This patch enables CONFIG_VMAP_STACK. For that, a few changes are
done in head_8xx.S.
Signed-off-by: Christophe Leroy <[email protected]>
---
arch/powerpc/kernel/head_8xx.S | 34 ++++++++++++++++++++++++++++------
arch/powerpc/platforms/Kconfig.cputype | 1 +
2 files changed, 29 insertions(+), 6 deletions(-)
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 225e242ce1c5..fc6d4d10e298 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -127,7 +127,7 @@ instruction_counter:
/* Machine check */
. = 0x200
MachineCheck:
- EXCEPTION_PROLOG
+ EXCEPTION_PROLOG dar
save_dar_dsisr_on_stack r4, r5, r11
li r6, RPN_PATTERN
mtspr SPRN_DAR, r6 /* Tag DAR, to be used in DTLB Error */
@@ -140,7 +140,7 @@ MachineCheck:
/* Alignment exception */
. = 0x600
Alignment:
- EXCEPTION_PROLOG
+ EXCEPTION_PROLOG dar
save_dar_dsisr_on_stack r4, r5, r11
li r6, RPN_PATTERN
mtspr SPRN_DAR, r6 /* Tag DAR, to be used in DTLB Error */
@@ -457,20 +457,26 @@ InstructionTLBError:
*/
. = 0x1400
DataTLBError:
- EXCEPTION_PROLOG_0
+ EXCEPTION_PROLOG_0 dar
mfspr r11, SPRN_DAR
cmpwi cr1, r11, RPN_PATTERN
beq- cr1, 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 */
+#endif
EXCEPTION_PROLOG_1
- EXCEPTION_PROLOG_2
+ EXCEPTION_PROLOG_2 dar
get_and_save_dar_dsisr_on_stack r4, r5, r11
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)
@@ -492,16 +498,20 @@ DARFixed:/* Return from dcbx instruction bug workaround */
*/
do_databreakpoint:
EXCEPTION_PROLOG_1
- EXCEPTION_PROLOG_2
+ EXCEPTION_PROLOG_2 dar
addi r3,r1,STACK_FRAME_OVERHEAD
mfspr r4,SPRN_BAR
stw r4,_DAR(r11)
+#ifdef CONFIG_VMAP_STACK
+ lwz r5,_DSISR(r11)
+#else
mfspr r5,SPRN_DSISR
+#endif
EXC_XFER_STD(0x1c00, do_break)
. = 0x1c00
DataBreakpoint:
- EXCEPTION_PROLOG_0
+ EXCEPTION_PROLOG_0 dar
mfspr r11, SPRN_SRR0
cmplwi cr1, r11, (.Ldtlbie - PAGE_OFFSET)@l
cmplwi cr7, r11, (.Litlbie - PAGE_OFFSET)@l
@@ -530,6 +540,11 @@ InstructionBreakpoint:
EXCEPTION(0x1e00, Trap_1e, unknown_exception, EXC_XFER_STD)
EXCEPTION(0x1f00, Trap_1f, unknown_exception, EXC_XFER_STD)
+#ifdef CONFIG_VMAP_STACK
+stack_ovf_trampoline:
+ b stack_ovf
+#endif
+
. = 0x2000
/* This is the procedure to calculate the data EA for buggy dcbx,dcbi instructions
@@ -650,7 +665,14 @@ FixupDAR:/* Entry point for dcbx workaround. */
152:
mfdar r11
mtctr r11 /* restore ctr reg from DAR */
+#ifdef CONFIG_VMAP_STACK
+ mfspr r11, SPRN_SPRG_THREAD
+ stw r10, DAR(r11)
+ mfspr r10, SPRN_DSISR
+ stw r10, DSISR(r11)
+#else
mtdar r10 /* save fault EA to DAR */
+#endif
mfspr r10,SPRN_M_TW
b DARFixed /* Go back to normal TLB handling */
diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
index 1e352c2eea7a..f0583251e9a3 100644
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -49,6 +49,7 @@ config PPC_8xx
select PPC_HAVE_KUEP
select PPC_HAVE_KUAP
select PPC_MM_SLICES if HUGETLB_PAGE
+ select HAVE_ARCH_VMAP_STACK
config 40x
bool "AMCC 40x"
--
2.13.3