[S390] add MACHINE_IS_LPAR flag

Introduce the MACHINE_IS_LPAR flag for code that should only be
executed if Linux is running in an LPAR.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/include/asm/setup.h

@@ -71,9 +71,12 @@ extern unsigned int user_mode;
 #define MACHINE_FLAG_KVM	(1UL << 9)
 #define MACHINE_FLAG_HPAGE	(1UL << 10)
 #define MACHINE_FLAG_PFMF	(1UL << 11)
+#define MACHINE_FLAG_LPAR	(1UL << 12)
 
 #define MACHINE_IS_VM		(S390_lowcore.machine_flags & MACHINE_FLAG_VM)
 #define MACHINE_IS_KVM		(S390_lowcore.machine_flags & MACHINE_FLAG_KVM)
+#define MACHINE_IS_LPAR		(S390_lowcore.machine_flags & MACHINE_FLAG_LPAR)
+
 #define MACHINE_HAS_DIAG9C	(S390_lowcore.machine_flags & MACHINE_FLAG_DIAG9C)
 
 #ifndef __s390x__

arch/s390/kernel/early.c

@@ -214,10 +214,13 @@ static __initdata struct sysinfo_3_2_2 vmms __aligned(PAGE_SIZE);
 
 static noinline __init void detect_machine_type(void)
 {
-	/* No VM information? Looks like LPAR */
-	if (stsi(&vmms, 3, 2, 2) == -ENOSYS)
+	/* Check current-configuration-level */
+	if ((stsi(NULL, 0, 0, 0) >> 28) <= 2) {
+		S390_lowcore.machine_flags |= MACHINE_FLAG_LPAR;
 		return;
-	if (!vmms.count)
+	}
+	/* Get virtual-machine cpu information. */
+	if (stsi(&vmms, 3, 2, 2) == -ENOSYS || !vmms.count)
 		return;
 
 	/* Running under KVM? If not we assume z/VM */

arch/s390/kernel/setup.c

@@ -804,7 +804,7 @@ setup_arch(char **cmdline_p)
 	if (MACHINE_IS_VM)
 		pr_info("Linux is running as a z/VM "
 			"guest operating system in 31-bit mode\n");
-	else
+	else if (MACHINE_IS_LPAR)
 		pr_info("Linux is running natively in 31-bit mode\n");
 	if (MACHINE_HAS_IEEE)
 		pr_info("The hardware system has IEEE compatible "
@@ -818,7 +818,7 @@ setup_arch(char **cmdline_p)
 			"guest operating system in 64-bit mode\n");
 	else if (MACHINE_IS_KVM)
 		pr_info("Linux is running under KVM in 64-bit mode\n");
-	else
+	else if (MACHINE_IS_LPAR)
 		pr_info("Linux is running natively in 64-bit mode\n");
 #endif /* CONFIG_64BIT */
 

drivers/s390/cio/cio.c

@@ -661,7 +661,7 @@ void __irq_entry do_IRQ(struct pt_regs *regs)
 		 * We don't do this for VM because a tpi drops the cpu
 		 * out of the sie which costs more cycles than it saves.
 		 */
-	} while (!MACHINE_IS_VM && tpi (NULL) != 0);
+	} while (MACHINE_IS_LPAR && tpi(NULL) != 0);
 	irq_exit();
 	set_irq_regs(old_regs);
 }

drivers/s390/cio/qdio_main.c

@@ -534,7 +534,7 @@ static int qdio_inbound_q_moved(struct qdio_q *q)
 
 	if ((bufnr != q->last_move) || q->qdio_error) {
 		q->last_move = bufnr;
-		if (!is_thinint_irq(q->irq_ptr) && !MACHINE_IS_VM)
+		if (!is_thinint_irq(q->irq_ptr) && MACHINE_IS_LPAR)
 			q->u.in.timestamp = get_usecs();
 		return 1;
 	} else