[V2] riscv: fix pfn_to_virt err in do_page_fault().

[liush]

The argument to pfn_to_virt() should be pfn not the value of CSR_SATP.

Signed-off-by: liush <li...@allwinnertech.com>
---
 arch/riscv/mm/fault.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/riscv/mm/fault.c b/arch/riscv/mm/fault.c
index 716d64e..3e560ec13 100644
--- a/arch/riscv/mm/fault.c
+++ b/arch/riscv/mm/fault.c
@@ -198,6 +198,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs)
                pmd_t *pmd, *pmd_k;
                pte_t *pte_k;
                int index;
+               unsigned long pfn;
 
                /* User mode accesses just cause a SIGSEGV */
                if (user_mode(regs))
@@ -212,7 +213,8 @@ asmlinkage void do_page_fault(struct pt_regs *regs)
                 * of a task switch.
                 */
                index = pgd_index(addr);
-               pgd = (pgd_t *)pfn_to_virt(csr_read(CSR_SATP)) + index;
+               pfn = csr_read(CSR_SATP) & SATP_PPN;
+               pgd = (pgd_t *)pfn_to_virt(pfn) + index;
                pgd_k = init_mm.pgd + index;
 
                if (!pgd_present(*pgd_k))
-- 
2.7.4