[S390] s390: move machine flags to lowcore

Currently the storage of the machine flags is a globally exported unsigned
long long variable. By moving the storage location into the lowcore struct we
allow assembler code to check machine_flags directly even without needing a
register. Addtionally the lowcore and therefore the machine flags too will be
in cache most of the time.

Signed-off-by: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 25 insertions, 0 deletions

diff --git a/arch/s390/include/asm/cpuid.h b/arch/s390/include/asm/cpuid.h
new file mode 100644
index 000000000000..07836a2e5222
--- /dev/null
+++ b/arch/s390/include/asm/cpuid.h
@@ -0,0 +1,25 @@
+/*
+ *    Copyright IBM Corp. 2000,2009
+ *    Author(s): Hartmut Penner <hp@de.ibm.com>,
+ *               Martin Schwidefsky <schwidefsky@de.ibm.com>
+ *               Christian Ehrhardt <ehrhardt@de.ibm.com>
+ */
+
+#ifndef _ASM_S390_CPUID_H_
+#define _ASM_S390_CPUID_H_
+
+/*
+ *  CPU type and hardware bug flags. Kept separately for each CPU.
+ *  Members of this structure are referenced in head.S, so think twice
+ *  before touching them. [mj]
+ */
+
+typedef struct
+{
+        unsigned int version :  8;
+        unsigned int ident   : 24;
+        unsigned int machine : 16;
+        unsigned int unused  : 16;
+} __attribute__ ((packed)) cpuid_t;
+
+#endif /* _ASM_S390_CPUID_H_ */