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>,
npiggin@gmail.com, msuchanek@suse.de
Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Subject: [PATCH v5 04/22] powerpc/32: Reorder instructions to avoid using CTR in syscall entry
Date: Mon, 8 Feb 2021 15:10:23 +0000 (UTC) [thread overview]
Message-ID: <8fa13a59f73647e058c95fc7e1c7a98f316bd20a.1612796617.git.christophe.leroy@csgroup.eu> (raw)
In-Reply-To: <cover.1612796617.git.christophe.leroy@csgroup.eu>
Now that we are using rfi instead of mtmsr to reactivate MMU, it is
possible to reorder instructions and avoid the need to use CTR for
stashing SRR0.
null_syscall on 8xx is reduced by 3 cycles (283 => 280 cycles).
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/kernel/head_32.h | 22 ++++++++++------------
1 file changed, 10 insertions(+), 12 deletions(-)
diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h
index 4029c51dce5d..24dc326e0d56 100644
--- a/arch/powerpc/kernel/head_32.h
+++ b/arch/powerpc/kernel/head_32.h
@@ -116,30 +116,28 @@
.endm
.macro SYSCALL_ENTRY trapno
- mfspr r12,SPRN_SPRG_THREAD
mfspr r9, SPRN_SRR1
- mfspr r11, SPRN_SRR0
- mtctr r11
+ mfspr r10, SPRN_SRR0
andi. r11, r9, MSR_PR
+ beq- 99f
+ LOAD_REG_IMMEDIATE(r11, MSR_KERNEL) /* can take exceptions */
+ lis r12, 1f@h
+ ori r12, r12, 1f@l
+ mtspr SPRN_SRR1, r11
+ mtspr SPRN_SRR0, r12
+ mfspr r12,SPRN_SPRG_THREAD
mr r11, r1
lwz r1,TASK_STACK-THREAD(r12)
- beq- 99f
+ tovirt(r12, r12)
addi r1, r1, THREAD_SIZE - INT_FRAME_SIZE
- LOAD_REG_IMMEDIATE(r10, MSR_KERNEL) /* can take exceptions */
- mtspr SPRN_SRR1, r10
- lis r10, 1f@h
- ori r10, r10, 1f@l
- mtspr SPRN_SRR0, r10
rfi
1:
- tovirt(r12, r12)
stw r11,GPR1(r1)
stw r11,0(r1)
mr r11, r1
+ stw r10,_NIP(r11)
mflr r10
stw r10, _LINK(r11)
- mfctr r10
- stw r10,_NIP(r11)
mfcr r10
rlwinm r10,r10,0,4,2 /* Clear SO bit in CR */
stw r10,_CCR(r11) /* save registers */
--
2.25.0
next prev parent reply other threads:[~2021-02-08 15:18 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-08 15:10 [PATCH v5 00/22] powerpc/32: Implement C syscall entry/exit Christophe Leroy
2021-02-08 15:10 ` [PATCH v5 01/22] powerpc/32s: Add missing call to kuep_lock on syscall entry Christophe Leroy
2021-02-08 15:10 ` [PATCH v5 02/22] powerpc/32: Always enable data translation " Christophe Leroy
2021-02-08 15:10 ` [PATCH v5 03/22] powerpc/32: On syscall entry, enable instruction translation at the same time as data Christophe Leroy
2021-02-08 15:10 ` Christophe Leroy [this message]
2021-02-08 15:10 ` [PATCH v5 05/22] powerpc/irq: Add helper to set regs->softe Christophe Leroy
2021-02-09 1:11 ` Nicholas Piggin
2021-02-09 5:57 ` Christophe Leroy
2021-02-09 7:47 ` Nicholas Piggin
2021-02-09 6:18 ` Christophe Leroy
2021-02-09 7:49 ` Nicholas Piggin
2021-03-05 8:54 ` Christophe Leroy
2021-03-08 8:47 ` Nicholas Piggin
2021-02-08 15:10 ` [PATCH v5 06/22] powerpc/irq: Rework helpers that manipulate MSR[EE/RI] Christophe Leroy
2021-02-09 1:14 ` Nicholas Piggin
2021-02-08 15:10 ` [PATCH v5 07/22] powerpc/irq: Add stub irq_soft_mask_return() for PPC32 Christophe Leroy
2021-02-09 1:19 ` Nicholas Piggin
2021-02-08 15:10 ` [PATCH v5 08/22] powerpc/syscall: Rename syscall_64.c into interrupt.c Christophe Leroy
2021-02-09 1:19 ` Nicholas Piggin
2021-02-08 15:10 ` [PATCH v5 09/22] powerpc/syscall: Make interrupt.c buildable on PPC32 Christophe Leroy
2021-02-09 1:27 ` Nicholas Piggin
2021-02-09 6:02 ` Christophe Leroy
2021-02-09 7:50 ` Nicholas Piggin
2021-02-08 15:10 ` [PATCH v5 10/22] powerpc/syscall: Use is_compat_task() Christophe Leroy
2021-02-09 1:29 ` Nicholas Piggin
2021-02-08 15:10 ` [PATCH v5 11/22] powerpc/syscall: Save r3 in regs->orig_r3 Christophe Leroy
2021-02-09 1:29 ` Nicholas Piggin
2021-02-08 15:10 ` [PATCH v5 12/22] powerpc/syscall: Change condition to check MSR_RI Christophe Leroy
2021-02-09 1:36 ` Nicholas Piggin
2021-02-08 15:10 ` [PATCH v5 13/22] powerpc/32: Always save non volatile GPRs at syscall entry Christophe Leroy
2021-02-08 15:10 ` [PATCH v5 14/22] powerpc/syscall: implement system call entry/exit logic in C for PPC32 Christophe Leroy
2021-02-08 15:10 ` [PATCH v5 15/22] powerpc/32: Remove verification of MSR_PR on syscall in the ASM entry Christophe Leroy
2021-02-08 15:10 ` [PATCH v5 16/22] powerpc/syscall: Avoid stack frame in likely part of system_call_exception() Christophe Leroy
2021-02-09 1:55 ` Nicholas Piggin
2021-02-09 16:13 ` Christophe Leroy
2021-02-10 1:56 ` Nicholas Piggin
2021-02-08 15:10 ` [PATCH v5 17/22] powerpc/syscall: Do not check unsupported scv vector on PPC32 Christophe Leroy
2021-02-09 2:00 ` Nicholas Piggin
2021-02-09 6:13 ` Christophe Leroy
2021-02-09 7:56 ` Nicholas Piggin
2021-02-08 15:10 ` [PATCH v5 18/22] powerpc/syscall: Remove FULL_REGS verification in system_call_exception Christophe Leroy
2021-02-09 2:02 ` Nicholas Piggin
2021-02-09 14:31 ` Christophe Leroy
2021-02-10 1:57 ` Nicholas Piggin
2021-02-08 15:10 ` [PATCH v5 19/22] powerpc/syscall: Optimise checks in beginning of system_call_exception() Christophe Leroy
2021-02-09 2:06 ` Nicholas Piggin
2021-02-09 14:32 ` Christophe Leroy
2021-02-08 15:10 ` [PATCH v5 20/22] powerpc/syscall: Avoid storing 'current' in another pointer Christophe Leroy
2021-02-09 2:36 ` Nicholas Piggin
2021-02-09 13:50 ` Segher Boessenkool
2021-02-09 14:31 ` David Laight
2021-02-09 17:03 ` Christophe Leroy
2021-02-09 17:16 ` David Laight
2021-02-10 2:00 ` Nicholas Piggin
2021-02-10 8:45 ` Christophe Leroy
2021-02-08 15:10 ` [PATCH v5 21/22] powerpc/32: Remove the counter in global_dbcr0 Christophe Leroy
2021-02-08 15:10 ` [PATCH v5 22/22] powerpc/32: Handle bookE debugging in C in syscall entry/exit Christophe Leroy
2021-02-09 1:03 ` [PATCH v5 00/22] powerpc/32: Implement C " Nicholas Piggin
2021-02-12 0:19 ` Michael Ellerman
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