Merge tag 'split-asm_system_h-for-linus-20120328' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-asm_system

Pull "Disintegrate and delete asm/system.h" from David Howells:
 "Here are a bunch of patches to disintegrate asm/system.h into a set of
  separate bits to relieve the problem of circular inclusion
  dependencies.

  I've built all the working defconfigs from all the arches that I can
  and made sure that they don't break.

  The reason for these patches is that I recently encountered a circular
  dependency problem that came about when I produced some patches to
  optimise get_order() by rewriting it to use ilog2().

  This uses bitops - and on the SH arch asm/bitops.h drags in
  asm-generic/get_order.h by a circuituous route involving asm/system.h.

  The main difficulty seems to be asm/system.h.  It holds a number of
  low level bits with no/few dependencies that are commonly used (eg.
  memory barriers) and a number of bits with more dependencies that
  aren't used in many places (eg.  switch_to()).

  These patches break asm/system.h up into the following core pieces:

    (1) asm/barrier.h

        Move memory barriers here.  This already done for MIPS and Alpha.

    (2) asm/switch_to.h

        Move switch_to() and related stuff here.

    (3) asm/exec.h

        Move arch_align_stack() here.  Other process execution related bits
        could perhaps go here from asm/processor.h.

    (4) asm/cmpxchg.h

        Move xchg() and cmpxchg() here as they're full word atomic ops and
        frequently used by atomic_xchg() and atomic_cmpxchg().

    (5) asm/bug.h

        Move die() and related bits.

    (6) asm/auxvec.h

        Move AT_VECTOR_SIZE_ARCH here.

  Other arch headers are created as needed on a per-arch basis."

Fixed up some conflicts from other header file cleanups and moving code
around that has happened in the meantime, so David's testing is somewhat
weakened by that.  We'll find out anything that got broken and fix it..

* tag 'split-asm_system_h-for-linus-20120328' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-asm_system: (38 commits)
  Delete all instances of asm/system.h
  Remove all #inclusions of asm/system.h
  Add #includes needed to permit the removal of asm/system.h
  Move all declarations of free_initmem() to linux/mm.h
  Disintegrate asm/system.h for OpenRISC
  Split arch_align_stack() out from asm-generic/system.h
  Split the switch_to() wrapper out of asm-generic/system.h
  Move the asm-generic/system.h xchg() implementation to asm-generic/cmpxchg.h
  Create asm-generic/barrier.h
  Make asm-generic/cmpxchg.h #include asm-generic/cmpxchg-local.h
  Disintegrate asm/system.h for Xtensa
  Disintegrate asm/system.h for Unicore32 [based on ver #3, changed by gxt]
  Disintegrate asm/system.h for Tile
  Disintegrate asm/system.h for Sparc
  Disintegrate asm/system.h for SH
  Disintegrate asm/system.h for Score
  Disintegrate asm/system.h for S390
  Disintegrate asm/system.h for PowerPC
  Disintegrate asm/system.h for PA-RISC
  Disintegrate asm/system.h for MN10300
  ...

7 files changed, 183 insertions, 149 deletions

diff --git a/include/asm-generic/atomic.h b/include/asm-generic/atomic.h
index e37963c1..1ced641 100644
--- a/include/asm-generic/atomic.h
+++ b/include/asm-generic/atomic.h
@@ -15,6 +15,8 @@
 #ifndef __ASM_GENERIC_ATOMIC_H
 #define __ASM_GENERIC_ATOMIC_H
 
+#include <asm/cmpxchg.h>
+
 #ifdef CONFIG_SMP
 /* Force people to define core atomics */
 # if !defined(atomic_add_return) || !defined(atomic_sub_return) || \
@@ -52,7 +54,6 @@
 #define atomic_set(v, i) (((v)->counter) = (i))
 
 #include <linux/irqflags.h>
-#include <asm/system.h>
 
 /**
  * atomic_add_return - add integer to atomic variable
diff --git a/include/asm-generic/barrier.h b/include/asm-generic/barrier.h
new file mode 100644
index 0000000..639d7a4
--- /dev/null
+++ b/include/asm-generic/barrier.h
@@ -0,0 +1,50 @@
+/* Generic barrier definitions, based on MN10300 definitions.
+ *
+ * It should be possible to use these on really simple architectures,
+ * but it serves more as a starting point for new ports.
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+#ifndef __ASM_GENERIC_BARRIER_H
+#define __ASM_GENERIC_BARRIER_H
+
+#ifndef __ASSEMBLY__
+
+#define nop() asm volatile ("nop")
+
+/*
+ * Force strict CPU ordering.
+ * And yes, this is required on UP too when we're talking
+ * to devices.
+ *
+ * This implementation only contains a compiler barrier.
+ */
+
+#define mb()	asm volatile ("": : :"memory")
+#define rmb()	mb()
+#define wmb()	asm volatile ("": : :"memory")
+
+#ifdef CONFIG_SMP
+#define smp_mb()	mb()
+#define smp_rmb()	rmb()
+#define smp_wmb()	wmb()
+#else
+#define smp_mb()	barrier()
+#define smp_rmb()	barrier()
+#define smp_wmb()	barrier()
+#endif
+
+#define set_mb(var, value)  do { var = value;  mb(); } while (0)
+#define set_wmb(var, value) do { var = value; wmb(); } while (0)
+
+#define read_barrier_depends()		do {} while (0)
+#define smp_read_barrier_depends()	do {} while (0)
+
+#endif /* !__ASSEMBLY__ */
+#endif /* __ASM_GENERIC_BARRIER_H */
diff --git a/include/asm-generic/bitops/atomic.h b/include/asm-generic/bitops/atomic.h
index ecc44a8..9ae6c34 100644
--- a/include/asm-generic/bitops/atomic.h
+++ b/include/asm-generic/bitops/atomic.h
@@ -2,7 +2,7 @@
 #define _ASM_GENERIC_BITOPS_ATOMIC_H_
 
 #include <asm/types.h>
-#include <asm/system.h>
+#include <linux/irqflags.h>
 
 #ifdef CONFIG_SMP
 #include <asm/spinlock.h>
diff --git a/include/asm-generic/cmpxchg.h b/include/asm-generic/cmpxchg.h
index 213ac6e..8a36183 100644
--- a/include/asm-generic/cmpxchg.h
+++ b/include/asm-generic/cmpxchg.h
@@ -1,22 +1,97 @@
+/*
+ * Generic UP xchg and cmpxchg using interrupt disablement.  Does not
+ * support SMP.
+ */
+
 #ifndef __ASM_GENERIC_CMPXCHG_H
 #define __ASM_GENERIC_CMPXCHG_H
 
-/*
- * Generic cmpxchg
- *
- * Uses the local cmpxchg. Does not support SMP.
- */
 #ifdef CONFIG_SMP
 #error "Cannot use generic cmpxchg on SMP"
 #endif
 
+#include <linux/irqflags.h>
+
+#ifndef xchg
+
+/*
+ * This function doesn't exist, so you'll get a linker error if
+ * something tries to do an invalidly-sized xchg().
+ */
+extern void __xchg_called_with_bad_pointer(void);
+
+static inline
+unsigned long __xchg(unsigned long x, volatile void *ptr, int size)
+{
+	unsigned long ret, flags;
+
+	switch (size) {
+	case 1:
+#ifdef __xchg_u8
+		return __xchg_u8(x, ptr);
+#else
+		local_irq_save(flags);
+		ret = *(volatile u8 *)ptr;
+		*(volatile u8 *)ptr = x;
+		local_irq_restore(flags);
+		return ret;
+#endif /* __xchg_u8 */
+
+	case 2:
+#ifdef __xchg_u16
+		return __xchg_u16(x, ptr);
+#else
+		local_irq_save(flags);
+		ret = *(volatile u16 *)ptr;
+		*(volatile u16 *)ptr = x;
+		local_irq_restore(flags);
+		return ret;
+#endif /* __xchg_u16 */
+
+	case 4:
+#ifdef __xchg_u32
+		return __xchg_u32(x, ptr);
+#else
+		local_irq_save(flags);
+		ret = *(volatile u32 *)ptr;
+		*(volatile u32 *)ptr = x;
+		local_irq_restore(flags);
+		return ret;
+#endif /* __xchg_u32 */
+
+#ifdef CONFIG_64BIT
+	case 8:
+#ifdef __xchg_u64
+		return __xchg_u64(x, ptr);
+#else
+		local_irq_save(flags);
+		ret = *(volatile u64 *)ptr;
+		*(volatile u64 *)ptr = x;
+		local_irq_restore(flags);
+		return ret;
+#endif /* __xchg_u64 */
+#endif /* CONFIG_64BIT */
+
+	default:
+		__xchg_called_with_bad_pointer();
+		return x;
+	}
+}
+
+#define xchg(ptr, x) \
+	((__typeof__(*(ptr))) __xchg((unsigned long)(x), (ptr), sizeof(*(ptr))))
+
+#endif /* xchg */
+
 /*
  * Atomic compare and exchange.
  *
  * Do not define __HAVE_ARCH_CMPXCHG because we want to use it to check whether
  * a cmpxchg primitive faster than repeated local irq save/restore exists.
  */
+#include <asm-generic/cmpxchg-local.h>
+
 #define cmpxchg(ptr, o, n)	cmpxchg_local((ptr), (o), (n))
 #define cmpxchg64(ptr, o, n)	cmpxchg64_local((ptr), (o), (n))
 
-#endif
+#endif /* __ASM_GENERIC_CMPXCHG_H */
diff --git a/include/asm-generic/exec.h b/include/asm-generic/exec.h
new file mode 100644
index 0000000..567766b
--- /dev/null
+++ b/include/asm-generic/exec.h
@@ -0,0 +1,19 @@
+/* Generic process execution definitions, based on MN10300 definitions.
+ *
+ * It should be possible to use these on really simple architectures,
+ * but it serves more as a starting point for new ports.
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+#ifndef __ASM_GENERIC_EXEC_H
+#define __ASM_GENERIC_EXEC_H
+
+#define arch_align_stack(x) (x)
+
+#endif /* __ASM_GENERIC_EXEC_H */
diff --git a/include/asm-generic/switch_to.h b/include/asm-generic/switch_to.h
new file mode 100644
index 0000000..052c4ac
--- /dev/null
+++ b/include/asm-generic/switch_to.h
@@ -0,0 +1,30 @@
+/* Generic task switch macro wrapper, based on MN10300 definitions.
+ *
+ * It should be possible to use these on really simple architectures,
+ * but it serves more as a starting point for new ports.
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+#ifndef __ASM_GENERIC_SWITCH_TO_H
+#define __ASM_GENERIC_SWITCH_TO_H
+
+#include <linux/thread_info.h>
+
+/*
+ * Context switching is now performed out-of-line in switch_to.S
+ */
+extern struct task_struct *__switch_to(struct task_struct *,
+				       struct task_struct *);
+
+#define switch_to(prev, next, last)					\
+	do {								\
+		((last) = __switch_to((prev), (next)));			\
+	} while (0)
+
+#endif /* __ASM_GENERIC_SWITCH_TO_H */
diff --git a/include/asm-generic/system.h b/include/asm-generic/system.h
deleted file mode 100644
index 215efa7..0000000
--- a/include/asm-generic/system.h
+++ /dev/null
@@ -1,141 +0,0 @@
-/* Generic system definitions, based on MN10300 definitions.
- *
- * It should be possible to use these on really simple architectures,
- * but it serves more as a starting point for new ports.
- *
- * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
- * Written by David Howells (dhowells@redhat.com)
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public Licence
- * as published by the Free Software Foundation; either version
- * 2 of the Licence, or (at your option) any later version.
- */
-#ifndef __ASM_GENERIC_SYSTEM_H
-#define __ASM_GENERIC_SYSTEM_H
-
-#ifndef __ASSEMBLY__
-
-#include <linux/types.h>
-#include <linux/irqflags.h>
-
-#include <asm/cmpxchg-local.h>
-#include <asm/cmpxchg.h>
-
-struct task_struct;
-
-/* context switching is now performed out-of-line in switch_to.S */
-extern struct task_struct *__switch_to(struct task_struct *,
-		struct task_struct *);
-#define switch_to(prev, next, last)					\
-	do {								\
-		((last) = __switch_to((prev), (next)));			\
-	} while (0)
-
-#define arch_align_stack(x) (x)
-
-#define nop() asm volatile ("nop")
-
-#endif /* !__ASSEMBLY__ */
-
-/*
- * Force strict CPU ordering.
- * And yes, this is required on UP too when we're talking
- * to devices.
- *
- * This implementation only contains a compiler barrier.
- */
-
-#define mb()	asm volatile ("": : :"memory")
-#define rmb()	mb()
-#define wmb()	asm volatile ("": : :"memory")
-
-#ifdef CONFIG_SMP
-#define smp_mb()	mb()
-#define smp_rmb()	rmb()
-#define smp_wmb()	wmb()
-#else
-#define smp_mb()	barrier()
-#define smp_rmb()	barrier()
-#define smp_wmb()	barrier()
-#endif
-
-#define set_mb(var, value)  do { var = value;  mb(); } while (0)
-#define set_wmb(var, value) do { var = value; wmb(); } while (0)
-
-#define read_barrier_depends()		do {} while (0)
-#define smp_read_barrier_depends()	do {} while (0)
-
-/*
- * we make sure local_irq_enable() doesn't cause priority inversion
- */
-#ifndef __ASSEMBLY__
-
-/* This function doesn't exist, so you'll get a linker error
- *    if something tries to do an invalid xchg().  */
-extern void __xchg_called_with_bad_pointer(void);
-
-static inline
-unsigned long __xchg(unsigned long x, volatile void *ptr, int size)
-{
-	unsigned long ret, flags;
-
-	switch (size) {
-	case 1:
-#ifdef __xchg_u8
-		return __xchg_u8(x, ptr);
-#else
-		local_irq_save(flags);
-		ret = *(volatile u8 *)ptr;
-		*(volatile u8 *)ptr = x;
-		local_irq_restore(flags);
-		return ret;
-#endif /* __xchg_u8 */
-
-	case 2:
-#ifdef __xchg_u16
-		return __xchg_u16(x, ptr);
-#else
-		local_irq_save(flags);
-		ret = *(volatile u16 *)ptr;
-		*(volatile u16 *)ptr = x;
-		local_irq_restore(flags);
-		return ret;
-#endif /* __xchg_u16 */
-
-	case 4:
-#ifdef __xchg_u32
-		return __xchg_u32(x, ptr);
-#else
-		local_irq_save(flags);
-		ret = *(volatile u32 *)ptr;
-		*(volatile u32 *)ptr = x;
-		local_irq_restore(flags);
-		return ret;
-#endif /* __xchg_u32 */
-
-#ifdef CONFIG_64BIT
-	case 8:
-#ifdef __xchg_u64
-		return __xchg_u64(x, ptr);
-#else
-		local_irq_save(flags);
-		ret = *(volatile u64 *)ptr;
-		*(volatile u64 *)ptr = x;
-		local_irq_restore(flags);
-		return ret;
-#endif /* __xchg_u64 */
-#endif /* CONFIG_64BIT */
-
-	default:
-		__xchg_called_with_bad_pointer();
-		return x;
-	}
-}
-
-#define xchg(ptr, x) \
-	((__typeof__(*(ptr))) __xchg((unsigned long)(x), (ptr), sizeof(*(ptr))))
-
-#endif /* !__ASSEMBLY__ */
-
-#endif /* __ASM_GENERIC_SYSTEM_H */