[PATCH] 2.5.22: common code changes for s/390.

1) Add __s390__ to the list of architectures that use unsigned int as
   type for rautofs_wqt_t. __s390__ is defined for both 31-bit and 64-bit
   linux for s/390. Both architectures are fine with unsigned int since
   sizeof(unsigned int) == sizeof(unsigned long) for 31 bit s/390.
2) Remove early initialization call ccwcache_init(). It doesn't exists
   anymore.
3) Remove special case for irq_stat. We moved the irq_stat structure out
   of the lowcore.
4) Replace acquire_console_sem with down_trylock & return to avoid an
   endless trap loop if console_unblank is called from interrupt context
   and the console semaphore is taken.

include/linux/auto_fs.h

@@ -45,7 +45,8 @@
  * If so, 32-bit user-space code should be backwards compatible.
  */
 
-#if defined(__sparc__) || defined(__mips__) || defined(__x86_64__) || defined(__powerpc__)
+#if defined(__sparc__) || defined(__mips__) || defined(__x86_64) \
+ || defined(__powerpc__) || defined(__s390__)
 typedef unsigned int autofs_wqt_t;
 #else
 typedef unsigned long autofs_wqt_t;

init/main.c

@@ -34,7 +34,6 @@
 
 #if defined(CONFIG_ARCH_S390)
 #include <asm/s390mach.h>
-#include <asm/ccwcache.h>
 #endif
 
 #ifdef CONFIG_MTRR
@@ -393,9 +392,6 @@ asmlinkage void __init start_kernel(void)
 	buffer_init();
 	vfs_caches_init(mempages);
 	radix_tree_init();
-#if defined(CONFIG_ARCH_S390)
-	ccwcache_init();
-#endif
 	signals_init();
 #ifdef CONFIG_PROC_FS
 	proc_root_init();

kernel/ksyms.c

@@ -388,9 +388,7 @@ EXPORT_SYMBOL(add_timer);
 EXPORT_SYMBOL(del_timer);
 EXPORT_SYMBOL(request_irq);
 EXPORT_SYMBOL(free_irq);
-#if !defined(CONFIG_ARCH_S390)
-EXPORT_SYMBOL(irq_stat);	/* No separate irq_stat for s390, it is part of PSA */
-#endif
+EXPORT_SYMBOL(irq_stat);
 
 /* waitqueue handling */
 EXPORT_SYMBOL(add_wait_queue);

kernel/printk.c

@@ -553,7 +553,14 @@ void console_unblank(void)
 {
 	struct console *c;
 
-	acquire_console_sem();
+	/*
+	 * Try to get the console semaphore. If someone else owns it
+	 * we have to return without unblanking because console_unblank
+	 * may be called in interrupt context.
+	 */
+	if (down_trylock(&console_sem) != 0)
+		return;
+	console_may_schedule = 0;
 	for (c = console_drivers; c != NULL; c = c->next)
 		if ((c->flags & CON_ENABLED) && c->unblank)
 			c->unblank();