From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Rutland Subject: Re: [PATCH v4 4/7] ARM: kernel: add device tree init map function Date: Mon, 19 Nov 2012 13:54:18 +0000 Message-ID: <20121119135418.GB2816@e106331-lin.cambridge.arm.com> References: <1353329106-24084-1-git-send-email-lorenzo.pieralisi@arm.com> <1353329106-24084-5-git-send-email-lorenzo.pieralisi@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1353329106-24084-5-git-send-email-lorenzo.pieralisi@arm.com> Content-Disposition: inline List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Lorenzo Pieralisi Cc: Nicolas Pitre , Dave Martin , Kukjin Kim , Russell King , Pawel Moll , Stephen Warren , Tony Lindgren , Catalin Marinas , "devicetree-discuss@lists.ozlabs.org" , Will Deacon , Amit Kucheria , Grant Likely , "rob.herring@calxeda.com" , Benjamin Herrenschmidt , Vincent Guittot , David Brown , Magnus Damm , "linux-arm-kernel@lists.infradead.org" List-Id: devicetree@vger.kernel.org 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 > Acked-by: Nicolas Pitre > --- > 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@0 { > + device_type = "cpu"; > + compatible = "arm, cortex-a15"; > + reg = <0x0>; > + }; > + > + CPU1: cpu@1 { > + device_type = "cpu"; > + compatible = "arm, cortex-a15"; > + reg = <0x1>; > + }; > + > + CPU2: cpu@100 { > + device_type = "cpu"; > + compatible = "arm, cortex-a7"; > + reg = <0x100>; > + }; > + > + CPU3: cpu@101 { > + device_type = "cpu"; > + compatible = "arm, cortex-a7"; > + reg = <0x101>; > + }; > + }; Those spaces in the compatible strings shouldn't be there. Otherwise, looks good to me. Thanks, Mark