powerpc/mm: Split mmu_context handling

[deliverable/linux.git] / arch / powerpc / kernel / head_32.S

diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S
index 8bb65751929948fbc35e29fce9fb899058d9b39a..be9f9e5470e83e2835ff9f23715e38f3df3868fb 100644 (file)
--- a/arch/powerpc/kernel/head_32.S
+++ b/arch/powerpc/kernel/head_32.S
@@ -31,6 +31,7 @@
 #include <asm/ppc_asm.h>
 #include <asm/asm-offsets.h>
 #include <asm/ptrace.h>
+#include <asm/bug.h>
 
 /* 601 only have IBAT; cr0.eq is set on 601 when using this macro */
 #define LOAD_BAT(n, reg, RA, RB)       \
@@ -110,6 +111,12 @@ __start:
 #ifdef CONFIG_PPC_MULTIPLATFORM
        cmpwi   0,r5,0
        beq     1f
+
+       /* find out where we are now */
+       bcl     20,31,$+4
+0:     mflr    r8                      /* r8 = runtime addr here */
+       addis   r8,r8,(_stext - 0b)@ha
+       addi    r8,r8,(_stext - 0b)@l   /* current runtime base addr */
        bl      prom_init
        trap
 #endif
@@ -369,13 +376,13 @@ i##n:                                                             \
 DataAccess:
        EXCEPTION_PROLOG
        mfspr   r10,SPRN_DSISR
+       stw     r10,_DSISR(r11)
        andis.  r0,r10,0xa470           /* weird error? */
        bne     1f                      /* if not, try to put a PTE */
        mfspr   r4,SPRN_DAR             /* into the hash table */
        rlwinm  r3,r10,32-15,21,21      /* DSISR_STORE -> _PAGE_RW */
        bl      hash_page
-1:     stw     r10,_DSISR(r11)
-       mr      r5,r10
+1:     lwz     r5,_DSISR(r11)          /* get DSISR value */
        mfspr   r4,SPRN_DAR
        EXC_XFER_EE_LITE(0x300, handle_page_fault)
 
@@ -1064,9 +1071,14 @@ start_here:
        RFI
 
 /*
+ * void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next);
+ *
  * Set up the segment registers for a new context.
  */
-_ENTRY(set_context)
+_ENTRY(switch_mmu_context)
+       lwz     r3,MMCONTEXTID(r4)
+       cmpwi   cr0,r3,0
+       blt-    4f
        mulli   r3,r3,897       /* multiply context by skew factor */
        rlwinm  r3,r3,4,8,27    /* VSID = (context & 0xfffff) << 4 */
        addis   r3,r3,0x6000    /* Set Ks, Ku bits */
@@ -1077,6 +1089,7 @@ _ENTRY(set_context)
        /* Context switch the PTE pointer for the Abatron BDI2000.
         * The PGDIR is passed as second argument.
         */
+       lwz     r4,MM_PGD(r4)
        lis     r5, KERNELBASE@h
        lwz     r5, 0xf0(r5)
        stw     r4, 0x4(r5)
@@ -1092,6 +1105,9 @@ _ENTRY(set_context)
        sync
        isync
        blr
+4:     trap
+       EMIT_BUG_ENTRY 4b,__FILE__,__LINE__,0
+       blr
 
 /*
  * An undocumented "feature" of 604e requires that the v bit