[PATCH 2/2] powerpc/85xx: describe the PAMU topology in the device tree

Gala Kumar-B11780 B11780 at freescale.com
Thu Jan 24 04:27:29 EST 2013


On Jan 17, 2013, at 4:34 PM, Timur Tabi wrote:

> From: Timur Tabi <timur at freescale.com>
> 
> The PAMU caches use the LIODNs to determine which cache lines hold the
> entries for the corresponding LIODs.  The LIODNs must therefore be
> carefully assigned to avoid cache thrashing -- two active LIODs with
> LIODNs that put them in the same cache line.
> 
> Currently, LIODNs are statically assigned by U-Boot, but this has
> limitations.  LIODNs are assigned even for devices that may be disabled
> or unused by the kernel.  Static assignments also do not allow for device
> drivers which may know which LIODs can be used simultaneously.  In
> other words, we really should assign LIODNs dynamically in Linux.
> 
> To do that, we need to describe the PAMU device and cache topologies in
> the device trees.
> 
> Signed-off-by: Timur Tabi <timur at freescale.com>
> ---
> .../devicetree/bindings/powerpc/fsl/guts.txt       |   14 ++-
> .../devicetree/bindings/powerpc/fsl/pamu.txt       |  142 ++++++++++++++++++++
> arch/powerpc/boot/dts/fsl/p2041si-post.dtsi        |   87 +++++++++++--
> arch/powerpc/boot/dts/fsl/p3041si-post.dtsi        |   87 +++++++++++--
> arch/powerpc/boot/dts/fsl/p4080si-post.dtsi        |   68 +++++++++-
> arch/powerpc/boot/dts/fsl/p5020si-post.dtsi        |   92 +++++++++++--
> arch/powerpc/boot/dts/fsl/p5040si-post.dtsi        |   92 +++++++++++--
> 7 files changed, 533 insertions(+), 49 deletions(-)
> create mode 100644 Documentation/devicetree/bindings/powerpc/fsl/pamu.txt

Scott, Stuart, does this have your guys Ack?

- k


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