Added sysfs primitives to padata subsystem. Now API user may
embedded kobject each padata instance contains into any sysfs
hierarchy. For now padata sysfs interface provides only
two objects:
serial_cpumask [RW] - cpumask for serial workers
parallel_cpumask [RW] - cpumask for parallel workers
Signed-off-by: Dan Kruchinin <[email protected]>
---
include/linux/padata.h | 5 +-
kernel/padata.c | 155 +++++++++++++++++++++++++++++++++++++++++++++---
2 files changed, 150 insertions(+), 10 deletions(-)
diff --git a/include/linux/padata.h b/include/linux/padata.h
index 621e773..293ad46 100644
--- a/include/linux/padata.h
+++ b/include/linux/padata.h
@@ -26,6 +26,7 @@
#include <linux/list.h>
#include <linux/timer.h>
#include <linux/notifier.h>
+#include <linux/kobject.h>
#define PADATA_CPU_SERIAL 0x01
#define PADATA_CPU_PARALLEL 0x02
@@ -142,7 +143,8 @@ struct parallel_data {
* cbcpu for parallel and serial works respectivly.
* @cpumask_change_notifier: Notifiers chain for user-defined notify
* callbacks that will be called when either @pcpu or @cbcpu
- * or both cpumasks change.
+ * or both cpumasks change.
+ * @kobj: padata instance kernel object.
* @lock: padata instance lock.
* @flags: padata flags.
*/
@@ -155,6 +157,7 @@ struct padata_instance {
cpumask_var_t cbcpu;
} cpumask;
struct blocking_notifier_head cpumask_change_notifier;
+ struct kobject kobj;
struct mutex lock;
u8 flags;
#define PADATA_INIT 1
diff --git a/kernel/padata.c b/kernel/padata.c
index 84d0ca9..526f9ea 100644
--- a/kernel/padata.c
+++ b/kernel/padata.c
@@ -26,6 +26,7 @@
#include <linux/mutex.h>
#include <linux/sched.h>
#include <linux/slab.h>
+#include <linux/sysfs.h>
#include <linux/rcupdate.h>
#define MAX_SEQ_NR (INT_MAX - NR_CPUS)
@@ -924,6 +925,149 @@ static int padata_cpu_callback(struct notifier_block *nfb,
}
#endif
+static void __padata_free(struct padata_instance *pinst)
+{
+#ifdef CONFIG_HOTPLUG_CPU
+ unregister_hotcpu_notifier(&pinst->cpu_notifier);
+#endif
+
+ padata_stop(pinst);
+ padata_free_pd(pinst->pd);
+ free_cpumask_var(pinst->cpumask.pcpu);
+ free_cpumask_var(pinst->cpumask.cbcpu);
+ kfree(pinst);
+}
+
+#define kobj2pinst(_kobj) \
+ container_of(_kobj, struct padata_instance, kobj)
+#define attr2pentry(_attr) \
+ container_of(_attr, struct padata_sysfs_entry, attr)
+
+static void padata_sysfs_release(struct kobject *kobj)
+{
+ struct padata_instance *pinst = kobj2pinst(kobj);
+ __padata_free(pinst);
+}
+
+struct padata_sysfs_entry {
+ struct attribute attr;
+ ssize_t (*show)(struct padata_instance *, struct attribute *, char *);
+ ssize_t (*store)(struct padata_instance *, struct attribute *,
+ const char *, size_t);
+};
+
+static ssize_t show_cpumask(struct padata_instance *pinst,
+ struct attribute *attr, char *buf)
+{
+ struct cpumask *cpumask;
+ ssize_t len;
+
+ mutex_lock(&pinst->lock);
+ if (!strcmp(attr->name, "serial_cpumask"))
+ cpumask = pinst->cpumask.cbcpu;
+ else
+ cpumask = pinst->cpumask.pcpu;
+
+ len = bitmap_scnprintf(buf, PAGE_SIZE, cpumask_bits(cpumask),
+ nr_cpu_ids);
+ if (PAGE_SIZE - len < 2)
+ len = -EINVAL;
+ else
+ len += sprintf(buf + len, "\n");
+
+ mutex_unlock(&pinst->lock);
+ return len;
+}
+
+static ssize_t store_cpumask(struct padata_instance *pinst,
+ struct attribute *attr,
+ const char *buf, size_t count)
+{
+ cpumask_var_t new_cpumask;
+ ssize_t ret;
+ int mask_type;
+
+ if (!alloc_cpumask_var(&new_cpumask, GFP_KERNEL))
+ return -ENOMEM;
+
+ ret = bitmap_parse(buf, count, cpumask_bits(new_cpumask),
+ nr_cpumask_bits);
+ if (ret < 0)
+ goto out;
+
+ mask_type = !strcmp(attr->name, "serial_cpumask") ?
+ PADATA_CPU_SERIAL : PADATA_CPU_PARALLEL;
+ ret = padata_set_cpumask(pinst, mask_type, new_cpumask);
+ if (!ret)
+ ret = count;
+
+out:
+ free_cpumask_var(new_cpumask);
+ return ret;
+}
+
+#define PADATA_ATTR_RW(_name, _show_name, _store_name) \
+ static struct padata_sysfs_entry _name##_attr = \
+ __ATTR(_name, 0644, _show_name, _store_name)
+#define PADATA_ATTR_RO(_name, _show_name) \
+ static struct padata_sysfs_entry _name##_attr = \
+ __ATTR(_name, 0400, _show_name, NULL)
+
+PADATA_ATTR_RW(serial_cpumask, show_cpumask, store_cpumask);
+PADATA_ATTR_RW(parallel_cpumask, show_cpumask, store_cpumask);
+
+/*
+ * Padata sysfs provides the following objects:
+ * serial_cpumask [RW] - cpumask for serial workers
+ * parallel_cpumask [RW] - cpumask for parallel workers
+ */
+static struct attribute *padata_default_attrs[] = {
+ &serial_cpumask_attr.attr,
+ ¶llel_cpumask_attr.attr,
+ NULL,
+};
+
+static ssize_t padata_sysfs_show(struct kobject *kobj,
+ struct attribute *attr, char *buf)
+{
+ struct padata_instance *pinst;
+ struct padata_sysfs_entry *pentry;
+ ssize_t ret = -EIO;
+
+ pinst = kobj2pinst(kobj);
+ pentry = attr2pentry(attr);
+ if (pentry->show)
+ ret = pentry->show(pinst, attr, buf);
+
+ return ret;
+}
+
+static ssize_t padata_sysfs_store(struct kobject *kobj, struct attribute *attr,
+ const char *buf, size_t count)
+{
+ struct padata_instance *pinst;
+ struct padata_sysfs_entry *pentry;
+ ssize_t ret = -EIO;
+
+ pinst = kobj2pinst(kobj);
+ pentry = attr2pentry(attr);
+ if (pentry->show)
+ ret = pentry->store(pinst, attr, buf, count);
+
+ return ret;
+}
+
+static const struct sysfs_ops padata_sysfs_ops = {
+ .show = padata_sysfs_show,
+ .store = padata_sysfs_store,
+};
+
+static struct kobj_type padata_attr_type = {
+ .sysfs_ops = &padata_sysfs_ops,
+ .default_attrs = padata_default_attrs,
+ .release = padata_sysfs_release,
+};
+
/**
* padata_alloc - Allocate and initialize padata instance.
* Use default cpumask(cpu_possible_mask)
@@ -989,6 +1133,7 @@ struct padata_instance *__padata_alloc(struct workqueue_struct *wq,
put_online_cpus();
BLOCKING_INIT_NOTIFIER_HEAD(&pinst->cpumask_change_notifier);
+ kobject_init(&pinst->kobj, &padata_attr_type);
mutex_init(&pinst->lock);
return pinst;
@@ -1011,14 +1156,6 @@ EXPORT_SYMBOL(__padata_alloc);
*/
void padata_free(struct padata_instance *pinst)
{
-#ifdef CONFIG_HOTPLUG_CPU
- unregister_hotcpu_notifier(&pinst->cpu_notifier);
-#endif
-
- padata_stop(pinst);
- padata_free_pd(pinst->pd);
- free_cpumask_var(pinst->cpumask.pcpu);
- free_cpumask_var(pinst->cpumask.cbcpu);
- kfree(pinst);
+ kobject_put(&pinst->kobj);
}
EXPORT_SYMBOL(padata_free);
--
1.7.1
--
W.B.R.
Dan Kruchinin