This patch enables CONFIG_VMAP_STACK. For that, a few changes are
done in head_8xx.S.
Signed-off-by: Christophe Leroy <christophe.le...@c-s.fr>
---
arch/powerpc/Kconfig | 1 +
arch/powerpc/kernel/head_8xx.S | 47 +++++++++++++++++++++++++++++++++++++++++-
2 files changed, 47 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 6137f5e3bb2d..ddbec19c3c22 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -178,6 +178,7 @@ config PPC
select HAVE_ARCH_NVRAM_OPS
select HAVE_ARCH_SECCOMP_FILTER
select HAVE_ARCH_TRACEHOOK
+ select HAVE_ARCH_VMAP_STACK if PPC_8xx
select HAVE_C_RECORDMCOUNT
select HAVE_CBPF_JIT if !PPC64
select HAVE_STACKPROTECTOR if PPC64 &&
$(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=r13)
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 2fa02ae7a88c..dfd68b72688e 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -127,8 +127,12 @@ instruction_counter:
. = 0x200
MachineCheck:
EXCEPTION_PROLOG
+#ifdef CONFIG_VMAP_STACK
+ lwz r4, _DAR(r11)
+#else
mfspr r4,SPRN_DAR
stw r4,_DAR(r11)
+#endif
li r5,RPN_PATTERN
mtspr SPRN_DAR,r5 /* Tag DAR, to be used in DTLB Error */
mfspr r5,SPRN_DSISR
@@ -143,8 +147,12 @@ MachineCheck:
. = 0x600
Alignment:
EXCEPTION_PROLOG
+#ifdef CONFIG_VMAP_STACK
+ lwz r4, _DAR(r11)
+#else
mfspr r4,SPRN_DAR
stw r4,_DAR(r11)
+#endif
li r5,RPN_PATTERN
mtspr SPRN_DAR,r5 /* Tag DAR, to be used in DTLB Error */
mfspr r5,SPRN_DSISR
@@ -467,17 +475,28 @@ DataTLBError:
cmpwi cr0, r11, RPN_PATTERN
beq- FixupDAR /* must be a buggy dcbX, icbi insn. */
DARFixed:/* Return from dcbx instruction bug workaround */
+#ifdef CONFIG_VMAP_STACK
+ li r11, RPN_PATTERN
+ mtspr SPRN_DAR, r11 /* Tag DAR, to be used in DTLB Error */
+ mfspr r11, SPRN_SRR1
+#endif
EXCEPTION_PROLOG_1
EXCEPTION_PROLOG_2
mfspr r5,SPRN_DSISR
stw r5,_DSISR(r11)
+#ifdef CONFIG_VMAP_STACK
+ lwz r4, _DAR(r11)
+#else
mfspr r4,SPRN_DAR
+#endif
andis. r10,r5,DSISR_NOHPTE@h
beq+ .Ldtlbie
tlbie r4
.Ldtlbie:
+#ifndef CONFIG_VMAP_STACK
li r10,RPN_PATTERN
mtspr SPRN_DAR,r10 /* Tag DAR, to be used in DTLB Error */
+#endif
/* 0x300 is DataAccess exception, needed by bad_page_fault() */
EXC_XFER_LITE(0x300, handle_page_fault)
@@ -498,6 +517,9 @@ DARFixed:/* Return from dcbx instruction bug workaround */
* using them.
*/
do_databreakpoint:
+#ifdef CONFIG_VMAP_STACK
+ mfspr r11, SPRN_SRR1
+#endif
EXCEPTION_PROLOG_1
EXCEPTION_PROLOG_2
addi r3,r1,STACK_FRAME_OVERHEAD
@@ -508,8 +530,21 @@ do_databreakpoint:
. = 0x1c00
DataBreakpoint:
- EXCEPTION_PROLOG_0
+ mtspr SPRN_SPRG_SCRATCH0, r10
+ mtspr SPRN_SPRG_SCRATCH1, r11
+#ifdef CONFIG_VMAP_STACK
+ mfspr r10, SPRN_SPRG_THREAD
+ mfspr r11, SPRN_DAR
+ stw r11, DAR(r10)
+ mfspr r11, SPRN_SRR1
+ stw r11, SRR1(r10)
+#endif
mfspr r11, SPRN_SRR0
+#ifdef CONFIG_VMAP_STACK
+ stw r11, SRR0(r10)
+#endif
+ mfcr r10
+
cmplwi cr0, r11, (.Ldtlbie - PAGE_OFFSET)@l
cmplwi cr7, r11, (.Litlbie - PAGE_OFFSET)@l
cror 4*cr0+eq, 4*cr0+eq, 4*cr7+eq
@@ -625,7 +660,12 @@ modified_instr:
.space 4 /* this is where the add instr. is stored */
bne+ 143f
subf r10,r0,r10 /* r10=r10-r0, only if reg RA is r0 */
+#ifdef CONFIG_VMAP_STACK
+143: mfspr r11, SPRN_SPRG_THREAD
+ stw r10, DAR(r11)
+#else
143: mtdar r10 /* store faulting EA in DAR */
+#endif
mfspr r10,SPRN_M_TW
b DARFixed /* Go back to normal TLB handling */
#else
@@ -679,7 +719,12 @@ modified_instr:
152:
mfdar r11
mtctr r11 /* restore ctr reg from DAR */
+#ifdef CONFIG_VMAP_STACK
+ mfspr r11, SPRN_SPRG_THREAD
+ stw r10, DAR(r11)
+#else
mtdar r10 /* save fault EA to DAR */
+#endif
mfspr r10,SPRN_M_TW
b DARFixed /* Go back to normal TLB handling */
--
2.13.3
