From e24e03aa00f0248a716ec7859c03f0034bb42fb2 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Thu, 23 Apr 2020 10:36:58 +0100 Subject: [PATCH] arm64: docs: Mandate that the I-cache doesn't hold stale kernel text 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. Acked-by: Mark Rutland Acked-by: Catalin Marinas Cc: Mark Rutland Cc: Catalin Marinas Link: https://lore.kernel.org/r/20200423093658.10602-1-will@kernel.org Signed-off-by: Will Deacon --- 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