From: Dmitry Adamushko <[email protected]>
Run ucode-updates via workqueue (keventd) instead of using set_cpus_allowed_ptr()
in cpu-hotplug handlers.
The target 'cpu' is not yet 'active' when set_cpu_allowed_ptr() gets called from
mc_cpu_callback() (i.e. tasks can't be migrated onto it).
This caused a bug#11197: http://www.ussg.iu.edu/hypermail/linux/kernel/0807.3/3791.html)
(Almost)-Signed-off-by: Dmitry Adamushko <[email protected]>
---
commit 242f1830266d714f0b8a2796eb9b239e0eeca2e7
Author: dimm <dimm@earth.(none)>
Date: Sun Aug 3 16:58:30 2008 +0200
microcode: workqueue support
diff --git a/arch/x86/kernel/microcode.c b/arch/x86/kernel/microcode.c
index f9447ba..dab52ff 100644
--- a/arch/x86/kernel/microcode.c
+++ b/arch/x86/kernel/microcode.c
@@ -89,6 +89,7 @@
#include <linux/cpu.h>
#include <linux/firmware.h>
#include <linux/platform_device.h>
+#include <linux/workqueue.h>
#include <asm/msr.h>
#include <asm/uaccess.h>
@@ -124,14 +125,24 @@ static DEFINE_SPINLOCK(microcode_update_lock);
/* no concurrent ->write()s are allowed on /dev/cpu/microcode */
static DEFINE_MUTEX(microcode_mutex);
-static struct ucode_cpu_info {
+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 struct ucode_work_info {
+ struct ucode_cpu_info uci;
+ int resume;
+ struct work_struct work;
+} ucode_work_info[NR_CPUS];
+
+static inline struct ucode_cpu_info *get_ucode_cpu_info(int cpu)
+{
+ return &ucode_work_info[cpu].uci;
+}
static void collect_cpu_info(int cpu_num, struct ucode_cpu_info *uci)
{
@@ -172,7 +183,7 @@ static void collect_cpu_info(int cpu_num, struct ucode_cpu_info *uci)
static inline int microcode_update_match(int cpu_num,
microcode_header_t *mc_header, int sig, int pf)
{
- struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
+ struct ucode_cpu_info *uci = get_ucode_cpu_info(cpu_num);
if (!sigmatch(sig, uci->sig, pf, uci->pf)
|| mc_header->rev <= uci->rev)
@@ -266,7 +277,7 @@ static int microcode_sanity_check(void *mc)
*/
static int get_maching_microcode(void *mc, int cpu)
{
- struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
+ struct ucode_cpu_info *uci = get_ucode_cpu_info(cpu);
microcode_header_t *mc_header = mc;
struct extended_sigtable *ext_header;
unsigned long total_size = get_totalsize(mc_header);
@@ -313,7 +324,7 @@ static void apply_microcode(int cpu)
unsigned long flags;
unsigned int val[2];
int cpu_num = raw_smp_processor_id();
- struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
+ struct ucode_cpu_info *uci = get_ucode_cpu_info(cpu_num);
/* We should bind the task to the CPU */
BUG_ON(cpu_num != cpu);
@@ -400,7 +411,7 @@ static int do_microcode_update (void)
* lets keep searching till the latest version
*/
for_each_online_cpu(cpu) {
- struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
+ struct ucode_cpu_info *uci = get_ucode_cpu_info(cpu);
if (!uci->valid)
continue;
@@ -571,34 +582,39 @@ static int cpu_request_microcode(int cpu)
static void microcode_fini_cpu(int cpu)
{
- struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
+ struct ucode_work_info *wi = ucode_work_info + cpu;
mutex_lock(µcode_mutex);
- uci->valid = 0;
- uci->resume = 0;
- vfree(uci->mc);
- uci->mc = NULL;
+ wi->uci.valid = 0;
+ vfree(wi->uci.mc);
+ wi->uci.mc = NULL;
+ wi->resume = 0;
mutex_unlock(µcode_mutex);
}
static void microcode_set_cpu_frozen(int cpu)
{
- struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
+ struct ucode_work_info *wi = ucode_work_info + cpu;
+
+ pr_debug("microcode: CPU%d frozen\n", cpu);
mutex_lock(µcode_mutex);
- if (uci->valid)
- uci->resume = 1;
+ if (wi->uci.valid)
+ wi->resume = 1;
mutex_unlock(µcode_mutex);
}
static int microcode_resume_cpu(int cpu, struct ucode_cpu_info *new_uci)
{
- struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
+ struct ucode_work_info *wi = ucode_work_info + cpu;
+ struct ucode_cpu_info *uci = &wi->uci;
- if (!uci->resume)
+ if (!wi->resume)
return 0;
- uci->resume = 0;
+ pr_debug("microcode: CPU%d resumed (ucode: %p)\n", cpu, uci->mc);
+
+ wi->resume = 0;
/* Check if the 'cached' microcode is ok: */
if (!uci->mc)
@@ -616,10 +632,13 @@ static int microcode_resume_cpu(int cpu, struct ucode_cpu_info *new_uci)
return 1;
}
-void microcode_update_cpu(int cpu)
+static void microcode_update_cpu(struct work_struct *w)
{
- struct ucode_cpu_info *uci = ucode_cpu_info + cpu,
- new_uci;
+ struct ucode_work_info *wi = container_of(w, struct ucode_work_info, work);
+ int cpu = raw_smp_processor_id(); /* keventd is per-cpu */
+ struct ucode_cpu_info new_uci;
+
+ pr_debug("microcode: CPU%d workqueue\n", cpu);
memset(&new_uci, 0, sizeof(new_uci));
@@ -632,7 +651,7 @@ void microcode_update_cpu(int cpu)
* otherwise just request a firmware:
*/
if (!microcode_resume_cpu(cpu, &new_uci)) {
- *uci = new_uci;
+ wi->uci = new_uci;
if (system_state == SYSTEM_RUNNING)
cpu_request_microcode(cpu);
@@ -641,20 +660,11 @@ void microcode_update_cpu(int cpu)
mutex_unlock(µcode_mutex);
}
-static void microcode_init_cpu(int cpu)
-{
- cpumask_t old = current->cpus_allowed;
-
- 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,
struct sysdev_attribute *attr,
const char *buf, size_t sz)
{
- struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;
+ struct ucode_cpu_info *uci = get_ucode_cpu_info(dev->id);
char *end;
unsigned long val = simple_strtoul(buf, &end, 0);
int err = 0;
@@ -684,7 +694,7 @@ static ssize_t reload_store(struct sys_device *dev,
static ssize_t version_show(struct sys_device *dev,
struct sysdev_attribute *attr, char *buf)
{
- struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;
+ struct ucode_cpu_info *uci = get_ucode_cpu_info(dev->id);
return sprintf(buf, "0x%x\n", uci->rev);
}
@@ -692,7 +702,7 @@ static ssize_t version_show(struct sys_device *dev,
static ssize_t pf_show(struct sys_device *dev,
struct sysdev_attribute *attr, char *buf)
{
- struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;
+ struct ucode_cpu_info *uci = get_ucode_cpu_info(dev->id);
return sprintf(buf, "0x%x\n", uci->pf);
}
@@ -716,19 +726,19 @@ static struct attribute_group mc_attr_group = {
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;
+ struct ucode_work_info *wi = ucode_work_info + cpu;
if (!cpu_online(cpu))
return 0;
pr_debug("microcode: CPU%d added\n", cpu);
- memset(uci, 0, sizeof(*uci));
+ memset(&wi->uci, 0, sizeof(wi->uci));
err = sysfs_create_group(&sys_dev->kobj, &mc_attr_group);
if (err)
return err;
- microcode_init_cpu(cpu);
+ schedule_work_on(cpu, &wi->work);
return 0;
}
@@ -774,6 +784,7 @@ mc_cpu_callback(struct notifier_block *nb, unsigned long action, void *hcpu)
switch (action) {
case CPU_ONLINE:
case CPU_ONLINE_FROZEN:
+ schedule_work_on(cpu, &ucode_work_info[cpu].work);
case CPU_DOWN_FAILED:
case CPU_DOWN_FAILED_FROZEN:
if (sysfs_create_group(&sys_dev->kobj, &mc_attr_group))
@@ -784,6 +795,7 @@ mc_cpu_callback(struct notifier_block *nb, unsigned long action, void *hcpu)
case CPU_DOWN_PREPARE_FROZEN:
/* Suspend is in progress, only remove the interface */
sysfs_remove_group(&sys_dev->kobj, &mc_attr_group);
+ cancel_work_sync(&ucode_work_info[cpu].work);
break;
case CPU_DEAD:
case CPU_UP_CANCELED_FROZEN:
@@ -803,7 +815,7 @@ static struct notifier_block __refdata mc_cpu_notifier = {
static int __init microcode_init (void)
{
- int error;
+ int error, i;
printk(KERN_INFO
"IA-32 Microcode Update Driver: v" MICROCODE_VERSION " <[email protected]>\n");
@@ -818,6 +830,9 @@ static int __init microcode_init (void)
return PTR_ERR(microcode_pdev);
}
+ for (i = 0; i < NR_CPUS; i++)
+ INIT_WORK(&ucode_work_info[i].work, microcode_update_cpu);
+
get_online_cpus();
error = sysdev_driver_register(&cpu_sysdev_class, &mc_sysdev_driver);
put_online_cpus();