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From: Will Deacon <will@kernel.org>
To: linux-arm-kernel@lists.infradead.org
Cc: Mark Rutland <mark.rutland@arm.com>,
	Will Deacon <will@kernel.org>,
	kernel-team@android.com,
	Catalin Marinas <catalin.marinas@arm.com>
Subject: [PATCH] arm64: docs: Mandate that the I-cache doesn't hold stale kernel text
Date: Thu, 23 Apr 2020 10:36:58 +0100	[thread overview]
Message-ID: <20200423093658.10602-1-will@kernel.org> (raw)

Although we require that the loaded kernel Image has been cleaned to the
PoC, we neglect to spell out the state of the I-cache. Although this
should be reasonably obvious, it doesn't hurt to be explicit.

Require that the I-cache doesn't hold any stale entries for the kernel
Image at boot.

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
---
 Documentation/arm64/booting.rst | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Documentation/arm64/booting.rst b/Documentation/arm64/booting.rst
index a3f1a47b6f1c..d063c05d5fb0 100644
--- a/Documentation/arm64/booting.rst
+++ b/Documentation/arm64/booting.rst
@@ -173,7 +173,8 @@ Before jumping into the kernel, the following conditions must be met:
 - Caches, MMUs
 
   The MMU must be off.
-  Instruction cache may be on or off.
+  The instruction cache may be on or off, and must not hold any stale
+  entries corresponding to the loaded kernel image.
   The address range corresponding to the loaded kernel image must be
   cleaned to the PoC. In the presence of a system cache or other
   coherent masters with caches enabled, this will typically require
-- 
2.26.1.301.g55bc3eb7cb9-goog


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             reply	other threads:[~2020-04-23  9:37 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-04-23  9:36 Will Deacon [this message]
2020-04-23  9:49 ` [PATCH] arm64: docs: Mandate that the I-cache doesn't hold stale kernel text Mark Rutland
2020-04-23  9:55 ` Catalin Marinas

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