Commit 8730c178 authored by Zong Li's avatar Zong Li Committed by Greentime Hu
Browse files

nds32: Fill all TLB entries with kernel image mapping 



We use earlycon replace with early_printk and doesn't use
early_io_map() to create UART mapping. It is not necessary
to reserve the one way in TLB for now.

It didn't make sense if use direct-mapped and reserve one
way at the same time. It allow the direct-mapped now.

Signed-off-by: default avatarZong Li <zong@andestech.com>
Signed-off-by: default avatarGreentime Hu <greentime@andestech.com>
parent 2e95c4d6

arch/nds32/kernel/head.S

+1 −8
Original line number Diff line number Diff line
@@ -123,14 +123,7 @@ _image_size_check: 
        andi    $r0, $r0, MMU_CFG_mskTBS

        srli    $r6, $r6, MMU_CFG_offTBW

        srli    $r0, $r0, MMU_CFG_offTBS

        /*

         * we just map the kernel to the maximum way - 1 of tlb

         * reserver one way for UART VA mapping

         * it will cause page fault if UART mapping cover the kernel mapping

         *

         * direct mapping is not supported now.

         */

        beqz    $r6, __error                 ! MMU_CFG.TBW = 0 is direct mappin

	addi    $r6, $r6, #0x1               ! MMU_CFG.TBW value -> meaning

        addi    $r0, $r0, #0x2               ! MMU_CFG.TBS value -> meaning

        sll     $r0, $r6, $r0                ! entries = k-way * n-set

        mul     $r6, $r0, $r5                ! max size = entries * page size

CRA Git | Maintained and supported by SUSTech CRA and CCSE