[tip:cpus4096] x86: cpumask: use work_on_cpu in arch/x86/kernel/microcode_core.c

From: Rusty Russell
Date: Wed Mar 18 2009 - 08:59:32 EST

Commit-ID: af5c820a3169e81af869c113e18ec7588836cd50
Gitweb: http://git.kernel.org/tip/af5c820a3169e81af869c113e18ec7588836cd50
Author: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
AuthorDate: Wed, 11 Mar 2009 16:32:36 +1030
Commit: Ingo Molnar <mingo@xxxxxxx>
CommitDate: Wed, 18 Mar 2009 13:50:47 +0100

x86: cpumask: use work_on_cpu in arch/x86/kernel/microcode_core.c

Impact: don't play with current's cpumask

Straightforward indirection through work_on_cpu(). One change is
that the error code from microcode_update_cpu() is now actually
plumbed back to microcode_init_cpu(), so now we printk if it fails
on cpu hotplug.

Signed-off-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Dmitry Adamushko <dmitry.adamushko@xxxxxxxxx>
Cc: Peter Oruba <peter.oruba@xxxxxxx>
LKML-Reference: <200903111632.37279.rusty@xxxxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>


---
arch/x86/kernel/microcode_core.c | 106 ++++++++++++++++++++++----------------
1 files changed, 61 insertions(+), 45 deletions(-)

diff --git a/arch/x86/kernel/microcode_core.c b/arch/x86/kernel/microcode_core.c
index c9b721b..9a8dbc0 100644
--- a/arch/x86/kernel/microcode_core.c
+++ b/arch/x86/kernel/microcode_core.c
@@ -108,29 +108,40 @@ struct ucode_cpu_info ucode_cpu_info[NR_CPUS];
EXPORT_SYMBOL_GPL(ucode_cpu_info);

#ifdef CONFIG_MICROCODE_OLD_INTERFACE
+struct update_for_cpu {
+ const void __user *buf;
+ size_t size;
+};
+
+static long update_for_cpu(void *_ufc)
+{
+ struct update_for_cpu *ufc = _ufc;
+ int error;
+
+ error = microcode_ops->request_microcode_user(smp_processor_id(),
+ ufc->buf, ufc->size);
+ if (error < 0)
+ return error;
+ if (!error)
+ microcode_ops->apply_microcode(smp_processor_id());
+ return error;
+}
+
static int do_microcode_update(const void __user *buf, size_t size)
{
- cpumask_t old;
int error = 0;
int cpu;
-
- old = current->cpus_allowed;
+ struct update_for_cpu ufc = { .buf = buf, .size = size };

for_each_online_cpu(cpu) {
struct ucode_cpu_info *uci = ucode_cpu_info + cpu;

if (!uci->valid)
continue;
-
- set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu));
- error = microcode_ops->request_microcode_user(cpu, buf, size);
+ error = work_on_cpu(cpu, update_for_cpu, &ufc);
if (error < 0)
- goto out;
- if (!error)
- microcode_ops->apply_microcode(cpu);
+ break;
}
-out:
- set_cpus_allowed_ptr(current, &old);
return error;
}

@@ -205,11 +216,26 @@ MODULE_ALIAS_MISCDEV(MICROCODE_MINOR);
/* fake device for request_firmware */
static struct platform_device *microcode_pdev;

+static long reload_for_cpu(void *unused)
+{
+ struct ucode_cpu_info *uci = ucode_cpu_info + smp_processor_id();
+ 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());
+ }
+ 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)
{
- struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;
char *end;
unsigned long val = simple_strtoul(buf, &end, 0);
int err = 0;
@@ -218,21 +244,9 @@ static ssize_t reload_store(struct sys_device *dev,
if (end == buf)
return -EINVAL;
if (val == 1) {
- cpumask_t old = current->cpus_allowed;
-
get_online_cpus();
- if (cpu_online(cpu)) {
- set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu));
- mutex_lock(&microcode_mutex);
- if (uci->valid) {
- err = microcode_ops->request_microcode_fw(cpu,
- &microcode_pdev->dev);
- if (!err)
- microcode_ops->apply_microcode(cpu);
- }
- mutex_unlock(&microcode_mutex);
- set_cpus_allowed_ptr(current, &old);
- }
+ if (cpu_online(cpu))
+ err = work_on_cpu(cpu, reload_for_cpu, NULL);
put_online_cpus();
}
if (err)
@@ -328,9 +342,9 @@ static int microcode_resume_cpu(int cpu)
return 0;
}

-static void microcode_update_cpu(int cpu)
+static long microcode_update_cpu(void *unused)
{
- struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
+ struct ucode_cpu_info *uci = ucode_cpu_info + smp_processor_id();
int err = 0;

/*
@@ -338,30 +352,27 @@ static void microcode_update_cpu(int cpu)
* otherwise just request a firmware:
*/
if (uci->valid) {
- err = microcode_resume_cpu(cpu);
+ err = microcode_resume_cpu(smp_processor_id());
} else {
- collect_cpu_info(cpu);
+ collect_cpu_info(smp_processor_id());
if (uci->valid && system_state == SYSTEM_RUNNING)
- err = microcode_ops->request_microcode_fw(cpu,
+ err = microcode_ops->request_microcode_fw(
+ smp_processor_id(),
&microcode_pdev->dev);
}
if (!err)
- microcode_ops->apply_microcode(cpu);
+ microcode_ops->apply_microcode(smp_processor_id());
+ return err;
}

-static void microcode_init_cpu(int cpu)
+static int microcode_init_cpu(int cpu)
{
- cpumask_t old = current->cpus_allowed;
-
- set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu));
- /* We should bind the task to the CPU */
- BUG_ON(raw_smp_processor_id() != cpu);
-
+ int err;
mutex_lock(&microcode_mutex);
- microcode_update_cpu(cpu);
+ err = work_on_cpu(cpu, microcode_update_cpu, NULL);
mutex_unlock(&microcode_mutex);

- set_cpus_allowed_ptr(current, &old);
+ return err;
}

static int mc_sysdev_add(struct sys_device *sys_dev)
@@ -379,8 +390,11 @@ static int mc_sysdev_add(struct sys_device *sys_dev)
if (err)
return err;

- microcode_init_cpu(cpu);
- return 0;
+ err = microcode_init_cpu(cpu);
+ if (err)
+ sysfs_remove_group(&sys_dev->kobj, &mc_attr_group);
+
+ return err;
}

static int mc_sysdev_remove(struct sys_device *sys_dev)
@@ -404,7 +418,7 @@ static int mc_sysdev_resume(struct sys_device *dev)
return 0;

/* only CPU 0 will apply ucode here */
- microcode_update_cpu(0);
+ microcode_update_cpu(NULL);
return 0;
}

@@ -424,7 +438,9 @@ mc_cpu_callback(struct notifier_block *nb, unsigned long action, void *hcpu)
switch (action) {
case CPU_ONLINE:
case CPU_ONLINE_FROZEN:
- microcode_init_cpu(cpu);
+ if (microcode_init_cpu(cpu))
+ printk(KERN_ERR "microcode: failed to init CPU%d\n",
+ cpu);
case CPU_DOWN_FAILED:
case CPU_DOWN_FAILED_FROZEN:
pr_debug("microcode: CPU%d added\n", cpu);
--
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