[PATCH] csky: Support vmlinux bootup with MMU off
From: guoren
Date: Sat Apr 13 2019 - 11:14:30 EST
From: Guo Ren <ren_guo@xxxxxxxxx>
Modify SETUP_MMU macro to fit on both MMU-on or MMU-off enviornment
and vmlinux could bootup from MMU off enviornment for some cases.
Unify the style of _start and _start_smp_secondary in head.S to make
head.S looks more concise and easy to understand.
Signed-off-by: Guo Ren <ren_guo@xxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
---
arch/csky/abiv1/inc/abi/entry.h | 29 ++++++++-------
arch/csky/abiv2/inc/abi/entry.h | 79 ++++++++++++++++++++++++++++++++---------
arch/csky/kernel/head.S | 60 ++++---------------------------
arch/csky/kernel/setup.c | 7 ++--
4 files changed, 90 insertions(+), 85 deletions(-)
diff --git a/arch/csky/abiv1/inc/abi/entry.h b/arch/csky/abiv1/inc/abi/entry.h
index 18e2023..7ab78bd 100644
--- a/arch/csky/abiv1/inc/abi/entry.h
+++ b/arch/csky/abiv1/inc/abi/entry.h
@@ -143,7 +143,12 @@
cpwcr \rx, cpcr8
.endm
-.macro SETUP_MMU rx
+.macro SETUP_MMU
+ /* Init psr and enable ee */
+ lrw r6, DEFAULT_PSR_VALUE
+ mtcr r6, psr
+ psrset ee
+
/* Select MMU as co-processor */
cpseti cp15
@@ -152,17 +157,17 @@
* 31 - 29 | 28 - 4 | 3 | 2 | 1 | 0
* BA Reserved C D V
*/
- cprcr \rx, cpcr30
- lsri \rx, 28
- lsli \rx, 28
- addi \rx, 0xe
- cpwcr \rx, cpcr30
-
- lsri \rx, 28
- addi \rx, 2
- lsli \rx, 28
- addi \rx, 0xe
- cpwcr \rx, cpcr31
+ cprcr r6, cpcr30
+ lsri r6, 28
+ lsli r6, 28
+ addi r6, 0xe
+ cpwcr r6, cpcr30
+
+ lsri r6, 28
+ addi r6, 2
+ lsli r6, 28
+ addi r6, 0xe
+ cpwcr r6, cpcr31
.endm
.macro ANDI_R3 rx, imm
diff --git a/arch/csky/abiv2/inc/abi/entry.h b/arch/csky/abiv2/inc/abi/entry.h
index c0a76c4..9897a16 100644
--- a/arch/csky/abiv2/inc/abi/entry.h
+++ b/arch/csky/abiv2/inc/abi/entry.h
@@ -162,31 +162,76 @@
mtcr \rx, cr<8, 15>
.endm
-.macro SETUP_MMU rx
- /* Check MMU on | off */
- mfcr \rx, cr18
- btsti \rx, 0
+.macro SETUP_MMU
+ /* Init psr and enable ee */
+ lrw r6, DEFAULT_PSR_VALUE
+ mtcr r6, psr
+ psrset ee
+
+ /* Invalid I/Dcache BTB BHT */
+ movi r6, 7
+ lsli r6, 16
+ addi r6, (1<<4) | 3
+ mtcr r6, cr17
+
+ /* Invalid all TLB */
+ bgeni r6, 26
+ mtcr r6, cr<8, 15> /* Set MCIR */
+
+ /* Check MMU on/off */
+ mfcr r6, cr18
+ btsti r6, 0
bt 1f
- grs \rx, 1f
+
+ /* MMU off: setup mapping tlb entry */
+ movi r6, 0
+ mtcr r6, cr<6, 15> /* Set MPR with 4K page size */
+
+ grs r6, 1f /* Get current pa by PC */
+ bmaski r7, (PAGE_SHIFT + 1) /* r7 = 0x1fff */
+ andn r6, r7
+ mtcr r6, cr<4, 15> /* Set MEH */
+
+ mov r8, r6
+ movi r7, 0x00000006
+ or r8, r7
+ mtcr r8, cr<2, 15> /* Set MEL0 */
+ movi r7, 0x00001006
+ or r8, r7
+ mtcr r8, cr<3, 15> /* Set MEL1 */
+
+ bgeni r8, 28
+ mtcr r8, cr<8, 15> /* Set MCIR to write TLB */
+
br 2f
1:
/*
- * cr<30, 15> format:
+ * MMU on: use origin MSA value from bootloader
+ *
+ * cr<30/31, 15> MSA register format:
* 31 - 29 | 28 - 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0
* BA Reserved SH WA B SO SEC C D V
*/
- mfcr \rx, cr<30, 15>
+ mfcr r6, cr<30, 15> /* Get MSA0 */
2:
- lsri \rx, 28
- lsli \rx, 28
- addi \rx, 0x1ce
- mtcr \rx, cr<30, 15>
-
- lsri \rx, 28
- addi \rx, 2
- lsli \rx, 28
- addi \rx, 0x1ce
- mtcr \rx, cr<31, 15>
+ lsri r6, 28
+ lsli r6, 28
+ addi r6, 0x1ce
+ mtcr r6, cr<30, 15> /* Set MSA0 */
+
+ lsri r6, 28
+ addi r6, 2
+ lsli r6, 28
+ addi r6, 0x1ce
+ mtcr r6, cr<31, 15> /* Set MSA1 */
+
+ /* enable MMU */
+ mfcr r6, cr18
+ bseti r6, 0
+ mtcr r6, cr18
+
+ jmpi 3f /* jump to va */
+3:
.endm
.macro ANDI_R3 rx, imm
diff --git a/arch/csky/kernel/head.S b/arch/csky/kernel/head.S
index 9c4ec47..61989f9 100644
--- a/arch/csky/kernel/head.S
+++ b/arch/csky/kernel/head.S
@@ -7,16 +7,11 @@
__HEAD
ENTRY(_start)
- /* set super user mode */
- lrw a3, DEFAULT_PSR_VALUE
- mtcr a3, psr
- psrset ee
-
- SETUP_MMU a3
+ SETUP_MMU
/* set stack point */
- lrw a3, init_thread_union + THREAD_SIZE
- mov sp, a3
+ lrw r6, init_thread_union + THREAD_SIZE
+ mov sp, r6
jmpi csky_start
END(_start)
@@ -24,53 +19,12 @@ END(_start)
#ifdef CONFIG_SMP
.align 10
ENTRY(_start_smp_secondary)
- /* Invalid I/Dcache BTB BHT */
- movi a3, 7
- lsli a3, 16
- addi a3, (1<<4) | 3
- mtcr a3, cr17
-
- tlbi.alls
-
- /* setup PAGEMASK */
- movi a3, 0
- mtcr a3, cr<6, 15>
-
- /* setup MEL0/MEL1 */
- grs a0, _start_smp_pc
-_start_smp_pc:
- bmaski a1, 13
- andn a0, a1
- movi a1, 0x00000006
- movi a2, 0x00001006
- or a1, a0
- or a2, a0
- mtcr a1, cr<2, 15>
- mtcr a2, cr<3, 15>
-
- /* setup MEH */
- mtcr a0, cr<4, 15>
-
- /* write TLB */
- bgeni a3, 28
- mtcr a3, cr<8, 15>
-
- SETUP_MMU a3
-
- /* enable MMU */
- movi a3, 1
- mtcr a3, cr18
-
- jmpi _goto_mmu_on
-_goto_mmu_on:
- lrw a3, DEFAULT_PSR_VALUE
- mtcr a3, psr
- psrset ee
+ SETUP_MMU
/* set stack point */
- lrw a3, secondary_stack
- ld.w a3, (a3, 0)
- mov sp, a3
+ lrw r6, secondary_stack
+ ld.w r6, (r6, 0)
+ mov sp, r6
jmpi csky_start_secondary
END(_start_smp_secondary)
diff --git a/arch/csky/kernel/setup.c b/arch/csky/kernel/setup.c
index c377194..36fc04b 100644
--- a/arch/csky/kernel/setup.c
+++ b/arch/csky/kernel/setup.c
@@ -145,7 +145,8 @@ void __init setup_arch(char **cmdline_p)
unsigned long phys_offset;
EXPORT_SYMBOL(phys_offset);
-asmlinkage __visible void __init csky_start(unsigned int unused, void *param)
+asmlinkage __visible void __init csky_start(unsigned int unused,
+ void *dtb_start)
{
/* Clean up bss section */
memset(__bss_start, 0, __bss_stop - __bss_start);
@@ -155,10 +156,10 @@ asmlinkage __visible void __init csky_start(unsigned int unused, void *param)
pre_trap_init();
pre_mmu_init();
- if (param == NULL)
+ if (dtb_start == NULL)
early_init_dt_scan(__dtb_start);
else
- early_init_dt_scan(param);
+ early_init_dt_scan(dtb_start);
start_kernel();
--
2.7.4