m68k: init the MMU hardware for the 54xx ColdFire

[firefly-linux-kernel-4.4.55.git] / arch / m68k / platform / coldfire / head.S

diff --git a/arch/m68k/platform/coldfire/head.S b/arch/m68k/platform/coldfire/head.S
index c33483824a2eed3573c6d1c8b1c07545b136a800..38f04a3f620713e5ea14cc5a100b5f41ad299d51 100644 (file)
--- a/arch/m68k/platform/coldfire/head.S
+++ b/arch/m68k/platform/coldfire/head.S
@@ -3,7 +3,7 @@
 /*
  *     head.S -- common startup code for ColdFire CPUs.
  *
- *     (C) Copyright 1999-2010, Greg Ungerer <gerg@snapgear.com>.
+ *     (C) Copyright 1999-2011, Greg Ungerer <gerg@snapgear.com>.
  */
 
 /*****************************************************************************/
@@ -13,6 +13,7 @@
 #include <asm/asm-offsets.h>
 #include <asm/coldfire.h>
 #include <asm/mcfsim.h>
+#include <asm/mcfmmu.h>
 #include <asm/thread_info.h>
 
 /*****************************************************************************/
@@ -135,6 +136,14 @@ _init_sp:
 
 __HEAD
 
+#ifdef CONFIG_MMU
+_start0:
+       jmp     _start
+.global kernel_pg_dir
+.equ   kernel_pg_dir,_start0
+.equ   .,_start0+0x1000
+#endif
+
 /*
  *     This is the codes first entry point. This is where it all
  *     begins...
@@ -143,6 +152,9 @@ __HEAD
 _start:
        nop                                     /* filler */
        movew   #0x2700, %sr                    /* no interrupts */
+       movel   #CACHE_INIT,%d0                 /* disable cache */
+       movec   %d0,%CACR
+       nop
 #if defined(CONFIG_UBOOT)
        movel   %sp,_init_sp                    /* save initial stack pointer */
 #endif
@@ -176,9 +188,6 @@ _start:
         *      it is very similar. Define the exact settings in the headers
         *      then the code here is the same for all.
         */
-       movel   #CACHE_INIT,%d0                 /* invalidate whole cache */
-       movec   %d0,%CACR
-       nop
        movel   #ACR0_MODE,%d0                  /* set RAM region for caching */
        movec   %d0,%ACR0
        movel   #ACR1_MODE,%d0                  /* anything else to cache? */
@@ -193,6 +202,26 @@ _start:
        movec   %d0,%CACR
        nop
 
+#ifdef CONFIG_MMU
+       /*
+        *      Identity mapping for the kernel region.
+        */
+       movel   #(MMUBASE+1),%d0                /* enable MMUBAR registers */
+       movec   %d0,%MMUBAR
+       movel   #MMUOR_CA,%d0                   /* clear TLB entries */
+       movel   %d0,MMUOR
+       movel   #0,%d0                          /* set ASID to 0 */
+       movec   %d0,%asid
+
+       movel   #MMUCR_EN,%d0                   /* Enable the identity map */
+       movel   %d0,MMUCR
+       nop                                     /* sync i-pipeline */
+
+       movel   #_vstart,%a0                    /* jump to "virtual" space */
+       jmp     %a0@
+_vstart:
+#endif /* CONFIG_MMU */
+
 #ifdef CONFIG_ROMFS_FS
        /*
         *      Move ROM filesystem above bss :-)
@@ -238,6 +267,22 @@ _clear_bss:
        lea     init_thread_union,%a0
        lea     THREAD_SIZE(%a0),%sp
 
+#ifdef CONFIG_MMU
+.global m68k_cputype
+.global m68k_mmutype
+.global m68k_fputype
+.global m68k_machtype
+       movel   #CPU_COLDFIRE,%d0
+       movel   %d0,m68k_cputype                /* Mark us as a ColdFire */
+       movel   #MMU_COLDFIRE,%d0
+       movel   %d0,m68k_mmutype
+       movel   #FPU_COLDFIRE,%d0
+       movel   %d0,m68k_fputype
+       movel   #MACH_M54XX,%d0
+       movel   %d0,m68k_machtype               /* Mark us as a 54xx machine */
+       lea     init_task,%a2                   /* Set "current" init task */
+#endif
+
        /*
         *      Assember start up done, start code proper.
         */