s390/hypfs: Add diagnose 0c support

With this feature, you can read the CPU performance metrics provided by the
z/VM diagnose 0C. This then allows to get the management time for each
online CPU of the guest where the diagnose is executed.

The new debugfs file /sys/kernel/debug/s390_hypfs/diag_0c exports the
diag0C binary data to user space via an open/read/close interface.

The binary data consists out of a header structure followed by an
array that contains the diagnose 0c data for each online CPU.

Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 32 insertions, 3 deletions

diff --git a/arch/s390/include/uapi/asm/hypfs.h b/arch/s390/include/uapi/asm/hypfs.h
index 37998b449531..b3fe12d8dd87 100644
--- a/arch/s390/include/uapi/asm/hypfs.h
+++ b/arch/s390/include/uapi/asm/hypfs.h
@@ -1,16 +1,19 @@
 /*
- * IOCTL interface for hypfs
+ * Structures for hypfs interface
  *
  * Copyright IBM Corp. 2013
  *
  * Author: Martin Schwidefsky <schwidefsky@de.ibm.com>
  */
 
-#ifndef _ASM_HYPFS_CTL_H
-#define _ASM_HYPFS_CTL_H
+#ifndef _ASM_HYPFS_H
+#define _ASM_HYPFS_H
 
 #include <linux/types.h>
 
+/*
+ * IOCTL for binary interface /sys/kernel/debug/diag_304
+ */
 struct hypfs_diag304 {
         __u32   args[2];
         __u64   data;
@@ -22,4 +25,30 @@ struct hypfs_diag304 {
 #define HYPFS_DIAG304 \
         _IOWR(HYPFS_IOCTL_MAGIC, 0x20, struct hypfs_diag304)
 
+/*
+ * Structures for binary interface /sys/kernel/debug/diag_0c
+ */
+struct hypfs_diag0c_hdr {
+        __u64   len;            /* Length of diag0c buffer without header */
+        __u16   version;        /* Version of header */
+        char    reserved1[6];   /* Reserved */
+        char    tod_ext[16];    /* TOD clock for diag0c */
+        __u64   count;          /* Number of entries (CPUs) in diag0c array */
+        char    reserved2[24];  /* Reserved */
+};
+
+struct hypfs_diag0c_entry {
+        char    date[8];        /* MM/DD/YY in EBCDIC */
+        char    time[8];        /* HH:MM:SS in EBCDIC */
+        __u64   virtcpu;        /* Virtual time consumed by the virt CPU (us) */
+        __u64   totalproc;      /* Total of virtual and simulation time (us) */
+        __u32   cpu;            /* Linux logical CPU number */
+        __u32   reserved;       /* Align to 8 byte */
+};
+
+struct hypfs_diag0c_data {
+        struct hypfs_diag0c_hdr         hdr;            /* 64 byte header */
+        struct hypfs_diag0c_entry       entry[];        /* diag0c entry array */
+};
+
 #endif