s390: add scm bus driver

Bus driver to manage Storage Class Memory.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/Kconfig

@@ -433,6 +433,13 @@ config CHSC_SCH
 
 	  If unsure, say N.
 
+config SCM_BUS
+	def_bool y
+	depends on 64BIT
+	prompt "SCM bus driver"
+	help
+	  Bus driver for Storage Class Memory.
+
 endmenu
 
 menu "Dump support"

arch/s390/include/asm/eadm.h

@@ -2,6 +2,8 @@
 #define _ASM_S390_EADM_H
 
 #include <linux/types.h>
+#include <linux/device.h>
+#include <linux/spinlock.h>
 
 struct arqb {
 	u64 data;
@@ -71,4 +73,53 @@ struct aob {
 	struct msb msb[AOB_NR_MSB];
 } __packed __aligned(PAGE_SIZE);
 
+struct aob_rq_header {
+	struct scm_device *scmdev;
+	char data[0];
+};
+
+struct scm_device {
+	u64 address;
+	u64 size;
+	unsigned int nr_max_block;
+	struct device dev;
+	spinlock_t lock;
+	struct {
+		unsigned int persistence:4;
+		unsigned int oper_state:4;
+		unsigned int data_state:4;
+		unsigned int rank:4;
+		unsigned int release:1;
+		unsigned int res_id:8;
+	} __packed attrs;
+};
+
+#define OP_STATE_GOOD		1
+#define OP_STATE_TEMP_ERR	2
+#define OP_STATE_PERM_ERR	3
+
+struct scm_driver {
+	struct device_driver drv;
+	int (*probe) (struct scm_device *scmdev);
+	int (*remove) (struct scm_device *scmdev);
+	void (*handler) (struct scm_device *scmdev, void *data, int error);
+};
+
+int scm_driver_register(struct scm_driver *scmdrv);
+void scm_driver_unregister(struct scm_driver *scmdrv);
+
+int scm_start_aob(struct aob *aob);
+void scm_irq_handler(struct aob *aob, int error);
+
+struct eadm_ops {
+	int (*eadm_start) (struct aob *aob);
+	struct module *owner;
+};
+
+int scm_get_ref(void);
+void scm_put_ref(void);
+
+void register_eadm_ops(struct eadm_ops *ops);
+void unregister_eadm_ops(struct eadm_ops *ops);
+
 #endif /* _ASM_S390_EADM_H */

drivers/s390/cio/Makefile

@@ -8,6 +8,7 @@ ccw_device-objs += device.o device_fsm.o device_ops.o
 ccw_device-objs += device_id.o device_pgid.o device_status.o
 obj-y += ccw_device.o cmf.o
 obj-$(CONFIG_CHSC_SCH) += chsc_sch.o
+obj-$(CONFIG_SCM_BUS) += scm.o
 obj-$(CONFIG_CCWGROUP) += ccwgroup.o
 
 qdio-objs := qdio_main.o qdio_thinint.o qdio_debug.o qdio_setup.o

drivers/s390/cio/scm.c

+/*
+ * Recognize and maintain s390 storage class memory.
+ *
+ * Copyright IBM Corp. 2012
+ * Author(s): Sebastian Ott <sebott@linux.vnet.ibm.com>
+ */
+
+#include <linux/spinlock.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/err.h>
+#include <asm/eadm.h>
+#include "chsc.h"
+
+static struct device *scm_root;
+static struct eadm_ops *eadm_ops;
+static DEFINE_MUTEX(eadm_ops_mutex);
+
+#define to_scm_dev(n) container_of(n, struct scm_device, dev)
+#define	to_scm_drv(d) container_of(d, struct scm_driver, drv)
+
+static int scmdev_probe(struct device *dev)
+{
+	struct scm_device *scmdev = to_scm_dev(dev);
+	struct scm_driver *scmdrv = to_scm_drv(dev->driver);
+
+	return scmdrv->probe ? scmdrv->probe(scmdev) : -ENODEV;
+}
+
+static int scmdev_remove(struct device *dev)
+{
+	struct scm_device *scmdev = to_scm_dev(dev);
+	struct scm_driver *scmdrv = to_scm_drv(dev->driver);
+
+	return scmdrv->remove ? scmdrv->remove(scmdev) : -ENODEV;
+}
+
+static int scmdev_uevent(struct device *dev, struct kobj_uevent_env *env)
+{
+	return add_uevent_var(env, "MODALIAS=scm:scmdev");
+}
+
+static struct bus_type scm_bus_type = {
+	.name  = "scm",
+	.probe = scmdev_probe,
+	.remove = scmdev_remove,
+	.uevent = scmdev_uevent,
+};
+
+/**
+ * scm_driver_register() - register a scm driver
+ * @scmdrv: driver to be registered
+ */
+int scm_driver_register(struct scm_driver *scmdrv)
+{
+	struct device_driver *drv = &scmdrv->drv;
+
+	drv->bus = &scm_bus_type;
+
+	return driver_register(drv);
+}
+EXPORT_SYMBOL_GPL(scm_driver_register);
+
+/**
+ * scm_driver_unregister() - deregister a scm driver
+ * @scmdrv: driver to be deregistered
+ */
+void scm_driver_unregister(struct scm_driver *scmdrv)
+{
+	driver_unregister(&scmdrv->drv);
+}
+EXPORT_SYMBOL_GPL(scm_driver_unregister);
+
+int scm_get_ref(void)
+{
+	int ret = 0;
+
+	mutex_lock(&eadm_ops_mutex);
+	if (!eadm_ops || !try_module_get(eadm_ops->owner))
+		ret = -ENOENT;
+	mutex_unlock(&eadm_ops_mutex);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(scm_get_ref);
+
+void scm_put_ref(void)
+{
+	mutex_lock(&eadm_ops_mutex);
+	module_put(eadm_ops->owner);
+	mutex_unlock(&eadm_ops_mutex);
+}
+EXPORT_SYMBOL_GPL(scm_put_ref);
+
+void register_eadm_ops(struct eadm_ops *ops)
+{
+	mutex_lock(&eadm_ops_mutex);
+	eadm_ops = ops;
+	mutex_unlock(&eadm_ops_mutex);
+}
+EXPORT_SYMBOL_GPL(register_eadm_ops);
+
+void unregister_eadm_ops(struct eadm_ops *ops)
+{
+	mutex_lock(&eadm_ops_mutex);
+	eadm_ops = NULL;
+	mutex_unlock(&eadm_ops_mutex);
+}
+EXPORT_SYMBOL_GPL(unregister_eadm_ops);
+
+int scm_start_aob(struct aob *aob)
+{
+	return eadm_ops->eadm_start(aob);
+}
+EXPORT_SYMBOL_GPL(scm_start_aob);
+
+void scm_irq_handler(struct aob *aob, int error)
+{
+	struct aob_rq_header *aobrq = (void *) aob->request.data;
+	struct scm_device *scmdev = aobrq->scmdev;
+	struct scm_driver *scmdrv = to_scm_drv(scmdev->dev.driver);
+
+	scmdrv->handler(scmdev, aobrq->data, error);
+}
+EXPORT_SYMBOL_GPL(scm_irq_handler);
+
+#define scm_attr(name)							\
+static ssize_t show_##name(struct device *dev,				\
+	       struct device_attribute *attr, char *buf)		\
+{									\
+	struct scm_device *scmdev = to_scm_dev(dev);			\
+	int ret;							\
+									\
+	spin_lock(&scmdev->lock);					\
+	ret = sprintf(buf, "%u\n", scmdev->attrs.name);			\
+	spin_unlock(&scmdev->lock);					\
+									\
+	return ret;							\
+}									\
+static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL);
+
+scm_attr(persistence);
+scm_attr(oper_state);
+scm_attr(data_state);
+scm_attr(rank);
+scm_attr(release);
+scm_attr(res_id);
+
+static struct attribute *scmdev_attrs[] = {
+	&dev_attr_persistence.attr,
+	&dev_attr_oper_state.attr,
+	&dev_attr_data_state.attr,
+	&dev_attr_rank.attr,
+	&dev_attr_release.attr,
+	&dev_attr_res_id.attr,
+	NULL,
+};
+
+static struct attribute_group scmdev_attr_group = {
+	.attrs = scmdev_attrs,
+};
+
+static const struct attribute_group *scmdev_attr_groups[] = {
+	&scmdev_attr_group,
+	NULL,
+};
+
+static void scmdev_release(struct device *dev)
+{
+	struct scm_device *scmdev = to_scm_dev(dev);
+
+	kfree(scmdev);
+}
+
+static void scmdev_setup(struct scm_device *scmdev, struct sale *sale,
+			 unsigned int size, unsigned int max_blk_count)
+{
+	dev_set_name(&scmdev->dev, "%016llx", (unsigned long long) sale->sa);
+	scmdev->nr_max_block = max_blk_count;
+	scmdev->address = sale->sa;
+	scmdev->size = 1UL << size;
+	scmdev->attrs.rank = sale->rank;
+	scmdev->attrs.persistence = sale->p;
+	scmdev->attrs.oper_state = sale->op_state;
+	scmdev->attrs.data_state = sale->data_state;
+	scmdev->attrs.rank = sale->rank;
+	scmdev->attrs.release = sale->r;
+	scmdev->attrs.res_id = sale->rid;
+	scmdev->dev.parent = scm_root;
+	scmdev->dev.bus = &scm_bus_type;
+	scmdev->dev.release = scmdev_release;
+	scmdev->dev.groups = scmdev_attr_groups;
+	spin_lock_init(&scmdev->lock);
+}
+
+static int scm_add(struct chsc_scm_info *scm_info, size_t num)
+{
+	struct sale *sale, *scmal = scm_info->scmal;
+	struct scm_device *scmdev;
+	int ret;
+
+	for (sale = scmal; sale < scmal + num; sale++) {
+		scmdev = kzalloc(sizeof(*scmdev), GFP_KERNEL);
+		if (!scmdev)
+			return -ENODEV;
+		scmdev_setup(scmdev, sale, scm_info->is, scm_info->mbc);
+		ret = device_register(&scmdev->dev);
+		if (ret) {
+			/* Release reference from device_initialize(). */
+			put_device(&scmdev->dev);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static int scm_update_information(void)
+{
+	struct chsc_scm_info *scm_info;
+	u64 token = 0;
+	size_t num;
+	int ret;
+
+	scm_info = (void *)__get_free_page(GFP_KERNEL | GFP_DMA);
+	if (!scm_info)
+		return -ENOMEM;
+
+	do {
+		ret = chsc_scm_info(scm_info, token);
+		if (ret)
+			break;
+
+		num = (scm_info->response.length -
+		       (offsetof(struct chsc_scm_info, scmal) -
+			offsetof(struct chsc_scm_info, response))
+		      ) / sizeof(struct sale);
+
+		ret = scm_add(scm_info, num);
+		if (ret)
+			break;
+
+		token = scm_info->restok;
+	} while (token);
+
+	free_page((unsigned long)scm_info);
+
+	return ret;
+}
+
+static int __init scm_init(void)
+{
+	int ret;
+
+	ret = bus_register(&scm_bus_type);
+	if (ret)
+		return ret;
+
+	scm_root = root_device_register("scm");
+	if (IS_ERR(scm_root)) {
+		bus_unregister(&scm_bus_type);
+		return PTR_ERR(scm_root);
+	}
+
+	scm_update_information();
+	return 0;
+}
+subsys_initcall_sync(scm_init);