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From: Mark Rutland <mark.rutland@arm.com>
To: linux-arm-kernel@lists.infradead.org
Cc: ardb@kernel.org, broonie@kernel.org, catalin.marinas@arm.com,
	james.morse@arm.com, madvenka@linux.microsoft.com,
	mark.rutland@arm.com, maz@kernel.org, suzuki.poulose@arm.com,
	will@kernel.org
Subject: [PATCH 3/6] arm64: smp: remove pointless secondary_data maintenance
Date: Thu, 20 May 2021 12:50:28 +0100	[thread overview]
Message-ID: <20210520115031.18509-4-mark.rutland@arm.com> (raw)
In-Reply-To: <20210520115031.18509-1-mark.rutland@arm.com>

All reads and writes of secondary_data occur with the MMU on, using
coherent attributes, so there's no need to perform any cache maintenance
for this.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Suzuki Poulose <suzuki.poulose@arm.com>
Cc: Will Deacon <will@kernel.org>
---
 arch/arm64/kernel/smp.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index dcd7041b2b07..92e83e8bac94 100644
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -122,7 +122,6 @@ int __cpu_up(unsigned int cpu, struct task_struct *idle)
 	secondary_data.task = idle;
 	secondary_data.stack = task_stack_page(idle) + THREAD_SIZE;
 	update_cpu_boot_status(CPU_MMU_OFF);
-	__flush_dcache_area(&secondary_data, sizeof(secondary_data));
 
 	/* Now bring the CPU into our world */
 	ret = boot_secondary(cpu, idle);
@@ -143,7 +142,6 @@ int __cpu_up(unsigned int cpu, struct task_struct *idle)
 	pr_crit("CPU%u: failed to come online\n", cpu);
 	secondary_data.task = NULL;
 	secondary_data.stack = NULL;
-	__flush_dcache_area(&secondary_data, sizeof(secondary_data));
 	status = READ_ONCE(secondary_data.status);
 	if (status == CPU_MMU_OFF)
 		status = READ_ONCE(__early_cpu_boot_status);
-- 
2.11.0


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  parent reply	other threads:[~2021-05-20 11:54 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-20 11:50 [PATCH 0/6] arm64: boot cleanups Mark Rutland
2021-05-20 11:50 ` [PATCH 1/6] arm64: Implement stack trace termination record Mark Rutland
2021-05-20 11:50 ` [PATCH 2/6] arm64: assembler: add set_this_cpu_offset Mark Rutland
2021-05-20 11:50 ` Mark Rutland [this message]
2021-05-20 11:50 ` [PATCH 4/6] arm64: smp: remove stack from secondary_data Mark Rutland
2021-05-20 11:50 ` [PATCH 5/6] arm64: smp: unify task and sp setup Mark Rutland
2021-05-20 11:50 ` [PATCH 6/6] arm64: smp: initialize cpu offset earlier Mark Rutland
2021-05-20 14:46 ` [PATCH 0/6] arm64: boot cleanups Ard Biesheuvel
2021-05-26 22:16 ` Will Deacon
2021-05-27  9:33   ` Mark Rutland

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