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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
Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
Subject: [RFC PATCH v1 11/41] powerpc/32: Use fast instruction to set MSR RI in exception prolog on 8xx
Date: Tue,  9 Feb 2021 09:56:35 +0000 (UTC)	[thread overview]
Message-ID: <6ad5503bb11a1bf9f41d8c1dffd29b8b0d6c3974.1612864003.git.christophe.leroy@csgroup.eu> (raw)
In-Reply-To: <cover.1612864003.git.christophe.leroy@csgroup.eu>

8xx has registers SPRN_NRI, SPRN_EID and SPRN_EIE for changing
MSR EE and RI.

Use SPRN_EID in exception prolog to set RI.

On an 8xx, it reduces the null_syscall test by 3 cycles.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/head_32.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h
index ac6b391f1493..25ee6b26ef5a 100644
--- a/arch/powerpc/kernel/head_32.h
+++ b/arch/powerpc/kernel/head_32.h
@@ -107,6 +107,8 @@
 #endif
 #ifdef CONFIG_40x
 	rlwinm	r9,r9,0,14,12		/* clear MSR_WE (necessary?) */
+#elif defined(CONFIG_PPC_8xx)
+	mtspr	SPRN_EID, r2		/* Set MSR_RI */
 #else
 #ifdef CONFIG_VMAP_STACK
 	li	r10, MSR_KERNEL & ~MSR_IR /* can take exceptions */
-- 
2.25.0


  parent reply	other threads:[~2021-02-09 10:03 UTC|newest]

Thread overview: 42+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-09  9:56 [RFC PATCH v1 00/41] powerpc/32: Switch to interrupt entry/exit in C Christophe Leroy
2021-02-09  9:56 ` [RFC PATCH v1 01/41] powerpc/32: Preserve cr1 in exception prolog stack check to fix build error Christophe Leroy
2021-02-09  9:56 ` [RFC PATCH v1 02/41] powerpc/40x: Don't use SPRN_SPRG_SCRATCH0/1 in TLB miss handlers Christophe Leroy
2021-02-09  9:56 ` [RFC PATCH v1 03/41] powerpc/40x: Change CRITICAL_EXCEPTION_PROLOG macro to a gas macro Christophe Leroy
2021-02-09  9:56 ` [RFC PATCH v1 04/41] powerpc/40x: Save SRR0/SRR1 and r10/r11 earlier in critical exception Christophe Leroy
2021-02-09  9:56 ` [RFC PATCH v1 05/41] powerpc/40x: Reorder a few instructions in critical exception prolog Christophe Leroy
2021-02-09  9:56 ` [RFC PATCH v1 06/41] powerpc/40x: Prepare for enabling MMU " Christophe Leroy
2021-02-09  9:56 ` [RFC PATCH v1 07/41] powerpc/40x: Prepare normal exception handler for enabling MMU early Christophe Leroy
2021-02-09  9:56 ` [RFC PATCH v1 08/41] powerpc/32: Reconcile interrupts in C Christophe Leroy
2021-02-09  9:56 ` [RFC PATCH v1 09/41] powerpc/32: Entry cpu time accounting " Christophe Leroy
2021-02-09  9:56 ` [RFC PATCH v1 10/41] powerpc/32: Handle bookE debugging in C in exception entry Christophe Leroy
2021-02-09  9:56 ` Christophe Leroy [this message]
2021-02-09  9:56 ` [RFC PATCH v1 12/41] powerpc/32: Remove ksp_limit Christophe Leroy
2021-02-09  9:56 ` [RFC PATCH v1 13/41] powerpc/32: Always enable data translation in exception prolog Christophe Leroy
2021-02-09  9:56 ` [RFC PATCH v1 14/41] powerpc/32: Tag DAR in EXCEPTION_PROLOG_2 for the 8xx Christophe Leroy
2021-02-09  9:56 ` [RFC PATCH v1 15/41] powerpc/32: Enable instruction translation at the same time as data translation Christophe Leroy
2021-02-09  9:56 ` [RFC PATCH v1 16/41] powerpc/32: Statically initialise first emergency context Christophe Leroy
2021-02-09  9:56 ` [RFC PATCH v1 17/41] powerpc/32: Add vmap_stack_overflow label inside the macro Christophe Leroy
2021-02-09  9:56 ` [RFC PATCH v1 18/41] powerpc/32: Use START_EXCEPTION() as much as possible Christophe Leroy
2021-02-09  9:56 ` [RFC PATCH v1 19/41] powerpc/32: Move exception prolog code into .text once MMU is back on Christophe Leroy
2021-02-09  9:56 ` [RFC PATCH v1 20/41] powerpc/32: Provide a name to exception prolog continuation in virtual mode Christophe Leroy
2021-02-09  9:56 ` [RFC PATCH v1 21/41] powerpc/32: Refactor booke critical registers saving Christophe Leroy
2021-02-09  9:56 ` [RFC PATCH v1 22/41] powerpc/32: Perform normal function call in exception entry Christophe Leroy
2021-02-09  9:56 ` [RFC PATCH v1 23/41] powerpc/32: Always save non volatile registers on " Christophe Leroy
2021-02-09  9:56 ` [RFC PATCH v1 24/41] powerpc/32: Replace ASM exception exit by C exception exit from ppc64 Christophe Leroy
2021-02-09  9:56 ` [RFC PATCH v1 25/41] powerpc/32: Set regs parameter in r3 in transfer_to_handler Christophe Leroy
2021-02-09  9:56 ` [RFC PATCH v1 26/41] powerpc/32: Remove handle_page_fault() Christophe Leroy
2021-02-09  9:56 ` [RFC PATCH v1 27/41] powerpc/32: Save trap number on stack in exception prolog Christophe Leroy
2021-02-09  9:56 ` [RFC PATCH v1 28/41] powerpc/32: Add a prepare_transfer_to_handler macro for exception prologs Christophe Leroy
2021-02-09  9:56 ` [RFC PATCH v1 29/41] powerpc/32: Only restore non volatile registers when required Christophe Leroy
2021-02-09  9:56 ` [RFC PATCH v1 30/41] powerpc/32: Dismantle EXC_XFER_STD/LITE/TEMPLATE Christophe Leroy
2021-02-09  9:56 ` [RFC PATCH v1 31/41] powerpc/32: Remove the xfer parameter in EXCEPTION() macro Christophe Leroy
2021-02-09  9:56 ` [RFC PATCH v1 32/41] powerpc/32: Refactor saving of volatile registers in exception prologs Christophe Leroy
2021-02-09  9:56 ` [RFC PATCH v1 33/41] powerpc/32: Save remaining registers in exception prolog Christophe Leroy
2021-02-09  9:56 ` [RFC PATCH v1 34/41] powerpc/32: Set current->thread.regs in C interrupt entry Christophe Leroy
2021-02-09  9:57 ` [RFC PATCH v1 35/41] powerpc/32: Return directly from power_save_ppc32_restore() Christophe Leroy
2021-02-09  9:57 ` [RFC PATCH v1 36/41] powerpc/32: Only use prepare_transfer_to_handler function on book3s/32 and e500 Christophe Leroy
2021-02-09  9:57 ` [RFC PATCH v1 37/41] powerpc/32s: Move KUEP locking/unlocking in C Christophe Leroy
2021-02-09  9:57 ` [RFC PATCH v1 38/41] powerpc/64s: Make kuap_check_amr() and kuap_get_and_check_amr() generic Christophe Leroy
2021-02-09  9:57 ` [RFC PATCH v1 39/41] powerpc/32s: Create C version of kuap save/restore/check helpers Christophe Leroy
2021-02-09  9:57 ` [RFC PATCH v1 40/41] powerpc/8xx: " Christophe Leroy
2021-02-09  9:57 ` [RFC PATCH v1 41/41] powerpc/32: Manage KUAP in C Christophe Leroy

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