powerpc/32: save DEAR/DAR before calling handle_page_fault

handle_page_fault() is the only function that save DAR/DEAR itself.

Save DAR/DEAR before calling handle_page_fault() to prepare for
VMAP stack which will require to save even before.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/3a4d58d378091086f00fde42b59610c80289e120.1576916812.git.christophe.leroy@c-s.fr

diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 6273b48..317ad9d 100644 (file)
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -621,7 +621,6 @@ ppc_swapcontext:
  */
        .globl  handle_page_fault
 handle_page_fault:
-       stw     r4,_DAR(r1)
        addi    r3,r1,STACK_FRAME_OVERHEAD
 #ifdef CONFIG_PPC_BOOK3S_32
        andis.  r0,r5,DSISR_DABRMATCH@h

diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S
index 9e86856..bebb49d 100644 (file)
--- a/arch/powerpc/kernel/head_32.S
+++ b/arch/powerpc/kernel/head_32.S
@@ -310,6 +310,7 @@ BEGIN_MMU_FTR_SECTION
 END_MMU_FTR_SECTION_IFSET(MMU_FTR_HPTE_TABLE)
 1:     lwz     r5,_DSISR(r11)          /* get DSISR value */
        mfspr   r4,SPRN_DAR
+       stw     r4, _DAR(r11)
        EXC_XFER_LITE(0x300, handle_page_fault)
 
 
@@ -327,6 +328,7 @@ BEGIN_MMU_FTR_SECTION
 END_MMU_FTR_SECTION_IFSET(MMU_FTR_HPTE_TABLE)
 1:     mr      r4,r12
        andis.  r5,r9,DSISR_SRR1_MATCH_32S@h /* Filter relevant SRR1 bits */
+       stw     r4, _DAR(r11)
        EXC_XFER_LITE(0x400, handle_page_fault)
 
 /* External interrupt */

diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index 585ea19..9bb6639 100644 (file)
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -313,6 +313,7 @@ _ENTRY(saved_ksp_limit)
        START_EXCEPTION(0x0400, InstructionAccess)
        EXCEPTION_PROLOG
        mr      r4,r12                  /* Pass SRR0 as arg2 */
+       stw     r4, _DEAR(r11)
        li      r5,0                    /* Pass zero as arg3 */
        EXC_XFER_LITE(0x400, handle_page_fault)
 
@@ -676,6 +677,7 @@ DataAccess:
        mfspr   r5,SPRN_ESR             /* Grab the ESR, save it, pass arg3 */
        stw     r5,_ESR(r11)
        mfspr   r4,SPRN_DEAR            /* Grab the DEAR, save it, pass arg2 */
+       stw     r4, _DEAR(r11)
        EXC_XFER_LITE(0x300, handle_page_fault)
 
 /* Other PowerPC processors, namely those derived from the 6xx-series

diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index dac7c0a..fb284d9 100644 (file)
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -486,6 +486,7 @@ InstructionTLBError:
        tlbie   r4
        /* 0x400 is InstructionAccess exception, needed by bad_page_fault() */
 .Litlbie:
+       stw     r4, _DAR(r11)
        EXC_XFER_LITE(0x400, handle_page_fault)
 
 /* This is the data TLB error on the MPC8xx.  This could be due to
@@ -504,6 +505,7 @@ DARFixed:/* Return from dcbx instruction bug workaround */
        mfspr   r5,SPRN_DSISR
        stw     r5,_DSISR(r11)
        mfspr   r4,SPRN_DAR
+       stw     r4, _DAR(r11)
        andis.  r10,r5,DSISR_NOHPTE@h
        beq+    .Ldtlbie
        tlbie   r4

diff --git a/arch/powerpc/kernel/head_booke.h b/arch/powerpc/kernel/head_booke.h
index 2ae635d..37fc84e 100644 (file)
--- a/arch/powerpc/kernel/head_booke.h
+++ b/arch/powerpc/kernel/head_booke.h
@@ -467,6 +467,7 @@ label:
        mfspr   r5,SPRN_ESR;            /* Grab the ESR and save it */        \
        stw     r5,_ESR(r11);                                                 \
        mfspr   r4,SPRN_DEAR;           /* Grab the DEAR */                   \
+       stw     r4, _DEAR(r11);                                               \
        EXC_XFER_LITE(0x0300, handle_page_fault)
 
 #define INSTRUCTION_STORAGE_EXCEPTION                                        \
@@ -475,6 +476,7 @@ label:
        mfspr   r5,SPRN_ESR;            /* Grab the ESR and save it */        \
        stw     r5,_ESR(r11);                                                 \
        mr      r4,r12;                 /* Pass SRR0 as arg2 */               \
+       stw     r4, _DEAR(r11);                                               \
        li      r5,0;                   /* Pass zero as arg3 */               \
        EXC_XFER_LITE(0x0400, handle_page_fault)
 

diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S
index 6f7a3a7..840af00 100644 (file)
--- a/arch/powerpc/kernel/head_fsl_booke.S
+++ b/arch/powerpc/kernel/head_fsl_booke.S
@@ -378,6 +378,7 @@ interrupt_base:
        mfspr   r4,SPRN_DEAR            /* Grab the DEAR, save it, pass arg2 */
        andis.  r10,r5,(ESR_ILK|ESR_DLK)@h
        bne     1f
+       stw     r4, _DEAR(r11)
        EXC_XFER_LITE(0x0300, handle_page_fault)
 1:
        addi    r3,r1,STACK_FRAME_OVERHEAD