[PATCH v4 4/7] ARM: kernel: add device tree init map function
Lorenzo Pieralisi
lorenzo.pieralisi at arm.com
Mon Nov 19 09:07:07 EST 2012
On Mon, Nov 19, 2012 at 01:54:18PM +0000, Mark Rutland wrote:
> On Mon, Nov 19, 2012 at 12:45:03PM +0000, Lorenzo Pieralisi wrote:
> > When booting through a device tree, the kernel cpu logical id map can be
> > initialized using device tree data passed by FW or through an embedded blob.
> >
> > This patch adds a function that parses device tree "cpu" nodes and
> > retrieves the corresponding CPUs hardware identifiers (MPIDR).
> > It sets the possible cpus and the cpu logical map values according to
> > the number of CPUs defined in the device tree and respective properties.
> >
> > The device tree HW identifiers are considered valid if all CPU nodes contain
> > a "reg" property, there are no duplicate "reg" entries and the DT defines a
> > CPU node whose "reg" property matches the MPIDR[23:0] of the boot CPU.
> >
> > The primary CPU is assigned cpu logical number 0 to keep the current convention
> > valid.
> >
> > Current bindings documentation is included in the patch:
> >
> > Documentation/devicetree/bindings/arm/cpus.txt
> >
> > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi at arm.com>
> > Acked-by: Nicolas Pitre <nico at linaro.org>
> > ---
> > Documentation/devicetree/bindings/arm/cpus.txt | 77 +++++++++++++++++++
> > arch/arm/include/asm/prom.h | 2 +
> > arch/arm/kernel/devtree.c | 100 +++++++++++++++++++++++++
> > 3 files changed, 179 insertions(+)
> > create mode 100644 Documentation/devicetree/bindings/arm/cpus.txt
> >
> > diff --git a/Documentation/devicetree/bindings/arm/cpus.txt b/Documentation/devicetree/bindings/arm/cpus.txt
> > new file mode 100644
> > index 0000000..46c3589
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/arm/cpus.txt
> > @@ -0,0 +1,77 @@
> > +* ARM CPUs binding description
> > +
> > +The device tree allows to describe the layout of CPUs in a system through
> > +the "cpus" node, which in turn contains a number of subnodes (ie "cpu")
> > +defining properties for every cpu.
> > +
> > +Bindings for CPU nodes follow the ePAPR standard, available from:
> > +
> > +http://devicetree.org
> > +
> > +For the ARM architecture every CPU node must contain the following properties:
> > +
> > +- device_type: must be "cpu"
> > +- reg: property matching the CPU MPIDR[23:0] register bits
> > + reg[31:24] bits must be set to 0
> > +- compatible: should be one of:
> > + "arm,arm1020"
> > + "arm,arm1020e"
> > + "arm,arm1022"
> > + "arm,arm1026"
> > + "arm,arm720"
> > + "arm,arm740"
> > + "arm,arm7tdmi"
> > + "arm,arm920"
> > + "arm,arm922"
> > + "arm,arm925"
> > + "arm,arm926"
> > + "arm,arm940"
> > + "arm,arm946"
> > + "arm,arm9tdmi"
> > + "arm,cortex-a5"
> > + "arm,cortex-a7"
> > + "arm,cortex-a8"
> > + "arm,cortex-a9"
> > + "arm,cortex-a15"
> > + "arm,arm1136"
> > + "arm,arm1156"
> > + "arm,arm1176"
> > + "arm,arm11mpcore"
> > + "faraday,fa526"
> > + "intel,sa110"
> > + "intel,sa1100"
> > + "marvell,feroceon"
> > + "marvell,mohawk"
> > + "marvell,xsc3"
> > + "marvell,xscale"
> > +
> > +Example:
> > +
> > + cpus {
> > + #size-cells = <0>;
> > + #address-cells = <1>;
> > +
> > + CPU0: cpu at 0 {
> > + device_type = "cpu";
> > + compatible = "arm, cortex-a15";
> > + reg = <0x0>;
> > + };
> > +
> > + CPU1: cpu at 1 {
> > + device_type = "cpu";
> > + compatible = "arm, cortex-a15";
> > + reg = <0x1>;
> > + };
> > +
> > + CPU2: cpu at 100 {
> > + device_type = "cpu";
> > + compatible = "arm, cortex-a7";
> > + reg = <0x100>;
> > + };
> > +
> > + CPU3: cpu at 101 {
> > + device_type = "cpu";
> > + compatible = "arm, cortex-a7";
> > + reg = <0x101>;
> > + };
> > + };
>
> Those spaces in the compatible strings shouldn't be there.
Thanks for your patience, I missed that, now fixed.
Thanks !
Lorenzo
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