From: punit.agrawal@arm•com (Punit Agrawal)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH] drivers: CCI: add ARM CCI PMU support
Date: Thu, 15 Aug 2013 10:10:02 +0100 [thread overview]
Message-ID: <520C9AEA.6030507@arm.com> (raw)
In-Reply-To: <2CD735CE-3FCF-4AB5-89C0-D813ECD19F11@codeaurora.org>
Hi Kumar,
Thanks for a review of the bindings.
On 14/08/13 22:03, Kumar Gala wrote:
>
> On Jul 23, 2013, at 4:19 AM, Punit Agrawal wrote:
>
>> The CCI PMU can profile bus transactions at the master and slave
>> interfaces of the CCI. The PMU can be used to observe an aggregated view
>> of the bus traffic between the various components connected to the CCI.
>>
>> Extend the existing CCI driver to support the PMU by registering a perf
>> backend for it.
>>
>> Document the device tree binding to describe the CCI PMU.
>>
>> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm•com>
>> Cc: Nicolas Pitre <nico@linaro•org>
>> Cc: Dave Martin <dave.martin@linaro•org>
>> Cc: Rob Herring <rob.herring@calxeda•com>
>> Cc: Will Deacon <will.deacon@arm•com>
>> Signed-off-by: Punit Agrawal <punit.agrawal@arm•com>
>> Reviewed-by: Will Deacon <will.deacon@arm•com>
>> ---
>> Documentation/devicetree/bindings/arm/cci.txt | 38 ++
>> drivers/bus/arm-cci.c | 642 +++++++++++++++++++++++++
>> 2 files changed, 680 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/arm/cci.txt b/Documentation/devicetree/bindings/arm/cci.txt
>> index 92d36e2..5bc95e5 100644
>> --- a/Documentation/devicetree/bindings/arm/cci.txt
>> +++ b/Documentation/devicetree/bindings/arm/cci.txt
>> @@ -79,6 +79,34 @@ specific to ARM.
>> corresponding interface programming
>> registers.
>>
>> + - CCI PMU node
>> +
>> + Node name must be "pmu".
>> + Parent node must be CCI interconnect node.
>> +
>> + A CCI pmu node must contain the following properties:
>> +
>> + - compatible
>> + Usage: required
>> + Value type: <string>
>> + Definition: must be set to one of
>> + "arm,cci-400-pmu"
>> + "arm,cci-400-pmu,rev0"
>> + "arm,cci-400-pmu,rev1"
>
> Do you really mean only one? Seems like ""arm,cci-400-pmu,rev0", "arm,cci-400-pmu" would be valid.
>
Hmm... yes both would be valid. But...
The event numbering scheme changed between Rev 0 and Rev 1 of the CCI.
If the revision is specified then it is used to get the event ranges to
validate the events. If not, i.e., "arm,cci-400-pmu" is used, then the
driver tries to find the the revision by reading the peripheral id
registers.
I was trying to make the bindings robust in the face of change in
behaviour between different revisons of the IP.
>> +
>> + - reg:
>> + Usage: required
>> + Value type: <prop-encoded-array>
>> + Definition: the base address and size of the
>> + corresponding interface programming
>> + registers.
>> +
>> + - interrupts:
>> + Usage: required
>> + Value type: <prop-encoded-array>
>> + Definition: comma-separated list of unique PMU
>> + interrupts
>
> What is the list of interrupts related to, should there be an associated interrupts-names
>
For the CCI PMU, each interrupt signal corresponds to the overflow of a
performance counter.
Here again, I was trying to be robust in the face of differing hardware
configurations - specially the scenario where multiple interrupt lines
from the CCI PMU are tied together to generate a single interrupt to the
CPU.
Cheers,
Punit
>> +
>> * CCI interconnect bus masters
>>
>> Description: masters in the device tree connected to a CCI port
>> @@ -163,6 +191,16 @@ Example:
>> interface-type = "ace";
>> reg = <0x5000 0x1000>;
>> };
>> +
>> + pmu at 9000 {
>> + compatible = "arm,cci-400-pmu,rev0";
>> + reg = <0x9000 0x5000>;
>> + interrupts = <0 101 4>,
>> + <0 102 4>,
>> + <0 103 4>,
>> + <0 104 4>,
>> + <0 105 4>;
>> + };
>> };
>>
>
> [ snip ]
>
> - k
>
> --
> Employee of Qualcomm Innovation Center, Inc.
> Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation
>
>
>
>
next prev parent reply other threads:[~2013-08-15 9:10 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-08-11 3:00 [PATCH] drivers: CCI: add ARM CCI PMU support Punit Agrawal
2013-08-05 11:37 ` Punit Agrawal
2013-08-07 1:45 ` Will Deacon
2013-08-12 13:59 ` Will Deacon
2013-08-12 16:08 ` Will Deacon
2013-08-12 16:58 ` Punit Agrawal
2013-08-14 21:03 ` Kumar Gala
2013-08-14 22:38 ` Rob Herring
2013-08-15 10:01 ` Punit Agrawal
2013-08-15 9:10 ` Punit Agrawal [this message]
2013-08-15 16:25 ` Kumar Gala
2013-08-16 10:31 ` Punit Agrawal
2013-08-16 10:53 ` Kumar Gala
2013-08-15 19:00 ` Kumar Gala
2013-08-16 10:56 ` Punit Agrawal
2013-08-16 11:31 ` Kumar Gala
2013-08-16 12:41 ` Punit Agrawal
2013-08-14 21:06 ` Stephen Warren
2013-08-14 21:09 ` Kumar Gala
2013-08-14 21:13 ` Stephen Warren
2013-08-14 21:16 ` Kumar Gala
2013-08-15 10:09 ` Punit Agrawal
2013-08-16 17:19 ` [PATCH v2] " Punit Agrawal
2013-08-16 18:31 ` Stephen Warren
2013-08-19 11:14 ` Punit Agrawal
2013-08-19 16:15 ` Stephen Warren
2013-08-16 18:47 ` Kumar Gala
2013-08-19 11:21 ` Punit Agrawal
2013-08-20 15:07 ` Will Deacon
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