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From: slash.tmp@free.fr (Mason)
To: linux-arm-kernel@lists.infradead.org
Subject: Trustzone: DSB before/after SMC
Date: Tue, 27 Oct 2015 14:31:38 +0100	[thread overview]
Message-ID: <562F7CBA.7060806@free.fr> (raw)

Hello,

I have a few questions about SMC. (I'm using Cortex-A9)

Platforms that use SMC often/always execute DSB beforehand.

1a) Is DSB required before SMC?
1b) Is DSB required  after SMC?
2a) Is DSB required before returning to non-secure OS?
2b) Is DSB required  after returning to non-secure OS?
3) Is this documented in the ARM ARM?

Bonus question: if DSB is required before SMC, why didn't ARM
make SMC implicitly do a DSB?

Regards.

             reply	other threads:[~2015-10-27 13:31 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-10-27 13:31 Mason [this message]
2015-10-27 13:43 ` Trustzone: DSB before/after SMC Mark Rutland
2015-10-27 14:05   ` Mason
2015-10-27 14:37     ` Mark Rutland
2015-10-27 14:54       ` Måns Rullgård
2015-10-27 15:01       ` Mason

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