diff options
| author | Nicholas Piggin <npiggin@gmail.com> | 2019-06-28 15:33:21 +1000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2019-07-02 21:39:48 +1000 |
| commit | 63d60d0c6946fd6874a099540e0ac9e26661f8dd (patch) | |
| tree | d96eecbe758ecd71a643174b26e09e0293b0abb8 /arch/powerpc/kernel/exceptions-64s.S | |
| parent | b0b2a93da4c95ac808c4c43f24a1873ae3166a1a (diff) | |
powerpc/64s/exception: avoid SPR RAW scoreboard stall in real mode entry
Move SPR reads ahead of writes. Real mode entry that is not a KVM
guest is rare these days, but bad practice propagates.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/kernel/exceptions-64s.S')
| -rw-r--r-- | arch/powerpc/kernel/exceptions-64s.S | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S index 564a77039701..3735b9d1bb65 100644 --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -183,19 +183,19 @@ END_FTR_SECTION_NESTED(ftr,ftr,943) .endif .if \hsrr mfspr r11,SPRN_HSRR0 /* save HSRR0 */ + mfspr r12,SPRN_HSRR1 /* and HSRR1 */ + mtspr SPRN_HSRR1,r10 .else mfspr r11,SPRN_SRR0 /* save SRR0 */ + mfspr r12,SPRN_SRR1 /* and SRR1 */ + mtspr SPRN_SRR1,r10 .endif - LOAD_HANDLER(r12, \label\()) + LOAD_HANDLER(r10, \label\()) .if \hsrr - mtspr SPRN_HSRR0,r12 - mfspr r12,SPRN_HSRR1 /* and HSRR1 */ - mtspr SPRN_HSRR1,r10 + mtspr SPRN_HSRR0,r10 HRFI_TO_KERNEL .else - mtspr SPRN_SRR0,r12 - mfspr r12,SPRN_SRR1 /* and SRR1 */ - mtspr SPRN_SRR1,r10 + mtspr SPRN_SRR0,r10 RFI_TO_KERNEL .endif b . /* prevent speculative execution */ |