From 40ff4cc06697e8ba3f8ce93b0592ddbcf70cd444 Mon Sep 17 00:00:00 2001
From: Sebastian Ott <sebott@linux.vnet.ibm.com>
Date: Tue, 28 Aug 2012 16:47:02 +0200
Subject: [PATCH] s390: add scm notification

Detect an scm change notification in store event information.
Update affected scm devices and notify their drivers.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---
 arch/s390/include/asm/eadm.h |  1 +
 drivers/s390/cio/chsc.c      | 17 ++++++++++++
 drivers/s390/cio/chsc.h      |  7 +++++
 drivers/s390/cio/scm.c       | 50 +++++++++++++++++++++++++++++++++++-
 4 files changed, 74 insertions(+), 1 deletion(-)

diff --git a/arch/s390/include/asm/eadm.h b/arch/s390/include/asm/eadm.h
index 3922f525717..4d6e103f6e2 100644
--- a/arch/s390/include/asm/eadm.h
+++ b/arch/s390/include/asm/eadm.h
@@ -102,6 +102,7 @@ struct scm_driver {
 	struct device_driver drv;
 	int (*probe) (struct scm_device *scmdev);
 	int (*remove) (struct scm_device *scmdev);
+	void (*notify) (struct scm_device *scmdev);
 	void (*handler) (struct scm_device *scmdev, void *data, int error);
 };
 
diff --git a/drivers/s390/cio/chsc.c b/drivers/s390/cio/chsc.c
index 121865385c0..4d51a7c4eb8 100644
--- a/drivers/s390/cio/chsc.c
+++ b/drivers/s390/cio/chsc.c
@@ -398,6 +398,20 @@ static void chsc_process_sei_chp_config(struct chsc_sei_area *sei_area)
 	}
 }
 
+static void chsc_process_sei_scm_change(struct chsc_sei_area *sei_area)
+{
+	int ret;
+
+	CIO_CRW_EVENT(4, "chsc: scm change notification\n");
+	if (sei_area->rs != 7)
+		return;
+
+	ret = scm_update_information();
+	if (ret)
+		CIO_CRW_EVENT(0, "chsc: updating change notification"
+			      " failed (rc=%d).\n", ret);
+}
+
 static void chsc_process_sei(struct chsc_sei_area *sei_area)
 {
 	/* Check if we might have lost some information. */
@@ -419,6 +433,9 @@ static void chsc_process_sei(struct chsc_sei_area *sei_area)
 	case 8: /* channel-path-configuration notification */
 		chsc_process_sei_chp_config(sei_area);
 		break;
+	case 12: /* scm change notification */
+		chsc_process_sei_scm_change(sei_area);
+		break;
 	default: /* other stuff */
 		CIO_CRW_EVENT(4, "chsc: unhandled sei content code %d\n",
 			      sei_area->cc);
diff --git a/drivers/s390/cio/chsc.h b/drivers/s390/cio/chsc.h
index 3aa94fe7a67..662dab4b93e 100644
--- a/drivers/s390/cio/chsc.h
+++ b/drivers/s390/cio/chsc.h
@@ -154,4 +154,11 @@ struct chsc_scm_info {
 
 int chsc_scm_info(struct chsc_scm_info *scm_area, u64 token);
 
+#ifdef CONFIG_SCM_BUS
+int scm_update_information(void);
+#else /* CONFIG_SCM_BUS */
+#define scm_update_information() 0
+#endif /* CONFIG_SCM_BUS */
+
+
 #endif
diff --git a/drivers/s390/cio/scm.c b/drivers/s390/cio/scm.c
index 874b64a4bf2..aa4476e9205 100644
--- a/drivers/s390/cio/scm.c
+++ b/drivers/s390/cio/scm.c
@@ -196,6 +196,47 @@ static void scmdev_setup(struct scm_device *scmdev, struct sale *sale,
 	spin_lock_init(&scmdev->lock);
 }
 
+/*
+ * Check for state-changes, notify the driver and userspace.
+ */
+static void scmdev_update(struct scm_device *scmdev, struct sale *sale)
+{
+	struct scm_driver *scmdrv;
+	bool changed;
+
+	device_lock(&scmdev->dev);
+	changed = scmdev->attrs.rank != sale->rank ||
+		  scmdev->attrs.oper_state != sale->op_state;
+	scmdev->attrs.rank = sale->rank;
+	scmdev->attrs.oper_state = sale->op_state;
+	if (!scmdev->dev.driver)
+		goto out;
+	scmdrv = to_scm_drv(scmdev->dev.driver);
+	if (changed && scmdrv->notify)
+		scmdrv->notify(scmdev);
+out:
+	device_unlock(&scmdev->dev);
+	if (changed)
+		kobject_uevent(&scmdev->dev.kobj, KOBJ_CHANGE);
+}
+
+static int check_address(struct device *dev, void *data)
+{
+	struct scm_device *scmdev = to_scm_dev(dev);
+	struct sale *sale = data;
+
+	return scmdev->address == sale->sa;
+}
+
+static struct scm_device *scmdev_find(struct sale *sale)
+{
+	struct device *dev;
+
+	dev = bus_find_device(&scm_bus_type, NULL, sale, check_address);
+
+	return dev ? to_scm_dev(dev) : NULL;
+}
+
 static int scm_add(struct chsc_scm_info *scm_info, size_t num)
 {
 	struct sale *sale, *scmal = scm_info->scmal;
@@ -203,6 +244,13 @@ static int scm_add(struct chsc_scm_info *scm_info, size_t num)
 	int ret;
 
 	for (sale = scmal; sale < scmal + num; sale++) {
+		scmdev = scmdev_find(sale);
+		if (scmdev) {
+			scmdev_update(scmdev, sale);
+			/* Release reference from scm_find(). */
+			put_device(&scmdev->dev);
+			continue;
+		}
 		scmdev = kzalloc(sizeof(*scmdev), GFP_KERNEL);
 		if (!scmdev)
 			return -ENODEV;
@@ -218,7 +266,7 @@ static int scm_add(struct chsc_scm_info *scm_info, size_t num)
 	return 0;
 }
 
-static int scm_update_information(void)
+int scm_update_information(void)
 {
 	struct chsc_scm_info *scm_info;
 	u64 token = 0;