From: Nicholas Piggin <npiggin@gmail.com>
To: linuxppc-dev@lists.ozlabs.org
Cc: Nicholas Piggin <npiggin@gmail.com>
Subject: [PATCH 5/5] powerpc/64s/exception: simplify hmi control flow
Date: Fri, 28 Jun 2019 16:33:22 +1000 [thread overview]
Message-ID: <20190628063322.11628-6-npiggin@gmail.com> (raw)
In-Reply-To: <20190628063322.11628-1-npiggin@gmail.com>
Branch to the relocated 0xc000 address early (still in real mode), to
simplify subsequent branches. Have the virt mode handler avoid just
'windup' and redo the exception from scratch, rather than branching
back to the trampoline.
Rearrange the stack setup instruction location to match the system
reset handler (e.g., right before EXCEPTION_PROLOG_COMMON).
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/kernel/exceptions-64s.S | 26 ++++++++++----------------
1 file changed, 10 insertions(+), 16 deletions(-)
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 23aba27b2f59..a91541956aa0 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -260,17 +260,6 @@ END_FTR_SECTION_NESTED(ftr,ftr,943)
mtctr reg; \
bctr
-#ifdef CONFIG_RELOCATABLE
-#define BRANCH_LINK_TO_FAR(label) \
- __LOAD_FAR_HANDLER(r12, label); \
- mtctr r12; \
- bctrl
-
-#else
-#define BRANCH_LINK_TO_FAR(label) \
- bl label
-#endif
-
#ifdef CONFIG_KVM_BOOK3S_64_HANDLER
#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
/*
@@ -1713,22 +1702,26 @@ EXC_REAL_BEGIN(hmi_exception, 0xe60, 0x20)
EXCEPTION_PROLOG_0 PACA_EXGEN
b hmi_exception_early
EXC_REAL_END(hmi_exception, 0xe60, 0x20)
-__TRAMP_REAL_OOL_MASKABLE_HV(hmi_exception, 0xe60, IRQS_DISABLED)
EXC_VIRT_NONE(0x4e60, 0x20)
TRAMP_KVM_HV(PACA_EXGEN, 0xe60)
TRAMP_REAL_BEGIN(hmi_exception_early)
EXCEPTION_PROLOG_1 EXC_HV, PACA_EXGEN, 1, 0xe60, 0, 0, 0
+ mfctr r10 /* save ctr, even for !RELOCATABLE */
+ BRANCH_TO_C000(r11, hmi_exception_early_common)
+
+EXC_COMMON_BEGIN(hmi_exception_early_common)
+ mtctr r10 /* Restore ctr */
+ 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 */
- mfspr r11,SPRN_HSRR0 /* Save HSRR0 */
- mfspr r12,SPRN_HSRR1 /* Save HSRR1 */
EXCEPTION_PROLOG_COMMON_1()
/* We don't touch AMR here, we never go to virtual mode */
EXCEPTION_PROLOG_COMMON_2(PACA_EXGEN)
EXCEPTION_PROLOG_COMMON_3(0xe60)
addi r3,r1,STACK_FRAME_OVERHEAD
- BRANCH_LINK_TO_FAR(DOTSYM(hmi_exception_realmode)) /* Function call ABI */
+ bl hmi_exception_realmode
cmpdi cr0,r3,0
bne 1f
@@ -1742,7 +1735,8 @@ TRAMP_REAL_BEGIN(hmi_exception_early)
*/
EXCEPTION_RESTORE_REGS EXC_HV
EXCEPTION_PROLOG_0 PACA_EXGEN
- b tramp_real_hmi_exception
+ EXCEPTION_PROLOG_1 EXC_HV, PACA_EXGEN, 1, 0xe60, 0, 0, IRQS_DISABLED
+ EXCEPTION_PROLOG_2_REAL hmi_exception_common, EXC_HV, 1
EXC_COMMON_BEGIN(hmi_exception_common)
EXCEPTION_COMMON(PACA_EXGEN, 0xe60)
--
2.20.1
prev parent reply other threads:[~2019-06-28 6:42 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-28 6:33 [PATCH 0/5] rework bad stack, sreset, hmi handling Nicholas Piggin
2019-06-28 6:33 ` [PATCH 1/5] powerpc/64s/exception: remove bad stack branch Nicholas Piggin
2019-07-04 15:52 ` Michael Ellerman
2019-06-28 6:33 ` [PATCH 2/5] powerpc/64s/exception: optimise system_reset for idle, clean up non-idle case Nicholas Piggin
2019-06-28 6:33 ` [PATCH 3/5] powerpc/64s/exception: sreset move trampoline ahead of common code Nicholas Piggin
2019-06-28 6:33 ` [PATCH 4/5] powerpc/64s/exception: hmi remove special case macro Nicholas Piggin
2019-06-28 6:33 ` Nicholas Piggin [this message]
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