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Diffstat (limited to 'arch/x86/kernel/microcode_core.c')
-rw-r--r--arch/x86/kernel/microcode_core.c329
1 files changed, 189 insertions, 140 deletions
diff --git a/arch/x86/kernel/microcode_core.c b/arch/x86/kernel/microcode_core.c
index 98c470c069d..9c4461501fc 100644
--- a/arch/x86/kernel/microcode_core.c
+++ b/arch/x86/kernel/microcode_core.c
@@ -71,27 +71,18 @@
* Thanks to Stuart Swales for pointing out this bug.
*/
#include <linux/platform_device.h>
-#include <linux/capability.h>
#include <linux/miscdevice.h>
-#include <linux/firmware.h>
+#include <linux/capability.h>
#include <linux/smp_lock.h>
-#include <linux/spinlock.h>
-#include <linux/cpumask.h>
-#include <linux/uaccess.h>
-#include <linux/vmalloc.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mutex.h>
-#include <linux/sched.h>
-#include <linux/init.h>
-#include <linux/slab.h>
#include <linux/cpu.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <asm/microcode.h>
#include <asm/processor.h>
-#include <asm/msr.h>
MODULE_DESCRIPTION("Microcode Update Driver");
MODULE_AUTHOR("Tigran Aivazian <tigran@aivazian.fsnet.co.uk>");
@@ -101,36 +92,110 @@ MODULE_LICENSE("GPL");
static struct microcode_ops *microcode_ops;
-/* no concurrent ->write()s are allowed on /dev/cpu/microcode */
+/*
+ * Synchronization.
+ *
+ * All non cpu-hotplug-callback call sites use:
+ *
+ * - microcode_mutex to synchronize with each other;
+ * - get/put_online_cpus() to synchronize with
+ * the cpu-hotplug-callback call sites.
+ *
+ * We guarantee that only a single cpu is being
+ * updated at any particular moment of time.
+ */
static DEFINE_MUTEX(microcode_mutex);
struct ucode_cpu_info ucode_cpu_info[NR_CPUS];
EXPORT_SYMBOL_GPL(ucode_cpu_info);
+/*
+ * Operations that are run on a target cpu:
+ */
+
+struct cpu_info_ctx {
+ struct cpu_signature *cpu_sig;
+ int err;
+};
+
+static void collect_cpu_info_local(void *arg)
+{
+ struct cpu_info_ctx *ctx = arg;
+
+ ctx->err = microcode_ops->collect_cpu_info(smp_processor_id(),
+ ctx->cpu_sig);
+}
+
+static int collect_cpu_info_on_target(int cpu, struct cpu_signature *cpu_sig)
+{
+ struct cpu_info_ctx ctx = { .cpu_sig = cpu_sig, .err = 0 };
+ int ret;
+
+ ret = smp_call_function_single(cpu, collect_cpu_info_local, &ctx, 1);
+ if (!ret)
+ ret = ctx.err;
+
+ return ret;
+}
+
+static int collect_cpu_info(int cpu)
+{
+ struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
+ int ret;
+
+ memset(uci, 0, sizeof(*uci));
+
+ ret = collect_cpu_info_on_target(cpu, &uci->cpu_sig);
+ if (!ret)
+ uci->valid = 1;
+
+ return ret;
+}
+
+struct apply_microcode_ctx {
+ int err;
+};
+
+static void apply_microcode_local(void *arg)
+{
+ struct apply_microcode_ctx *ctx = arg;
+
+ ctx->err = microcode_ops->apply_microcode(smp_processor_id());
+}
+
+static int apply_microcode_on_target(int cpu)
+{
+ struct apply_microcode_ctx ctx = { .err = 0 };
+ int ret;
+
+ ret = smp_call_function_single(cpu, apply_microcode_local, &ctx, 1);
+ if (!ret)
+ ret = ctx.err;
+
+ return ret;
+}
+
#ifdef CONFIG_MICROCODE_OLD_INTERFACE
static int do_microcode_update(const void __user *buf, size_t size)
{
- cpumask_t old;
int error = 0;
int cpu;
- old = current->cpus_allowed;
-
for_each_online_cpu(cpu) {
struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
+ enum ucode_state ustate;
if (!uci->valid)
continue;
- set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu));
- error = microcode_ops->request_microcode_user(cpu, buf, size);
- if (error < 0)
- goto out;
- if (!error)
- microcode_ops->apply_microcode(cpu);
+ ustate = microcode_ops->request_microcode_user(cpu, buf, size);
+ if (ustate == UCODE_ERROR) {
+ error = -1;
+ break;
+ } else if (ustate == UCODE_OK)
+ apply_microcode_on_target(cpu);
}
-out:
- set_cpus_allowed_ptr(current, &old);
+
return error;
}
@@ -143,19 +208,17 @@ static int microcode_open(struct inode *unused1, struct file *unused2)
static ssize_t microcode_write(struct file *file, const char __user *buf,
size_t len, loff_t *ppos)
{
- ssize_t ret;
+ ssize_t ret = -EINVAL;
if ((len >> PAGE_SHIFT) > num_physpages) {
- printk(KERN_ERR "microcode: too much data (max %ld pages)\n",
- num_physpages);
- return -EINVAL;
+ pr_err("microcode: too much data (max %ld pages)\n", num_physpages);
+ return ret;
}
get_online_cpus();
mutex_lock(&microcode_mutex);
- ret = do_microcode_update(buf, len);
- if (!ret)
+ if (do_microcode_update(buf, len) == 0)
ret = (ssize_t)len;
mutex_unlock(&microcode_mutex);
@@ -165,15 +228,15 @@ static ssize_t microcode_write(struct file *file, const char __user *buf,
}
static const struct file_operations microcode_fops = {
- .owner = THIS_MODULE,
- .write = microcode_write,
- .open = microcode_open,
+ .owner = THIS_MODULE,
+ .write = microcode_write,
+ .open = microcode_open,
};
static struct miscdevice microcode_dev = {
- .minor = MICROCODE_MINOR,
- .name = "microcode",
- .fops = &microcode_fops,
+ .minor = MICROCODE_MINOR,
+ .name = "microcode",
+ .fops = &microcode_fops,
};
static int __init microcode_dev_init(void)
@@ -182,9 +245,7 @@ static int __init microcode_dev_init(void)
error = misc_register(&microcode_dev);
if (error) {
- printk(KERN_ERR
- "microcode: can't misc_register on minor=%d\n",
- MICROCODE_MINOR);
+ pr_err("microcode: can't misc_register on minor=%d\n", MICROCODE_MINOR);
return error;
}
@@ -205,42 +266,51 @@ MODULE_ALIAS_MISCDEV(MICROCODE_MINOR);
/* fake device for request_firmware */
static struct platform_device *microcode_pdev;
-static long reload_for_cpu(void *unused)
+static int reload_for_cpu(int cpu)
{
- struct ucode_cpu_info *uci = ucode_cpu_info + smp_processor_id();
+ struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
int err = 0;
mutex_lock(&microcode_mutex);
if (uci->valid) {
- err = microcode_ops->request_microcode_fw(smp_processor_id(),
- &microcode_pdev->dev);
- if (!err)
- microcode_ops->apply_microcode(smp_processor_id());
+ enum ucode_state ustate;
+
+ ustate = microcode_ops->request_microcode_fw(cpu, &microcode_pdev->dev);
+ if (ustate == UCODE_OK)
+ apply_microcode_on_target(cpu);
+ else
+ if (ustate == UCODE_ERROR)
+ err = -EINVAL;
}
mutex_unlock(&microcode_mutex);
+
return err;
}
static ssize_t reload_store(struct sys_device *dev,
struct sysdev_attribute *attr,
- const char *buf, size_t sz)
+ const char *buf, size_t size)
{
- char *end;
- unsigned long val = simple_strtoul(buf, &end, 0);
- int err = 0;
+ unsigned long val;
int cpu = dev->id;
+ int ret = 0;
+ char *end;
+ val = simple_strtoul(buf, &end, 0);
if (end == buf)
return -EINVAL;
+
if (val == 1) {
get_online_cpus();
if (cpu_online(cpu))
- err = work_on_cpu(cpu, reload_for_cpu, NULL);
+ ret = reload_for_cpu(cpu);
put_online_cpus();
}
- if (err)
- return err;
- return sz;
+
+ if (!ret)
+ ret = size;
+
+ return ret;
}
static ssize_t version_show(struct sys_device *dev,
@@ -271,11 +341,11 @@ static struct attribute *mc_default_attrs[] = {
};
static struct attribute_group mc_attr_group = {
- .attrs = mc_default_attrs,
- .name = "microcode",
+ .attrs = mc_default_attrs,
+ .name = "microcode",
};
-static void __microcode_fini_cpu(int cpu)
+static void microcode_fini_cpu(int cpu)
{
struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
@@ -283,103 +353,68 @@ static void __microcode_fini_cpu(int cpu)
uci->valid = 0;
}
-static void microcode_fini_cpu(int cpu)
-{
- mutex_lock(&microcode_mutex);
- __microcode_fini_cpu(cpu);
- mutex_unlock(&microcode_mutex);
-}
-
-static void collect_cpu_info(int cpu)
+static enum ucode_state microcode_resume_cpu(int cpu)
{
struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
- memset(uci, 0, sizeof(*uci));
- if (!microcode_ops->collect_cpu_info(cpu, &uci->cpu_sig))
- uci->valid = 1;
+ if (!uci->mc)
+ return UCODE_NFOUND;
+
+ pr_debug("microcode: CPU%d updated upon resume\n", cpu);
+ apply_microcode_on_target(cpu);
+
+ return UCODE_OK;
}
-static int microcode_resume_cpu(int cpu)
+static enum ucode_state microcode_init_cpu(int cpu)
{
- struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
- struct cpu_signature nsig;
+ enum ucode_state ustate;
- pr_debug("microcode: CPU%d resumed\n", cpu);
+ if (collect_cpu_info(cpu))
+ return UCODE_ERROR;
- if (!uci->mc)
- return 1;
+ /* --dimm. Trigger a delayed update? */
+ if (system_state != SYSTEM_RUNNING)
+ return UCODE_NFOUND;
- /*
- * Let's verify that the 'cached' ucode does belong
- * to this cpu (a bit of paranoia):
- */
- if (microcode_ops->collect_cpu_info(cpu, &nsig)) {
- __microcode_fini_cpu(cpu);
- printk(KERN_ERR "failed to collect_cpu_info for resuming cpu #%d\n",
- cpu);
- return -1;
- }
+ ustate = microcode_ops->request_microcode_fw(cpu, &microcode_pdev->dev);
- if ((nsig.sig != uci->cpu_sig.sig) || (nsig.pf != uci->cpu_sig.pf)) {
- __microcode_fini_cpu(cpu);
- printk(KERN_ERR "cached ucode doesn't match the resuming cpu #%d\n",
- cpu);
- /* Should we look for a new ucode here? */
- return 1;
+ if (ustate == UCODE_OK) {
+ pr_debug("microcode: CPU%d updated upon init\n", cpu);
+ apply_microcode_on_target(cpu);
}
- return 0;
+ return ustate;
}
-static long microcode_update_cpu(void *unused)
+static enum ucode_state microcode_update_cpu(int cpu)
{
- struct ucode_cpu_info *uci = ucode_cpu_info + smp_processor_id();
- int err = 0;
+ struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
+ enum ucode_state ustate;
- /*
- * Check if the system resume is in progress (uci->valid != NULL),
- * otherwise just request a firmware:
- */
- if (uci->valid) {
- err = microcode_resume_cpu(smp_processor_id());
- } else {
- collect_cpu_info(smp_processor_id());
- if (uci->valid && system_state == SYSTEM_RUNNING)
- err = microcode_ops->request_microcode_fw(
- smp_processor_id(),
- &microcode_pdev->dev);
- }
- if (!err)
- microcode_ops->apply_microcode(smp_processor_id());
- return err;
-}
+ if (uci->valid)
+ ustate = microcode_resume_cpu(cpu);
+ else
+ ustate = microcode_init_cpu(cpu);
-static int microcode_init_cpu(int cpu)
-{
- int err;
- mutex_lock(&microcode_mutex);
- err = work_on_cpu(cpu, microcode_update_cpu, NULL);
- mutex_unlock(&microcode_mutex);
-
- return err;
+ return ustate;
}
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;
if (!cpu_online(cpu))
return 0;
pr_debug("microcode: CPU%d added\n", cpu);
- memset(uci, 0, sizeof(*uci));
err = sysfs_create_group(&sys_dev->kobj, &mc_attr_group);
if (err)
return err;
- err = microcode_init_cpu(cpu);
+ if (microcode_init_cpu(cpu) == UCODE_ERROR)
+ err = -EINVAL;
return err;
}
@@ -400,19 +435,30 @@ static int mc_sysdev_remove(struct sys_device *sys_dev)
static int mc_sysdev_resume(struct sys_device *dev)
{
int cpu = dev->id;
+ struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
if (!cpu_online(cpu))
return 0;
- /* only CPU 0 will apply ucode here */
- microcode_update_cpu(NULL);
+ /*
+ * All non-bootup cpus are still disabled,
+ * so only CPU 0 will apply ucode here.
+ *
+ * Moreover, there can be no concurrent
+ * updates from any other places at this point.
+ */
+ WARN_ON(cpu != 0);
+
+ if (uci->valid && uci->mc)
+ microcode_ops->apply_microcode(cpu);
+
return 0;
}
static struct sysdev_driver mc_sysdev_driver = {
- .add = mc_sysdev_add,
- .remove = mc_sysdev_remove,
- .resume = mc_sysdev_resume,
+ .add = mc_sysdev_add,
+ .remove = mc_sysdev_remove,
+ .resume = mc_sysdev_resume,
};
static __cpuinit int
@@ -425,15 +471,12 @@ mc_cpu_callback(struct notifier_block *nb, unsigned long action, void *hcpu)
switch (action) {
case CPU_ONLINE:
case CPU_ONLINE_FROZEN:
- if (microcode_init_cpu(cpu))
- printk(KERN_ERR "microcode: failed to init CPU%d\n",
- cpu);
+ microcode_update_cpu(cpu);
case CPU_DOWN_FAILED:
case CPU_DOWN_FAILED_FROZEN:
pr_debug("microcode: CPU%d added\n", cpu);
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);
+ pr_err("microcode: Failed to create group for CPU%d\n", cpu);
break;
case CPU_DOWN_PREPARE:
case CPU_DOWN_PREPARE_FROZEN:
@@ -465,13 +508,10 @@ static int __init microcode_init(void)
microcode_ops = init_amd_microcode();
if (!microcode_ops) {
- printk(KERN_ERR "microcode: no support for this CPU vendor\n");
+ pr_err("microcode: no support for this CPU vendor\n");
return -ENODEV;
}
- error = microcode_dev_init();
- if (error)
- return error;
microcode_pdev = platform_device_register_simple("microcode", -1,
NULL, 0);
if (IS_ERR(microcode_pdev)) {
@@ -480,23 +520,31 @@ static int __init microcode_init(void)
}
get_online_cpus();
+ mutex_lock(&microcode_mutex);
+
error = sysdev_driver_register(&cpu_sysdev_class, &mc_sysdev_driver);
+
+ mutex_unlock(&microcode_mutex);
put_online_cpus();
+
if (error) {
- microcode_dev_exit();
platform_device_unregister(microcode_pdev);
return error;
}
+ error = microcode_dev_init();
+ if (error)
+ return error;
+
register_hotcpu_notifier(&mc_cpu_notifier);
- printk(KERN_INFO
- "Microcode Update Driver: v" MICROCODE_VERSION
+ pr_info("Microcode Update Driver: v" MICROCODE_VERSION
" <tigran@aivazian.fsnet.co.uk>,"
" Peter Oruba\n");
return 0;
}
+module_init(microcode_init);
static void __exit microcode_exit(void)
{
@@ -505,16 +553,17 @@ static void __exit microcode_exit(void)
unregister_hotcpu_notifier(&mc_cpu_notifier);
get_online_cpus();
+ mutex_lock(&microcode_mutex);
+
sysdev_driver_unregister(&cpu_sysdev_class, &mc_sysdev_driver);
+
+ mutex_unlock(&microcode_mutex);
put_online_cpus();
platform_device_unregister(microcode_pdev);
microcode_ops = NULL;
- printk(KERN_INFO
- "Microcode Update Driver: v" MICROCODE_VERSION " removed.\n");
+ pr_info("Microcode Update Driver: v" MICROCODE_VERSION " removed.\n");
}
-
-module_init(microcode_init);
module_exit(microcode_exit);