From: Christophe Leroy <christophe.leroy@csgroup.eu>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>,
Michael Ellerman <mpe@ellerman.id.au>
Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
Subject: [PATCH v1 4/6] powerpc/8xx: Use SPRN_SPRG_SCRATCH2 in ITLB miss exception
Date: Tue, 24 Nov 2020 15:24:57 +0000 (UTC) [thread overview]
Message-ID: <abc78e8e9577d473691ebb9996c6413b37bfd9ca.1606231483.git.christophe.leroy@csgroup.eu> (raw)
In-Reply-To: <e796c5fcb5898de827c803cf1ab8ba1d7a5d4b76.1606231483.git.christophe.leroy@csgroup.eu>
In order to re-enable MMU earlier, ensure ITLB miss exception
cannot clobber SPRN_SPRG_SCRATCH0 and SPRN_SPRG_SCRATCH1.
Do so by using SPRN_SPRG_SCRATCH2 and SPRN_M_TW instead, like
the DTLB miss exception.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/kernel/head_8xx.S | 12 ++++++------
arch/powerpc/perf/8xx-pmu.c | 4 ++--
2 files changed, 8 insertions(+), 8 deletions(-)
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 558c8e615ef9..45239b06b6ce 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -190,8 +190,8 @@ SystemCall:
#endif
InstructionTLBMiss:
- mtspr SPRN_SPRG_SCRATCH0, r10
- mtspr SPRN_SPRG_SCRATCH1, r11
+ mtspr SPRN_SPRG_SCRATCH2, r10
+ mtspr SPRN_M_TW, r11
/* If we are faulting a kernel address, we have to use the
* kernel page tables.
@@ -230,8 +230,8 @@ InstructionTLBMiss:
mtspr SPRN_MI_RPN, r10 /* Update TLB entry */
/* Restore registers */
-0: mfspr r10, SPRN_SPRG_SCRATCH0
- mfspr r11, SPRN_SPRG_SCRATCH1
+0: mfspr r10, SPRN_SPRG_SCRATCH2
+ mfspr r11, SPRN_M_TW
rfi
patch_site 0b, patch__itlbmiss_exit_1
@@ -240,8 +240,8 @@ InstructionTLBMiss:
0: lwz r10, (itlb_miss_counter - PAGE_OFFSET)@l(0)
addi r10, r10, 1
stw r10, (itlb_miss_counter - PAGE_OFFSET)@l(0)
- mfspr r10, SPRN_SPRG_SCRATCH0
- mfspr r11, SPRN_SPRG_SCRATCH1
+ mfspr r10, SPRN_SPRG_SCRATCH2
+ mfspr r11, SPRN_M_TW
rfi
#endif
diff --git a/arch/powerpc/perf/8xx-pmu.c b/arch/powerpc/perf/8xx-pmu.c
index e53c3c161257..02db58c7427a 100644
--- a/arch/powerpc/perf/8xx-pmu.c
+++ b/arch/powerpc/perf/8xx-pmu.c
@@ -165,9 +165,9 @@ static void mpc8xx_pmu_del(struct perf_event *event, int flags)
break;
case PERF_8xx_ID_ITLB_LOAD_MISS:
if (atomic_dec_return(&itlb_miss_ref) == 0) {
- /* mfspr r10, SPRN_SPRG_SCRATCH0 */
+ /* mfspr r10, SPRN_SPRG_SCRATCH2 */
struct ppc_inst insn = ppc_inst(PPC_INST_MFSPR | __PPC_RS(R10) |
- __PPC_SPR(SPRN_SPRG_SCRATCH0));
+ __PPC_SPR(SPRN_SPRG_SCRATCH2));
patch_instruction_site(&patch__itlbmiss_exit_1, insn);
}
--
2.25.0
next prev parent reply other threads:[~2020-11-24 15:25 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-24 15:24 [PATCH v1 1/6] powerpc/8xx: DEBUG_PAGEALLOC doesn't require an ITLB miss exception handler Christophe Leroy
2020-11-24 15:24 ` [PATCH v1 2/6] powerpc/8xx: Always pin kernel text TLB Christophe Leroy
2020-12-09 10:43 ` Michael Ellerman
2020-12-09 11:50 ` Christophe Leroy
2020-12-10 0:21 ` Michael Ellerman
2020-11-24 15:24 ` [PATCH v1 3/6] powerpc/8xx: Simplify INVALIDATE_ADJACENT_PAGES_CPU15 Christophe Leroy
2020-11-24 15:24 ` Christophe Leroy [this message]
2020-11-24 15:24 ` [PATCH v1 5/6] powerpc/8xx: Use SPRN_SPRG_SCRATCH2 in DTLB miss exception Christophe Leroy
2020-11-24 15:24 ` [PATCH v1 6/6] powerpc/ppc-opcode: Add PPC_RAW_MFSPR() Christophe Leroy
2020-12-15 10:48 ` [PATCH v1 1/6] powerpc/8xx: DEBUG_PAGEALLOC doesn't require an ITLB miss exception handler Michael Ellerman
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