[S390] service level interface.

Add a new proc interface /proc/service_levels that allows any code
to report a relevant service level, e.g. the microcode level of
devices, the service level of the hypervisor, etc.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 125 insertions, 2 deletions

diff --git a/drivers/s390/sysinfo.c b/drivers/s390/sysinfo.c
index c3e4ab07b9cc..0eea90781385 100644
--- a/drivers/s390/sysinfo.c
+++ b/drivers/s390/sysinfo.c
@@ -1,17 +1,21 @@
 /*
  *  drivers/s390/sysinfo.c
  *
- *    Copyright (C) 2001 IBM Deutschland Entwicklung GmbH, IBM Corporation
- *    Author(s): Ulrich Weigand (Ulrich.Weigand@de.ibm.com)
+ *  Copyright IBM Corp. 2001, 2008
+ *  Author(s): Ulrich Weigand (Ulrich.Weigand@de.ibm.com)
+ *             Martin Schwidefsky <schwidefsky@de.ibm.com>
  */
 
 #include <linux/kernel.h>
 #include <linux/mm.h>
 #include <linux/proc_fs.h>
+#include <linux/seq_file.h>
 #include <linux/init.h>
 #include <linux/delay.h>
+#include <linux/module.h>
 #include <asm/ebcdic.h>
 #include <asm/sysinfo.h>
+#include <asm/cpcmd.h>
 
 /* Sigh, math-emu. Don't ask. */
 #include <asm/sfp-util.h>
@@ -271,6 +275,125 @@ static __init int create_proc_sysinfo(void)
 
 __initcall(create_proc_sysinfo);
 
+/*
+ * Service levels interface.
+ */
+
+static DECLARE_RWSEM(service_level_sem);
+static LIST_HEAD(service_level_list);
+
+int register_service_level(struct service_level *slr)
+{
+        struct service_level *ptr;
+
+        down_write(&service_level_sem);
+        list_for_each_entry(ptr, &service_level_list, list)
+                if (ptr == slr) {
+                        up_write(&service_level_sem);
+                        return -EEXIST;
+                }
+        list_add_tail(&slr->list, &service_level_list);
+        up_write(&service_level_sem);
+        return 0;
+}
+EXPORT_SYMBOL(register_service_level);
+
+int unregister_service_level(struct service_level *slr)
+{
+        struct service_level *ptr, *next;
+        int rc = -ENOENT;
+
+        down_write(&service_level_sem);
+        list_for_each_entry_safe(ptr, next, &service_level_list, list) {
+                if (ptr != slr)
+                        continue;
+                list_del(&ptr->list);
+                rc = 0;
+                break;
+        }
+        up_write(&service_level_sem);
+        return rc;
+}
+EXPORT_SYMBOL(unregister_service_level);
+
+static void *service_level_start(struct seq_file *m, loff_t *pos)
+{
+        down_read(&service_level_sem);
+        return seq_list_start(&service_level_list, *pos);
+}
+
+static void *service_level_next(struct seq_file *m, void *p, loff_t *pos)
+{
+        return seq_list_next(p, &service_level_list, pos);
+}
+
+static void service_level_stop(struct seq_file *m, void *p)
+{
+        up_read(&service_level_sem);
+}
+
+static int service_level_show(struct seq_file *m, void *p)
+{
+        struct service_level *slr;
+
+        slr = list_entry(p, struct service_level, list);
+        slr->seq_print(m, slr);
+        return 0;
+}
+
+static const struct seq_operations service_level_seq_ops = {
+        .start          = service_level_start,
+        .next           = service_level_next,
+        .stop           = service_level_stop,
+        .show           = service_level_show
+};
+
+static int service_level_open(struct inode *inode, struct file *file)
+{
+        return seq_open(file, &service_level_seq_ops);
+}
+
+static const struct file_operations service_level_ops = {
+        .open           = service_level_open,
+        .read           = seq_read,
+        .llseek         = seq_lseek,
+        .release        = seq_release
+};
+
+static void service_level_vm_print(struct seq_file *m,
+                                   struct service_level *slr)
+{
+        char *query_buffer, *str;
+
+        query_buffer = kmalloc(1024, GFP_KERNEL | GFP_DMA);
+        if (!query_buffer)
+                return;
+        cpcmd("QUERY CPLEVEL", query_buffer, 1024, NULL);
+        str = strchr(query_buffer, '\n');
+        if (str)
+                *str = 0;
+        seq_printf(m, "VM: %s\n", query_buffer);
+        kfree(query_buffer);
+}
+
+static struct service_level service_level_vm = {
+        .seq_print = service_level_vm_print
+};
+
+static __init int create_proc_service_level(void)
+{
+        proc_create("service_levels", 0, NULL, &service_level_ops);
+        if (MACHINE_IS_VM)
+                register_service_level(&service_level_vm);
+        return 0;
+}
+
+subsys_initcall(create_proc_service_level);
+
+/*
+ * Bogomips calculation based on cpu capability.
+ */
+
 int get_cpu_capability(unsigned int *capability)
 {
         struct sysinfo_1_2_2 *info;