[PATCH 4.19 01/14] powerpc/64s: move some exception handlers out of line

From: Greg Kroah-Hartman
Date: Fri Nov 20 2020 - 06:06:00 EST


From: Daniel Axtens <dja@xxxxxxxxxx>

(backport only)

We're about to grow the exception handlers, which will make a bunch of them
no longer fit within the space available. We move them out of line.

This is a fiddly and error-prone business, so in the interests of reviewability
I haven't merged this in with the addition of the entry flush.

Signed-off-by: Daniel Axtens <dja@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/powerpc/kernel/exceptions-64s.S | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)

--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -572,13 +572,16 @@ ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TY
EXC_REAL_BEGIN(data_access_slb, 0x380, 0x80)
SET_SCRATCH0(r13)
EXCEPTION_PROLOG_0(PACA_EXSLB)
+ b tramp_data_access_slb
+EXC_REAL_END(data_access_slb, 0x380, 0x80)
+
+TRAMP_REAL_BEGIN(tramp_data_access_slb)
EXCEPTION_PROLOG_1(PACA_EXSLB, KVMTEST_PR, 0x380)
mr r12,r3 /* save r3 */
mfspr r3,SPRN_DAR
mfspr r11,SPRN_SRR1
crset 4*cr6+eq
BRANCH_TO_COMMON(r10, slb_miss_common)
-EXC_REAL_END(data_access_slb, 0x380, 0x80)

EXC_VIRT_BEGIN(data_access_slb, 0x4380, 0x80)
SET_SCRATCH0(r13)
@@ -616,13 +619,16 @@ ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TY
EXC_REAL_BEGIN(instruction_access_slb, 0x480, 0x80)
SET_SCRATCH0(r13)
EXCEPTION_PROLOG_0(PACA_EXSLB)
+ b tramp_instruction_access_slb
+EXC_REAL_END(instruction_access_slb, 0x480, 0x80)
+
+TRAMP_REAL_BEGIN(tramp_instruction_access_slb)
EXCEPTION_PROLOG_1(PACA_EXSLB, KVMTEST_PR, 0x480)
mr r12,r3 /* save r3 */
mfspr r3,SPRN_SRR0 /* SRR0 is faulting address */
mfspr r11,SPRN_SRR1
crclr 4*cr6+eq
BRANCH_TO_COMMON(r10, slb_miss_common)
-EXC_REAL_END(instruction_access_slb, 0x480, 0x80)

EXC_VIRT_BEGIN(instruction_access_slb, 0x4480, 0x80)
SET_SCRATCH0(r13)