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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	stable@vger.kernel.org, Marc Zyngier <marc.zyngier@arm.com>,
	Mark Rutland <mark.rutland@arm.com>,
	Will Deacon <will.deacon@arm.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Nathan Chancellor <nathan@kernel.org>
Subject: [PATCH 4.9 13/21] arm64: reduce el2_setup branching
Date: Mon, 10 Jan 2022 08:23:00 +0100	[thread overview]
Message-ID: <20220110071813.246928726@linuxfoundation.org> (raw)
In-Reply-To: <20220110071812.806606886@linuxfoundation.org>

From: Mark Rutland <mark.rutland@arm.com>

commit 3ad47d055aa88d9f4189253f5b5c485f4c4626b2 upstream.

The early el2_setup code is a little convoluted, with two branches where
one would do. This makes the code more painful to read than is
necessary.

We can remove a branch and simplify the logic by moving the early return
in the booted-at-EL1 case earlier in the function. This separates it
from all the setup logic that only makes sense for EL2.

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 arch/arm64/kernel/head.S |   15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -489,13 +489,8 @@ ENTRY(el2_setup)
 	msr	SPsel, #1			// We want to use SP_EL{1,2}
 	mrs	x0, CurrentEL
 	cmp	x0, #CurrentEL_EL2
-	b.ne	1f
-	mrs	x0, sctlr_el2
-CPU_BE(	orr	x0, x0, #(1 << 25)	)	// Set the EE bit for EL2
-CPU_LE(	bic	x0, x0, #(1 << 25)	)	// Clear the EE bit for EL2
-	msr	sctlr_el2, x0
-	b	2f
-1:	mrs	x0, sctlr_el1
+	b.eq	1f
+	mrs	x0, sctlr_el1
 CPU_BE(	orr	x0, x0, #(3 << 24)	)	// Set the EE and E0E bits for EL1
 CPU_LE(	bic	x0, x0, #(3 << 24)	)	// Clear the EE and E0E bits for EL1
 	msr	sctlr_el1, x0
@@ -503,7 +498,11 @@ CPU_LE(	bic	x0, x0, #(3 << 24)	)	// Clea
 	isb
 	ret
 
-2:
+1:	mrs	x0, sctlr_el2
+CPU_BE(	orr	x0, x0, #(1 << 25)	)	// Set the EE bit for EL2
+CPU_LE(	bic	x0, x0, #(1 << 25)	)	// Clear the EE bit for EL2
+	msr	sctlr_el2, x0
+
 #ifdef CONFIG_ARM64_VHE
 	/*
 	 * Check for VHE being present. For the rest of the EL2 setup,



  parent reply	other threads:[~2022-01-10  7:26 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-01-10  7:22 [PATCH 4.9 00/21] 4.9.297-rc1 review Greg Kroah-Hartman
2022-01-10  7:22 ` [PATCH 4.9 01/21] Bluetooth: btusb: Apply QCA Rome patches for some ATH3012 models Greg Kroah-Hartman
2022-01-10  7:22 ` [PATCH 4.9 02/21] tracing: Fix check for trace_percpu_buffer validity in get_trace_buf() Greg Kroah-Hartman
2022-01-10  7:22 ` [PATCH 4.9 03/21] tracing: Tag trace_percpu_buffer as a percpu pointer Greg Kroah-Hartman
2022-01-10  7:22 ` [PATCH 4.9 04/21] virtio_pci: Support surprise removal of virtio pci device Greg Kroah-Hartman
2022-01-10  7:22 ` [PATCH 4.9 05/21] ieee802154: atusb: fix uninit value in atusb_set_extended_addr Greg Kroah-Hartman
2022-01-10  7:22 ` [PATCH 4.9 06/21] mac80211: initialize variable have_higher_than_11mbit Greg Kroah-Hartman
2022-01-10  7:22 ` [PATCH 4.9 07/21] i40e: Fix incorrect netdevs real number of RX/TX queues Greg Kroah-Hartman
2022-01-10  7:22 ` [PATCH 4.9 08/21] sch_qfq: prevent shift-out-of-bounds in qfq_init_qdisc Greg Kroah-Hartman
2022-01-10  7:22 ` [PATCH 4.9 09/21] xfs: map unwritten blocks in XFS_IOC_{ALLOC,FREE}SP just like fallocate Greg Kroah-Hartman
2022-01-10  7:22 ` [PATCH 4.9 10/21] rndis_host: support Hytera digital radios Greg Kroah-Hartman
2022-01-10  7:22 ` [PATCH 4.9 11/21] bug: split BUILD_BUG stuff out into <linux/build_bug.h> Greg Kroah-Hartman
2022-01-10  7:22 ` [PATCH 4.9 12/21] arm64: Remove a redundancy in sysreg.h Greg Kroah-Hartman
2022-01-10  7:23 ` Greg Kroah-Hartman [this message]
2022-01-10  7:23 ` [PATCH 4.9 14/21] arm64: move !VHE work to end of el2_setup Greg Kroah-Hartman
2022-01-10  7:23 ` [PATCH 4.9 15/21] arm64: sysreg: Move to use definitions for all the SCTLR bits Greg Kroah-Hartman
2022-01-10  7:23 ` [PATCH 4.9 16/21] phonet: refcount leak in pep_sock_accep Greg Kroah-Hartman
2022-01-10  7:23 ` [PATCH 4.9 17/21] scsi: libiscsi: Fix UAF in iscsi_conn_get_param()/iscsi_conn_teardown() Greg Kroah-Hartman
2022-01-10  7:23 ` [PATCH 4.9 18/21] ip6_vti: initialize __ip6_tnl_parm struct in vti6_siocdevprivate Greg Kroah-Hartman
2022-01-10  7:23 ` [PATCH 4.9 19/21] net: udp: fix alignment problem in udp4_seq_show() Greg Kroah-Hartman
2022-01-10  7:23 ` [PATCH 4.9 20/21] mISDN: change function names to avoid conflicts Greg Kroah-Hartman
2022-01-10  7:23 ` [PATCH 4.9 21/21] power: reset: ltc2952: Fix use of floating point literals Greg Kroah-Hartman
2022-01-10 11:49 ` [PATCH 4.9 00/21] 4.9.297-rc1 review Jon Hunter
2022-01-10 18:58 ` Florian Fainelli
2022-01-10 23:01 ` Shuah Khan
2022-01-10 23:48 ` Guenter Roeck
2022-01-11  8:39 ` Naresh Kamboju

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