[PATCH] s390: remove pagex support

Remove pagex pseudo page fault code.  It does not work together with the
system call speedup that makes the complete system call path enabled for
interrupts.  To make pagex and the syscall speedup code work together we would
have to add code to the program check handler to do a critical section cleanup
like the asynchronous interrupt code.  This would make program checks slower.
Not what we want.

Newer versions of z/VM have the improved pfault pseudo page fault interface.
This replaces the old pagex interface and does not have the problem.  So its
better to just rip out the pagex code.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 3 insertions, 26 deletions

diff --git a/arch/s390/kernel/traps.c b/arch/s390/kernel/traps.c
index 6b8703ec2ae6..c5bd36fae56b 100644
--- a/arch/s390/kernel/traps.c
+++ b/arch/s390/kernel/traps.c
@@ -57,7 +57,6 @@ int sysctl_userprocess_debug = 0;
 
 extern pgm_check_handler_t do_protection_exception;
 extern pgm_check_handler_t do_dat_exception;
-extern pgm_check_handler_t do_pseudo_page_fault;
 #ifdef CONFIG_PFAULT
 extern int pfault_init(void);
 extern void pfault_fini(void);
@@ -676,20 +675,6 @@ asmlinkage void kernel_stack_overflow(struct pt_regs * regs)
 	panic("Corrupt kernel stack, can't continue.");
 }
 
-#ifndef CONFIG_ARCH_S390X
-static int
-pagex_reboot_event(struct notifier_block *this, unsigned long event, void *ptr)
-{
-	if (MACHINE_IS_VM)
-		cpcmd("SET PAGEX OFF", NULL, 0, NULL);
-	return NOTIFY_DONE;
-}
-
-static struct notifier_block pagex_reboot_notifier = {
-	.notifier_call = &pagex_reboot_event,
-};
-#endif
-
 /* init is done in lowcore.S and head.S */
 
 void __init trap_init(void)
@@ -717,9 +702,7 @@ void __init trap_init(void)
         pgm_check_table[0x11] = &do_dat_exception;
         pgm_check_table[0x12] = &translation_exception;
         pgm_check_table[0x13] = &special_op_exception;
-#ifndef CONFIG_ARCH_S390X
- 	pgm_check_table[0x14] = &do_pseudo_page_fault;
-#else /* CONFIG_ARCH_S390X */
+#ifdef CONFIG_ARCH_S390X
         pgm_check_table[0x38] = &do_dat_exception;
 	pgm_check_table[0x39] = &do_dat_exception;
 	pgm_check_table[0x3A] = &do_dat_exception;
@@ -731,12 +714,10 @@ void __init trap_init(void)
 	pgm_check_table[0x40] = &do_monitor_call;
 
 	if (MACHINE_IS_VM) {
+#ifdef CONFIG_PFAULT
 		/*
-		 * First try to get pfault pseudo page faults going.
-		 * If this isn't available turn on pagex page faults.
+		 * Try to get pfault pseudo page faults going.
 		 */
-#ifdef CONFIG_PFAULT
-		/* request the 0x2603 external interrupt */
 		if (register_early_external_interrupt(0x2603, pfault_interrupt,
 						      &ext_int_pfault) != 0)
 			panic("Couldn't request external interrupt 0x2603");
@@ -748,9 +729,5 @@ void __init trap_init(void)
 		unregister_early_external_interrupt(0x2603, pfault_interrupt,
 						    &ext_int_pfault);
 #endif
-#ifndef CONFIG_ARCH_S390X
-		register_reboot_notifier(&pagex_reboot_notifier);
-		cpcmd("SET PAGEX ON", NULL, 0, NULL);
-#endif
 	}
 }