Commit 205353fa authored by Guo Ren's avatar Guo Ren
Browse files

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: default avatarGuo Ren <ren_guo@c-sky.com>
Cc: Arnd Bergmann <arnd@arndb.de>
parent b4bf2741

arch/csky/abiv1/inc/abi/entry.h

+17 −12
Original line number Diff line number Diff line
@@ -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

arch/csky/abiv2/inc/abi/entry.h

+62 −17
Original line number Diff line number Diff line
@@ -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

arch/csky/kernel/head.S

+7 −53
Original line number Diff line number Diff line
@@ -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)

arch/csky/kernel/setup.c

+4 −3
Original line number Diff line number Diff line
@@ -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();

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