[PATCH] MIPS: Kconfig: microMIPS and SmartMIPS are mutually exclusive

[PATCH] MIPS: Kconfig: microMIPS and SmartMIPS are mutually exclusive

[Markos Chandras]

Fixes the following build problem on randconfig:

Warning: the 32-bit microMIPS architecture does not support the `smartmips'
extension
arch/mips/kernel/entry.S:90: Error: unrecognized opcode `mtlhx $24'
[...]
arch/mips/kernel/entry.S:109: Error: unrecognized opcode `mtlhx $24'

Link: https://dmz-portal.mips.com/bugz/show_bug.cgi?id=1021
Reviewed-by: Steven J. Hill <Steven.Hill@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
---
 arch/mips/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 2fe8e60..ffde3d6 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -2063,7 +2063,7 @@ config ARCH_PHYS_ADDR_T_64BIT
        def_bool 64BIT_PHYS_ADDR
 
 config CPU_HAS_SMARTMIPS
-	depends on SYS_SUPPORTS_SMARTMIPS
+	depends on SYS_SUPPORTS_SMARTMIPS && !CPU_MICROMIPS
 	bool "Support for the SmartMIPS ASE"
 	help
 	  SmartMIPS is a extension of the MIPS32 architecture aimed at
-- 
1.9.3

[PATCH] MIPS: Kconfig: microMIPS and SmartMIPS are mutually exclusive

[Markos Chandras]

Fixes the following build problem on randconfig:

Warning: the 32-bit microMIPS architecture does not support the `smartmips'
extension
arch/mips/kernel/entry.S:90: Error: unrecognized opcode `mtlhx $24'
[...]
arch/mips/kernel/entry.S:109: Error: unrecognized opcode `mtlhx $24'

Link: https://dmz-portal.mips.com/bugz/show_bug.cgi?id=1021
Reviewed-by: Steven J. Hill <Steven.Hill@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
---
 arch/mips/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 2fe8e60..ffde3d6 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -2063,7 +2063,7 @@ config ARCH_PHYS_ADDR_T_64BIT
        def_bool 64BIT_PHYS_ADDR
 
 config CPU_HAS_SMARTMIPS
-	depends on SYS_SUPPORTS_SMARTMIPS
+	depends on SYS_SUPPORTS_SMARTMIPS && !CPU_MICROMIPS
 	bool "Support for the SmartMIPS ASE"
 	help
 	  SmartMIPS is a extension of the MIPS32 architecture aimed at
-- 
1.9.3

Re: [PATCH] MIPS: Kconfig: microMIPS and SmartMIPS are mutually exclusive

[Ralf Baechle]

On Tue, Jun 03, 2014 at 09:46:17AM +0100, Markos Chandras wrote:

> Warning: the 32-bit microMIPS architecture does not support the `smartmips'
> extension
> arch/mips/kernel/entry.S:90: Error: unrecognized opcode `mtlhx $24'
> [...]
> arch/mips/kernel/entry.S:109: Error: unrecognized opcode `mtlhx $24'
> 
> Link: https://dmz-portal.mips.com/bugz/show_bug.cgi?id=1021
> Reviewed-by: Steven J. Hill <Steven.Hill@imgtec.com>
> Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
> ---
>  arch/mips/Kconfig | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
> index 2fe8e60..ffde3d6 100644
> --- a/arch/mips/Kconfig
> +++ b/arch/mips/Kconfig
> @@ -2063,7 +2063,7 @@ config ARCH_PHYS_ADDR_T_64BIT
>         def_bool 64BIT_PHYS_ADDR
>  
>  config CPU_HAS_SMARTMIPS
> -	depends on SYS_SUPPORTS_SMARTMIPS
> +	depends on SYS_SUPPORTS_SMARTMIPS && !CPU_MICROMIPS
>  	bool "Support for the SmartMIPS ASE"
>  	help
>  	  SmartMIPS is a extension of the MIPS32 architecture aimed at

From a user's perspective that's a bit quirky; a user has to first
disable CPU_MICROMIPS before he can enable CPU_HAS_SMARTMIPS.  So I
think this should become a choice statement.

  Ralf

Re: [PATCH] MIPS: Kconfig: microMIPS and SmartMIPS are mutually exclusive

[Ralf Baechle]

On Tue, Jun 03, 2014 at 09:46:17AM +0100, Markos Chandras wrote:

> Warning: the 32-bit microMIPS architecture does not support the `smartmips'
> extension
> arch/mips/kernel/entry.S:90: Error: unrecognized opcode `mtlhx $24'
> [...]
> arch/mips/kernel/entry.S:109: Error: unrecognized opcode `mtlhx $24'
> 
> Link: https://dmz-portal.mips.com/bugz/show_bug.cgi?id=1021
> Reviewed-by: Steven J. Hill <Steven.Hill@imgtec.com>
> Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
> ---
>  arch/mips/Kconfig | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
> index 2fe8e60..ffde3d6 100644
> --- a/arch/mips/Kconfig
> +++ b/arch/mips/Kconfig
> @@ -2063,7 +2063,7 @@ config ARCH_PHYS_ADDR_T_64BIT
>         def_bool 64BIT_PHYS_ADDR
>  
>  config CPU_HAS_SMARTMIPS
> -	depends on SYS_SUPPORTS_SMARTMIPS
> +	depends on SYS_SUPPORTS_SMARTMIPS && !CPU_MICROMIPS
>  	bool "Support for the SmartMIPS ASE"
>  	help
>  	  SmartMIPS is a extension of the MIPS32 architecture aimed at

Re: [PATCH] MIPS: Kconfig: microMIPS and SmartMIPS are mutually exclusive

[Markos Chandras]

On 06/03/2014 10:34 AM, Ralf Baechle wrote:
> On Tue, Jun 03, 2014 at 09:46:17AM +0100, Markos Chandras wrote:
> 
>> Warning: the 32-bit microMIPS architecture does not support the `smartmips'
>> extension
>> arch/mips/kernel/entry.S:90: Error: unrecognized opcode `mtlhx $24'
>> [...]
>> arch/mips/kernel/entry.S:109: Error: unrecognized opcode `mtlhx $24'
>>
>> Link: https://dmz-portal.mips.com/bugz/show_bug.cgi?id=1021
>> Reviewed-by: Steven J. Hill <Steven.Hill@imgtec.com>
>> Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
>> ---
>>  arch/mips/Kconfig | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
>> index 2fe8e60..ffde3d6 100644
>> --- a/arch/mips/Kconfig
>> +++ b/arch/mips/Kconfig
>> @@ -2063,7 +2063,7 @@ config ARCH_PHYS_ADDR_T_64BIT
>>         def_bool 64BIT_PHYS_ADDR
>>  
>>  config CPU_HAS_SMARTMIPS
>> -	depends on SYS_SUPPORTS_SMARTMIPS
>> +	depends on SYS_SUPPORTS_SMARTMIPS && !CPU_MICROMIPS
>>  	bool "Support for the SmartMIPS ASE"
>>  	help
>>  	  SmartMIPS is a extension of the MIPS32 architecture aimed at
> 
> From a user's perspective that's a bit quirky; a user has to first
> disable CPU_MICROMIPS before he can enable CPU_HAS_SMARTMIPS.  So I
> think this should become a choice statement.
> 
>   Ralf
> 
James (now on CC) suggested the same thing and I told him that choice
statements make sense for symbols that are somehow related. For example
SMVP or SMTC or no-MT. In this case, these symbols totally different so
in my opinion a choice symbol will be rather confusing. But I will not
object. Whatever works best.

-- 
markos

Re: [PATCH] MIPS: Kconfig: microMIPS and SmartMIPS are mutually exclusive

[Markos Chandras]

On 06/03/2014 10:34 AM, Ralf Baechle wrote:
> On Tue, Jun 03, 2014 at 09:46:17AM +0100, Markos Chandras wrote:
> 
>> Warning: the 32-bit microMIPS architecture does not support the `smartmips'
>> extension
>> arch/mips/kernel/entry.S:90: Error: unrecognized opcode `mtlhx $24'
>> [...]
>> arch/mips/kernel/entry.S:109: Error: unrecognized opcode `mtlhx $24'
>>
>> Link: https://dmz-portal.mips.com/bugz/show_bug.cgi?id=1021
>> Reviewed-by: Steven J. Hill <Steven.Hill@imgtec.com>
>> Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
>> ---
>>  arch/mips/Kconfig | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
>> index 2fe8e60..ffde3d6 100644
>> --- a/arch/mips/Kconfig
>> +++ b/arch/mips/Kconfig
>> @@ -2063,7 +2063,7 @@ config ARCH_PHYS_ADDR_T_64BIT
>>         def_bool 64BIT_PHYS_ADDR
>>  
>>  config CPU_HAS_SMARTMIPS
>> -	depends on SYS_SUPPORTS_SMARTMIPS
>> +	depends on SYS_SUPPORTS_SMARTMIPS && !CPU_MICROMIPS
>>  	bool "Support for the SmartMIPS ASE"
>>  	help
>>  	  SmartMIPS is a extension of the MIPS32 architecture aimed at
> 
> From a user's perspective that's a bit quirky; a user has to first
> disable CPU_MICROMIPS before he can enable CPU_HAS_SMARTMIPS.  So I
> think this should become a choice statement.
> 
>   Ralf
> 
James (now on CC) suggested the same thing and I told him that choice
statements make sense for symbols that are somehow related. For example
SMVP or SMTC or no-MT. In this case, these symbols totally different so
in my opinion a choice symbol will be rather confusing. But I will not
object. Whatever works best.

-- 
markos

Re: [PATCH] MIPS: Kconfig: microMIPS and SmartMIPS are mutually exclusive

[Maciej W. Rozycki]

On Tue, 3 Jun 2014, Ralf Baechle wrote:

> > Warning: the 32-bit microMIPS architecture does not support the `smartmips'
> > extension
> > arch/mips/kernel/entry.S:90: Error: unrecognized opcode `mtlhx $24'
> > [...]
> > arch/mips/kernel/entry.S:109: Error: unrecognized opcode `mtlhx $24'
> > 
> > Link: https://dmz-portal.mips.com/bugz/show_bug.cgi?id=1021
> > Reviewed-by: Steven J. Hill <Steven.Hill@imgtec.com>
> > Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
> > ---
> >  arch/mips/Kconfig | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
> > index 2fe8e60..ffde3d6 100644
> > --- a/arch/mips/Kconfig
> > +++ b/arch/mips/Kconfig
> > @@ -2063,7 +2063,7 @@ config ARCH_PHYS_ADDR_T_64BIT
> >         def_bool 64BIT_PHYS_ADDR
> >  
> >  config CPU_HAS_SMARTMIPS
> > -	depends on SYS_SUPPORTS_SMARTMIPS
> > +	depends on SYS_SUPPORTS_SMARTMIPS && !CPU_MICROMIPS
> >  	bool "Support for the SmartMIPS ASE"
> >  	help
> >  	  SmartMIPS is a extension of the MIPS32 architecture aimed at
> 
> >From a user's perspective that's a bit quirky; a user has to first
> disable CPU_MICROMIPS before he can enable CPU_HAS_SMARTMIPS.  So I
> think this should become a choice statement.

 Do we need this CPU_HAS_SMARTMIPS setting at all?  Can't we just 
save/restore this SmartMIPS ACX register on context switches where 
available (straightforward to detect at the run time) and have the 
relevant pieces of code excluded (#ifdef-ed out or suchlike) on 
non-supported configurations such as microMIPS or MIPS64?

  Maciej

Re: [PATCH] MIPS: Kconfig: microMIPS and SmartMIPS are mutually exclusive

[Ralf Baechle]

On Tue, Jun 03, 2014 at 12:18:43PM +0100, Maciej W. Rozycki wrote:

>  Do we need this CPU_HAS_SMARTMIPS setting at all?  Can't we just 
> save/restore this SmartMIPS ACX register on context switches where 
> available (straightforward to detect at the run time) and have the 
> relevant pieces of code excluded (#ifdef-ed out or suchlike) on 
> non-supported configurations such as microMIPS or MIPS64?

SmartMIPS has new instructions which are hardcoded in various assembler
fragments, where something like if (cpu_has_smartmips) won't work.
So until a more complex solution is implemented CPU_HAS_SMARTMIPS is
what there is.

  Ralf

Re: [PATCH] MIPS: Kconfig: microMIPS and SmartMIPS are mutually exclusive

[Maciej W. Rozycki]

On Tue, 3 Jun 2014, Ralf Baechle wrote:

> >  Do we need this CPU_HAS_SMARTMIPS setting at all?  Can't we just 
> > save/restore this SmartMIPS ACX register on context switches where 
> > available (straightforward to detect at the run time) and have the 
> > relevant pieces of code excluded (#ifdef-ed out or suchlike) on 
> > non-supported configurations such as microMIPS or MIPS64?
> 
> SmartMIPS has new instructions which are hardcoded in various assembler
> fragments, where something like if (cpu_has_smartmips) won't work.
> So until a more complex solution is implemented CPU_HAS_SMARTMIPS is
> what there is.

 Well:

	.set	push
	.set	smartmips
	# Whatever SmartMIPS stuff.
	.set	pop

should do.  It has been supported by GAS since forever (well, since it has 
included SmartMIPS instructions that is, which is 2.18; to support older 
versions we can use $(call as-instr,...) and some #ifdef-ry that we have 
anyway).  It's <asm/stackframe.h> only BTW for six instructions total.

 So I think that is straightforward to implement and much more reasonable 
than the hacks we have now.  A SmartMIPS-enabled kernel doesn't even check 
if the CPU it's run on implements the ASE so it'll just crash at some 
point trying to execute MFLHXU or MTLHX if it does not -- and obviously if 
two SmartMIPS user programs are run concurrently on a SmartMIPS-disabled 
kernel and use the ACX register, then they will yield random results.

  Maciej

[PATCH v2] MIPS: Kconfig: Add choice symbol to select microMIPS or SmartMIPS

[Markos Chandras]

microMIPS and SmartMIPS can't be used together. This fixes the
following build problem:

Warning: the 32-bit microMIPS architecture does not support the `smartmips'
extension
arch/mips/kernel/entry.S:90: Error: unrecognized opcode `mtlhx $24'
[...]
arch/mips/kernel/entry.S:109: Error: unrecognized opcode `mtlhx $24'

Link: https://dmz-portal.mips.com/bugz/show_bug.cgi?id=1021
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
---
Hi Ralf,

Here is v2 of that patch, making SmartMIPS and microMIPS a
choice symbol as you requested in
http://www.linux-mips.org/archives/linux-mips/2014-06/msg00011.html

However, I still feel this is wrong since these two ASEs are completely
unrelated. The v1 of the patch is probably better in my opinion.
If the user fails to find the 'smartmips' option due to having 'micromips'
enabled, he/she can always search for the 'smartmips' symbol in the
menuconfig and he/she will notice the dependency on !micromips.
And if the user knows what he is doing he will probably never want to
use 'smartmips' and 'micromips' together.
---

 arch/mips/Kconfig | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 4e238e6e661c..f30a43a52a09 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -2090,9 +2090,17 @@ config 64BIT_PHYS_ADDR
 config ARCH_PHYS_ADDR_T_64BIT
        def_bool 64BIT_PHYS_ADDR
 
+choice
+	prompt "SmartMIPS or microMIPS ASE support"
+
+config CPU_NEEDS_NO_SMARTMIPS_OR_MICROMIPS
+	bool "None"
+	help
+	  Select this if you want neither microMIPS nor SmartMIPS support
+
 config CPU_HAS_SMARTMIPS
 	depends on SYS_SUPPORTS_SMARTMIPS
-	bool "Support for the SmartMIPS ASE"
+	bool "SmartMIPS"
 	help
 	  SmartMIPS is a extension of the MIPS32 architecture aimed at
 	  increased security at both hardware and software level for
@@ -2104,11 +2112,13 @@ config CPU_HAS_SMARTMIPS
 
 config CPU_MICROMIPS
 	depends on SYS_SUPPORTS_MICROMIPS
-	bool "Build kernel using microMIPS ISA"
+	bool "microMIPS"
 	help
 	  When this option is enabled the kernel will be built using the
 	  microMIPS ISA
 
+endchoice
+
 config CPU_HAS_MSA
 	bool "Support for the MIPS SIMD Architecture"
 	depends on CPU_SUPPORTS_MSA
-- 
2.0.0

[PATCH v2] MIPS: Kconfig: Add choice symbol to select microMIPS or SmartMIPS

[Markos Chandras]

microMIPS and SmartMIPS can't be used together. This fixes the
following build problem:

Warning: the 32-bit microMIPS architecture does not support the `smartmips'
extension
arch/mips/kernel/entry.S:90: Error: unrecognized opcode `mtlhx $24'
[...]
arch/mips/kernel/entry.S:109: Error: unrecognized opcode `mtlhx $24'

Link: https://dmz-portal.mips.com/bugz/show_bug.cgi?id=1021
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
---
Hi Ralf,

Here is v2 of that patch, making SmartMIPS and microMIPS a
choice symbol as you requested in
http://www.linux-mips.org/archives/linux-mips/2014-06/msg00011.html

However, I still feel this is wrong since these two ASEs are completely
unrelated. The v1 of the patch is probably better in my opinion.
If the user fails to find the 'smartmips' option due to having 'micromips'
enabled, he/she can always search for the 'smartmips' symbol in the
menuconfig and he/she will notice the dependency on !micromips.
And if the user knows what he is doing he will probably never want to
use 'smartmips' and 'micromips' together.
---

 arch/mips/Kconfig | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 4e238e6e661c..f30a43a52a09 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -2090,9 +2090,17 @@ config 64BIT_PHYS_ADDR
 config ARCH_PHYS_ADDR_T_64BIT
        def_bool 64BIT_PHYS_ADDR
 
+choice
+	prompt "SmartMIPS or microMIPS ASE support"
+
+config CPU_NEEDS_NO_SMARTMIPS_OR_MICROMIPS
+	bool "None"
+	help
+	  Select this if you want neither microMIPS nor SmartMIPS support
+
 config CPU_HAS_SMARTMIPS
 	depends on SYS_SUPPORTS_SMARTMIPS
-	bool "Support for the SmartMIPS ASE"
+	bool "SmartMIPS"
 	help
 	  SmartMIPS is a extension of the MIPS32 architecture aimed at
 	  increased security at both hardware and software level for
@@ -2104,11 +2112,13 @@ config CPU_HAS_SMARTMIPS
 
 config CPU_MICROMIPS
 	depends on SYS_SUPPORTS_MICROMIPS
-	bool "Build kernel using microMIPS ISA"
+	bool "microMIPS"
 	help
 	  When this option is enabled the kernel will be built using the
 	  microMIPS ISA
 
+endchoice
+
 config CPU_HAS_MSA
 	bool "Support for the MIPS SIMD Architecture"
 	depends on CPU_SUPPORTS_MSA
-- 
2.0.0

Re: [PATCH v2] MIPS: Kconfig: Add choice symbol to select microMIPS or SmartMIPS

[Markos Chandras]

On 07/21/2014 08:46 AM, Markos Chandras wrote:
> microMIPS and SmartMIPS can't be used together. This fixes the
> following build problem:
> 
> Warning: the 32-bit microMIPS architecture does not support the `smartmips'
> extension
> arch/mips/kernel/entry.S:90: Error: unrecognized opcode `mtlhx $24'
> [...]
> arch/mips/kernel/entry.S:109: Error: unrecognized opcode `mtlhx $24'
> 
> Link: https://dmz-portal.mips.com/bugz/show_bug.cgi?id=1021
> Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
> ---
> Hi Ralf,
> 
> Here is v2 of that patch, making SmartMIPS and microMIPS a
> choice symbol as you requested in
> http://www.linux-mips.org/archives/linux-mips/2014-06/msg00011.html
> 
> However, I still feel this is wrong since these two ASEs are completely
> unrelated. The v1 of the patch is probably better in my opinion.
> If the user fails to find the 'smartmips' option due to having 'micromips'
> enabled, he/she can always search for the 'smartmips' symbol in the
> menuconfig and he/she will notice the dependency on !micromips.
> And if the user knows what he is doing he will probably never want to
> use 'smartmips' and 'micromips' together.
> ---
> 
Hi,

Any comments on that one?

-- 
markos

Re: [PATCH v2] MIPS: Kconfig: Add choice symbol to select microMIPS or SmartMIPS

[Markos Chandras]

On 07/21/2014 08:46 AM, Markos Chandras wrote:
> microMIPS and SmartMIPS can't be used together. This fixes the
> following build problem:
> 
> Warning: the 32-bit microMIPS architecture does not support the `smartmips'
> extension
> arch/mips/kernel/entry.S:90: Error: unrecognized opcode `mtlhx $24'
> [...]
> arch/mips/kernel/entry.S:109: Error: unrecognized opcode `mtlhx $24'
> 
> Link: https://dmz-portal.mips.com/bugz/show_bug.cgi?id=1021
> Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
> ---
> Hi Ralf,
> 
> Here is v2 of that patch, making SmartMIPS and microMIPS a
> choice symbol as you requested in
> http://www.linux-mips.org/archives/linux-mips/2014-06/msg00011.html
> 
> However, I still feel this is wrong since these two ASEs are completely
> unrelated. The v1 of the patch is probably better in my opinion.
> If the user fails to find the 'smartmips' option due to having 'micromips'
> enabled, he/she can always search for the 'smartmips' symbol in the
> menuconfig and he/she will notice the dependency on !micromips.
> And if the user knows what he is doing he will probably never want to
> use 'smartmips' and 'micromips' together.
> ---
> 
Hi,

Any comments on that one?

-- 
markos