RISC-V: Move all address space definition macros to one place

We get the following compilation error if CONFIG_SPARSEMEM_VMEMMAP is set.

---------------------------------------------------------------
./arch/riscv/include/asm/pgtable-64.h: In function ‘pud_page’:
./include/asm-generic/memory_model.h:54:29: error: ‘vmemmap’ undeclared
(first use in this function); did you mean ‘mem_map’?
 #define __pfn_to_page(pfn) (vmemmap + (pfn))
                             ^~~~~~~
./include/asm-generic/memory_model.h:82:21: note: in expansion of
macro ‘__pfn_to_page’

 #define pfn_to_page __pfn_to_page
                     ^~~~~~~~~~~~~
./arch/riscv/include/asm/pgtable-64.h:70:9: note: in expansion of macro
‘pfn_to_page’
  return pfn_to_page(pud_val(pud) >> _PAGE_PFN_SHIFT);
---------------------------------------------------------------

Fix the compliation errors by moving all the address space definition
macros before including pgtable-64.h.

Fixes: 8ad8b72 (riscv: Add KASAN support)

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

Author: atishp04

arch/riscv/include/asm/pgtable.h

@@ -19,6 +19,47 @@
 #include <asm/tlbflush.h>
 #include <linux/mm_types.h>
 
+#ifdef CONFIG_MMU
+
+#define VMALLOC_SIZE     (KERN_VIRT_SIZE >> 1)
+#define VMALLOC_END      (PAGE_OFFSET - 1)
+#define VMALLOC_START    (PAGE_OFFSET - VMALLOC_SIZE)
+
+#define BPF_JIT_REGION_SIZE	(SZ_128M)
+#define BPF_JIT_REGION_START	(PAGE_OFFSET - BPF_JIT_REGION_SIZE)
+#define BPF_JIT_REGION_END	(VMALLOC_END)
+
+/*
+ * Roughly size the vmemmap space to be large enough to fit enough
+ * struct pages to map half the virtual address space. Then
+ * position vmemmap directly below the VMALLOC region.
+ */
+#define VMEMMAP_SHIFT \
+	(CONFIG_VA_BITS - PAGE_SHIFT - 1 + STRUCT_PAGE_MAX_SHIFT)
+#define VMEMMAP_SIZE	BIT(VMEMMAP_SHIFT)
+#define VMEMMAP_END	(VMALLOC_START - 1)
+#define VMEMMAP_START	(VMALLOC_START - VMEMMAP_SIZE)
+
+/*
+ * Define vmemmap for pfn_to_page & page_to_pfn calls. Needed if kernel
+ * is configured with CONFIG_SPARSEMEM_VMEMMAP enabled.
+ */
+#define vmemmap		((struct page *)VMEMMAP_START)
+
+#define PCI_IO_SIZE      SZ_16M
+#define PCI_IO_END       VMEMMAP_START
+#define PCI_IO_START     (PCI_IO_END - PCI_IO_SIZE)
+
+#define FIXADDR_TOP      PCI_IO_START
+#ifdef CONFIG_64BIT
+#define FIXADDR_SIZE     PMD_SIZE
+#else
+#define FIXADDR_SIZE     PGDIR_SIZE
+#endif
+#define FIXADDR_START    (FIXADDR_TOP - FIXADDR_SIZE)
+
+#endif
+
 #ifdef CONFIG_64BIT
 #include <asm/pgtable-64.h>
 #else
@@ -90,31 +131,6 @@ extern pgd_t swapper_pg_dir[];
 #define __S110	PAGE_SHARED_EXEC
 #define __S111	PAGE_SHARED_EXEC
 
-#define VMALLOC_SIZE     (KERN_VIRT_SIZE >> 1)
-#define VMALLOC_END      (PAGE_OFFSET - 1)
-#define VMALLOC_START    (PAGE_OFFSET - VMALLOC_SIZE)
-
-#define BPF_JIT_REGION_SIZE	(SZ_128M)
-#define BPF_JIT_REGION_START	(PAGE_OFFSET - BPF_JIT_REGION_SIZE)
-#define BPF_JIT_REGION_END	(VMALLOC_END)
-
-/*
- * Roughly size the vmemmap space to be large enough to fit enough
- * struct pages to map half the virtual address space. Then
- * position vmemmap directly below the VMALLOC region.
- */
-#define VMEMMAP_SHIFT \
-	(CONFIG_VA_BITS - PAGE_SHIFT - 1 + STRUCT_PAGE_MAX_SHIFT)
-#define VMEMMAP_SIZE	BIT(VMEMMAP_SHIFT)
-#define VMEMMAP_END	(VMALLOC_START - 1)
-#define VMEMMAP_START	(VMALLOC_START - VMEMMAP_SIZE)
-
-/*
- * Define vmemmap for pfn_to_page & page_to_pfn calls. Needed if kernel
- * is configured with CONFIG_SPARSEMEM_VMEMMAP enabled.
- */
-#define vmemmap		((struct page *)VMEMMAP_START)
-
 static inline int pmd_present(pmd_t pmd)
 {
 	return (pmd_val(pmd) & (_PAGE_PRESENT | _PAGE_PROT_NONE));
@@ -432,18 +448,6 @@ static inline int ptep_clear_flush_young(struct vm_area_struct *vma,
 #define __pte_to_swp_entry(pte)	((swp_entry_t) { pte_val(pte) })
 #define __swp_entry_to_pte(x)	((pte_t) { (x).val })
 
-#define PCI_IO_SIZE      SZ_16M
-#define PCI_IO_END       VMEMMAP_START
-#define PCI_IO_START     (PCI_IO_END - PCI_IO_SIZE)
-
-#define FIXADDR_TOP      PCI_IO_START
-#ifdef CONFIG_64BIT
-#define FIXADDR_SIZE     PMD_SIZE
-#else
-#define FIXADDR_SIZE     PGDIR_SIZE
-#endif
-#define FIXADDR_START    (FIXADDR_TOP - FIXADDR_SIZE)
-
 /*
  * Task size is 0x4000000000 for RV64 or 0x9fc00000 for RV32.
  * Note that PGDIR_SIZE must evenly divide TASK_SIZE.