
@@ -711,39 +711,31 @@ static int mc_sysdev_add(struct sys_device *sys_dev)
                return 0;
 
        pr_debug("Microcode:CPU %d added\n", cpu);
-       /* If suspend_cpu_hotplug is set, the system is resuming and we should
-        * use the data from before the suspend.
-        */
-       if (suspend_cpu_hotplug) {
-               err = apply_microcode_on_cpu(cpu);
-               if (err)
-                       microcode_fini_cpu(cpu);
-       }
-       if (!uci->valid)
-               memset(uci, 0, sizeof(*uci));
+       memset(uci, 0, sizeof(*uci));
 
        err = sysfs_create_group(&sys_dev->kobj, &mc_attr_group);
        if (err)
                return err;
 
-       if (!uci->valid)
-               microcode_init_cpu(cpu);
+       microcode_init_cpu(cpu, resume);
 
        return 0;
 }
 
+static int mc_sysdev_add(struct sys_device *sys_dev)
+{
+       return __mc_sysdev_add(sys_dev, 0);
+}
+
 static int mc_sysdev_remove(struct sys_device *sys_dev)
 {
        int cpu = sys_dev->id;
 
        if (!cpu_online(cpu))
                return 0;
+
        pr_debug("Microcode:CPU %d removed\n", cpu);
-       /* If suspend_cpu_hotplug is set, the system is suspending and we should
-        * keep the microcode in memory for the resume.
-        */
-       if (!suspend_cpu_hotplug)
-               microcode_fini_cpu(cpu);
+       microcode_fini_cpu(cpu);
        sysfs_remove_group(&sys_dev->kobj, &mc_attr_group);
        return 0;
 }
@@ -774,16 +766,34 @@ mc_cpu_callback(struct notifier_block *nb, unsigned long action, void *hcpu)
 
        sys_dev = get_cpu_sysdev(cpu);
        switch (action) {
+       case CPU_UP_CANCELED_FROZEN:
+               /* The CPU refused to come up during a system resume */
+               microcode_fini_cpu(cpu);
+               break;
        case CPU_ONLINE:
-       case CPU_ONLINE_FROZEN:
        case CPU_DOWN_FAILED:
-       case CPU_DOWN_FAILED_FROZEN:
                mc_sysdev_add(sys_dev);
                break;
+       case CPU_ONLINE_FROZEN:
+               /* System-wide resume is in progress, try to apply microcode */
+               if (apply_microcode_check_cpu(cpu)) {
+                       /* The application of microcode failed */
+                       microcode_fini_cpu(cpu);
+                       __mc_sysdev_add(sys_dev, 1);
+                       break;
+               }
+       case CPU_DOWN_FAILED_FROZEN:
+               if (sysfs_create_group(&sys_dev->kobj, &mc_attr_group))
+                       printk(KERN_ERR "Microcode: Failed to create the sysfs "
+                               "group for CPU%d\n", cpu);
+               break;
        case CPU_DOWN_PREPARE:
-       case CPU_DOWN_PREPARE_FROZEN:
                mc_sysdev_remove(sys_dev);
                break;
+       case CPU_DOWN_PREPARE_FROZEN:
+               /* Suspend is in progress, only remove the interface */
+               sysfs_remove_group(&sys_dev->kobj, &mc_attr_group);
+               break;
        }
        return NOTIFY_OK;
 }

diff --git a/kernel/cpu.c b/kernel/cpu.c
index 369d289..208cf34 100644 (file)
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -262,12 +262,6 @@ int __cpuinit cpu_up(unsigned int cpu)
 }
 
 #ifdef CONFIG_SUSPEND_SMP
-/* Needed to prevent the microcode driver from requesting firmware in its CPU
- * hotplug notifier during the suspend/resume.
- */
-int suspend_cpu_hotplug;
-EXPORT_SYMBOL(suspend_cpu_hotplug);
-
 static cpumask_t frozen_cpus;
 
 int disable_nonboot_cpus(void)
@@ -275,7 +269,6 @@ int disable_nonboot_cpus(void)
        int cpu, first_cpu, error = 0;
 
        mutex_lock(&cpu_add_remove_lock);
-       suspend_cpu_hotplug = 1;
        first_cpu = first_cpu(cpu_online_map);
        /* We take down all of the non-boot CPUs in one shot to avoid races
         * with the userspace trying to use the CPU hotplug at the same time
@@ -302,7 +295,6 @@ int disable_nonboot_cpus(void)
        } else {
                printk(KERN_ERR "Non-boot CPUs are not disabled\n");
        }
-       suspend_cpu_hotplug = 0;
        mutex_unlock(&cpu_add_remove_lock);
        return error;
 }
@@ -317,7 +309,6 @@ void enable_nonboot_cpus(void)
        if (cpus_empty(frozen_cpus))
                goto out;
 
-       suspend_cpu_hotplug = 1;
        printk("Enabling non-boot CPUs ...\n");
        for_each_cpu_mask(cpu, frozen_cpus) {
                error = _cpu_up(cpu, 1);
@@ -328,7 +319,6 @@ void enable_nonboot_cpus(void)
                printk(KERN_WARNING "Error taking CPU%d up: %d\n", cpu, error);
        }
        cpus_clear(frozen_cpus);
-       suspend_cpu_hotplug = 0;
 out:
        mutex_unlock(&cpu_add_remove_lock);
 }