From: <ilialin@codeaurora.org>
To: 'Sudeep Holla' <sudeep.holla@arm.com>,
mturquette@baylibre.com, sboyd@kernel.org, robh@kernel.org,
mark.rutland@arm.com, viresh.kumar@linaro.org, nm@ti.com,
lgirdwood@gmail.com, broonie@kernel.org, andy.gross@linaro.org,
david.brown@linaro.org, catalin.marinas@arm.com,
will.deacon@arm.com, rjw@rjwysocki.net,
linux-clk@vger.kernel.org
Cc: devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-pm@vger.kernel.org, linux-arm-msm@vger.kernel.org,
linux-soc@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
rnayak@codeaurora.org, amit.kucheria@linaro.org,
nicolas.dechesne@linaro.org, celster@codeaurora.org,
tfinkel@codeaurora.org
Subject: RE: [PATCH] cpufreq: Add Kryo CPU scaling driver
Date: Tue, 22 May 2018 09:56:19 +0300 [thread overview]
Message-ID: <001201d3f19a$0130a860$0391f920$@codeaurora.org> (raw)
In-Reply-To: <2ace10bc-e1c4-2060-94d3-eb71e966ffbe@arm.com>
> -----Original Message-----
> From: Sudeep Holla <sudeep.holla@arm.com>
> Sent: Monday, May 21, 2018 16:05
> To: ilialin@codeaurora.org; mturquette@baylibre.com; sboyd@kernel.org;
> robh@kernel.org; mark.rutland@arm.com; viresh.kumar@linaro.org;
> nm@ti.com; lgirdwood@gmail.com; broonie@kernel.org;
> andy.gross@linaro.org; david.brown@linaro.org; catalin.marinas@arm.com;
> will.deacon@arm.com; rjw@rjwysocki.net; linux-clk@vger.kernel.org
> Cc: Sudeep Holla <sudeep.holla@arm.com>; devicetree@vger.kernel.org;
> linux-kernel@vger.kernel.org; linux-pm@vger.kernel.org; linux-arm-
> msm@vger.kernel.org; linux-soc@vger.kernel.org; linux-arm-
> kernel@lists.infradead.org; rnayak@codeaurora.org;
> amit.kucheria@linaro.org; nicolas.dechesne@linaro.org;
> celster@codeaurora.org; tfinkel@codeaurora.org
> Subject: Re: [PATCH] cpufreq: Add Kryo CPU scaling driver
>
>
>
> On 21/05/18 13:57, ilialin@codeaurora.org wrote:
> >
> [...]
>
> >>> +#include <linux/cpu.h>
> >>> +#include <linux/err.h>
> >>> +#include <linux/init.h>
> >>> +#include <linux/kernel.h>
> >>> +#include <linux/module.h>
> >>> +#include <linux/nvmem-consumer.h>
> >>> +#include <linux/of.h>
> >>> +#include <linux/platform_device.h>
> >>> +#include <linux/pm_opp.h>
> >>> +#include <linux/slab.h>
> >>> +#include <linux/soc/qcom/smem.h>
> >>> +
> >>> +#define MSM_ID_SMEM 137
> >>> +#define SILVER_LEAD 0
> >>> +#define GOLD_LEAD 2
> >>> +
> >>
> >> So I gather form other emails, that these are physical cpu number(not
> >> even unique identifier like MPIDR). Will this work on parts or
> >> platforms that need to boot in GOLD LEAD cpus.
> >
> > The driver is for Kryo CPU, which (and AFAIK all multicore MSMs)
> > always boots on the CPU0.
>
>
> That may be true and I am not that bothered about it. But assuming physical
> ordering from the logical cpu number is *incorrect* and will break if kernel
> decides to change the allocation algorithm. Kernel provides no guarantee on
> that, so you need to depend on some physical ID or may be DT to achieve
> what your want. But the current code as it stands is wrong.
Got your point. In fact CPUs are numbered 0-3 and ordered into 2 clusters in the DT:
cpus {
#address-cells = <2>;
#size-cells = <0>;
CPU0: cpu@0 {
...
reg = <0x0 0x0>;
...
};
CPU1: cpu@1 {
...
reg = <0x0 0x1>;
...
};
CPU2: cpu@100 {
...
reg = <0x0 0x100>;
...
};
CPU3: cpu@101 {
...
reg = <0x0 0x101>;
...
};
cpu-map {
cluster0 {
core0 {
cpu = <&CPU0>;
};
core1 {
cpu = <&CPU1>;
};
};
cluster1 {
core0 {
cpu = <&CPU2>;
};
core1 {
cpu = <&CPU3>;
};
};
};
};
As far, as I understand, they are probed in the same order. However, to be certain that the physical CPU is the one I intend to configure, I have to fetch the device structure pointer for the cpu-map -> clusterX -> core0 -> cpu path. Could you suggest a kernel API to do that?
>
> --
> Regards,
> Sudeep
next prev parent reply other threads:[~2018-05-22 6:56 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-17 11:19 [PATCH v8 00/15] CPU scaling support for msm8996 Ilia Lin
2018-05-17 11:19 ` [PATCH v8 01/15] soc: qcom: Separate kryo l2 accessors from PMU driver Ilia Lin
2018-05-17 11:19 ` [PATCH v8 02/15] clk: qcom: Make clk_alpha_pll_configure available to modules Ilia Lin
2018-05-17 11:19 ` [PATCH v8 03/15] clk: Use devm_ in the register fixed factor clock Ilia Lin
2018-05-17 11:19 ` [PATCH v8 04/15] clk: qcom: Add CPU clock driver for msm8996 Ilia Lin
2018-05-22 13:49 ` kbuild test robot
2018-05-17 11:19 ` [PATCH v8 05/15] dt-bindings: clk: qcom: Add bindings for CPU clock " Ilia Lin
2018-05-17 11:19 ` [PATCH v8 06/15] clk: qcom: cpu-8996: Add support to switch to alternate PLL Ilia Lin
2018-05-17 11:19 ` [PATCH v8 07/15] clk: qcom: cpu-8996: Add support to switch below 600Mhz Ilia Lin
2018-05-17 11:19 ` [PATCH v8 08/15] clk: qcom: Add ACD path to CPU clock driver for msm8996 Ilia Lin
2018-05-17 11:19 ` [PATCH v8 09/15] dt: qcom: Add opp and thermal to the msm8996 Ilia Lin
2018-05-17 11:19 ` [PATCH v8 10/15] cpufreq: Add Kryo CPU scaling driver Ilia Lin
2018-05-18 1:45 ` Viresh Kumar
2018-05-19 11:09 ` ilialin
2018-05-19 11:54 ` Russell King - ARM Linux
2018-05-19 11:41 ` ilialin
2018-05-19 11:45 ` ilialin
2018-05-21 4:49 ` Viresh Kumar
2018-05-21 9:00 ` ilialin
2018-05-21 9:05 ` Viresh Kumar
2018-05-19 11:35 ` [PATCH] " Ilia Lin
2018-05-21 5:04 ` Viresh Kumar
2018-05-21 12:50 ` Sudeep Holla
2018-05-21 12:57 ` ilialin
2018-05-21 13:04 ` Sudeep Holla
2018-05-22 6:56 ` ilialin [this message]
2018-05-22 9:12 ` Sudeep Holla
2018-05-22 7:59 ` ilialin
2018-05-22 9:18 ` Sudeep Holla
2018-05-22 9:38 ` Viresh Kumar
2018-05-22 11:29 ` Ilia Lin
2018-05-22 13:07 ` Sudeep Holla
2018-05-23 5:44 ` Viresh Kumar
2018-05-23 9:05 ` Ilia Lin
2018-05-23 9:32 ` Viresh Kumar
2018-05-23 9:40 ` Russell King - ARM Linux
2018-05-23 9:59 ` Viresh Kumar
2018-05-21 10:31 ` Ilia Lin
2018-05-21 10:37 ` Viresh Kumar
2018-05-21 10:54 ` Russell King - ARM Linux
2018-05-21 11:05 ` ilialin
2018-05-21 12:11 ` Russell King - ARM Linux
2018-05-21 12:35 ` ilialin
2018-05-21 12:41 ` Russell King - ARM Linux
2018-05-17 11:19 ` [PATCH v8 11/15] dt-bindings: cpufreq: Document operating-points-v2-kryo-cpu Ilia Lin
2018-05-18 14:26 ` Rob Herring
2018-05-17 11:19 ` [PATCH v8 12/15] dt: qcom: Add qcom-cpufreq-kryo driver configuration Ilia Lin
2018-05-17 11:19 ` [PATCH v8 13/15] regulator: qcom_spmi: Add support for SAW Ilia Lin
2018-05-17 11:19 ` [PATCH v8 14/15] dt-bindings: qcom_spmi: Document SAW support Ilia Lin
2018-05-17 11:19 ` [PATCH v8 15/15] dt: qcom: Add SAW regulator for 8x96 CPUs Ilia Lin
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