RISC-V: mm: Fix set_satp_mode() for platform not having Sv57

When Sv57 is not available the satp.MODE test in set_satp_mode() will
fail and lead to pgdir re-programming for Sv48. The pgdir re-programming
will fail as well due to pre-existing pgdir entry used for Sv57 and as
a result kernel fails to boot on RISC-V platform not having Sv57.

To fix above issue, we should clear the pgdir memory in set_satp_mode()
before re-programming.

Fixes: 011f09d12052 ("riscv: mm: Set sv57 on defaultly")
Reported-by: Mayuresh Chitale <mchitale@ventanamicro.com>
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index 9535bea..b0793dc 100644 (file)
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -718,6 +718,7 @@ retry:
                if (!check_l4) {
                        disable_pgtable_l5();
                        check_l4 = true;
+                       memset(early_pg_dir, 0, PAGE_SIZE);
                        goto retry;
                }
                disable_pgtable_l4();