[PATCH 0/2] Remove the no longer used mechanism

[PATCH 0/2] Remove the no longer used mechanism

[Zong Li]

This patchset remove the no longer used mechanism as follows:
1. Reserve the TLB space for UART mapping during booting.
2. Assign a value for UART display when an error ocurred during booting.

Zong Li (2):
  nds32: Remove the redundant assignment
  nds32: Fill all TLB entries with kernel image mapping

 arch/nds32/kernel/head.S | 11 +----------
 1 file changed, 1 insertion(+), 10 deletions(-)

-- 
2.7.4

[PATCH 1/2] nds32: Remove the redundant assignment

[Zong Li]

For early version, the value of r2 register was used to display
a character on UART when error occurred. Remove these r2 assignments
because we no longer show the character.

Signed-off-by: Zong Li <zong@andestech.com>
---
 arch/nds32/kernel/head.S | 2 --
 1 file changed, 2 deletions(-)

diff --git a/arch/nds32/kernel/head.S b/arch/nds32/kernel/head.S
index c5fdae1..1ce653d 100644
--- a/arch/nds32/kernel/head.S
+++ b/arch/nds32/kernel/head.S
@@ -130,14 +130,12 @@ _image_size_check:
          *
          * direct mapping is not supported now.
          */
-        li      $r2, 't'
         beqz    $r6, __error                 ! MMU_CFG.TBW = 0 is direct mappin
         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
         /* check kernel image size */
         la      $r3, (_end - PAGE_OFFSET)
-        li      $r2, 's'
         bgt     $r3, $r6, __error
 
 	li      $r2, #(PHYS_OFFSET + TLB_DATA_kernel_text_attr)
-- 
2.7.4

[PATCH 2/2] nds32: Fill all TLB entries with kernel image mapping

[Zong Li]

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: Zong Li <zong@andestech.com>
---
 arch/nds32/kernel/head.S | 9 +--------
 1 file changed, 1 insertion(+), 8 deletions(-)

diff --git a/arch/nds32/kernel/head.S b/arch/nds32/kernel/head.S
index 1ce653d..2c8aac6 100644
--- a/arch/nds32/kernel/head.S
+++ b/arch/nds32/kernel/head.S
@@ -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
-- 
2.7.4

Re: [PATCH 0/2] Remove the no longer used mechanism

[Greentime Hu]

Zong Li <zongbox@gmail.com> 於 2018年10月17日 週三 下午9:17寫道：
>
> This patchset remove the no longer used mechanism as follows:
> 1. Reserve the TLB space for UART mapping during booting.
> 2. Assign a value for UART display when an error ocurred during booting.
>
> Zong Li (2):
>   nds32: Remove the redundant assignment
>   nds32: Fill all TLB entries with kernel image mapping
>
>  arch/nds32/kernel/head.S | 11 +----------
>  1 file changed, 1 insertion(+), 10 deletions(-)
>
Zong, Thank you.
Acked-by: Greentime Hu <greentime@andestech.com>