powerpc/64s/exception: simplify hmi control flow

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>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Nicholas Piggin 2019-06-28 16:33:22 +10:00 committed by Michael Ellerman
parent f34c9675ca
commit 293c2e27b9
1 changed files with 10 additions and 16 deletions

View File

@ -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)