[PATCH v2 13/35] powerpc/64s/exception: remove confusing IEARLY option

From: Michal Suchanek
Date: Tue Nov 26 2019 - 15:14:25 EST


From: Nicholas Piggin <npiggin@xxxxxxxxx>

Replace IEARLY=1 and IEARLY=2 with IBRANCH_COMMON, which controls if
the entry code branches to a common handler; and IREALMODE_COMMON,
which controls whether the common handler should remain in real mode.

These special cases no longer avoid loading the SRR registers, there
is no point as most of them load the registers immediately anyway.

Signed-off-by: Nicholas Piggin <npiggin@xxxxxxxxx>
---
arch/powerpc/kernel/exceptions-64s.S | 48 ++++++++++++++--------------
1 file changed, 24 insertions(+), 24 deletions(-)

diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 7db76e7be0aa..716a95ba814f 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -174,7 +174,8 @@ END_FTR_SECTION_NESTED(ftr,ftr,943)
#define IDAR .L_IDAR_\name\()
#define IDSISR .L_IDSISR_\name\()
#define ISET_RI .L_ISET_RI_\name\()
-#define IEARLY .L_IEARLY_\name\()
+#define IBRANCH_TO_COMMON .L_IBRANCH_TO_COMMON_\name\()
+#define IREALMODE_COMMON .L_IREALMODE_COMMON_\name\()
#define IMASK .L_IMASK_\name\()
#define IKVM_SKIP .L_IKVM_SKIP_\name\()
#define IKVM_REAL .L_IKVM_REAL_\name\()
@@ -218,8 +219,15 @@ do_define_int n
.ifndef ISET_RI
ISET_RI=1
.endif
- .ifndef IEARLY
- IEARLY=0
+ .ifndef IBRANCH_TO_COMMON
+ IBRANCH_TO_COMMON=1
+ .endif
+ .ifndef IREALMODE_COMMON
+ IREALMODE_COMMON=0
+ .else
+ .if ! IBRANCH_TO_COMMON
+ .error "IREALMODE_COMMON=1 but IBRANCH_TO_COMMON=0"
+ .endif
.endif
.ifndef IMASK
IMASK=0
@@ -353,6 +361,11 @@ END_FTR_SECTION_NESTED(CPU_FTR_HAS_PPR,CPU_FTR_HAS_PPR,948)
*/

.macro GEN_BRANCH_TO_COMMON name, virt
+ .if IREALMODE_COMMON
+ LOAD_HANDLER(r10, \name\()_common)
+ mtctr r10
+ bctr
+ .else
.if \virt
#ifndef CONFIG_RELOCATABLE
b \name\()_common_virt
@@ -366,6 +379,7 @@ END_FTR_SECTION_NESTED(CPU_FTR_HAS_PPR,CPU_FTR_HAS_PPR,948)
mtctr r10
bctr
.endif
+ .endif
.endm

.macro GEN_INT_ENTRY name, virt, ool=0
@@ -421,11 +435,6 @@ END_FTR_SECTION_NESTED(CPU_FTR_HAS_PPR,CPU_FTR_HAS_PPR,948)
stw r10,IAREA+EX_DSISR(r13)
.endif

- .if IEARLY == 2
- /* nothing more */
- .elseif IEARLY
- BRANCH_TO_C000(r11, \name\()_common)
- .else
.if IHSRR == EXC_HV_OR_STD
BEGIN_FTR_SECTION
mfspr r11,SPRN_HSRR0 /* save HSRR0 */
@@ -441,6 +450,8 @@ END_FTR_SECTION_NESTED(CPU_FTR_HAS_PPR,CPU_FTR_HAS_PPR,948)
mfspr r11,SPRN_SRR0 /* save SRR0 */
mfspr r12,SPRN_SRR1 /* and SRR1 */
.endif
+
+ .if IBRANCH_TO_COMMON
GEN_BRANCH_TO_COMMON \name \virt
.endif

@@ -926,6 +937,7 @@ INT_DEFINE_BEGIN(machine_check_early)
IVEC=0x200
IAREA=PACA_EXMC
IVIRT=0 /* no virt entry point */
+ IREALMODE_COMMON=1
/*
* MSR_RI is not enabled, because PACA_EXMC is being used, so a
* nested machine check corrupts it. machine_check_common enables
@@ -933,7 +945,6 @@ INT_DEFINE_BEGIN(machine_check_early)
*/
ISET_RI=0
ISTACK=0
- IEARLY=1
IDAR=1
IDSISR=1
IRECONCILE=0
@@ -973,9 +984,6 @@ TRAMP_REAL_BEGIN(machine_check_fwnmi)
EXCEPTION_RESTORE_REGS EXC_STD

EXC_COMMON_BEGIN(machine_check_early_common)
- mfspr r11,SPRN_SRR0
- mfspr r12,SPRN_SRR1
-
/*
* Switch to mc_emergency stack and handle re-entrancy (we limit
* the nested MCE upto level 4 to avoid stack overflow).
@@ -1822,7 +1830,7 @@ EXC_COMMON_BEGIN(emulation_assist_common)
INT_DEFINE_BEGIN(hmi_exception_early)
IVEC=0xe60
IHSRR=EXC_HV
- IEARLY=1
+ IREALMODE_COMMON=1
ISTACK=0
IRECONCILE=0
IKUAP=0 /* We don't touch AMR here, we never go to virtual mode */
@@ -1842,8 +1850,6 @@ EXC_REAL_END(hmi_exception, 0xe60, 0x20)
EXC_VIRT_NONE(0x4e60, 0x20)

EXC_COMMON_BEGIN(hmi_exception_early_common)
- mfspr r11,SPRN_HSRR0 /* Save HSRR0 */
- mfspr r12,SPRN_HSRR1 /* Save HSRR1 */
mr r10,r1 /* Save r1 */
ld r1,PACAEMERGSP(r13) /* Use emergency stack for realmode */
subi r1,r1,INT_FRAME_SIZE /* alloc stack frame */
@@ -2169,29 +2175,23 @@ EXC_VIRT_NONE(0x5400, 0x100)
INT_DEFINE_BEGIN(denorm_exception)
IVEC=0x1500
IHSRR=EXC_HV
- IEARLY=2
+ IBRANCH_TO_COMMON=0
IKVM_REAL=1
INT_DEFINE_END(denorm_exception)

EXC_REAL_BEGIN(denorm_exception, 0x1500, 0x100)
GEN_INT_ENTRY denorm_exception, virt=0
#ifdef CONFIG_PPC_DENORMALISATION
- mfspr r10,SPRN_HSRR1
- andis. r10,r10,(HSRR1_DENORM)@h /* denorm? */
+ andis. r10,r12,(HSRR1_DENORM)@h /* denorm? */
bne+ denorm_assist
#endif
- mfspr r11,SPRN_HSRR0
- mfspr r12,SPRN_HSRR1
GEN_BRANCH_TO_COMMON denorm_exception, virt=0
EXC_REAL_END(denorm_exception, 0x1500, 0x100)
#ifdef CONFIG_PPC_DENORMALISATION
EXC_VIRT_BEGIN(denorm_exception, 0x5500, 0x100)
GEN_INT_ENTRY denorm_exception, virt=1
- mfspr r10,SPRN_HSRR1
- andis. r10,r10,(HSRR1_DENORM)@h /* denorm? */
+ andis. r10,r12,(HSRR1_DENORM)@h /* denorm? */
bne+ denorm_assist
- mfspr r11,SPRN_HSRR0
- mfspr r12,SPRN_HSRR1
GEN_BRANCH_TO_COMMON denorm_exception, virt=1
EXC_VIRT_END(denorm_exception, 0x5500, 0x100)
#else
--
2.23.0