From: Dmitry Adamushko <[email protected]>
(1) Introduce microcode_update_cpu() which is a generic routine to do ucode-updates (for both bootup-path
and system-resume-path);
(2) Adapt the logic of cpu-hotplug handlers;
(3) Fix a race with sched_setaffinity() in reload_store()
We introduce another mechanism to run ucode-updates on a target cpu
to replace set_cpus_allowed_ptr() being called from cpu-hotplug events
(which causes a bug#11197: http://www.ussg.iu.edu/hypermail/linux/kernel/0807.3/3791.html)
microcode_update_cpu() can be run either from start_secondary()
(perhaps via a function pointer) or scheduled via keventd (implemented by the following patch).
all in all, we remove more lines than we add (84/79)
(Almost)-Signed-off-by: Dmitry Adamushko <[email protected]>
---
--- a/arch/x86/kernel/microcode.c
+++ b/arch/x86/kernel/microcode.c
@@ -126,16 +126,16 @@ static DEFINE_MUTEX(microcode_mutex);
static struct ucode_cpu_info {
int valid;
+ int resume;
unsigned int sig;
unsigned int pf;
unsigned int rev;
microcode_t *mc;
} ucode_cpu_info[NR_CPUS];
-static void collect_cpu_info(int cpu_num)
+static void collect_cpu_info(int cpu_num, struct ucode_cpu_info *uci)
{
struct cpuinfo_x86 *c = &cpu_data(cpu_num);
- struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
unsigned int val[2];
/* We should bind the task to the CPU */
@@ -569,79 +569,85 @@ static int cpu_request_microcode(int cpu)
return error;
}
-static int apply_microcode_check_cpu(int cpu)
+static void microcode_fini_cpu(int cpu)
{
- struct cpuinfo_x86 *c = &cpu_data(cpu);
struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
- cpumask_t old;
- unsigned int val[2];
- int err = 0;
- /* Check if the microcode is available */
- if (!uci->mc)
- return 0;
+ mutex_lock(µcode_mutex);
+ uci->valid = 0;
+ uci->resume = 0;
+ vfree(uci->mc);
+ uci->mc = NULL;
+ mutex_unlock(µcode_mutex);
+}
- old = current->cpus_allowed;
- set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu));
+static void microcode_set_cpu_frozen(int cpu)
+{
+ struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
- /* Check if the microcode we have in memory matches the CPU */
- if (c->x86_vendor != X86_VENDOR_INTEL || c->x86 < 6 ||
- cpu_has(c, X86_FEATURE_IA64) || uci->sig != cpuid_eax(0x00000001))
- err = -EINVAL;
+ mutex_lock(µcode_mutex);
+ if (uci->valid)
+ uci->resume = 1;
+ mutex_unlock(µcode_mutex);
+}
- if (!err && ((c->x86_model >= 5) || (c->x86 > 6))) {
- /* get processor flags from MSR 0x17 */
- rdmsr(MSR_IA32_PLATFORM_ID, val[0], val[1]);
- if (uci->pf != (1 << ((val[1] >> 18) & 7)))
- err = -EINVAL;
- }
+static int microcode_resume_cpu(int cpu, struct ucode_cpu_info *new_uci)
+{
+ struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
- if (!err) {
- wrmsr(MSR_IA32_UCODE_REV, 0, 0);
- /* see notes above for revision 1.07. Apparent chip bug */
- sync_core();
- /* get the current revision from MSR 0x8B */
- rdmsr(MSR_IA32_UCODE_REV, val[0], val[1]);
- if (uci->rev != val[1])
- err = -EINVAL;
- }
+ if (!uci->resume)
+ return 0;
+
+ uci->resume = 0;
- if (!err)
+ /* Check if the 'cached' microcode is ok: */
+ if (!uci->mc)
+ return 1;
+
+ if (new_uci->sig == uci->sig &&
+ new_uci->pf == uci->pf &&
+ new_uci->rev == uci->rev) {
apply_microcode(cpu);
- else
- printk(KERN_ERR "microcode: Could not apply microcode to CPU%d:"
- " sig=0x%x, pf=0x%x, rev=0x%x\n",
- cpu, uci->sig, uci->pf, uci->rev);
+ } else {
+ microcode_fini_cpu(cpu);
+ *uci = *new_uci;
+ }
- set_cpus_allowed_ptr(current, &old);
- return err;
+ return 1;
}
-static void microcode_init_cpu(int cpu, int resume)
+void microcode_update_cpu(int cpu)
{
- cpumask_t old;
- struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
+ struct ucode_cpu_info *uci = ucode_cpu_info + cpu,
+ new_uci;
- old = current->cpus_allowed;
+ memset(&new_uci, 0, sizeof(new_uci));
- set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu));
mutex_lock(µcode_mutex);
- collect_cpu_info(cpu);
- if (uci->valid && system_state == SYSTEM_RUNNING && !resume)
- cpu_request_microcode(cpu);
+ collect_cpu_info(cpu, &new_uci);
+
+ if (new_uci.valid) {
+ /*
+ * Check if the system resume is in progress,
+ * otherwise just request a firmware:
+ */
+ if (!microcode_resume_cpu(cpu, &new_uci)) {
+ *uci = new_uci;
+
+ if (system_state == SYSTEM_RUNNING)
+ cpu_request_microcode(cpu);
+ }
+ }
mutex_unlock(µcode_mutex);
- set_cpus_allowed_ptr(current, &old);
}
-static void microcode_fini_cpu(int cpu)
+static void microcode_init_cpu(int cpu)
{
- struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
+ cpumask_t old = current->cpus_allowed;
- mutex_lock(µcode_mutex);
- uci->valid = 0;
- vfree(uci->mc);
- uci->mc = NULL;
- mutex_unlock(µcode_mutex);
+ set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu));
+ microcode_update_cpu(cpu);
+ set_cpus_allowed_ptr(current, &old);
}
static ssize_t reload_store(struct sys_device *dev,
@@ -660,14 +666,15 @@ static ssize_t reload_store(struct sys_device *dev,
cpumask_t old = current->cpus_allowed;
get_online_cpus();
- set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu));
-
- mutex_lock(µcode_mutex);
- if (uci->valid)
- err = cpu_request_microcode(cpu);
- mutex_unlock(µcode_mutex);
+ if (cpu_online(cpu)) {
+ set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu));
+ mutex_lock(µcode_mutex);
+ if (uci->valid)
+ err = cpu_request_microcode(cpu);
+ mutex_unlock(µcode_mutex);
+ set_cpus_allowed_ptr(current, &old);
+ }
put_online_cpus();
- set_cpus_allowed_ptr(current, &old);
}
if (err)
return err;
@@ -706,7 +713,7 @@ static struct attribute_group mc_attr_group = {
.name = "microcode",
};
-static int __mc_sysdev_add(struct sys_device *sys_dev, int resume)
+static int mc_sysdev_add(struct sys_device *sys_dev)
{
int err, cpu = sys_dev->id;
struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
@@ -721,16 +728,11 @@ static int __mc_sysdev_add(struct sys_device *sys_dev, int resume)
if (err)
return err;
- microcode_init_cpu(cpu, resume);
+ microcode_init_cpu(cpu);
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;
@@ -770,34 +772,27 @@ 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_DOWN_FAILED:
- 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:
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:
- 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;
+ case CPU_DEAD:
+ case CPU_UP_CANCELED_FROZEN:
+ /* The CPU refused to come up during a system resume */
+ microcode_fini_cpu(cpu);
+ break;
+ case CPU_DEAD_FROZEN:
+ microcode_set_cpu_frozen(cpu);
+ break;
}
return NOTIFY_OK;
}