arc: get rid of private asm/unaligned.h

Declarations local to arch/*/kernel/*.c are better off *not* in a public
header - arch/arc/kernel/unaligned.h is just fine for those
bits.

Unlike the parisc case, here we have an extra twist - asm/mmu.h
has an implicit dependency on struct pt_regs, and in some users
that used to be satisfied by include of asm/ptrace.h from
asm/unaligned.h (note that asm/mmu.h itself did _not_ pull asm/unaligned.h
- it relied upon the users having pulled asm/unaligned.h before asm/mmu.h
got there).

Seeing that asm/mmu.h only wants struct pt_regs * arguments in
an extern, just pre-declare it there - less brittle that way.

With that done _all_ asm/unaligned.h instances are reduced to include
of asm-generic/unaligned.h and can be removed - unaligned.h is in
mandatory-y in include/asm-generic/Kbuild.

What's more, we can move asm-generic/unaligned.h to linux/unaligned.h
and switch includes of <asm/unaligned.h> to <linux/unaligned.h>; that's
better off as an auto-generated commit, though, to be done by Linus
at -rc1 time next cycle.
Acked-by: Vineet Gupta <vgupta@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

arch/arc/include/asm/mmu.h

@@ -14,6 +14,7 @@ typedef struct {
 	unsigned long asid[NR_CPUS];	/* 8 bit MMU PID + Generation cycle */
 } mm_context_t;
 
+struct pt_regs;
 extern void do_tlb_overlap_fault(unsigned long, unsigned long, struct pt_regs *);
 
 #endif

arch/arc/kernel/traps.c

@@ -20,6 +20,7 @@
 #include <asm/setup.h>
 #include <asm/unaligned.h>
 #include <asm/kprobes.h>
+#include "unaligned.h"
 
 void die(const char *str, struct pt_regs *regs, unsigned long address)
 {

arch/arc/kernel/unaligned.c

@@ -12,6 +12,7 @@
 #include <linux/ptrace.h>
 #include <linux/uaccess.h>
 #include <asm/disasm.h>
+#include "unaligned.h"
 
 #ifdef CONFIG_CPU_BIG_ENDIAN
 #define BE		1

arch/arc/include/asm/unaligned.h → arch/arc/kernel/unaligned.h

-/* SPDX-License-Identifier: GPL-2.0-only */
-/*
- * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
- */
-
-#ifndef _ASM_ARC_UNALIGNED_H
-#define _ASM_ARC_UNALIGNED_H
-
-/* ARC700 can't handle unaligned Data accesses. */
-
-#include <asm-generic/unaligned.h>
-#include <asm/ptrace.h>
+struct pt_regs;
+struct callee_regs;
 
 #ifdef CONFIG_ARC_EMUL_UNALIGNED
 int misaligned_fixup(unsigned long address, struct pt_regs *regs,
@@ -24,4 +14,3 @@ misaligned_fixup(unsigned long address, struct pt_regs *regs,
 }
 #endif
 
-#endif /* _ASM_ARC_UNALIGNED_H */