Increasing build coverage for drivers/spi/spi-ppc4xx.c

Increasing build coverage for drivers/spi/spi-ppc4xx.c

[Uwe Kleine-König]

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Hello,

recently the spi-ppc4xx.c driver suffered from build errors and warnings
that were undetected for longer than I expected. I think it would be
very beneficial if this driver was enabled in (at least) a powerpc
allmodconfig build.

The challenge to do so is that spi-ppc4xx.c uses dcri_clrset() which is
only defined for 4xx (as these select PPC_DCR_NATIVE).

I wonder if dcri_clrset() could be defined for the PPC_DCR_MMIO case,
too. I tried and failed. The best I came up without extensive doc
reading is:

diff --git a/arch/powerpc/include/asm/dcr-native.h b/arch/powerpc/include/asm/dcr-native.h
index a92059964579..159ab7abfe46 100644
--- a/arch/powerpc/include/asm/dcr-native.h
+++ b/arch/powerpc/include/asm/dcr-native.h
@@ -115,15 +115,11 @@ static inline void __dcri_clrset(int base_addr, int base_data, int reg,
 	unsigned int val;
 
 	spin_lock_irqsave(&dcr_ind_lock, flags);
-	if (cpu_has_feature(CPU_FTR_INDEXED_DCR)) {
-		mtdcrx(base_addr, reg);
-		val = (mfdcrx(base_data) & ~clr) | set;
-		mtdcrx(base_data, val);
-	} else {
-		__mtdcr(base_addr, reg);
-		val = (__mfdcr(base_data) & ~clr) | set;
-		__mtdcr(base_data, val);
-	}
+
+	mtdcr(base_addr, reg);
+	val = (mfdcr(base_data) & ~clr) | set;
+	mtdcr(base_data, val);
+
 	spin_unlock_irqrestore(&dcr_ind_lock, flags);
 }
 
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index bc7021da2fe9..9a0a5e8c70c8 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -810,7 +810,8 @@ config SPI_PL022
 
 config SPI_PPC4xx
 	tristate "PPC4xx SPI Controller"
-	depends on PPC32 && 4xx
+	depends on 4xx || COMPILE_TEST
+	depends on PPC32 || PPC64
 	select SPI_BITBANG
 	help
 	  This selects a driver for the PPC4xx SPI Controller.

While this is a step in the right direction (I think) it's not enough to
make the driver build (but maybe make it easier to define
dcri_clrset()?)

Could someone with more powerpc knowledge jump in and help (for the
benefit of better compile coverage of the spi driver and so less
breakage)? (If you do so based on my changes above, you don't need to
credit me for my effort, claim it as your's. I'm happy enough if the
situation improves.)

Thanks
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | https://www.pengutronix.de/ |

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Re: Increasing build coverage for drivers/spi/spi-ppc4xx.c

[Tudor Ambarus]

On 2/27/24 08:46, Uwe Kleine-König wrote:
> recently the spi-ppc4xx.c driver suffered from build errors and warnings
> that were undetected for longer than I expected. I think it would be

long enough so that we remove the driver altogether?

Re: Increasing build coverage for drivers/spi/spi-ppc4xx.c

[Uwe Kleine-König]

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Hello,

On Tue, Feb 27, 2024 at 08:54:03AM +0000, Tudor Ambarus wrote:
> On 2/27/24 08:46, Uwe Kleine-König wrote:
> > recently the spi-ppc4xx.c driver suffered from build errors and warnings
> > that were undetected for longer than I expected. I think it would be
> 
> long enough so that we remove the driver altogether?

I know at least one user who noticed the driver being broken because he
needs it and not because a build bot stumbled.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | https://www.pengutronix.de/ |

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Re: Increasing build coverage for drivers/spi/spi-ppc4xx.c

[Christophe Leroy]

Le 27/02/2024 à 09:46, Uwe Kleine-König a écrit :
> Hello,
> 
> recently the spi-ppc4xx.c driver suffered from build errors and warnings
> that were undetected for longer than I expected. I think it would be
> very beneficial if this driver was enabled in (at least) a powerpc
> allmodconfig build.
> 
> The challenge to do so is that spi-ppc4xx.c uses dcri_clrset() which is
> only defined for 4xx (as these select PPC_DCR_NATIVE).
> 
> I wonder if dcri_clrset() could be defined for the PPC_DCR_MMIO case,
> too. I tried and failed. The best I came up without extensive doc
> reading is:
> 
> diff --git a/arch/powerpc/include/asm/dcr-native.h b/arch/powerpc/include/asm/dcr-native.h
> index a92059964579..159ab7abfe46 100644
> --- a/arch/powerpc/include/asm/dcr-native.h
> +++ b/arch/powerpc/include/asm/dcr-native.h
> @@ -115,15 +115,11 @@ static inline void __dcri_clrset(int base_addr, int base_data, int reg,
>   	unsigned int val;
>   
>   	spin_lock_irqsave(&dcr_ind_lock, flags);
> -	if (cpu_has_feature(CPU_FTR_INDEXED_DCR)) {
> -		mtdcrx(base_addr, reg);
> -		val = (mfdcrx(base_data) & ~clr) | set;
> -		mtdcrx(base_data, val);
> -	} else {
> -		__mtdcr(base_addr, reg);
> -		val = (__mfdcr(base_data) & ~clr) | set;
> -		__mtdcr(base_data, val);
> -	}
> +
> +	mtdcr(base_addr, reg);
> +	val = (mfdcr(base_data) & ~clr) | set;
> +	mtdcr(base_data, val);
> +
>   	spin_unlock_irqrestore(&dcr_ind_lock, flags);
>   }
>   
> diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
> index bc7021da2fe9..9a0a5e8c70c8 100644
> --- a/drivers/spi/Kconfig
> +++ b/drivers/spi/Kconfig
> @@ -810,7 +810,8 @@ config SPI_PL022
>   
>   config SPI_PPC4xx
>   	tristate "PPC4xx SPI Controller"
> -	depends on PPC32 && 4xx
> +	depends on 4xx || COMPILE_TEST
> +	depends on PPC32 || PPC64
>   	select SPI_BITBANG
>   	help
>   	  This selects a driver for the PPC4xx SPI Controller.
> 
> While this is a step in the right direction (I think) it's not enough to
> make the driver build (but maybe make it easier to define
> dcri_clrset()?)
> 
> Could someone with more powerpc knowledge jump in and help (for the
> benefit of better compile coverage of the spi driver and so less
> breakage)? (If you do so based on my changes above, you don't need to
> credit me for my effort, claim it as your's. I'm happy enough if the
> situation improves.)

What about this ?

diff --git a/arch/powerpc/include/asm/dcr-mmio.h 
b/arch/powerpc/include/asm/dcr-mmio.h
index fc6d93ef4a13..38b515afbffc 100644
--- a/arch/powerpc/include/asm/dcr-mmio.h
+++ b/arch/powerpc/include/asm/dcr-mmio.h
@@ -38,6 +38,11 @@ static inline void dcr_write_mmio(dcr_host_mmio_t host,
  	out_be32(host.token + ((host.base + dcr_n) * host.stride), value);
  }

+static inline void __dcri_clrset(int base_addr, int base_data, int reg,
+				 unsigned clr, unsigned set)
+{
+}
+
  #endif /* __KERNEL__ */
  #endif /* _ASM_POWERPC_DCR_MMIO_H */

diff --git a/arch/powerpc/include/asm/dcr-native.h 
b/arch/powerpc/include/asm/dcr-native.h
index a92059964579..2f6221bf5406 100644
--- a/arch/powerpc/include/asm/dcr-native.h
+++ b/arch/powerpc/include/asm/dcr-native.h
@@ -135,10 +135,6 @@ static inline void __dcri_clrset(int base_addr, int 
base_data, int reg,
  					 DCRN_ ## base ## _CONFIG_DATA,	\
  					 reg, data)

-#define dcri_clrset(base, reg, clr, set)	__dcri_clrset(DCRN_ ## base ## 
_CONFIG_ADDR,	\
-							      DCRN_ ## base ## _CONFIG_DATA,	\
-							      reg, clr, set)
-
  #endif /* __ASSEMBLY__ */
  #endif /* __KERNEL__ */
  #endif /* _ASM_POWERPC_DCR_NATIVE_H */
diff --git a/arch/powerpc/include/asm/dcr.h b/arch/powerpc/include/asm/dcr.h
index 64030e3a1f30..15c123ae38a1 100644
--- a/arch/powerpc/include/asm/dcr.h
+++ b/arch/powerpc/include/asm/dcr.h
@@ -18,6 +18,9 @@
  #include <asm/dcr-mmio.h>
  #endif

+#define dcri_clrset(base, reg, clr, set)	__dcri_clrset(DCRN_ ## base ## 
_CONFIG_ADDR,	\
+							      DCRN_ ## base ## _CONFIG_DATA,	\
+							      reg, clr, set)

  /* Indirection layer for providing both NATIVE and MMIO support. */

diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index ddae0fde798e..7b003c5dd613 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -810,7 +810,7 @@ config SPI_PL022

  config SPI_PPC4xx
  	tristate "PPC4xx SPI Controller"
-	depends on PPC32 && 4xx
+	depends on PPC && (4xx || COMPILE_TEST)
  	select SPI_BITBANG
  	help
  	  This selects a driver for the PPC4xx SPI Controller.

Re: Increasing build coverage for drivers/spi/spi-ppc4xx.c

[Uwe Kleine-König]

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Hello Christophe,

On Tue, Feb 27, 2024 at 10:25:15AM +0000, Christophe Leroy wrote:
> Le 27/02/2024 à 09:46, Uwe Kleine-König a écrit :
> > recently the spi-ppc4xx.c driver suffered from build errors and warnings
> > that were undetected for longer than I expected. I think it would be
> > very beneficial if this driver was enabled in (at least) a powerpc
> > allmodconfig build.
> > 
> > The challenge to do so is that spi-ppc4xx.c uses dcri_clrset() which is
> > only defined for 4xx (as these select PPC_DCR_NATIVE).
> > 
> > I wonder if dcri_clrset() could be defined for the PPC_DCR_MMIO case,
> > too. I tried and failed. The best I came up without extensive doc
> > reading is:
> > 
> > diff --git a/arch/powerpc/include/asm/dcr-native.h b/arch/powerpc/include/asm/dcr-native.h
> > index a92059964579..159ab7abfe46 100644
> > --- a/arch/powerpc/include/asm/dcr-native.h
> > +++ b/arch/powerpc/include/asm/dcr-native.h
> > @@ -115,15 +115,11 @@ static inline void __dcri_clrset(int base_addr, int base_data, int reg,
> >   	unsigned int val;
> >   
> >   	spin_lock_irqsave(&dcr_ind_lock, flags);
> > -	if (cpu_has_feature(CPU_FTR_INDEXED_DCR)) {
> > -		mtdcrx(base_addr, reg);
> > -		val = (mfdcrx(base_data) & ~clr) | set;
> > -		mtdcrx(base_data, val);
> > -	} else {
> > -		__mtdcr(base_addr, reg);
> > -		val = (__mfdcr(base_data) & ~clr) | set;
> > -		__mtdcr(base_data, val);
> > -	}
> > +
> > +	mtdcr(base_addr, reg);
> > +	val = (mfdcr(base_data) & ~clr) | set;
> > +	mtdcr(base_data, val);
> > +
> >   	spin_unlock_irqrestore(&dcr_ind_lock, flags);
> >   }
> >   
> > diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
> > index bc7021da2fe9..9a0a5e8c70c8 100644
> > --- a/drivers/spi/Kconfig
> > +++ b/drivers/spi/Kconfig
> > @@ -810,7 +810,8 @@ config SPI_PL022
> >   
> >   config SPI_PPC4xx
> >   	tristate "PPC4xx SPI Controller"
> > -	depends on PPC32 && 4xx
> > +	depends on 4xx || COMPILE_TEST
> > +	depends on PPC32 || PPC64
> >   	select SPI_BITBANG
> >   	help
> >   	  This selects a driver for the PPC4xx SPI Controller.
> > 
> > While this is a step in the right direction (I think) it's not enough to
> > make the driver build (but maybe make it easier to define
> > dcri_clrset()?)
> > 
> > Could someone with more powerpc knowledge jump in and help (for the
> > benefit of better compile coverage of the spi driver and so less
> > breakage)? (If you do so based on my changes above, you don't need to
> > credit me for my effort, claim it as your's. I'm happy enough if the
> > situation improves.)
> 
> What about this ?
> 
> diff --git a/arch/powerpc/include/asm/dcr-mmio.h 
> b/arch/powerpc/include/asm/dcr-mmio.h
> index fc6d93ef4a13..38b515afbffc 100644
> --- a/arch/powerpc/include/asm/dcr-mmio.h
> +++ b/arch/powerpc/include/asm/dcr-mmio.h
> @@ -38,6 +38,11 @@ static inline void dcr_write_mmio(dcr_host_mmio_t host,
>   	out_be32(host.token + ((host.base + dcr_n) * host.stride), value);
>   }
> 
> +static inline void __dcri_clrset(int base_addr, int base_data, int reg,
> +				 unsigned clr, unsigned set)
> +{
> +}
> +

The downside of that one is that if we find a matching device where
dcr-mmio is used, the driver claims to work but silently fails. Is this
good enough?

>   #endif /* __KERNEL__ */
>   #endif /* _ASM_POWERPC_DCR_MMIO_H */
> 
> diff --git a/arch/powerpc/include/asm/dcr-native.h 
> b/arch/powerpc/include/asm/dcr-native.h
> index a92059964579..2f6221bf5406 100644
> --- a/arch/powerpc/include/asm/dcr-native.h
> +++ b/arch/powerpc/include/asm/dcr-native.h
> @@ -135,10 +135,6 @@ static inline void __dcri_clrset(int base_addr, int 
> base_data, int reg,
>   					 DCRN_ ## base ## _CONFIG_DATA,	\
>   					 reg, data)
> 
> -#define dcri_clrset(base, reg, clr, set)	__dcri_clrset(DCRN_ ## base ## 
> _CONFIG_ADDR,	\
> -							      DCRN_ ## base ## _CONFIG_DATA,	\
> -							      reg, clr, set)
> -
>   #endif /* __ASSEMBLY__ */
>   #endif /* __KERNEL__ */
>   #endif /* _ASM_POWERPC_DCR_NATIVE_H */
> diff --git a/arch/powerpc/include/asm/dcr.h b/arch/powerpc/include/asm/dcr.h
> index 64030e3a1f30..15c123ae38a1 100644
> --- a/arch/powerpc/include/asm/dcr.h
> +++ b/arch/powerpc/include/asm/dcr.h
> @@ -18,6 +18,9 @@
>   #include <asm/dcr-mmio.h>
>   #endif
> 
> +#define dcri_clrset(base, reg, clr, set)	__dcri_clrset(DCRN_ ## base ## 
> _CONFIG_ADDR,	\
> +							      DCRN_ ## base ## _CONFIG_DATA,	\
> +							      reg, clr, set)
> 
>   /* Indirection layer for providing both NATIVE and MMIO support. */
> 
> diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
> index ddae0fde798e..7b003c5dd613 100644
> --- a/drivers/spi/Kconfig
> +++ b/drivers/spi/Kconfig
> @@ -810,7 +810,7 @@ config SPI_PL022
> 
>   config SPI_PPC4xx
>   	tristate "PPC4xx SPI Controller"
> -	depends on PPC32 && 4xx
> +	depends on PPC && (4xx || COMPILE_TEST)

Ah, I wondered about not finding a global powerpc symbol. Just missed it
because I expected it at the top of arch/powerpc/Kconfig.

I would have split the depends line into

	depends on PPC
	depends on 4xx || COMPILE_TEST

but apart from that I like it. Maybe split the change into the powerpc
stuff and then a separate patch changing SPI_PPC4xx?

Another thing I wondered is: Should SPI_PPC4xx better depend on
PPC_DCR_NATIVE instead of 4xx? This is an orthogonal change however.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | https://www.pengutronix.de/ |

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Re: Increasing build coverage for drivers/spi/spi-ppc4xx.c

[Christophe Leroy]

Le 27/02/2024 à 11:58, Uwe Kleine-König a écrit :
> Hello Christophe,
> 
> On Tue, Feb 27, 2024 at 10:25:15AM +0000, Christophe Leroy wrote:
>> Le 27/02/2024 à 09:46, Uwe Kleine-König a écrit :
>>> recently the spi-ppc4xx.c driver suffered from build errors and warnings
>>> that were undetected for longer than I expected. I think it would be
>>> very beneficial if this driver was enabled in (at least) a powerpc
>>> allmodconfig build.
>>>
>>> The challenge to do so is that spi-ppc4xx.c uses dcri_clrset() which is
>>> only defined for 4xx (as these select PPC_DCR_NATIVE).
>>>
>>> I wonder if dcri_clrset() could be defined for the PPC_DCR_MMIO case,
>>> too. I tried and failed. The best I came up without extensive doc
>>> reading is:
>>>
>>> diff --git a/arch/powerpc/include/asm/dcr-native.h b/arch/powerpc/include/asm/dcr-native.h
>>> index a92059964579..159ab7abfe46 100644
>>> --- a/arch/powerpc/include/asm/dcr-native.h
>>> +++ b/arch/powerpc/include/asm/dcr-native.h
>>> @@ -115,15 +115,11 @@ static inline void __dcri_clrset(int base_addr, int base_data, int reg,
>>>    	unsigned int val;
>>>    
>>>    	spin_lock_irqsave(&dcr_ind_lock, flags);
>>> -	if (cpu_has_feature(CPU_FTR_INDEXED_DCR)) {
>>> -		mtdcrx(base_addr, reg);
>>> -		val = (mfdcrx(base_data) & ~clr) | set;
>>> -		mtdcrx(base_data, val);
>>> -	} else {
>>> -		__mtdcr(base_addr, reg);
>>> -		val = (__mfdcr(base_data) & ~clr) | set;
>>> -		__mtdcr(base_data, val);
>>> -	}
>>> +
>>> +	mtdcr(base_addr, reg);
>>> +	val = (mfdcr(base_data) & ~clr) | set;
>>> +	mtdcr(base_data, val);
>>> +
>>>    	spin_unlock_irqrestore(&dcr_ind_lock, flags);
>>>    }
>>>    
>>> diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
>>> index bc7021da2fe9..9a0a5e8c70c8 100644
>>> --- a/drivers/spi/Kconfig
>>> +++ b/drivers/spi/Kconfig
>>> @@ -810,7 +810,8 @@ config SPI_PL022
>>>    
>>>    config SPI_PPC4xx
>>>    	tristate "PPC4xx SPI Controller"
>>> -	depends on PPC32 && 4xx
>>> +	depends on 4xx || COMPILE_TEST
>>> +	depends on PPC32 || PPC64
>>>    	select SPI_BITBANG
>>>    	help
>>>    	  This selects a driver for the PPC4xx SPI Controller.
>>>
>>> While this is a step in the right direction (I think) it's not enough to
>>> make the driver build (but maybe make it easier to define
>>> dcri_clrset()?)
>>>
>>> Could someone with more powerpc knowledge jump in and help (for the
>>> benefit of better compile coverage of the spi driver and so less
>>> breakage)? (If you do so based on my changes above, you don't need to
>>> credit me for my effort, claim it as your's. I'm happy enough if the
>>> situation improves.)
>>
>> What about this ?
>>
>> diff --git a/arch/powerpc/include/asm/dcr-mmio.h
>> b/arch/powerpc/include/asm/dcr-mmio.h
>> index fc6d93ef4a13..38b515afbffc 100644
>> --- a/arch/powerpc/include/asm/dcr-mmio.h
>> +++ b/arch/powerpc/include/asm/dcr-mmio.h
>> @@ -38,6 +38,11 @@ static inline void dcr_write_mmio(dcr_host_mmio_t host,
>>    	out_be32(host.token + ((host.base + dcr_n) * host.stride), value);
>>    }
>>
>> +static inline void __dcri_clrset(int base_addr, int base_data, int reg,
>> +				 unsigned clr, unsigned set)
>> +{
>> +}
>> +
> 
> The downside of that one is that if we find a matching device where
> dcr-mmio is used, the driver claims to work but silently fails. Is this
> good enough?

I don't know the details of DCR, but it looks like this spi-ppc4xx 
driver is really specific to 4xx, which is PPC32.

Do you really need/want it to be built with allmodconfig ?

Maybe it would be easier to have it work with ppc32_allmodconfig ?

Or even easier with ppc44x_defconfig ?

Christophe


> 
>>    #endif /* __KERNEL__ */
>>    #endif /* _ASM_POWERPC_DCR_MMIO_H */
>>
>> diff --git a/arch/powerpc/include/asm/dcr-native.h
>> b/arch/powerpc/include/asm/dcr-native.h
>> index a92059964579..2f6221bf5406 100644
>> --- a/arch/powerpc/include/asm/dcr-native.h
>> +++ b/arch/powerpc/include/asm/dcr-native.h
>> @@ -135,10 +135,6 @@ static inline void __dcri_clrset(int base_addr, int
>> base_data, int reg,
>>    					 DCRN_ ## base ## _CONFIG_DATA,	\
>>    					 reg, data)
>>
>> -#define dcri_clrset(base, reg, clr, set)	__dcri_clrset(DCRN_ ## base ##
>> _CONFIG_ADDR,	\
>> -							      DCRN_ ## base ## _CONFIG_DATA,	\
>> -							      reg, clr, set)
>> -
>>    #endif /* __ASSEMBLY__ */
>>    #endif /* __KERNEL__ */
>>    #endif /* _ASM_POWERPC_DCR_NATIVE_H */
>> diff --git a/arch/powerpc/include/asm/dcr.h b/arch/powerpc/include/asm/dcr.h
>> index 64030e3a1f30..15c123ae38a1 100644
>> --- a/arch/powerpc/include/asm/dcr.h
>> +++ b/arch/powerpc/include/asm/dcr.h
>> @@ -18,6 +18,9 @@
>>    #include <asm/dcr-mmio.h>
>>    #endif
>>
>> +#define dcri_clrset(base, reg, clr, set)	__dcri_clrset(DCRN_ ## base ##
>> _CONFIG_ADDR,	\
>> +							      DCRN_ ## base ## _CONFIG_DATA,	\
>> +							      reg, clr, set)
>>
>>    /* Indirection layer for providing both NATIVE and MMIO support. */
>>
>> diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
>> index ddae0fde798e..7b003c5dd613 100644
>> --- a/drivers/spi/Kconfig
>> +++ b/drivers/spi/Kconfig
>> @@ -810,7 +810,7 @@ config SPI_PL022
>>
>>    config SPI_PPC4xx
>>    	tristate "PPC4xx SPI Controller"
>> -	depends on PPC32 && 4xx
>> +	depends on PPC && (4xx || COMPILE_TEST)
> 
> Ah, I wondered about not finding a global powerpc symbol. Just missed it
> because I expected it at the top of arch/powerpc/Kconfig.
> 
> I would have split the depends line into
> 
> 	depends on PPC
> 	depends on 4xx || COMPILE_TEST
> 
> but apart from that I like it. Maybe split the change into the powerpc
> stuff and then a separate patch changing SPI_PPC4xx?
> 
> Another thing I wondered is: Should SPI_PPC4xx better depend on
> PPC_DCR_NATIVE instead of 4xx? This is an orthogonal change however.
> 
> Best regards
> Uwe
> 

Re: Increasing build coverage for drivers/spi/spi-ppc4xx.c

[Uwe Kleine-König]

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On Tue, Feb 27, 2024 at 01:52:07PM +0000, Christophe Leroy wrote:
> 
> 
> Le 27/02/2024 à 11:58, Uwe Kleine-König a écrit :
> > Hello Christophe,
> > 
> > On Tue, Feb 27, 2024 at 10:25:15AM +0000, Christophe Leroy wrote:
> >> Le 27/02/2024 à 09:46, Uwe Kleine-König a écrit :
> >>> recently the spi-ppc4xx.c driver suffered from build errors and warnings
> >>> that were undetected for longer than I expected. I think it would be
> >>> very beneficial if this driver was enabled in (at least) a powerpc
> >>> allmodconfig build.
> >>>
> >>> The challenge to do so is that spi-ppc4xx.c uses dcri_clrset() which is
> >>> only defined for 4xx (as these select PPC_DCR_NATIVE).
> >>>
> >>> I wonder if dcri_clrset() could be defined for the PPC_DCR_MMIO case,
> >>> too. I tried and failed. The best I came up without extensive doc
> >>> reading is:
> >>>
> >>> diff --git a/arch/powerpc/include/asm/dcr-native.h b/arch/powerpc/include/asm/dcr-native.h
> >>> index a92059964579..159ab7abfe46 100644
> >>> --- a/arch/powerpc/include/asm/dcr-native.h
> >>> +++ b/arch/powerpc/include/asm/dcr-native.h
> >>> @@ -115,15 +115,11 @@ static inline void __dcri_clrset(int base_addr, int base_data, int reg,
> >>>    	unsigned int val;
> >>>    
> >>>    	spin_lock_irqsave(&dcr_ind_lock, flags);
> >>> -	if (cpu_has_feature(CPU_FTR_INDEXED_DCR)) {
> >>> -		mtdcrx(base_addr, reg);
> >>> -		val = (mfdcrx(base_data) & ~clr) | set;
> >>> -		mtdcrx(base_data, val);
> >>> -	} else {
> >>> -		__mtdcr(base_addr, reg);
> >>> -		val = (__mfdcr(base_data) & ~clr) | set;
> >>> -		__mtdcr(base_data, val);
> >>> -	}
> >>> +
> >>> +	mtdcr(base_addr, reg);
> >>> +	val = (mfdcr(base_data) & ~clr) | set;
> >>> +	mtdcr(base_data, val);
> >>> +
> >>>    	spin_unlock_irqrestore(&dcr_ind_lock, flags);
> >>>    }
> >>>    
> >>> diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
> >>> index bc7021da2fe9..9a0a5e8c70c8 100644
> >>> --- a/drivers/spi/Kconfig
> >>> +++ b/drivers/spi/Kconfig
> >>> @@ -810,7 +810,8 @@ config SPI_PL022
> >>>    
> >>>    config SPI_PPC4xx
> >>>    	tristate "PPC4xx SPI Controller"
> >>> -	depends on PPC32 && 4xx
> >>> +	depends on 4xx || COMPILE_TEST
> >>> +	depends on PPC32 || PPC64
> >>>    	select SPI_BITBANG
> >>>    	help
> >>>    	  This selects a driver for the PPC4xx SPI Controller.
> >>>
> >>> While this is a step in the right direction (I think) it's not enough to
> >>> make the driver build (but maybe make it easier to define
> >>> dcri_clrset()?)
> >>>
> >>> Could someone with more powerpc knowledge jump in and help (for the
> >>> benefit of better compile coverage of the spi driver and so less
> >>> breakage)? (If you do so based on my changes above, you don't need to
> >>> credit me for my effort, claim it as your's. I'm happy enough if the
> >>> situation improves.)
> >>
> >> What about this ?
> >>
> >> diff --git a/arch/powerpc/include/asm/dcr-mmio.h
> >> b/arch/powerpc/include/asm/dcr-mmio.h
> >> index fc6d93ef4a13..38b515afbffc 100644
> >> --- a/arch/powerpc/include/asm/dcr-mmio.h
> >> +++ b/arch/powerpc/include/asm/dcr-mmio.h
> >> @@ -38,6 +38,11 @@ static inline void dcr_write_mmio(dcr_host_mmio_t host,
> >>    	out_be32(host.token + ((host.base + dcr_n) * host.stride), value);
> >>    }
> >>
> >> +static inline void __dcri_clrset(int base_addr, int base_data, int reg,
> >> +				 unsigned clr, unsigned set)
> >> +{
> >> +}
> >> +
> > 
> > The downside of that one is that if we find a matching device where
> > dcr-mmio is used, the driver claims to work but silently fails. Is this
> > good enough?
> 
> I don't know the details of DCR, but it looks like this spi-ppc4xx 
> driver is really specific to 4xx, which is PPC32.
> 
> Do you really need/want it to be built with allmodconfig ?
> 
> Maybe it would be easier to have it work with ppc32_allmodconfig ?
> 
> Or even easier with ppc44x_defconfig ?

The reason I'd like to see it in allmodconfig is that testing
allmodconfig on several archs is the check I do for my patch series.
Also I assume I'm not the only one relying on allmodconfig for this
purpose. So in my eyes every driver that is built there is a net win.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | https://www.pengutronix.de/ |

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Re: Increasing build coverage for drivers/spi/spi-ppc4xx.c

[Christophe Leroy]

Le 27/02/2024 à 15:00, Uwe Kleine-König a écrit :
> On Tue, Feb 27, 2024 at 01:52:07PM +0000, Christophe Leroy wrote:
>>
>>
>> Le 27/02/2024 à 11:58, Uwe Kleine-König a écrit :
>>> Hello Christophe,
>>>
>>> On Tue, Feb 27, 2024 at 10:25:15AM +0000, Christophe Leroy wrote:
>>>> Le 27/02/2024 à 09:46, Uwe Kleine-König a écrit :
>>>>> recently the spi-ppc4xx.c driver suffered from build errors and warnings
>>>>> that were undetected for longer than I expected. I think it would be
>>>>> very beneficial if this driver was enabled in (at least) a powerpc
>>>>> allmodconfig build.
>>>>>
>>>>> The challenge to do so is that spi-ppc4xx.c uses dcri_clrset() which is
>>>>> only defined for 4xx (as these select PPC_DCR_NATIVE).
>>>>>
>>>>> I wonder if dcri_clrset() could be defined for the PPC_DCR_MMIO case,
>>>>> too. I tried and failed. The best I came up without extensive doc
>>>>> reading is:
>>>>>
>>>>> diff --git a/arch/powerpc/include/asm/dcr-native.h b/arch/powerpc/include/asm/dcr-native.h
>>>>> index a92059964579..159ab7abfe46 100644
>>>>> --- a/arch/powerpc/include/asm/dcr-native.h
>>>>> +++ b/arch/powerpc/include/asm/dcr-native.h
>>>>> @@ -115,15 +115,11 @@ static inline void __dcri_clrset(int base_addr, int base_data, int reg,
>>>>>     	unsigned int val;
>>>>>     
>>>>>     	spin_lock_irqsave(&dcr_ind_lock, flags);
>>>>> -	if (cpu_has_feature(CPU_FTR_INDEXED_DCR)) {
>>>>> -		mtdcrx(base_addr, reg);
>>>>> -		val = (mfdcrx(base_data) & ~clr) | set;
>>>>> -		mtdcrx(base_data, val);
>>>>> -	} else {
>>>>> -		__mtdcr(base_addr, reg);
>>>>> -		val = (__mfdcr(base_data) & ~clr) | set;
>>>>> -		__mtdcr(base_data, val);
>>>>> -	}
>>>>> +
>>>>> +	mtdcr(base_addr, reg);
>>>>> +	val = (mfdcr(base_data) & ~clr) | set;
>>>>> +	mtdcr(base_data, val);
>>>>> +
>>>>>     	spin_unlock_irqrestore(&dcr_ind_lock, flags);
>>>>>     }
>>>>>     
>>>>> diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
>>>>> index bc7021da2fe9..9a0a5e8c70c8 100644
>>>>> --- a/drivers/spi/Kconfig
>>>>> +++ b/drivers/spi/Kconfig
>>>>> @@ -810,7 +810,8 @@ config SPI_PL022
>>>>>     
>>>>>     config SPI_PPC4xx
>>>>>     	tristate "PPC4xx SPI Controller"
>>>>> -	depends on PPC32 && 4xx
>>>>> +	depends on 4xx || COMPILE_TEST
>>>>> +	depends on PPC32 || PPC64
>>>>>     	select SPI_BITBANG
>>>>>     	help
>>>>>     	  This selects a driver for the PPC4xx SPI Controller.
>>>>>
>>>>> While this is a step in the right direction (I think) it's not enough to
>>>>> make the driver build (but maybe make it easier to define
>>>>> dcri_clrset()?)
>>>>>
>>>>> Could someone with more powerpc knowledge jump in and help (for the
>>>>> benefit of better compile coverage of the spi driver and so less
>>>>> breakage)? (If you do so based on my changes above, you don't need to
>>>>> credit me for my effort, claim it as your's. I'm happy enough if the
>>>>> situation improves.)
>>>>
>>>> What about this ?
>>>>
>>>> diff --git a/arch/powerpc/include/asm/dcr-mmio.h
>>>> b/arch/powerpc/include/asm/dcr-mmio.h
>>>> index fc6d93ef4a13..38b515afbffc 100644
>>>> --- a/arch/powerpc/include/asm/dcr-mmio.h
>>>> +++ b/arch/powerpc/include/asm/dcr-mmio.h
>>>> @@ -38,6 +38,11 @@ static inline void dcr_write_mmio(dcr_host_mmio_t host,
>>>>     	out_be32(host.token + ((host.base + dcr_n) * host.stride), value);
>>>>     }
>>>>
>>>> +static inline void __dcri_clrset(int base_addr, int base_data, int reg,
>>>> +				 unsigned clr, unsigned set)
>>>> +{
>>>> +}
>>>> +
>>>
>>> The downside of that one is that if we find a matching device where
>>> dcr-mmio is used, the driver claims to work but silently fails. Is this
>>> good enough?
>>
>> I don't know the details of DCR, but it looks like this spi-ppc4xx
>> driver is really specific to 4xx, which is PPC32.
>>
>> Do you really need/want it to be built with allmodconfig ?
>>
>> Maybe it would be easier to have it work with ppc32_allmodconfig ?
>>
>> Or even easier with ppc44x_defconfig ?
> 
> The reason I'd like to see it in allmodconfig is that testing
> allmodconfig on several archs is the check I do for my patch series.

I think for powerpc you should really check ppc32_allmodconfig in 
addition to allmodconfig

> Also I assume I'm not the only one relying on allmodconfig for this
> purpose. So in my eyes every driver that is built there is a net win.

When I look into drivers/net/ethernet/ibm/emac/core.c it is not much 
different, they #ifdef out the call to dcri_clrset() when 
CONFIG_PPC_DCR_NATIVE is not defined.

A possible way is to do:

+static inline void __dcri_clrset(int base_addr, int base_data, int reg,
+				 unsigned clr, unsigned set)
+{
+	BUILD_BUG_ON(!IS_ENABLED(CONFIG_COMPILE_TEST);
+}


Christophe

Re: Increasing build coverage for drivers/spi/spi-ppc4xx.c

[Michael Ellerman]

Christophe Leroy <christophe.leroy@csgroup.eu> writes:
> Le 27/02/2024 à 15:00, Uwe Kleine-König a écrit :
>> On Tue, Feb 27, 2024 at 01:52:07PM +0000, Christophe Leroy wrote:
>>> Le 27/02/2024 à 11:58, Uwe Kleine-König a écrit :
>>>> On Tue, Feb 27, 2024 at 10:25:15AM +0000, Christophe Leroy wrote:
>>>>> Le 27/02/2024 à 09:46, Uwe Kleine-König a écrit :
>>>>>> recently the spi-ppc4xx.c driver suffered from build errors and warnings
>>>>>> that were undetected for longer than I expected. I think it would be
>>>>>> very beneficial if this driver was enabled in (at least) a powerpc
>>>>>> allmodconfig build.
>>>>>>
>>>>>> The challenge to do so is that spi-ppc4xx.c uses dcri_clrset() which is
>>>>>> only defined for 4xx (as these select PPC_DCR_NATIVE).
...
>> 
>> The reason I'd like to see it in allmodconfig is that testing
>> allmodconfig on several archs is the check I do for my patch series.
>
> I think for powerpc you should really check ppc32_allmodconfig in 
> addition to allmodconfig

Yeah.

arch/powerpc is really ~7 separate sub architectures.

Building allmodconfig and ppc32_allmodconfig at least covers the bulk of
the code. But it doesn't include 4xx, or several other platforms.

I think the best/easiest option is just to enable this driver in the 44x
defconfig. At least that way the auto builders should catch any problems.

eg.

diff --git a/arch/powerpc/configs/ppc44x_defconfig b/arch/powerpc/configs/ppc44x_defconfig
index 8b595f67068c..95a1e7efb79f 100644
--- a/arch/powerpc/configs/ppc44x_defconfig
+++ b/arch/powerpc/configs/ppc44x_defconfig
@@ -67,6 +67,8 @@ CONFIG_I2C=m
 CONFIG_I2C_CHARDEV=m
 CONFIG_I2C_GPIO=m
 CONFIG_I2C_IBM_IIC=m
+CONFIG_SPI=y
+CONFIG_SPI_PPC4xx=y
 # CONFIG_HWMON is not set
 CONFIG_FB=m
 CONFIG_USB=m

cheers