sh: nommu: Support building without an uncached mapping.

Now that nommu selects 32BIT we run in to the situation where SH-2A
supports an uncached identity mapping by way of the BSC, while the SH-2
does not. This provides stubs for the PC manglers and tidies up some of
the system*.h mess in the process.

Signed-off-by: Paul Mundt <[e-mail]>

arch/sh/include/asm/system.h

···
 #include <linux/compiler.h>
 #include <linux/linkage.h>
 #include <asm/types.h>
+#include <asm/uncached.h>
 
 #define AT_VECTOR_SIZE_ARCH 5 /* entries in ARCH_DLINFO */
 
···
 #else
 #define instruction_size(insn)	(4)
 #endif
-
-extern unsigned long cached_to_uncached;
-extern unsigned long uncached_size;
 
 void per_cpu_trap_init(void);
 void default_idle(void);

arch/sh/include/asm/system_32.h

···
 		__restore_dsp(prev);				\
 } while (0)
 
-/*
- * Jump to uncached area.
- * When handling TLB or caches, we need to do it from an uncached area.
- */
-#define jump_to_uncached()			\
-do {						\
-	unsigned long __dummy;			\
-						\
-	__asm__ __volatile__(			\
-		"mova	1f, %0\n\t"		\
-		"add	%1, %0\n\t"		\
-		"jmp	@%0\n\t"		\
-		" nop\n\t"			\
-		".balign 4\n"			\
-		"1:"				\
-		: "=&z" (__dummy)		\
-		: "r" (cached_to_uncached));	\
-} while (0)
-
-/*
- * Back to cached area.
- */
-#define back_to_cached()				\
-do {							\
-	unsigned long __dummy;				\
-	ctrl_barrier();					\
-	__asm__ __volatile__(				\
-		"mov.l	1f, %0\n\t"			\
-		"jmp	@%0\n\t"			\
-		" nop\n\t"				\
-		".balign 4\n"				\
-		"1:	.long 2f\n"			\
-		"2:"					\
-		: "=&r" (__dummy));			\
-} while (0)
-
 #ifdef CONFIG_CPU_HAS_SR_RB
 #define lookup_exception_vector()	\
 ({					\

arch/sh/include/asm/system_64.h

···
 			      &next->thread);			\
 } while (0)
 
-#define jump_to_uncached()	do { } while (0)
-#define back_to_cached()	do { } while (0)
-
 #define __icbi(addr)	__asm__ __volatile__ ( "icbi %0, 0\n\t" : : "r" (addr))
 #define __ocbp(addr)	__asm__ __volatile__ ( "ocbp %0, 0\n\t" : : "r" (addr))
 #define __ocbi(addr)	__asm__ __volatile__ ( "ocbi %0, 0\n\t" : : "r" (addr))

arch/sh/include/asm/uncached.h

···
 #include <linux/bug.h>
 
 #ifdef CONFIG_UNCACHED_MAPPING
+extern unsigned long cached_to_uncached;
+extern unsigned long uncached_size;
 extern unsigned long uncached_start, uncached_end;
 
 extern int virt_addr_uncached(unsigned long kaddr);
 extern void uncached_init(void);
 extern void uncached_resize(unsigned long size);
+
+/*
+ * Jump to uncached area.
+ * When handling TLB or caches, we need to do it from an uncached area.
+ */
+#define jump_to_uncached()			\
+do {						\
+	unsigned long __dummy;			\
+						\
+	__asm__ __volatile__(			\
+		"mova	1f, %0\n\t"		\
+		"add	%1, %0\n\t"		\
+		"jmp	@%0\n\t"		\
+		" nop\n\t"			\
+		".balign 4\n"			\
+		"1:"				\
+		: "=&z" (__dummy)		\
+		: "r" (cached_to_uncached));	\
+} while (0)
+
+/*
+ * Back to cached area.
+ */
+#define back_to_cached()				\
+do {							\
+	unsigned long __dummy;				\
+	ctrl_barrier();					\
+	__asm__ __volatile__(				\
+		"mov.l	1f, %0\n\t"			\
+		"jmp	@%0\n\t"			\
+		" nop\n\t"				\
+		".balign 4\n"				\
+		"1:	.long 2f\n"			\
+		"2:"					\
+		: "=&r" (__dummy));			\
+} while (0)
 #else
 #define virt_addr_uncached(kaddr)	(0)
 #define uncached_init()			do { } while (0)
 #define uncached_resize(size)		BUG()
+#define jump_to_uncached()		do { } while (0)
+#define back_to_cached()		do { } while (0)
 #endif
 
 #endif /* __ASM_SH_UNCACHED_H */