5 files changed, 164 insertions, 41 deletions

diff --git a/arch/s390/hypfs/Makefile b/arch/s390/hypfs/Makefile
index 06f8d95a16cd..2ee25ba252d6 100644
--- a/arch/s390/hypfs/Makefile
+++ b/arch/s390/hypfs/Makefile
@@ -5,3 +5,4 @@
 obj-$(CONFIG_S390_HYPFS_FS) += s390_hypfs.o
 
 s390_hypfs-objs := inode.o hypfs_diag.o hypfs_vm.o hypfs_dbfs.o hypfs_sprp.o
+s390_hypfs-objs += hypfs_diag0c.o
diff --git a/arch/s390/hypfs/hypfs.h b/arch/s390/hypfs/hypfs.h
index b34b5ab90a31..eecde500ed49 100644
--- a/arch/s390/hypfs/hypfs.h
+++ b/arch/s390/hypfs/hypfs.h
@@ -37,6 +37,10 @@ extern int hypfs_vm_init(void);
 extern void hypfs_vm_exit(void);
 extern int hypfs_vm_create_files(struct dentry *root);
 
+/* VM diagnose 0c */
+int hypfs_diag0c_init(void);
+void hypfs_diag0c_exit(void);
+
 /* Set Partition-Resource Parameter */
 int hypfs_sprp_init(void);
 void hypfs_sprp_exit(void);
@@ -49,7 +53,6 @@ struct hypfs_dbfs_data {
 	void			*buf_free_ptr;
 	size_t			size;
 	struct hypfs_dbfs_file	*dbfs_file;
-	struct kref		kref;
 };
 
 struct hypfs_dbfs_file {
@@ -61,8 +64,6 @@ struct hypfs_dbfs_file {
 					   unsigned long);
 
 	/* Private data for hypfs_dbfs.c */
-	struct hypfs_dbfs_data	*data;
-	struct delayed_work	data_free_work;
 	struct mutex		lock;
 	struct dentry		*dentry;
 };
diff --git a/arch/s390/hypfs/hypfs_dbfs.c b/arch/s390/hypfs/hypfs_dbfs.c
index 47fe1055c714..752f6df3e697 100644
--- a/arch/s390/hypfs/hypfs_dbfs.c
+++ b/arch/s390/hypfs/hypfs_dbfs.c
@@ -17,33 +17,16 @@ static struct hypfs_dbfs_data *hypfs_dbfs_data_alloc(struct hypfs_dbfs_file *f)
 	data = kmalloc(sizeof(*data), GFP_KERNEL);
 	if (!data)
 		return NULL;
-	kref_init(&data->kref);
 	data->dbfs_file = f;
 	return data;
 }
 
-static void hypfs_dbfs_data_free(struct kref *kref)
+static void hypfs_dbfs_data_free(struct hypfs_dbfs_data *data)
 {
-	struct hypfs_dbfs_data *data;
-
-	data = container_of(kref, struct hypfs_dbfs_data, kref);
 	data->dbfs_file->data_free(data->buf_free_ptr);
 	kfree(data);
 }
 
-static void data_free_delayed(struct work_struct *work)
-{
-	struct hypfs_dbfs_data *data;
-	struct hypfs_dbfs_file *df;
-
-	df = container_of(work, struct hypfs_dbfs_file, data_free_work.work);
-	mutex_lock(&df->lock);
-	data = df->data;
-	df->data = NULL;
-	mutex_unlock(&df->lock);
-	kref_put(&data->kref, hypfs_dbfs_data_free);
-}
-
 static ssize_t dbfs_read(struct file *file, char __user *buf,
 			 size_t size, loff_t *ppos)
 {
@@ -56,28 +39,21 @@ static ssize_t dbfs_read(struct file *file, char __user *buf,
 
 	df = file_inode(file)->i_private;
 	mutex_lock(&df->lock);
-	if (!df->data) {
-		data = hypfs_dbfs_data_alloc(df);
-		if (!data) {
-			mutex_unlock(&df->lock);
-			return -ENOMEM;
-		}
-		rc = df->data_create(&data->buf, &data->buf_free_ptr,
-				     &data->size);
-		if (rc) {
-			mutex_unlock(&df->lock);
-			kfree(data);
-			return rc;
-		}
-		df->data = data;
-		schedule_delayed_work(&df->data_free_work, HZ);
+	data = hypfs_dbfs_data_alloc(df);
+	if (!data) {
+		mutex_unlock(&df->lock);
+		return -ENOMEM;
+	}
+	rc = df->data_create(&data->buf, &data->buf_free_ptr, &data->size);
+	if (rc) {
+		mutex_unlock(&df->lock);
+		kfree(data);
+		return rc;
 	}
-	data = df->data;
-	kref_get(&data->kref);
 	mutex_unlock(&df->lock);
 
 	rc = simple_read_from_buffer(buf, size, ppos, data->buf, data->size);
-	kref_put(&data->kref, hypfs_dbfs_data_free);
+	hypfs_dbfs_data_free(data);
 	return rc;
 }
 
@@ -108,7 +84,6 @@ int hypfs_dbfs_create_file(struct hypfs_dbfs_file *df)
 	if (IS_ERR(df->dentry))
 		return PTR_ERR(df->dentry);
 	mutex_init(&df->lock);
-	INIT_DELAYED_WORK(&df->data_free_work, data_free_delayed);
 	return 0;
 }
 
diff --git a/arch/s390/hypfs/hypfs_diag0c.c b/arch/s390/hypfs/hypfs_diag0c.c
new file mode 100644
index 000000000000..d4c0d3717543
--- /dev/null
+++ b/arch/s390/hypfs/hypfs_diag0c.c
@@ -0,0 +1,139 @@
+/*
+ * Hypervisor filesystem for Linux on s390
+ *
+ * Diag 0C implementation
+ *
+ * Copyright IBM Corp. 2014
+ */
+
+#include <linux/slab.h>
+#include <linux/cpu.h>
+#include <asm/hypfs.h>
+#include "hypfs.h"
+
+#define DBFS_D0C_HDR_VERSION 0
+
+/*
+ * Execute diagnose 0c in 31 bit mode
+ */
+static void diag0c(struct hypfs_diag0c_entry *entry)
+{
+	asm volatile (
+#ifdef CONFIG_64BIT
+		"	sam31\n"
+		"	diag	%0,%0,0x0c\n"
+		"	sam64\n"
+#else
+		"	diag %0,%0,0x0c\n"
+#endif
+		: /* no output register */
+		: "a" (entry)
+		: "memory");
+}
+
+/*
+ * Get hypfs_diag0c_entry from CPU vector and store diag0c data
+ */
+static void diag0c_fn(void *data)
+{
+	diag0c(((void **) data)[smp_processor_id()]);
+}
+
+/*
+ * Allocate buffer and store diag 0c data
+ */
+static void *diag0c_store(unsigned int *count)
+{
+	struct hypfs_diag0c_data *diag0c_data;
+	unsigned int cpu_count, cpu, i;
+	void **cpu_vec;
+
+	get_online_cpus();
+	cpu_count = num_online_cpus();
+	cpu_vec = kmalloc(sizeof(*cpu_vec) * num_possible_cpus(), GFP_KERNEL);
+	if (!cpu_vec)
+		goto fail_put_online_cpus;
+	/* Note: Diag 0c needs 8 byte alignment and real storage */
+	diag0c_data = kzalloc(sizeof(struct hypfs_diag0c_hdr) +
+			      cpu_count * sizeof(struct hypfs_diag0c_entry),
+			      GFP_KERNEL | GFP_DMA);
+	if (!diag0c_data)
+		goto fail_kfree_cpu_vec;
+	i = 0;
+	/* Fill CPU vector for each online CPU */
+	for_each_online_cpu(cpu) {
+		diag0c_data->entry[i].cpu = cpu;
+		cpu_vec[cpu] = &diag0c_data->entry[i++];
+	}
+	/* Collect data all CPUs */
+	on_each_cpu(diag0c_fn, cpu_vec, 1);
+	*count = cpu_count;
+	kfree(cpu_vec);
+	put_online_cpus();
+	return diag0c_data;
+
+fail_kfree_cpu_vec:
+	kfree(cpu_vec);
+fail_put_online_cpus:
+	put_online_cpus();
+	return ERR_PTR(-ENOMEM);
+}
+
+/*
+ * Hypfs DBFS callback: Free diag 0c data
+ */
+static void dbfs_diag0c_free(const void *data)
+{
+	kfree(data);
+}
+
+/*
+ * Hypfs DBFS callback: Create diag 0c data
+ */
+static int dbfs_diag0c_create(void **data, void **data_free_ptr, size_t *size)
+{
+	struct hypfs_diag0c_data *diag0c_data;
+	unsigned int count;
+
+	diag0c_data = diag0c_store(&count);
+	if (IS_ERR(diag0c_data))
+		return PTR_ERR(diag0c_data);
+	memset(&diag0c_data->hdr, 0, sizeof(diag0c_data->hdr));
+	get_tod_clock_ext(diag0c_data->hdr.tod_ext);
+	diag0c_data->hdr.len = count * sizeof(struct hypfs_diag0c_entry);
+	diag0c_data->hdr.version = DBFS_D0C_HDR_VERSION;
+	diag0c_data->hdr.count = count;
+	*data = diag0c_data;
+	*data_free_ptr = diag0c_data;
+	*size = diag0c_data->hdr.len + sizeof(struct hypfs_diag0c_hdr);
+	return 0;
+}
+
+/*
+ * Hypfs DBFS file structure
+ */
+static struct hypfs_dbfs_file dbfs_file_0c = {
+	.name		= "diag_0c",
+	.data_create	= dbfs_diag0c_create,
+	.data_free	= dbfs_diag0c_free,
+};
+
+/*
+ * Initialize diag 0c interface for z/VM
+ */
+int __init hypfs_diag0c_init(void)
+{
+	if (!MACHINE_IS_VM)
+		return 0;
+	return hypfs_dbfs_create_file(&dbfs_file_0c);
+}
+
+/*
+ * Shutdown diag 0c interface for z/VM
+ */
+void hypfs_diag0c_exit(void)
+{
+	if (!MACHINE_IS_VM)
+		return;
+	hypfs_dbfs_remove_file(&dbfs_file_0c);
+}
diff --git a/arch/s390/hypfs/inode.c b/arch/s390/hypfs/inode.c
index c952b981e4f2..4c8008dd938e 100644
--- a/arch/s390/hypfs/inode.c
+++ b/arch/s390/hypfs/inode.c
@@ -482,10 +482,14 @@ static int __init hypfs_init(void)
 		rc = -ENODATA;
 		goto fail_hypfs_vm_exit;
 	}
+	if (hypfs_diag0c_init()) {
+		rc = -ENODATA;
+		goto fail_hypfs_sprp_exit;
+	}
 	s390_kobj = kobject_create_and_add("s390", hypervisor_kobj);
 	if (!s390_kobj) {
 		rc = -ENOMEM;
-		goto fail_hypfs_sprp_exit;
+		goto fail_hypfs_diag0c_exit;
 	}
 	rc = register_filesystem(&hypfs_type);
 	if (rc)
@@ -494,6 +498,8 @@ static int __init hypfs_init(void)
 
 fail_filesystem:
 	kobject_put(s390_kobj);
+fail_hypfs_diag0c_exit:
+	hypfs_diag0c_exit();
 fail_hypfs_sprp_exit:
 	hypfs_sprp_exit();
 fail_hypfs_vm_exit:
@@ -510,6 +516,7 @@ static void __exit hypfs_exit(void)
 {
 	unregister_filesystem(&hypfs_type);
 	kobject_put(s390_kobj);
+	hypfs_diag0c_exit();
 	hypfs_sprp_exit();
 	hypfs_vm_exit();
 	hypfs_diag_exit();