From: Nicholas Piggin <npiggin@gmail.com>
To: linuxppc-dev@lists.ozlabs.org
Cc: Nicholas Piggin <npiggin@gmail.com>
Subject: [PATCH v3 02/13] powerpc/64s/exception: avoid SPR RAW scoreboard stall in real mode entry
Date: Fri, 28 Jun 2019 15:33:21 +1000 [thread overview]
Message-ID: <20190628053332.22366-3-npiggin@gmail.com> (raw)
In-Reply-To: <20190628053332.22366-1-npiggin@gmail.com>
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>
---
arch/powerpc/kernel/exceptions-64s.S | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 98321ded8df6..c3a9cb8cdfd3 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 */
--
2.20.1
next prev parent reply other threads:[~2019-06-28 5:38 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-28 5:33 [PATCH v3 00/13] next batch of interrupt handler improvements Nicholas Piggin
2019-06-28 5:33 ` [PATCH v3 01/13] powerpc/64s/exception: clean up system call entry Nicholas Piggin
2019-07-04 15:52 ` Michael Ellerman
2019-06-28 5:33 ` Nicholas Piggin [this message]
2019-06-28 5:33 ` [PATCH v3 03/13] powerpc/64s/exception: mtmsrd L=1 cleanup Nicholas Piggin
2019-06-28 5:33 ` [PATCH v3 04/13] powerpc/64s/exception: windup use r9 consistently to restore SPRs Nicholas Piggin
2019-06-28 5:33 ` [PATCH v3 05/13] powerpc/64s/exception: move machine check windup in_mce handling Nicholas Piggin
2019-06-28 5:33 ` [PATCH v3 06/13] powerpc/64s/exception: simplify hmi windup code Nicholas Piggin
2019-06-28 5:33 ` [PATCH v3 07/13] powerpc/64s/exception: shuffle windup code around Nicholas Piggin
2019-06-28 5:33 ` [PATCH v3 08/13] powerpc/64s/exception: use common macro for windup Nicholas Piggin
2019-06-28 5:33 ` [PATCH v3 09/13] powerpc/64s/exception: add dar and dsisr options to exception macro Nicholas Piggin
2019-06-28 5:33 ` [PATCH v3 10/13] powerpc/64s/exception: machine check use standard macros to save dar/dsisr Nicholas Piggin
2019-06-28 5:33 ` [PATCH v3 11/13] powerpc/64s/exception: denorm handler use standard scratch save macro Nicholas Piggin
2019-06-28 5:33 ` [PATCH v3 12/13] powerpc/64s/exception: move SET_SCRATCH0 into EXCEPTION_PROLOG_0 Nicholas Piggin
2019-06-28 5:33 ` [PATCH v3 13/13] powerpc/tm: update comment about interrupt re-entrancy Nicholas Piggin
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