Re: [PATCH 2/3] arm64: Add Kconfig option for Samsung GH7 SoC family

2014-02-24 Thread Kukjin Kim

On 02/19/14 05:00, Olof Johansson wrote:

On Tue, Feb 18, 2014 at 11:52 AM, John Stultzjohn.stu...@linaro.org  wrote:

On Tue, Feb 18, 2014 at 10:13 AM, Arnd Bergmanna...@arndb.de  wrote:

On Tuesday 18 February 2014 08:16:13 Olof Johansson wrote:

On Mon, Feb 17, 2014 at 5:10 PM, Kukjin Kimkgene@samsung.com  wrote:

On 02/15/14 02:06, Arnd Bergmann wrote:

My feeling is that we don't need to use the levels for Kconfig, although
we might want to use them DT compatible strings, even if it ends up
looking
a little funny when you do

 compatible = arm,sbsa-l3, arm,sbsa-l2, arm,sbsa-l1;


What kind of features are you expecting though? More IP
blocks/devices? Those are just kernel config options to enable,
ideally as modules.



Right, I think we can just put them into defconfig. No need to
select them from Kconfig since the extra options wouldn't be
required for booting or using the system.


As I commented above, how about MCT? Samsung has a plan to use MCT on ARMv8,
it is not for used for GH7 though...


It looks like the clocksource drivers are all based around being
enabled based on platforms instead of individually selectable. That
causes a problem here. I think we should change the clocksource
Kconfig instead. Then it's just a matter of making sure your defconfig
has the needed driver enabled.

(Adding Daniel and Thomas in case they have objections to that approach)


+John Stultz

IIRC it was John who insisted on doing it the current way, although
I can't remember his reasoning.


Are we really expecting there to be SoC specific clocksources here? I
thought we were getting away from that sort of stuff with the
architecture timer?


Unfortunately vendors can do crazy stuff if they want to. But we also
have an option to choose to enable it. Maybe the answer here is to say
no to MCT on 64-bit, they get to use the arch timers like everybody
else. Or at least motivate why they're not good enough.


I'm fine with clocksources being selected by other functionality
options (ie: on x86 ACPI PM timer clocksource doesn't have a prompt,
but depends on the ACPI option). I just don't want to force users to
have to navigate through tons of deep menus to select clocksource
options that logically duplicate other selections already made.

But again, I handed this maintainership over to Daniel, so I can be
considered just a crank yelling from the sidelines :)


I think you have a good point. Until we hear why MCT is needed this is
mostly speculation, so let's see what Kukjin says about that.



Using MCT on ARMv8 is an example, it's true on some Samsung ARMv8 SoC 
though. I don't want to argue what's the benefit of MCT in this thread, 
but just possibility. As you know, generally ARM SoC vendor is open to 
use any IPs...So I'd like to say we need to consider the situation.


Anyway, basically I agree with you guys suggestion to use common CONFIG 
on ARMv8 like multiplatform supporting on arm32.


Thanks,
Kukji
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Re: [PATCH 2/3] arm64: Add Kconfig option for Samsung GH7 SoC family

2014-02-24 Thread Kukjin Kim

On 02/21/14 03:58, Catalin Marinas wrote:

On Thu, Feb 20, 2014 at 05:09:59PM +, Olof Johansson wrote:

On Thu, Feb 20, 2014 at 3:22 AM, Catalin Marinas

Two additional points:

1. Single arm64 defconfig file covering everything
2. Modules rather than built-in by default where possible (especially
for server platforms)


Sounds good to me. Are you also willing to pick up one defconfig per
vendor (but not more)? I think it's been useful to have those on arm,
even on multiplatform kernels. We used them on powerpc as well, where
we had a two-layer approach (ppc64_defconfig and per-platform configs,
pseries/iseries/pasemi/g5/cell).


Initially I would keep a single defconfig with everything just to get
wider coverage of single Image. Later on, if just deselecting config
entries doesn't work, we can revisit per-vendor defconfigs.

OK, agreed with single defconfig on ARMv8 for now. And as Olof said, 
it's expected that each vendor maybe needs to use per-vendor defconfig 
soon and agreed too :-)


Thanks,
Kukjin
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Re: [PATCH 2/3] arm64: Add Kconfig option for Samsung GH7 SoC family

2014-02-24 Thread Kukjin Kim

On 02/20/14 18:03, Olof Johansson wrote:

[...]


I.e. I'd be OK with an
ARCH_EXYNOS/ARCH_TEGRA/ARCH_IMX/ARCH_whatever, but I don't think we
should add more finegrained options than that globally on ARM64, at
least not until truly proven to be needed. We're trying to push back
against new per-SoC Kconfig entries on 32-bit as well right now.


OK, agreed.

- Kukjin
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Re: [PATCH 2/3] arm64: Add Kconfig option for Samsung GH7 SoC family

2014-02-20 Thread Olof Johansson
On Tue, Feb 18, 2014 at 12:06 PM, John Stultz john.stu...@linaro.org wrote:
 On Tue, Feb 18, 2014 at 12:00 PM, Olof Johansson o...@lixom.net wrote:
 On Tue, Feb 18, 2014 at 11:52 AM, John Stultz john.stu...@linaro.org wrote:
 On Tue, Feb 18, 2014 at 10:13 AM, Arnd Bergmann a...@arndb.de wrote:
 On Tuesday 18 February 2014 08:16:13 Olof Johansson wrote:
 On Mon, Feb 17, 2014 at 5:10 PM, Kukjin Kim kgene@samsung.com wrote:
  On 02/15/14 02:06, Arnd Bergmann wrote:
  My feeling is that we don't need to use the levels for Kconfig, 
  although
  we might want to use them DT compatible strings, even if it ends up
  looking
  a little funny when you do
 
  compatible = arm,sbsa-l3, arm,sbsa-l2, arm,sbsa-l1;
 
  What kind of features are you expecting though? More IP
  blocks/devices? Those are just kernel config options to enable,
  ideally as modules.
 
 
  Right, I think we can just put them into defconfig. No need to
  select them from Kconfig since the extra options wouldn't be
  required for booting or using the system.
 
  As I commented above, how about MCT? Samsung has a plan to use MCT on 
  ARMv8,
  it is not for used for GH7 though...

 It looks like the clocksource drivers are all based around being
 enabled based on platforms instead of individually selectable. That
 causes a problem here. I think we should change the clocksource
 Kconfig instead. Then it's just a matter of making sure your defconfig
 has the needed driver enabled.

 (Adding Daniel and Thomas in case they have objections to that approach)

 +John Stultz

 IIRC it was John who insisted on doing it the current way, although
 I can't remember his reasoning.

 Are we really expecting there to be SoC specific clocksources here? I
 thought we were getting away from that sort of stuff with the
 architecture timer?

 Unfortunately vendors can do crazy stuff if they want to. But we also
 have an option to choose to enable it. Maybe the answer here is to say
 no to MCT on 64-bit, they get to use the arch timers like everybody
 else. Or at least motivate why they're not good enough.

 I'm fine with clocksources being selected by other functionality
 options (ie: on x86 ACPI PM timer clocksource doesn't have a prompt,
 but depends on the ACPI option). I just don't want to force users to
 have to navigate through tons of deep menus to select clocksource
 options that logically duplicate other selections already made.

 But again, I handed this maintainership over to Daniel, so I can be
 considered just a crank yelling from the sidelines :)

 I think you have a good point. Until we hear why MCT is needed this is
 mostly speculation, so let's see what Kukjin says about that.

 Yea. And on x86 (well, i386 actually) there are system specific
 clocksources as well, such as the cyclone timer used by summit based
 x440 and similar NUMA systems, but those systems had more general
 config options that had to be enabled which the cyclone clocksource
 depended on.

So, after giving this some more thought (and getting my hands dirty in
some of this code), I think I'm going to change my mind on this. For
mobile platforms I think it might make sense to bring over the
toplevel platform Kconfig from arch/arm, to simplify dependencies
without tearing up the driver subtree with churn like this.

This, of course, only holds true for v8 mobile platforms. Samsung
isn't saying if GH7 is a server platform and not, and they don't have
to tell us. But I think we should consider only enabling and bringing
over the mobile ones (and ideally try to avoid even that, but it might
make sense to do some of them at least initially -- it does provide
some convenient ways to enable larger subsets of default drivers per
platform/vendor family).

I.e. I'd be OK with an
ARCH_EXYNOS/ARCH_TEGRA/ARCH_IMX/ARCH_whatever, but I don't think we
should add more finegrained options than that globally on ARM64, at
least not until truly proven to be needed. We're trying to push back
against new per-SoC Kconfig entries on 32-bit as well right now.


-Olof
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Re: [PATCH 2/3] arm64: Add Kconfig option for Samsung GH7 SoC family

2014-02-20 Thread Catalin Marinas
On Thu, Feb 20, 2014 at 09:03:30AM +, Olof Johansson wrote:
 So, after giving this some more thought (and getting my hands dirty in
 some of this code), I think I'm going to change my mind on this. For
 mobile platforms I think it might make sense to bring over the
 toplevel platform Kconfig from arch/arm, to simplify dependencies
 without tearing up the driver subtree with churn like this.
 
 This, of course, only holds true for v8 mobile platforms. Samsung
 isn't saying if GH7 is a server platform and not, and they don't have
 to tell us. But I think we should consider only enabling and bringing
 over the mobile ones (and ideally try to avoid even that, but it might
 make sense to do some of them at least initially -- it does provide
 some convenient ways to enable larger subsets of default drivers per
 platform/vendor family).
 
 I.e. I'd be OK with an
 ARCH_EXYNOS/ARCH_TEGRA/ARCH_IMX/ARCH_whatever, but I don't think we
 should add more finegrained options than that globally on ARM64, at
 least not until truly proven to be needed. We're trying to push back
 against new per-SoC Kconfig entries on 32-bit as well right now.

I'm fine with this. Do we still need something for ARMv8 server
platforms like ARCH_ARM_SBSA? The only advantage would be to make it
easier for mobile targeted kernel builds to disable server features but
I'm not sure there are so many such features, people can trim the
.config manually.

Two additional points:

1. Single arm64 defconfig file covering everything
2. Modules rather than built-in by default where possible (especially
   for server platforms)

-- 
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Re: [PATCH 2/3] arm64: Add Kconfig option for Samsung GH7 SoC family

2014-02-20 Thread Arnd Bergmann
On Thursday 20 February 2014 11:22:48 Catalin Marinas wrote:
 
 I'm fine with this. Do we still need something for ARMv8 server
 platforms like ARCH_ARM_SBSA? The only advantage would be to make it
 easier for mobile targeted kernel builds to disable server features but
 I'm not sure there are so many such features, people can trim the
 .config manually.

I think in particular for SBSA compliant platforms we should not
have per-platform options at all the way we do for embedded,
as they will be much more homogenous.

 Two additional points:
 
 1. Single arm64 defconfig file covering everything
 2. Modules rather than built-in by default where possible (especially
for server platforms)

+1

Arnd
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Re: [PATCH 2/3] arm64: Add Kconfig option for Samsung GH7 SoC family

2014-02-20 Thread Olof Johansson
On Thu, Feb 20, 2014 at 3:22 AM, Catalin Marinas
catalin.mari...@arm.com wrote:
 On Thu, Feb 20, 2014 at 09:03:30AM +, Olof Johansson wrote:
 So, after giving this some more thought (and getting my hands dirty in
 some of this code), I think I'm going to change my mind on this. For
 mobile platforms I think it might make sense to bring over the
 toplevel platform Kconfig from arch/arm, to simplify dependencies
 without tearing up the driver subtree with churn like this.

 This, of course, only holds true for v8 mobile platforms. Samsung
 isn't saying if GH7 is a server platform and not, and they don't have
 to tell us. But I think we should consider only enabling and bringing
 over the mobile ones (and ideally try to avoid even that, but it might
 make sense to do some of them at least initially -- it does provide
 some convenient ways to enable larger subsets of default drivers per
 platform/vendor family).

 I.e. I'd be OK with an
 ARCH_EXYNOS/ARCH_TEGRA/ARCH_IMX/ARCH_whatever, but I don't think we
 should add more finegrained options than that globally on ARM64, at
 least not until truly proven to be needed. We're trying to push back
 against new per-SoC Kconfig entries on 32-bit as well right now.

 I'm fine with this. Do we still need something for ARMv8 server
 platforms like ARCH_ARM_SBSA? The only advantage would be to make it
 easier for mobile targeted kernel builds to disable server features but
 I'm not sure there are so many such features, people can trim the
 .config manually.

I don't think there's all that much that's unique to SBSA for a
Kconfig entry. If anything it could be useful to describe dependencies
(i.e. you very likely don't want to turn off the standardized UART
driver, etc). But doing that through Kconfig is a bit clumsy, we might
be better off doing it through example defconfigs. I'm not sure we
want to do it through selects.

 Two additional points:

 1. Single arm64 defconfig file covering everything
 2. Modules rather than built-in by default where possible (especially
for server platforms)

Sounds good to me. Are you also willing to pick up one defconfig per
vendor (but not more)? I think it's been useful to have those on arm,
even on multiplatform kernels. We used them on powerpc as well, where
we had a two-layer approach (ppc64_defconfig and per-platform configs,
pseries/iseries/pasemi/g5/cell).


-Olof
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Re: [PATCH 2/3] arm64: Add Kconfig option for Samsung GH7 SoC family

2014-02-20 Thread Catalin Marinas
On Thu, Feb 20, 2014 at 05:09:59PM +, Olof Johansson wrote:
 On Thu, Feb 20, 2014 at 3:22 AM, Catalin Marinas
  Two additional points:
 
  1. Single arm64 defconfig file covering everything
  2. Modules rather than built-in by default where possible (especially
 for server platforms)
 
 Sounds good to me. Are you also willing to pick up one defconfig per
 vendor (but not more)? I think it's been useful to have those on arm,
 even on multiplatform kernels. We used them on powerpc as well, where
 we had a two-layer approach (ppc64_defconfig and per-platform configs,
 pseries/iseries/pasemi/g5/cell).

Initially I would keep a single defconfig with everything just to get
wider coverage of single Image. Later on, if just deselecting config
entries doesn't work, we can revisit per-vendor defconfigs.

-- 
Catalin
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Re: [PATCH 2/3] arm64: Add Kconfig option for Samsung GH7 SoC family

2014-02-18 Thread Arnd Bergmann
On Tuesday 18 February 2014 10:10:30 Kukjin Kim wrote:
 On 02/15/14 02:06, Arnd Bergmann wrote:
  On Thursday 13 February 2014, Olof Johansson wrote:
  On Mon, Feb 10, 2014 at 6:52 PM, Kukjin Kimkgene@samsung.com  wrote:
  On 02/13/14 04:14, Arnd Bergmann wrote:
  On Wednesday 12 February 2014 13:04:40 Kumar Gala wrote:
  Basically, I agreed with Arnd's suggestion to use ARCH_SBSA. Or we need to
  define level in Kconfig like ARCH_SBSA_L1 for level1. BTW, how about
  compliant with SBSA Level1 and having some specific features?
 
 Well, how about ARMv8 mobile SoC? I think, it is not compatible with 
 SBSA. For example, you know MCT can be used for ARMv8 cores instead of 
 ARCH Timer. So I'm not sure ARCH_SBSA is really good choice...

Sure, if you are talking about an embedded SoC that is not SBSA compliant,
we shouldn't try to make it work with ARCH_SBSA and instead give it
its own Kconfig symbol.

  My feeling is that we don't need to use the levels for Kconfig, although
  we might want to use them DT compatible strings, even if it ends up looking
  a little funny when you do
 
  compatible = arm,sbsa-l3, arm,sbsa-l2, arm,sbsa-l1;
 
  What kind of features are you expecting though? More IP
  blocks/devices? Those are just kernel config options to enable,
  ideally as modules.
 
  Right, I think we can just put them into defconfig. No need to
  select them from Kconfig since the extra options wouldn't be
  required for booting or using the system.
 
 As I commented above, how about MCT? Samsung has a plan to use MCT on 
 ARMv8, it is not for used for GH7 though...

If it's just one driver that is needed in addition to the usual stuff,
we can also just make it a standalone option and turn it on in the
generic defconfig. We won't need a per-platform option in that case.

Arnd
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Re: [PATCH 2/3] arm64: Add Kconfig option for Samsung GH7 SoC family

2014-02-18 Thread Olof Johansson
On Mon, Feb 17, 2014 at 5:10 PM, Kukjin Kim kgene@samsung.com wrote:
 On 02/15/14 02:06, Arnd Bergmann wrote:

 On Thursday 13 February 2014, Olof Johansson wrote:

 On Mon, Feb 10, 2014 at 6:52 PM, Kukjin Kimkgene@samsung.com
 wrote:

 On 02/13/14 04:14, Arnd Bergmann wrote:

 On Wednesday 12 February 2014 13:04:40 Kumar Gala wrote:

 Basically, I agreed with Arnd's suggestion to use ARCH_SBSA. Or we need
 to
 define level in Kconfig like ARCH_SBSA_L1 for level1. BTW, how about
 compliant with SBSA Level1 and having some specific features?


 Well, how about ARMv8 mobile SoC? I think, it is not compatible with SBSA.
 For example, you know MCT can be used for ARMv8 cores instead of ARCH Timer.
 So I'm not sure ARCH_SBSA is really good choice...


 My feeling is that we don't need to use the levels for Kconfig, although
 we might want to use them DT compatible strings, even if it ends up
 looking
 a little funny when you do

 compatible = arm,sbsa-l3, arm,sbsa-l2, arm,sbsa-l1;

 What kind of features are you expecting though? More IP
 blocks/devices? Those are just kernel config options to enable,
 ideally as modules.


 Right, I think we can just put them into defconfig. No need to
 select them from Kconfig since the extra options wouldn't be
 required for booting or using the system.

 As I commented above, how about MCT? Samsung has a plan to use MCT on ARMv8,
 it is not for used for GH7 though...

It looks like the clocksource drivers are all based around being
enabled based on platforms instead of individually selectable. That
causes a problem here. I think we should change the clocksource
Kconfig instead. Then it's just a matter of making sure your defconfig
has the needed driver enabled.

(Adding Daniel and Thomas in case they have objections to that approach)


-Olof
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Re: [PATCH 2/3] arm64: Add Kconfig option for Samsung GH7 SoC family

2014-02-18 Thread Catalin Marinas
On Tue, Feb 18, 2014 at 01:10:30AM +, Kukjin Kim wrote:
 As I commented above, how about MCT? Samsung has a plan to use MCT on 
 ARMv8, it is not for used for GH7 though...

Any reason for not using the generic timer?

-- 
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Re: [PATCH 2/3] arm64: Add Kconfig option for Samsung GH7 SoC family

2014-02-18 Thread Arnd Bergmann
On Tuesday 18 February 2014 08:16:13 Olof Johansson wrote:
 On Mon, Feb 17, 2014 at 5:10 PM, Kukjin Kim kgene@samsung.com wrote:
  On 02/15/14 02:06, Arnd Bergmann wrote:
  My feeling is that we don't need to use the levels for Kconfig, although
  we might want to use them DT compatible strings, even if it ends up
  looking
  a little funny when you do
 
  compatible = arm,sbsa-l3, arm,sbsa-l2, arm,sbsa-l1;
 
  What kind of features are you expecting though? More IP
  blocks/devices? Those are just kernel config options to enable,
  ideally as modules.
 
 
  Right, I think we can just put them into defconfig. No need to
  select them from Kconfig since the extra options wouldn't be
  required for booting or using the system.
 
  As I commented above, how about MCT? Samsung has a plan to use MCT on ARMv8,
  it is not for used for GH7 though...
 
 It looks like the clocksource drivers are all based around being
 enabled based on platforms instead of individually selectable. That
 causes a problem here. I think we should change the clocksource
 Kconfig instead. Then it's just a matter of making sure your defconfig
 has the needed driver enabled.
 
 (Adding Daniel and Thomas in case they have objections to that approach)

+John Stultz

IIRC it was John who insisted on doing it the current way, although
I can't remember his reasoning.

Arnd
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Re: [PATCH 2/3] arm64: Add Kconfig option for Samsung GH7 SoC family

2014-02-18 Thread John Stultz
On Tue, Feb 18, 2014 at 10:13 AM, Arnd Bergmann a...@arndb.de wrote:
 On Tuesday 18 February 2014 08:16:13 Olof Johansson wrote:
 On Mon, Feb 17, 2014 at 5:10 PM, Kukjin Kim kgene@samsung.com wrote:
  On 02/15/14 02:06, Arnd Bergmann wrote:
  My feeling is that we don't need to use the levels for Kconfig, although
  we might want to use them DT compatible strings, even if it ends up
  looking
  a little funny when you do
 
  compatible = arm,sbsa-l3, arm,sbsa-l2, arm,sbsa-l1;
 
  What kind of features are you expecting though? More IP
  blocks/devices? Those are just kernel config options to enable,
  ideally as modules.
 
 
  Right, I think we can just put them into defconfig. No need to
  select them from Kconfig since the extra options wouldn't be
  required for booting or using the system.
 
  As I commented above, how about MCT? Samsung has a plan to use MCT on 
  ARMv8,
  it is not for used for GH7 though...

 It looks like the clocksource drivers are all based around being
 enabled based on platforms instead of individually selectable. That
 causes a problem here. I think we should change the clocksource
 Kconfig instead. Then it's just a matter of making sure your defconfig
 has the needed driver enabled.

 (Adding Daniel and Thomas in case they have objections to that approach)

 +John Stultz

 IIRC it was John who insisted on doing it the current way, although
 I can't remember his reasoning.

Are we really expecting there to be SoC specific clocksources here? I
thought we were getting away from that sort of stuff with the
architecture timer?

I'm fine with clocksources being selected by other functionality
options (ie: on x86 ACPI PM timer clocksource doesn't have a prompt,
but depends on the ACPI option). I just don't want to force users to
have to navigate through tons of deep menus to select clocksource
options that logically duplicate other selections already made.

But again, I handed this maintainership over to Daniel, so I can be
considered just a crank yelling from the sidelines :)

thanks
-john
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Re: [PATCH 2/3] arm64: Add Kconfig option for Samsung GH7 SoC family

2014-02-18 Thread Olof Johansson
On Tue, Feb 18, 2014 at 11:52 AM, John Stultz john.stu...@linaro.org wrote:
 On Tue, Feb 18, 2014 at 10:13 AM, Arnd Bergmann a...@arndb.de wrote:
 On Tuesday 18 February 2014 08:16:13 Olof Johansson wrote:
 On Mon, Feb 17, 2014 at 5:10 PM, Kukjin Kim kgene@samsung.com wrote:
  On 02/15/14 02:06, Arnd Bergmann wrote:
  My feeling is that we don't need to use the levels for Kconfig, although
  we might want to use them DT compatible strings, even if it ends up
  looking
  a little funny when you do
 
  compatible = arm,sbsa-l3, arm,sbsa-l2, arm,sbsa-l1;
 
  What kind of features are you expecting though? More IP
  blocks/devices? Those are just kernel config options to enable,
  ideally as modules.
 
 
  Right, I think we can just put them into defconfig. No need to
  select them from Kconfig since the extra options wouldn't be
  required for booting or using the system.
 
  As I commented above, how about MCT? Samsung has a plan to use MCT on 
  ARMv8,
  it is not for used for GH7 though...

 It looks like the clocksource drivers are all based around being
 enabled based on platforms instead of individually selectable. That
 causes a problem here. I think we should change the clocksource
 Kconfig instead. Then it's just a matter of making sure your defconfig
 has the needed driver enabled.

 (Adding Daniel and Thomas in case they have objections to that approach)

 +John Stultz

 IIRC it was John who insisted on doing it the current way, although
 I can't remember his reasoning.

 Are we really expecting there to be SoC specific clocksources here? I
 thought we were getting away from that sort of stuff with the
 architecture timer?

Unfortunately vendors can do crazy stuff if they want to. But we also
have an option to choose to enable it. Maybe the answer here is to say
no to MCT on 64-bit, they get to use the arch timers like everybody
else. Or at least motivate why they're not good enough.

 I'm fine with clocksources being selected by other functionality
 options (ie: on x86 ACPI PM timer clocksource doesn't have a prompt,
 but depends on the ACPI option). I just don't want to force users to
 have to navigate through tons of deep menus to select clocksource
 options that logically duplicate other selections already made.

 But again, I handed this maintainership over to Daniel, so I can be
 considered just a crank yelling from the sidelines :)

I think you have a good point. Until we hear why MCT is needed this is
mostly speculation, so let's see what Kukjin says about that.


-Olof
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Re: [PATCH 2/3] arm64: Add Kconfig option for Samsung GH7 SoC family

2014-02-18 Thread John Stultz
On Tue, Feb 18, 2014 at 12:00 PM, Olof Johansson o...@lixom.net wrote:
 On Tue, Feb 18, 2014 at 11:52 AM, John Stultz john.stu...@linaro.org wrote:
 On Tue, Feb 18, 2014 at 10:13 AM, Arnd Bergmann a...@arndb.de wrote:
 On Tuesday 18 February 2014 08:16:13 Olof Johansson wrote:
 On Mon, Feb 17, 2014 at 5:10 PM, Kukjin Kim kgene@samsung.com wrote:
  On 02/15/14 02:06, Arnd Bergmann wrote:
  My feeling is that we don't need to use the levels for Kconfig, although
  we might want to use them DT compatible strings, even if it ends up
  looking
  a little funny when you do
 
  compatible = arm,sbsa-l3, arm,sbsa-l2, arm,sbsa-l1;
 
  What kind of features are you expecting though? More IP
  blocks/devices? Those are just kernel config options to enable,
  ideally as modules.
 
 
  Right, I think we can just put them into defconfig. No need to
  select them from Kconfig since the extra options wouldn't be
  required for booting or using the system.
 
  As I commented above, how about MCT? Samsung has a plan to use MCT on 
  ARMv8,
  it is not for used for GH7 though...

 It looks like the clocksource drivers are all based around being
 enabled based on platforms instead of individually selectable. That
 causes a problem here. I think we should change the clocksource
 Kconfig instead. Then it's just a matter of making sure your defconfig
 has the needed driver enabled.

 (Adding Daniel and Thomas in case they have objections to that approach)

 +John Stultz

 IIRC it was John who insisted on doing it the current way, although
 I can't remember his reasoning.

 Are we really expecting there to be SoC specific clocksources here? I
 thought we were getting away from that sort of stuff with the
 architecture timer?

 Unfortunately vendors can do crazy stuff if they want to. But we also
 have an option to choose to enable it. Maybe the answer here is to say
 no to MCT on 64-bit, they get to use the arch timers like everybody
 else. Or at least motivate why they're not good enough.

 I'm fine with clocksources being selected by other functionality
 options (ie: on x86 ACPI PM timer clocksource doesn't have a prompt,
 but depends on the ACPI option). I just don't want to force users to
 have to navigate through tons of deep menus to select clocksource
 options that logically duplicate other selections already made.

 But again, I handed this maintainership over to Daniel, so I can be
 considered just a crank yelling from the sidelines :)

 I think you have a good point. Until we hear why MCT is needed this is
 mostly speculation, so let's see what Kukjin says about that.

Yea. And on x86 (well, i386 actually) there are system specific
clocksources as well, such as the cyclone timer used by summit based
x440 and similar NUMA systems, but those systems had more general
config options that had to be enabled which the cyclone clocksource
depended on.

thanks
-john
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Re: [PATCH 2/3] arm64: Add Kconfig option for Samsung GH7 SoC family

2014-02-17 Thread Kukjin Kim

On 02/15/14 02:06, Arnd Bergmann wrote:

On Thursday 13 February 2014, Olof Johansson wrote:

On Mon, Feb 10, 2014 at 6:52 PM, Kukjin Kimkgene@samsung.com  wrote:

On 02/13/14 04:14, Arnd Bergmann wrote:

On Wednesday 12 February 2014 13:04:40 Kumar Gala wrote:

Basically, I agreed with Arnd's suggestion to use ARCH_SBSA. Or we need to
define level in Kconfig like ARCH_SBSA_L1 for level1. BTW, how about
compliant with SBSA Level1 and having some specific features?


Well, how about ARMv8 mobile SoC? I think, it is not compatible with 
SBSA. For example, you know MCT can be used for ARMv8 cores instead of 
ARCH Timer. So I'm not sure ARCH_SBSA is really good choice...



My feeling is that we don't need to use the levels for Kconfig, although
we might want to use them DT compatible strings, even if it ends up looking
a little funny when you do

compatible = arm,sbsa-l3, arm,sbsa-l2, arm,sbsa-l1;


What kind of features are you expecting though? More IP
blocks/devices? Those are just kernel config options to enable,
ideally as modules.


Right, I think we can just put them into defconfig. No need to
select them from Kconfig since the extra options wouldn't be
required for booting or using the system.

As I commented above, how about MCT? Samsung has a plan to use MCT on 
ARMv8, it is not for used for GH7 though...


- Kukjin
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Re: [PATCH 2/3] arm64: Add Kconfig option for Samsung GH7 SoC family

2014-02-14 Thread Arnd Bergmann
On Thursday 13 February 2014, Olof Johansson wrote:
 On Mon, Feb 10, 2014 at 6:52 PM, Kukjin Kim kgene@samsung.com wrote:
  On 02/13/14 04:14, Arnd Bergmann wrote:
  On Wednesday 12 February 2014 13:04:40 Kumar Gala wrote:
  Basically, I agreed with Arnd's suggestion to use ARCH_SBSA. Or we need to
  define level in Kconfig like ARCH_SBSA_L1 for level1. BTW, how about
  compliant with SBSA Level1 and having some specific features?

My feeling is that we don't need to use the levels for Kconfig, although
we might want to use them DT compatible strings, even if it ends up looking
a little funny when you do 

compatible = arm,sbsa-l3, arm,sbsa-l2, arm,sbsa-l1;

 What kind of features are you expecting though? More IP
 blocks/devices? Those are just kernel config options to enable,
 ideally as modules.

Right, I think we can just put them into defconfig. No need to
select them from Kconfig since the extra options wouldn't be
required for booting or using the system.

Arnd
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Re: [PATCH 2/3] arm64: Add Kconfig option for Samsung GH7 SoC family

2014-02-13 Thread Olof Johansson
On Mon, Feb 10, 2014 at 6:52 PM, Kukjin Kim kgene@samsung.com wrote:
 On 02/13/14 04:14, Arnd Bergmann wrote:

 On Wednesday 12 February 2014 13:04:40 Kumar Gala wrote:

 On Feb 12, 2014, at 12:12 PM, Catalin Marinascatalin.mari...@arm.com
 wrote:

 On 12 Feb 2014, at 16:25, Kumar Galaga...@codeaurora.org  wrote:

 One reason to keep around ARCH_* is for drivers shared between arm and
 arm64 that depend on it.


 We already converted some of them (those depending on ARCH_VEXPRESS) to
 just depend on ARM64. Ideally, at some point I'd like to see them as
 defaulting to modules but I don't think we are there yet (we had some
 discussions at the last KS, I'm not sure anyone started looking into
 this).


 I'm torn about this, I think for something like VEXPRESS it makes sense,
 however I think  its reasonable to still have an config symbol for a full
 SoC family or something of that nature.


 I think for SBSA compliant systems, we should be able to live with a
 generic ARCH_SBSA Kconfig symbol. For more irregular embedded platforms,
 we may need something more specific.

 Basically, I agreed with Arnd's suggestion to use ARCH_SBSA. Or we need to
 define level in Kconfig like ARCH_SBSA_L1 for level1. BTW, how about
 compliant with SBSA Level1 and having some specific features?

(It's a little hard to answer since nobody can download the doc and
then talk about it.)

What kind of features are you expecting though? More IP
blocks/devices? Those are just kernel config options to enable,
ideally as modules.

x86 doesn't need config options for each generation of their platform,
and neither should ARM64. Sure, there might be drivers that don't make
sense to enable on some platforms, but that's what defconfigs (or
distro configs), and modules are for -- the modules won't load unless
the hardware is there.

As long as we're not talking about massive amounts of code that is
part of the base platform, separating out per version again doesn't
make sense -- just enable for SBSA and it'll support Level 1 through
whatever. If the kernel size becomes a concern we can revisit, but
let's not start out that way.


-Olof
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Re: [PATCH 2/3] arm64: Add Kconfig option for Samsung GH7 SoC family

2014-02-12 Thread Catalin Marinas
On Tue, Feb 11, 2014 at 11:39:27PM +, Olof Johansson wrote:
 On Mon, Feb 10, 2014 at 10:29 PM, Kukjin Kim kgene@samsung.com wrote:
  This patch adds support for Samsung GH7 SoC in arm64/Kconfig.
 
  Signed-off-by: Kukjin Kim kgene@samsung.com
  Cc: Catalin Marinas catalin.mari...@arm.com
 
 The overhead of building one more device tree isn't very large, and I
 don't see any other need to have a Kconfig entry per SoC at this time.
 It's of course up to Catalin, but you might just want to always
 compile all dts files instead.

For arm64, I thought of getting rid of ARCH_* Kconfig entries entirely,
only that I haven't heard any strong opinion either way (in which case
I'll do it, with a risk of single Image getting bigger and bigger and
people needing smaller Image can trim their .config).

-- 
Catalin
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Re: [PATCH 2/3] arm64: Add Kconfig option for Samsung GH7 SoC family

2014-02-12 Thread Kumar Gala

On Feb 12, 2014, at 4:38 AM, Catalin Marinas catalin.mari...@arm.com wrote:

 On Tue, Feb 11, 2014 at 11:39:27PM +, Olof Johansson wrote:
 On Mon, Feb 10, 2014 at 10:29 PM, Kukjin Kim kgene@samsung.com wrote:
 This patch adds support for Samsung GH7 SoC in arm64/Kconfig.
 
 Signed-off-by: Kukjin Kim kgene@samsung.com
 Cc: Catalin Marinas catalin.mari...@arm.com
 
 The overhead of building one more device tree isn't very large, and I
 don't see any other need to have a Kconfig entry per SoC at this time.
 It's of course up to Catalin, but you might just want to always
 compile all dts files instead.
 
 For arm64, I thought of getting rid of ARCH_* Kconfig entries entirely,
 only that I haven't heard any strong opinion either way (in which case
 I'll do it, with a risk of single Image getting bigger and bigger and
 people needing smaller Image can trim their .config).

One reason to keep around ARCH_* is for drivers shared between arm and arm64 
that depend on it.

- k

-- 
Employee of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by 
The Linux Foundation

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Re: [PATCH 2/3] arm64: Add Kconfig option for Samsung GH7 SoC family

2014-02-12 Thread Catalin Marinas
On 12 Feb 2014, at 16:25, Kumar Gala ga...@codeaurora.org wrote:
 On Feb 12, 2014, at 4:38 AM, Catalin Marinas catalin.mari...@arm.com wrote:
 
 On Tue, Feb 11, 2014 at 11:39:27PM +, Olof Johansson wrote:
 On Mon, Feb 10, 2014 at 10:29 PM, Kukjin Kim kgene@samsung.com wrote:
 This patch adds support for Samsung GH7 SoC in arm64/Kconfig.
 
 Signed-off-by: Kukjin Kim kgene@samsung.com
 Cc: Catalin Marinas catalin.mari...@arm.com
 
 The overhead of building one more device tree isn't very large, and I
 don't see any other need to have a Kconfig entry per SoC at this time.
 It's of course up to Catalin, but you might just want to always
 compile all dts files instead.
 
 For arm64, I thought of getting rid of ARCH_* Kconfig entries entirely,
 only that I haven't heard any strong opinion either way (in which case
 I'll do it, with a risk of single Image getting bigger and bigger and
 people needing smaller Image can trim their .config).
 
 One reason to keep around ARCH_* is for drivers shared between arm and arm64 
 that depend on it.

We already converted some of them (those depending on ARCH_VEXPRESS) to
just depend on ARM64. Ideally, at some point I’d like to see them as
defaulting to modules but I don’t think we are there yet (we had some
discussions at the last KS, I’m not sure anyone started looking into
this).--
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Re: [PATCH 2/3] arm64: Add Kconfig option for Samsung GH7 SoC family

2014-02-12 Thread Kumar Gala

On Feb 12, 2014, at 12:12 PM, Catalin Marinas catalin.mari...@arm.com wrote:

 On 12 Feb 2014, at 16:25, Kumar Gala ga...@codeaurora.org wrote:
 On Feb 12, 2014, at 4:38 AM, Catalin Marinas catalin.mari...@arm.com wrote:
 
 On Tue, Feb 11, 2014 at 11:39:27PM +, Olof Johansson wrote:
 On Mon, Feb 10, 2014 at 10:29 PM, Kukjin Kim kgene@samsung.com wrote:
 This patch adds support for Samsung GH7 SoC in arm64/Kconfig.
 
 Signed-off-by: Kukjin Kim kgene@samsung.com
 Cc: Catalin Marinas catalin.mari...@arm.com
 
 The overhead of building one more device tree isn't very large, and I
 don't see any other need to have a Kconfig entry per SoC at this time.
 It's of course up to Catalin, but you might just want to always
 compile all dts files instead.
 
 For arm64, I thought of getting rid of ARCH_* Kconfig entries entirely,
 only that I haven't heard any strong opinion either way (in which case
 I'll do it, with a risk of single Image getting bigger and bigger and
 people needing smaller Image can trim their .config).
 
 One reason to keep around ARCH_* is for drivers shared between arm and arm64 
 that depend on it.
 
 We already converted some of them (those depending on ARCH_VEXPRESS) to
 just depend on ARM64. Ideally, at some point I’d like to see them as
 defaulting to modules but I don’t think we are there yet (we had some
 discussions at the last KS, I’m not sure anyone started looking into
 this).

I’m torn about this, I think for something like VEXPRESS it makes sense, 
however I think its reasonable to still have an config symbol for a full SoC 
family or something of that nature.

- k

-- 
Employee of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by 
The Linux Foundation

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Re: [PATCH 2/3] arm64: Add Kconfig option for Samsung GH7 SoC family

2014-02-12 Thread Arnd Bergmann
On Wednesday 12 February 2014 13:04:40 Kumar Gala wrote:
 On Feb 12, 2014, at 12:12 PM, Catalin Marinas catalin.mari...@arm.com wrote:
  On 12 Feb 2014, at 16:25, Kumar Gala ga...@codeaurora.org wrote:
  One reason to keep around ARCH_* is for drivers shared between arm and 
  arm64 that depend on it.
  
  We already converted some of them (those depending on ARCH_VEXPRESS) to
  just depend on ARM64. Ideally, at some point I’d like to see them as
  defaulting to modules but I don’t think we are there yet (we had some
  discussions at the last KS, I’m not sure anyone started looking into
  this).
 
 I’m torn about this, I think for something like VEXPRESS it makes sense,
 however I think  its reasonable to still have an config symbol for a full
 SoC family or something of that nature.

I think for SBSA compliant systems, we should be able to live with a
generic ARCH_SBSA Kconfig symbol. For more irregular embedded platforms,
we may need something more specific.

Arnd
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Re: [PATCH 2/3] arm64: Add Kconfig option for Samsung GH7 SoC family

2014-02-12 Thread Kukjin Kim

On 02/13/14 04:14, Arnd Bergmann wrote:

On Wednesday 12 February 2014 13:04:40 Kumar Gala wrote:

On Feb 12, 2014, at 12:12 PM, Catalin Marinascatalin.mari...@arm.com  wrote:

On 12 Feb 2014, at 16:25, Kumar Galaga...@codeaurora.org  wrote:

One reason to keep around ARCH_* is for drivers shared between arm and arm64 
that depend on it.


We already converted some of them (those depending on ARCH_VEXPRESS) to
just depend on ARM64. Ideally, at some point I’d like to see them as
defaulting to modules but I don’t think we are there yet (we had some
discussions at the last KS, I’m not sure anyone started looking into
this).


I’m torn about this, I think for something like VEXPRESS it makes sense,
however I think  its reasonable to still have an config symbol for a full
SoC family or something of that nature.


I think for SBSA compliant systems, we should be able to live with a
generic ARCH_SBSA Kconfig symbol. For more irregular embedded platforms,
we may need something more specific.

Basically, I agreed with Arnd's suggestion to use ARCH_SBSA. Or we need 
to define level in Kconfig like ARCH_SBSA_L1 for level1. BTW, how about 
compliant with SBSA Level1 and having some specific features?


- Kukjin
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Re: [PATCH 2/3] arm64: Add Kconfig option for Samsung GH7 SoC family

2014-02-11 Thread Olof Johansson
On Mon, Feb 10, 2014 at 10:29 PM, Kukjin Kim kgene@samsung.com wrote:
 This patch adds support for Samsung GH7 SoC in arm64/Kconfig.

 Signed-off-by: Kukjin Kim kgene@samsung.com
 Cc: Catalin Marinas catalin.mari...@arm.com

The overhead of building one more device tree isn't very large, and I
don't see any other need to have a Kconfig entry per SoC at this time.
It's of course up to Catalin, but you might just want to always
compile all dts files instead.


-Olof
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[PATCH 2/3] arm64: Add Kconfig option for Samsung GH7 SoC family

2014-02-10 Thread Kukjin Kim
This patch adds support for Samsung GH7 SoC in arm64/Kconfig.

Signed-off-by: Kukjin Kim kgene@samsung.com
Cc: Catalin Marinas catalin.mari...@arm.com
---
 arch/arm64/Kconfig   |5 +
 arch/arm64/boot/dts/Makefile |1 +
 2 files changed, 6 insertions(+)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index dd4327f..7d71823 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -111,6 +111,11 @@ source kernel/Kconfig.freezer
 
 menu Platform selection
 
+config ARCH_GH7
+   bool Samsung ARMv8 GH7 SoC
+   help
+ This enables support for Samsung GH7 SoC
+
 config ARCH_VEXPRESS
bool ARMv8 software model (Versatile Express)
select ARCH_REQUIRE_GPIOLIB
diff --git a/arch/arm64/boot/dts/Makefile b/arch/arm64/boot/dts/Makefile
index c52bdb0..54fb0cf 100644
--- a/arch/arm64/boot/dts/Makefile
+++ b/arch/arm64/boot/dts/Makefile
@@ -1,3 +1,4 @@
+dtb-$(CONFIG_ARCH_GH7) += samsung-ssdk-gh7.dtb
 dtb-$(CONFIG_ARCH_VEXPRESS) += rtsm_ve-aemv8a.dtb foundation-v8.dtb
 dtb-$(CONFIG_ARCH_XGENE) += apm-mustang.dtb
 
-- 
1.7.10.4

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