| Message ID | 20200423093658.10602-1-will@kernel.org (mailing list archive) |
|---|---|
| State | Mainlined |
| Commit | e24e03aa00f0248a716ec7859c03f0034bb42fb2 |
| Headers | show |
| Series | arm64: docs: Mandate that the I-cache doesn't hold stale kernel text | expand |
On Thu, Apr 23, 2020 at 10:36:58AM +0100, Will Deacon wrote: > 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> This was certianly the intent, so: Acked-by: Mark Rutland <mark.rutland@arm.com> Thanks, Mark. > --- > 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 >
On Thu, Apr 23, 2020 at 10:36:58AM +0100, Will Deacon wrote: > 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> Acked-by: Catalin Marinas <catalin.marinas@arm.com>
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
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(-)