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>

diff --git a/arch/csky/abiv1/inc/abi/entry.h b/arch/csky/abiv1/inc/abi/entry.h
index 18e2023bf165536df708726fa960cab5e75c9e30..7ab78bd0f3b13f7e52be13445314ef956566fa73 100644 (file)
--- 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 c0a76c43cdedaec3e0bcc0feb60de5788e3bc874..9897a16b45e5dcc75b4e6638a8ecd1153be661e9 100644 (file)
--- 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 9c4ec473b76ba0792822e6fd968b83e22efc7a89..61989f9241c021b8e4d12b554aed9247fd14641d 100644 (file)
--- 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 c377194e4b8f9169900e768f35d3d742d172892c..36fc04b9417df3cc6db65cac11a8465ab7e6f0c3 100644 (file)
--- 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();