csky: Support vmlinux bootup with MMU off

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@c-sky.com>
Cc: Arnd Bergmann <arnd@arndb.de>
This commit is contained in:
Guo Ren 2019-04-12 19:08:34 +08:00
parent b4bf274198
commit 205353fa06
4 changed files with 88 additions and 83 deletions

View File

@ -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
cprcr r6, cpcr30
lsri r6, 28
lsli r6, 28
addi r6, 0xe
cpwcr r6, cpcr30
lsri \rx, 28
addi \rx, 2
lsli \rx, 28
addi \rx, 0xe
cpwcr \rx, cpcr31
lsri r6, 28
addi r6, 2
lsli r6, 28
addi r6, 0xe
cpwcr r6, cpcr31
.endm
.macro ANDI_R3 rx, imm

View File

@ -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 r6, 28
lsli r6, 28
addi r6, 0x1ce
mtcr r6, cr<30, 15> /* Set MSA0 */
lsri \rx, 28
addi \rx, 2
lsli \rx, 28
addi \rx, 0x1ce
mtcr \rx, cr<31, 15>
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

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@ -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)

View File

@ -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();