RISC-V: mm: Support huge page in vmalloc_fault()

Since RISC-V supports ioremap() with huge page (pud/pmd) mapping,
However, vmalloc_fault() assumes that the vmalloc range is limited
to pte mappings. To complete the vmalloc_fault() function by adding
huge page support.

Fixes: 310f541 ("riscv: Enable HAVE_ARCH_HUGE_VMAP for 64BIT")
Cc: stable@vger.kernel.org
Signed-off-by: Dylan Jhong <dylan@andestech.com>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20230310075021.3919290-1-dylan@andestech.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

Author: Dylan-Jhong

arch/riscv/mm/fault.c

@@ -143,6 +143,8 @@ static inline void vmalloc_fault(struct pt_regs *regs, int code, unsigned long a
 		no_context(regs, addr);
 		return;
 	}
+	if (pud_leaf(*pud_k))
+		goto flush_tlb;
 
 	/*
 	 * Since the vmalloc area is global, it is unnecessary
@@ -153,6 +155,8 @@ static inline void vmalloc_fault(struct pt_regs *regs, int code, unsigned long a
 		no_context(regs, addr);
 		return;
 	}
+	if (pmd_leaf(*pmd_k))
+		goto flush_tlb;
 
 	/*
 	 * Make sure the actual PTE exists as well to
@@ -172,6 +176,7 @@ static inline void vmalloc_fault(struct pt_regs *regs, int code, unsigned long a
 	 * ordering constraint, not a cache flush; it is
 	 * necessary even after writing invalid entries.
 	 */
+flush_tlb:
 	local_flush_tlb_page(addr);
 }