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From: Suzuki K Poulose <suzuki.poulose@arm.com>
To: Mark Brown <broonie@kernel.org>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v8 4/4] arm64: Use a variable to store non-global mappings decision
Date: Mon, 11 Nov 2019 14:39:18 +0000	[thread overview]
Message-ID: <facc5c49-719e-f63a-3bec-67c369eb5cea@arm.com> (raw)
In-Reply-To: <20191108170116.32105-5-broonie@kernel.org>



On 08/11/2019 17:01, Mark Brown wrote:
> Refactor the code which checks to see if we need to use non-global
> mappings to use a variable instead of checking with the CPU capabilities
> each time, doing the initial check for KPTI early in boot before we
> start allocating memory so we still avoid transitioning to non-global
> mappings in common cases.
> 
> Since this variable always matches our decision about non-global
> mappings this means we can also combine arm64_kernel_use_ng_mappings()
> and arm64_unmap_kernel_at_el0() into a single function, the variable
> simply stores the result and the decision code is elsewhere. We could
> just have the users check the variable directly but having a function
> makes it clear that these uses are read-only.
> 
> The result is that we simplify the code a bit and reduces the amount of
> code executed at runtime.
> 
> Signed-off-by: Mark Brown <broonie@kernel.org>

Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>

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      reply	other threads:[~2019-11-11 14:39 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-11-08 17:01 [PATCH v8 0/4] E0PD support Mark Brown
2019-11-08 17:01 ` [PATCH v8 1/4] arm64: Add initial support for E0PD Mark Brown
2019-11-11 14:22   ` Suzuki K Poulose
2019-11-11 17:35     ` Mark Brown
2019-11-08 17:01 ` [PATCH v8 2/4] arm64: Factor out checks for KASLR in KPTI code into separate function Mark Brown
2019-11-11 14:31   ` Suzuki K Poulose
2019-11-08 17:01 ` [PATCH v8 3/4] arm64: Don't use KPTI where we have E0PD Mark Brown
2019-11-11 14:36   ` Suzuki K Poulose
2019-11-11 16:36     ` Mark Brown
2019-11-11 17:36       ` Suzuki K Poulose
2019-11-08 17:01 ` [PATCH v8 4/4] arm64: Use a variable to store non-global mappings decision Mark Brown
2019-11-11 14:39   ` Suzuki K Poulose [this message]

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