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: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
Subject: [PATCH v4 22/23] powerpc/syscall: Optimise checks in beginning of system_call_exception()
Date: Mon, 25 Jan 2021 14:48:35 +0000 (UTC) [thread overview]
Message-ID: <8d08b80adf3f5aebb3ffc679629bcfa27829bf5a.1611585031.git.christophe.leroy@csgroup.eu> (raw)
In-Reply-To: <cover.1611585031.git.christophe.leroy@csgroup.eu>
Combine all tests of regs->msr into a single logical one.
Before the patch:
0: 81 6a 00 84 lwz r11,132(r10)
4: 90 6a 00 88 stw r3,136(r10)
8: 69 60 00 02 xori r0,r11,2
c: 54 00 ff fe rlwinm r0,r0,31,31,31
10: 0f 00 00 00 twnei r0,0
14: 69 63 40 00 xori r3,r11,16384
18: 54 63 97 fe rlwinm r3,r3,18,31,31
1c: 0f 03 00 00 twnei r3,0
20: 69 6b 80 00 xori r11,r11,32768
24: 55 6b 8f fe rlwinm r11,r11,17,31,31
28: 0f 0b 00 00 twnei r11,0
After the patch:
0: 81 6a 00 84 lwz r11,132(r10)
4: 90 6a 00 88 stw r3,136(r10)
8: 7d 6b 58 f8 not r11,r11
c: 71 6b c0 02 andi. r11,r11,49154
10: 0f 0b 00 00 twnei r11,0
6 cycles less on powerpc 8xx (328 => 322 cycles).
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/kernel/syscall.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/kernel/syscall.c b/arch/powerpc/kernel/syscall.c
index a40775daa88b..47ae55f94d1c 100644
--- a/arch/powerpc/kernel/syscall.c
+++ b/arch/powerpc/kernel/syscall.c
@@ -28,6 +28,7 @@ notrace long system_call_exception(long r3, long r4, long r5,
unsigned long r0, struct pt_regs *regs)
{
syscall_fn f;
+ unsigned long expected_msr;
regs->orig_gpr3 = r3;
@@ -39,10 +40,13 @@ notrace long system_call_exception(long r3, long r4, long r5,
trace_hardirqs_off(); /* finish reconciling */
+ expected_msr = MSR_PR;
if (!IS_ENABLED(CONFIG_BOOKE) && !IS_ENABLED(CONFIG_40x))
- BUG_ON(!(regs->msr & MSR_RI));
- BUG_ON(!(regs->msr & MSR_PR));
- BUG_ON(arch_irq_disabled_regs(regs));
+ expected_msr |= MSR_RI;
+ if (IS_ENABLED(CONFIG_PPC32))
+ expected_msr |= MSR_EE;
+ BUG_ON((regs->msr & expected_msr) ^ expected_msr);
+ BUG_ON(IS_ENABLED(CONFIG_PPC64) && arch_irq_disabled_regs(regs));
#ifdef CONFIG_PPC_PKEY
if (mmu_has_feature(MMU_FTR_PKEY)) {
--
2.25.0
next prev parent reply other threads:[~2021-01-25 15:04 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-25 14:48 [PATCH v4 00/23] powerpc/32: Implement C syscall entry/exit Christophe Leroy
2021-01-25 14:48 ` [PATCH v4 01/23] powerpc/32s: Add missing call to kuep_lock on syscall entry Christophe Leroy
2021-01-25 14:48 ` [PATCH v4 02/23] powerpc/32: Always enable data translation " Christophe Leroy
2021-01-25 14:48 ` [PATCH v4 03/23] powerpc/32: On syscall entry, enable instruction translation at the same time as data Christophe Leroy
2021-01-25 14:48 ` [PATCH v4 04/23] powerpc/32: Reorder instructions to avoid using CTR in syscall entry Christophe Leroy
2021-01-25 14:48 ` [PATCH v4 05/23] powerpc/64s: Make kuap_check_amr() and kuap_get_and_check_amr() generic Christophe Leroy
2021-01-25 14:48 ` [PATCH v4 06/23] powerpc/32s: Create C version of kuap_user/kernel_restore() and friends Christophe Leroy
2021-01-25 14:48 ` [PATCH v4 07/23] powerpc/8xx: " Christophe Leroy
2021-01-25 14:48 ` [PATCH v4 08/23] powerpc/irq: Add helper to set regs->softe Christophe Leroy
2021-01-25 14:48 ` [PATCH v4 09/23] powerpc/irq: Rework helpers that manipulate MSR[EE/RI] Christophe Leroy
2021-01-25 14:48 ` [PATCH v4 10/23] powerpc/irq: Add stub irq_soft_mask_return() for PPC32 Christophe Leroy
2021-01-25 14:48 ` [PATCH v4 11/23] powerpc/syscall: Rename syscall_64.c into syscall.c Christophe Leroy
2021-01-26 10:21 ` Nicholas Piggin
2021-01-26 10:28 ` David Laight
2021-01-27 23:50 ` Nicholas Piggin
2021-02-02 6:15 ` Christophe Leroy
2021-02-02 6:38 ` Nicholas Piggin
2021-02-02 6:58 ` Christophe Leroy
2021-02-02 20:10 ` Segher Boessenkool
2021-02-08 17:47 ` Christophe Leroy
2021-01-25 14:48 ` [PATCH v4 12/23] powerpc/syscall: Make syscall.c buildable on PPC32 Christophe Leroy
2021-01-25 14:48 ` [PATCH v4 13/23] powerpc/syscall: Use is_compat_task() Christophe Leroy
2021-01-25 14:48 ` [PATCH v4 14/23] powerpc/syscall: Save r3 in regs->orig_r3 Christophe Leroy
2021-01-26 10:18 ` Nicholas Piggin
2021-02-08 17:47 ` Christophe Leroy
2021-01-25 14:48 ` [PATCH v4 15/23] powerpc/syscall: Change condition to check MSR_RI Christophe Leroy
2021-01-25 14:48 ` [PATCH v4 16/23] powerpc/32: Always save non volatile GPRs at syscall entry Christophe Leroy
2021-01-25 14:48 ` [PATCH v4 17/23] powerpc/syscall: implement system call entry/exit logic in C for PPC32 Christophe Leroy
2021-01-25 14:48 ` [PATCH v4 18/23] powerpc/32: Remove verification of MSR_PR on syscall in the ASM entry Christophe Leroy
2021-01-25 14:48 ` [PATCH v4 19/23] powerpc/syscall: Avoid stack frame in likely part of system_call_exception() Christophe Leroy
2021-01-26 10:14 ` Nicholas Piggin
2021-01-25 14:48 ` [PATCH v4 20/23] powerpc/syscall: Do not check unsupported scv vector on PPC32 Christophe Leroy
2021-01-26 10:16 ` Nicholas Piggin
2021-02-08 17:45 ` Christophe Leroy
2021-01-25 14:48 ` [PATCH v4 21/23] powerpc/syscall: Remove FULL_REGS verification in system_call_exception Christophe Leroy
2021-01-25 14:48 ` Christophe Leroy [this message]
2021-01-25 14:48 ` [PATCH v4 23/23] powerpc/syscall: Avoid storing 'current' in another pointer Christophe Leroy
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