RISC-V: Always define XIP_FIXUP

XIP depends on MMU, but XIP_FIXUP is used throughout the kernel in
order to avoid excessive ifdefs.  This just makes sure to always define
XIP_FIXUP, which will fix MMU=n builds.  XIP_OFFSET is used by assembly
but XIP_FIXUP is C-only, so they're split.

Fixes: 44c9225 ("RISC-V: enable XIP")
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Tested-by: Alexandre Ghiti <alex@ghiti.fr>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

arch/riscv/include/asm/pgtable.h

@@ -73,18 +73,10 @@
 #endif
 #define FIXADDR_START    (FIXADDR_TOP - FIXADDR_SIZE)
 
+#endif
+
 #ifdef CONFIG_XIP_KERNEL
 #define XIP_OFFSET		SZ_8M
-#define XIP_FIXUP(addr) ({							\
-	uintptr_t __a = (uintptr_t)(addr);					\
-	(__a >= CONFIG_XIP_PHYS_ADDR && __a < CONFIG_XIP_PHYS_ADDR + SZ_16M) ?	\
-		__a - CONFIG_XIP_PHYS_ADDR + CONFIG_PHYS_RAM_BASE - XIP_OFFSET :\
-		__a;								\
-	})
-#else
-#define XIP_FIXUP(addr)		(addr)
-#endif /* CONFIG_XIP_KERNEL */
-
 #endif
 
 #ifndef __ASSEMBLY__
@@ -101,6 +93,17 @@
 #include <asm/pgtable-32.h>
 #endif /* CONFIG_64BIT */
 
+#ifdef CONFIG_XIP_KERNEL
+#define XIP_FIXUP(addr) ({							\
+	uintptr_t __a = (uintptr_t)(addr);					\
+	(__a >= CONFIG_XIP_PHYS_ADDR && __a < CONFIG_XIP_PHYS_ADDR + SZ_16M) ?	\
+		__a - CONFIG_XIP_PHYS_ADDR + CONFIG_PHYS_RAM_BASE - XIP_OFFSET :\
+		__a;								\
+	})
+#else
+#define XIP_FIXUP(addr)		(addr)
+#endif /* CONFIG_XIP_KERNEL */
+
 #ifdef CONFIG_MMU
 /* Number of entries in the page global directory */
 #define PTRS_PER_PGD    (PAGE_SIZE / sizeof(pgd_t))