[PATCH v3 03/15] powerpc/32: save DEAR/DAR before calling handle_page_fault

From: Christophe Leroy
Date: Tue Sep 10 2019 - 05:18:06 EST


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@xxxxxx>
---
arch/powerpc/kernel/entry_32.S | 1 -
arch/powerpc/kernel/head_32.S | 2 ++
arch/powerpc/kernel/head_40x.S | 2 ++
arch/powerpc/kernel/head_8xx.S | 2 ++
arch/powerpc/kernel/head_booke.h | 2 ++
arch/powerpc/kernel/head_fsl_booke.S | 1 +
6 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 6273b4862482..317ad9df8ba8 100644
--- 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 9e868567b716..bebb49d877f2 100644
--- 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 585ea1976550..9bb663977e84 100644
--- 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 dac7c0a34eea..fb284d95c76a 100644
--- 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 2ae635df9026..37fc84ed90e3 100644
--- a/arch/powerpc/kernel/head_booke.h
+++ b/arch/powerpc/kernel/head_booke.h
@@ -467,6 +467,7 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV)
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 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV)
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 adf0505dbe02..442aaac292b0 100644
--- a/arch/powerpc/kernel/head_fsl_booke.S
+++ b/arch/powerpc/kernel/head_fsl_booke.S
@@ -376,6 +376,7 @@ 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
--
2.13.3