[PATCH] riscv/mm: Add XIP_FIXUP for riscv_pfn_base

[Palmer Dabbelt <palmer@xxxxxxxxxxxx>]

This manifests as a crash early in boot on VexRiscv.

Signed-off-by: Myrtle Shah <gatecat@xxxxxx>
[Palmer: split commit]
Fixes: 44c922572952 ("RISC-V: enable XIP")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Palmer Dabbelt <palmer@xxxxxxxxxxxx>

diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index eecfacac2cc5..c27294128e18 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -232,6 +232,7 @@ static pmd_t __maybe_unused early_dtb_pmd[PTRS_PER_PMD] __initdata __aligned(PAG
 
 #ifdef CONFIG_XIP_KERNEL
 #define pt_ops			(*(struct pt_alloc_ops *)XIP_FIXUP(&pt_ops))
+#define riscv_pfn_base         (*(unsigned long  *)XIP_FIXUP(&riscv_pfn_base))
 #define trampoline_pg_dir      ((pgd_t *)XIP_FIXUP(trampoline_pg_dir))
 #define fixmap_pte             ((pte_t *)XIP_FIXUP(fixmap_pte))
 #define early_pg_dir           ((pgd_t *)XIP_FIXUP(early_pg_dir))