[PATCH] powerpc: enable a 30-bit ZONE_DMA for 32-bit pmac

[PATCH] powerpc: enable a 30-bit ZONE_DMA for 32-bit pmac

[Christoph Hellwig]

With the strict dma mask checking introduced with the switch to
the generic DMA direct code common wifi chips on 32-bit powerbooks
stopped working.  Add a 30-bit ZONE_DMA to the 32-bit pmac builds
to allow them to reliably allocate dma coherent memory.

Fixes: 65a21b71f948 ("powerpc/dma: remove dma_nommu_dma_supported")
Reported-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 arch/powerpc/include/asm/page.h         | 7 +++++++
 arch/powerpc/mm/mem.c                   | 3 ++-
 arch/powerpc/platforms/powermac/Kconfig | 1 +
 3 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h
index b8286a2013b4..0d52f57fca04 100644
--- a/arch/powerpc/include/asm/page.h
+++ b/arch/powerpc/include/asm/page.h
@@ -319,6 +319,13 @@ struct vm_area_struct;
 #endif /* __ASSEMBLY__ */
 #include <asm/slice.h>
 
+/*
+ * Allow 30-bit DMA for very limited Broadcom wifi chips on many powerbooks.
+ */
+#ifdef CONFIG_PPC32
+#define ARCH_ZONE_DMA_BITS 30
+#else
 #define ARCH_ZONE_DMA_BITS 31
+#endif
 
 #endif /* _ASM_POWERPC_PAGE_H */
diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index cba29131bccc..2540d3b2588c 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -248,7 +248,8 @@ void __init paging_init(void)
 	       (long int)((top_of_ram - total_ram) >> 20));
 
 #ifdef CONFIG_ZONE_DMA
-	max_zone_pfns[ZONE_DMA]	= min(max_low_pfn, 0x7fffffffUL >> PAGE_SHIFT);
+	max_zone_pfns[ZONE_DMA]	= min(max_low_pfn,
+			((1UL << ARCH_ZONE_DMA_BITS) - 1) >> PAGE_SHIFT);
 #endif
 	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
 #ifdef CONFIG_HIGHMEM
diff --git a/arch/powerpc/platforms/powermac/Kconfig b/arch/powerpc/platforms/powermac/Kconfig
index f834a19ed772..c02d8c503b29 100644
--- a/arch/powerpc/platforms/powermac/Kconfig
+++ b/arch/powerpc/platforms/powermac/Kconfig
@@ -7,6 +7,7 @@ config PPC_PMAC
 	select PPC_INDIRECT_PCI if PPC32
 	select PPC_MPC106 if PPC32
 	select PPC_NATIVE
+	select ZONE_DMA if PPC32
 	default y
 
 config PPC_PMAC64
-- 
2.20.1

Re: [PATCH] powerpc: enable a 30-bit ZONE_DMA for 32-bit pmac

[Larry Finger]

On 6/13/19 3:24 AM, Christoph Hellwig wrote:
> With the strict dma mask checking introduced with the switch to
> the generic DMA direct code common wifi chips on 32-bit powerbooks
> stopped working.  Add a 30-bit ZONE_DMA to the 32-bit pmac builds
> to allow them to reliably allocate dma coherent memory.
> 
> Fixes: 65a21b71f948 ("powerpc/dma: remove dma_nommu_dma_supported")
> Reported-by: Aaro Koskinen <aaro.koskinen@iki.fi>
> Signed-off-by: Christoph Hellwig <hch@lst.de>

As expected, it works. The patch needs
Cc: Stable <stable*vger.kernel.org> # v5.1+

Tested-by: Larry Finger <Larry.Finger@lwfinger.net>
Acked-by: Larry Finger <Larry.Finger@lwfinger.net>

Thanks for the help, and the patience with my debugging problems with u64 variables.

Larry

Re: [PATCH] powerpc: enable a 30-bit ZONE_DMA for 32-bit pmac

[Mathieu Malaterre]

On Thu, Jun 13, 2019 at 10:27 AM Christoph Hellwig <hch@lst.de> wrote:
>
> With the strict dma mask checking introduced with the switch to
> the generic DMA direct code common wifi chips on 32-bit powerbooks
> stopped working.  Add a 30-bit ZONE_DMA to the 32-bit pmac builds
> to allow them to reliably allocate dma coherent memory.
>
> Fixes: 65a21b71f948 ("powerpc/dma: remove dma_nommu_dma_supported")
> Reported-by: Aaro Koskinen <aaro.koskinen@iki.fi>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  arch/powerpc/include/asm/page.h         | 7 +++++++
>  arch/powerpc/mm/mem.c                   | 3 ++-
>  arch/powerpc/platforms/powermac/Kconfig | 1 +
>  3 files changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h
> index b8286a2013b4..0d52f57fca04 100644
> --- a/arch/powerpc/include/asm/page.h
> +++ b/arch/powerpc/include/asm/page.h
> @@ -319,6 +319,13 @@ struct vm_area_struct;
>  #endif /* __ASSEMBLY__ */
>  #include <asm/slice.h>
>
> +/*
> + * Allow 30-bit DMA for very limited Broadcom wifi chips on many powerbooks.

nit: would it be possible to mention explicit reference to b43-legacy.
Using b43 on my macmini g4 never showed those symptoms (using
5.2.0-rc2+)

$ dmesg | grep b43
[   14.327189] bus: 'pci': add driver b43-pci-bridge
[   14.345354] bus: 'pci': driver_probe_device: matched device
0001:10:12.0 with driver b43-pci-bridge
[   14.380110] bus: 'pci': really_probe: probing driver b43-pci-bridge
with device 0001:10:12.0
[   14.440295] b43-pci-bridge 0001:10:12.0: enabling device (0004 -> 0006)
[   14.637223] b43-pci-bridge 0001:10:12.0: Sonics Silicon Backplane
found on PCI device 0001:10:12.0
[   14.644858] driver: 'b43-pci-bridge': driver_bound: bound to device
'0001:10:12.0'
[   14.743341] bus: 'pci': really_probe: bound device 0001:10:12.0 to
driver b43-pci-bridge
[   18.724343] bus: 'bcma': add driver b43
[   18.728635] bus: 'ssb': add driver b43
[   18.734305] bus: 'ssb': driver_probe_device: matched device ssb0:0
with driver b43
[   18.743155] bus: 'ssb': really_probe: probing driver b43 with device ssb0:0
[   18.747782] b43-phy0: Broadcom 4306 WLAN found (core revision 5)
[   18.767439] b43-phy0: Found PHY: Analog 2, Type 2 (G), Revision 2
[   18.771759] b43-phy0: Found Radio: Manuf 0x17F, ID 0x2050, Revision
2, Version 0
[   18.795467] driver: 'b43': driver_bound: bound to device 'ssb0:0'
[   18.801533] bus: 'ssb': really_probe: bound device ssb0:0 to driver b43
[   22.143084] b43-phy0: Loading firmware version 666.2 (2011-02-23 01:15:07)
[   25.133011] b43 ssb0:0 wlan0: disabling HT as WMM/QoS is not
supported by the AP
[   25.140221] b43 ssb0:0 wlan0: disabling VHT as WMM/QoS is not
supported by the AP


> + */
> +#ifdef CONFIG_PPC32
> +#define ARCH_ZONE_DMA_BITS 30
> +#else
>  #define ARCH_ZONE_DMA_BITS 31
> +#endif
>
>  #endif /* _ASM_POWERPC_PAGE_H */
> diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
> index cba29131bccc..2540d3b2588c 100644
> --- a/arch/powerpc/mm/mem.c
> +++ b/arch/powerpc/mm/mem.c
> @@ -248,7 +248,8 @@ void __init paging_init(void)
>                (long int)((top_of_ram - total_ram) >> 20));
>
>  #ifdef CONFIG_ZONE_DMA
> -       max_zone_pfns[ZONE_DMA] = min(max_low_pfn, 0x7fffffffUL >> PAGE_SHIFT);
> +       max_zone_pfns[ZONE_DMA] = min(max_low_pfn,
> +                       ((1UL << ARCH_ZONE_DMA_BITS) - 1) >> PAGE_SHIFT);
>  #endif
>         max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
>  #ifdef CONFIG_HIGHMEM
> diff --git a/arch/powerpc/platforms/powermac/Kconfig b/arch/powerpc/platforms/powermac/Kconfig
> index f834a19ed772..c02d8c503b29 100644
> --- a/arch/powerpc/platforms/powermac/Kconfig
> +++ b/arch/powerpc/platforms/powermac/Kconfig
> @@ -7,6 +7,7 @@ config PPC_PMAC
>         select PPC_INDIRECT_PCI if PPC32
>         select PPC_MPC106 if PPC32
>         select PPC_NATIVE
> +       select ZONE_DMA if PPC32
>         default y
>
>  config PPC_PMAC64
> --
> 2.20.1
>

Re: [PATCH] powerpc: enable a 30-bit ZONE_DMA for 32-bit pmac

[Aaro Koskinen]

Hi,

On Thu, Jun 13, 2019 at 10:24:46AM +0200, Christoph Hellwig wrote:
> With the strict dma mask checking introduced with the switch to
> the generic DMA direct code common wifi chips on 32-bit powerbooks
> stopped working.  Add a 30-bit ZONE_DMA to the 32-bit pmac builds
> to allow them to reliably allocate dma coherent memory.
> 
> Fixes: 65a21b71f948 ("powerpc/dma: remove dma_nommu_dma_supported")
> Reported-by: Aaro Koskinen <aaro.koskinen@iki.fi>
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Tested-by: Aaro Koskinen <aaro.koskinen@iki.fi>

A.

> ---
>  arch/powerpc/include/asm/page.h         | 7 +++++++
>  arch/powerpc/mm/mem.c                   | 3 ++-
>  arch/powerpc/platforms/powermac/Kconfig | 1 +
>  3 files changed, 10 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h
> index b8286a2013b4..0d52f57fca04 100644
> --- a/arch/powerpc/include/asm/page.h
> +++ b/arch/powerpc/include/asm/page.h
> @@ -319,6 +319,13 @@ struct vm_area_struct;
>  #endif /* __ASSEMBLY__ */
>  #include <asm/slice.h>
>  
> +/*
> + * Allow 30-bit DMA for very limited Broadcom wifi chips on many powerbooks.
> + */
> +#ifdef CONFIG_PPC32
> +#define ARCH_ZONE_DMA_BITS 30
> +#else
>  #define ARCH_ZONE_DMA_BITS 31
> +#endif
>  
>  #endif /* _ASM_POWERPC_PAGE_H */
> diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
> index cba29131bccc..2540d3b2588c 100644
> --- a/arch/powerpc/mm/mem.c
> +++ b/arch/powerpc/mm/mem.c
> @@ -248,7 +248,8 @@ void __init paging_init(void)
>  	       (long int)((top_of_ram - total_ram) >> 20));
>  
>  #ifdef CONFIG_ZONE_DMA
> -	max_zone_pfns[ZONE_DMA]	= min(max_low_pfn, 0x7fffffffUL >> PAGE_SHIFT);
> +	max_zone_pfns[ZONE_DMA]	= min(max_low_pfn,
> +			((1UL << ARCH_ZONE_DMA_BITS) - 1) >> PAGE_SHIFT);
>  #endif
>  	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
>  #ifdef CONFIG_HIGHMEM
> diff --git a/arch/powerpc/platforms/powermac/Kconfig b/arch/powerpc/platforms/powermac/Kconfig
> index f834a19ed772..c02d8c503b29 100644
> --- a/arch/powerpc/platforms/powermac/Kconfig
> +++ b/arch/powerpc/platforms/powermac/Kconfig
> @@ -7,6 +7,7 @@ config PPC_PMAC
>  	select PPC_INDIRECT_PCI if PPC32
>  	select PPC_MPC106 if PPC32
>  	select PPC_NATIVE
> +	select ZONE_DMA if PPC32
>  	default y
>  
>  config PPC_PMAC64
> -- 
> 2.20.1
> 

Re: [PATCH] powerpc: enable a 30-bit ZONE_DMA for 32-bit pmac

[Aaro Koskinen]

Hi,

On Fri, Jun 14, 2019 at 09:24:16AM +0200, Mathieu Malaterre wrote:
> On Thu, Jun 13, 2019 at 10:27 AM Christoph Hellwig <hch@lst.de> wrote:
> > With the strict dma mask checking introduced with the switch to
> > the generic DMA direct code common wifi chips on 32-bit powerbooks
> > stopped working.  Add a 30-bit ZONE_DMA to the 32-bit pmac builds
> > to allow them to reliably allocate dma coherent memory.
> >
> > Fixes: 65a21b71f948 ("powerpc/dma: remove dma_nommu_dma_supported")
> > Reported-by: Aaro Koskinen <aaro.koskinen@iki.fi>
> > Signed-off-by: Christoph Hellwig <hch@lst.de>
> > ---
> >  arch/powerpc/include/asm/page.h         | 7 +++++++
> >  arch/powerpc/mm/mem.c                   | 3 ++-
> >  arch/powerpc/platforms/powermac/Kconfig | 1 +
> >  3 files changed, 10 insertions(+), 1 deletion(-)
> >
> > diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h
> > index b8286a2013b4..0d52f57fca04 100644
> > --- a/arch/powerpc/include/asm/page.h
> > +++ b/arch/powerpc/include/asm/page.h
> > @@ -319,6 +319,13 @@ struct vm_area_struct;
> >  #endif /* __ASSEMBLY__ */
> >  #include <asm/slice.h>
> >
> > +/*
> > + * Allow 30-bit DMA for very limited Broadcom wifi chips on many powerbooks.
> 
> nit: would it be possible to mention explicit reference to b43-legacy.
> Using b43 on my macmini g4 never showed those symptoms (using
> 5.2.0-rc2+)

According to Wikipedia Mac mini G4 is limited to 1 GB RAM, so that's
why you don't see the issue.

A.

Re: [PATCH] powerpc: enable a 30-bit ZONE_DMA for 32-bit pmac

[Larry Finger]

On 6/14/19 2:15 PM, Aaro Koskinen wrote:
> Hi,
> 
> On Fri, Jun 14, 2019 at 09:24:16AM +0200, Mathieu Malaterre wrote:
>> On Thu, Jun 13, 2019 at 10:27 AM Christoph Hellwig <hch@lst.de> wrote:
>>> With the strict dma mask checking introduced with the switch to
>>> the generic DMA direct code common wifi chips on 32-bit powerbooks
>>> stopped working.  Add a 30-bit ZONE_DMA to the 32-bit pmac builds
>>> to allow them to reliably allocate dma coherent memory.
>>>
>>> Fixes: 65a21b71f948 ("powerpc/dma: remove dma_nommu_dma_supported")
>>> Reported-by: Aaro Koskinen <aaro.koskinen@iki.fi>
>>> Signed-off-by: Christoph Hellwig <hch@lst.de>
>>> ---
>>>   arch/powerpc/include/asm/page.h         | 7 +++++++
>>>   arch/powerpc/mm/mem.c                   | 3 ++-
>>>   arch/powerpc/platforms/powermac/Kconfig | 1 +
>>>   3 files changed, 10 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h
>>> index b8286a2013b4..0d52f57fca04 100644
>>> --- a/arch/powerpc/include/asm/page.h
>>> +++ b/arch/powerpc/include/asm/page.h
>>> @@ -319,6 +319,13 @@ struct vm_area_struct;
>>>   #endif /* __ASSEMBLY__ */
>>>   #include <asm/slice.h>
>>>
>>> +/*
>>> + * Allow 30-bit DMA for very limited Broadcom wifi chips on many powerbooks.
>>
>> nit: would it be possible to mention explicit reference to b43-legacy.
>> Using b43 on my macmini g4 never showed those symptoms (using
>> 5.2.0-rc2+)
> 
> According to Wikipedia Mac mini G4 is limited to 1 GB RAM, so that's
> why you don't see the issue.

He wouldn't see it with b43. Those cards have 32-bit DMA.

Larry

Re: [PATCH] powerpc: enable a 30-bit ZONE_DMA for 32-bit pmac

[Christoph Hellwig]

Any chance this could get picked up to fix the regression?

On Thu, Jun 13, 2019 at 10:24:46AM +0200, Christoph Hellwig wrote:
> With the strict dma mask checking introduced with the switch to
> the generic DMA direct code common wifi chips on 32-bit powerbooks
> stopped working.  Add a 30-bit ZONE_DMA to the 32-bit pmac builds
> to allow them to reliably allocate dma coherent memory.
> 
> Fixes: 65a21b71f948 ("powerpc/dma: remove dma_nommu_dma_supported")
> Reported-by: Aaro Koskinen <aaro.koskinen@iki.fi>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  arch/powerpc/include/asm/page.h         | 7 +++++++
>  arch/powerpc/mm/mem.c                   | 3 ++-
>  arch/powerpc/platforms/powermac/Kconfig | 1 +
>  3 files changed, 10 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h
> index b8286a2013b4..0d52f57fca04 100644
> --- a/arch/powerpc/include/asm/page.h
> +++ b/arch/powerpc/include/asm/page.h
> @@ -319,6 +319,13 @@ struct vm_area_struct;
>  #endif /* __ASSEMBLY__ */
>  #include <asm/slice.h>
>  
> +/*
> + * Allow 30-bit DMA for very limited Broadcom wifi chips on many powerbooks.
> + */
> +#ifdef CONFIG_PPC32
> +#define ARCH_ZONE_DMA_BITS 30
> +#else
>  #define ARCH_ZONE_DMA_BITS 31
> +#endif
>  
>  #endif /* _ASM_POWERPC_PAGE_H */
> diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
> index cba29131bccc..2540d3b2588c 100644
> --- a/arch/powerpc/mm/mem.c
> +++ b/arch/powerpc/mm/mem.c
> @@ -248,7 +248,8 @@ void __init paging_init(void)
>  	       (long int)((top_of_ram - total_ram) >> 20));
>  
>  #ifdef CONFIG_ZONE_DMA
> -	max_zone_pfns[ZONE_DMA]	= min(max_low_pfn, 0x7fffffffUL >> PAGE_SHIFT);
> +	max_zone_pfns[ZONE_DMA]	= min(max_low_pfn,
> +			((1UL << ARCH_ZONE_DMA_BITS) - 1) >> PAGE_SHIFT);
>  #endif
>  	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
>  #ifdef CONFIG_HIGHMEM
> diff --git a/arch/powerpc/platforms/powermac/Kconfig b/arch/powerpc/platforms/powermac/Kconfig
> index f834a19ed772..c02d8c503b29 100644
> --- a/arch/powerpc/platforms/powermac/Kconfig
> +++ b/arch/powerpc/platforms/powermac/Kconfig
> @@ -7,6 +7,7 @@ config PPC_PMAC
>  	select PPC_INDIRECT_PCI if PPC32
>  	select PPC_MPC106 if PPC32
>  	select PPC_NATIVE
> +	select ZONE_DMA if PPC32
>  	default y
>  
>  config PPC_PMAC64
> -- 
> 2.20.1
---end quoted text---

Re: [PATCH] powerpc: enable a 30-bit ZONE_DMA for 32-bit pmac

[Michael Ellerman]

Christoph Hellwig <hch@lst.de> writes:
> Any chance this could get picked up to fix the regression?

Was hoping Ben would Ack it. He's still powermac maintainer :)

I guess he OK'ed it in the other thread, will add it to my queue.

cheers

> On Thu, Jun 13, 2019 at 10:24:46AM +0200, Christoph Hellwig wrote:
>> With the strict dma mask checking introduced with the switch to
>> the generic DMA direct code common wifi chips on 32-bit powerbooks
>> stopped working.  Add a 30-bit ZONE_DMA to the 32-bit pmac builds
>> to allow them to reliably allocate dma coherent memory.
>> 
>> Fixes: 65a21b71f948 ("powerpc/dma: remove dma_nommu_dma_supported")
>> Reported-by: Aaro Koskinen <aaro.koskinen@iki.fi>
>> Signed-off-by: Christoph Hellwig <hch@lst.de>
>> ---
>>  arch/powerpc/include/asm/page.h         | 7 +++++++
>>  arch/powerpc/mm/mem.c                   | 3 ++-
>>  arch/powerpc/platforms/powermac/Kconfig | 1 +
>>  3 files changed, 10 insertions(+), 1 deletion(-)
>> 
>> diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h
>> index b8286a2013b4..0d52f57fca04 100644
>> --- a/arch/powerpc/include/asm/page.h
>> +++ b/arch/powerpc/include/asm/page.h
>> @@ -319,6 +319,13 @@ struct vm_area_struct;
>>  #endif /* __ASSEMBLY__ */
>>  #include <asm/slice.h>
>>  
>> +/*
>> + * Allow 30-bit DMA for very limited Broadcom wifi chips on many powerbooks.
>> + */
>> +#ifdef CONFIG_PPC32
>> +#define ARCH_ZONE_DMA_BITS 30
>> +#else
>>  #define ARCH_ZONE_DMA_BITS 31
>> +#endif
>>  
>>  #endif /* _ASM_POWERPC_PAGE_H */
>> diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
>> index cba29131bccc..2540d3b2588c 100644
>> --- a/arch/powerpc/mm/mem.c
>> +++ b/arch/powerpc/mm/mem.c
>> @@ -248,7 +248,8 @@ void __init paging_init(void)
>>  	       (long int)((top_of_ram - total_ram) >> 20));
>>  
>>  #ifdef CONFIG_ZONE_DMA
>> -	max_zone_pfns[ZONE_DMA]	= min(max_low_pfn, 0x7fffffffUL >> PAGE_SHIFT);
>> +	max_zone_pfns[ZONE_DMA]	= min(max_low_pfn,
>> +			((1UL << ARCH_ZONE_DMA_BITS) - 1) >> PAGE_SHIFT);
>>  #endif
>>  	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
>>  #ifdef CONFIG_HIGHMEM
>> diff --git a/arch/powerpc/platforms/powermac/Kconfig b/arch/powerpc/platforms/powermac/Kconfig
>> index f834a19ed772..c02d8c503b29 100644
>> --- a/arch/powerpc/platforms/powermac/Kconfig
>> +++ b/arch/powerpc/platforms/powermac/Kconfig
>> @@ -7,6 +7,7 @@ config PPC_PMAC
>>  	select PPC_INDIRECT_PCI if PPC32
>>  	select PPC_MPC106 if PPC32
>>  	select PPC_NATIVE
>> +	select ZONE_DMA if PPC32
>>  	default y
>>  
>>  config PPC_PMAC64
>> -- 
>> 2.20.1
> ---end quoted text---

Re: [PATCH] powerpc: enable a 30-bit ZONE_DMA for 32-bit pmac

[Benjamin Herrenschmidt]

On Wed, 2019-06-19 at 22:32 +1000, Michael Ellerman wrote:
> Christoph Hellwig <hch@lst.de> writes:
> > Any chance this could get picked up to fix the regression?
> 
> Was hoping Ben would Ack it. He's still powermac maintainer :)
> 
> I guess he OK'ed it in the other thread, will add it to my queue.

Yeah ack. If I had written it myself, I would have made the DMA bits a
variable and only set it down to 30 if I see that device in the DT
early on, but I can't be bothered now, if it works, ship it :-)

Note: The patch affects all ppc32, though I don't think it will cause
any significant issue on those who don't need it.

Cheers,
Ben.

> cheers
> 
> > On Thu, Jun 13, 2019 at 10:24:46AM +0200, Christoph Hellwig wrote:
> > > With the strict dma mask checking introduced with the switch to
> > > the generic DMA direct code common wifi chips on 32-bit
> > > powerbooks
> > > stopped working.  Add a 30-bit ZONE_DMA to the 32-bit pmac builds
> > > to allow them to reliably allocate dma coherent memory.
> > > 
> > > Fixes: 65a21b71f948 ("powerpc/dma: remove
> > > dma_nommu_dma_supported")
> > > Reported-by: Aaro Koskinen <aaro.koskinen@iki.fi>
> > > Signed-off-by: Christoph Hellwig <hch@lst.de>
> > > ---
> > >  arch/powerpc/include/asm/page.h         | 7 +++++++
> > >  arch/powerpc/mm/mem.c                   | 3 ++-
> > >  arch/powerpc/platforms/powermac/Kconfig | 1 +
> > >  3 files changed, 10 insertions(+), 1 deletion(-)
> > > 
> > > diff --git a/arch/powerpc/include/asm/page.h
> > > b/arch/powerpc/include/asm/page.h
> > > index b8286a2013b4..0d52f57fca04 100644
> > > --- a/arch/powerpc/include/asm/page.h
> > > +++ b/arch/powerpc/include/asm/page.h
> > > @@ -319,6 +319,13 @@ struct vm_area_struct;
> > >  #endif /* __ASSEMBLY__ */
> > >  #include <asm/slice.h>
> > >  
> > > +/*
> > > + * Allow 30-bit DMA for very limited Broadcom wifi chips on many
> > > powerbooks.
> > > + */
> > > +#ifdef CONFIG_PPC32
> > > +#define ARCH_ZONE_DMA_BITS 30
> > > +#else
> > >  #define ARCH_ZONE_DMA_BITS 31
> > > +#endif
> > >  
> > >  #endif /* _ASM_POWERPC_PAGE_H */
> > > diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
> > > index cba29131bccc..2540d3b2588c 100644
> > > --- a/arch/powerpc/mm/mem.c
> > > +++ b/arch/powerpc/mm/mem.c
> > > @@ -248,7 +248,8 @@ void __init paging_init(void)
> > >  	       (long int)((top_of_ram - total_ram) >> 20));
> > >  
> > >  #ifdef CONFIG_ZONE_DMA
> > > -	max_zone_pfns[ZONE_DMA]	= min(max_low_pfn, 0x7fffffffUL
> > > >> PAGE_SHIFT);
> > > +	max_zone_pfns[ZONE_DMA]	= min(max_low_pfn,
> > > +			((1UL << ARCH_ZONE_DMA_BITS) - 1) >>
> > > PAGE_SHIFT);
> > >  #endif
> > >  	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
> > >  #ifdef CONFIG_HIGHMEM
> > > diff --git a/arch/powerpc/platforms/powermac/Kconfig
> > > b/arch/powerpc/platforms/powermac/Kconfig
> > > index f834a19ed772..c02d8c503b29 100644
> > > --- a/arch/powerpc/platforms/powermac/Kconfig
> > > +++ b/arch/powerpc/platforms/powermac/Kconfig
> > > @@ -7,6 +7,7 @@ config PPC_PMAC
> > >  	select PPC_INDIRECT_PCI if PPC32
> > >  	select PPC_MPC106 if PPC32
> > >  	select PPC_NATIVE
> > > +	select ZONE_DMA if PPC32
> > >  	default y
> > >  
> > >  config PPC_PMAC64
> > > -- 
> > > 2.20.1
> > 
> > ---end quoted text---

Re: [PATCH] powerpc: enable a 30-bit ZONE_DMA for 32-bit pmac

[Mathieu Malaterre]

On Wed, Jun 19, 2019 at 4:18 PM Benjamin Herrenschmidt
<benh@kernel.crashing.org> wrote:
>
> On Wed, 2019-06-19 at 22:32 +1000, Michael Ellerman wrote:
> > Christoph Hellwig <hch@lst.de> writes:
> > > Any chance this could get picked up to fix the regression?
> >
> > Was hoping Ben would Ack it. He's still powermac maintainer :)
> >
> > I guess he OK'ed it in the other thread, will add it to my queue.
>
> Yeah ack. If I had written it myself, I would have made the DMA bits a
> variable and only set it down to 30 if I see that device in the DT
> early on, but I can't be bothered now, if it works, ship it :-)
>
> Note: The patch affects all ppc32, though I don't think it will cause
> any significant issue on those who don't need it.

Thanks, that answer my earlier question.

> Cheers,
> Ben.
>
> > cheers
> >
> > > On Thu, Jun 13, 2019 at 10:24:46AM +0200, Christoph Hellwig wrote:
> > > > With the strict dma mask checking introduced with the switch to
> > > > the generic DMA direct code common wifi chips on 32-bit
> > > > powerbooks
> > > > stopped working.  Add a 30-bit ZONE_DMA to the 32-bit pmac builds
> > > > to allow them to reliably allocate dma coherent memory.
> > > >
> > > > Fixes: 65a21b71f948 ("powerpc/dma: remove
> > > > dma_nommu_dma_supported")
> > > > Reported-by: Aaro Koskinen <aaro.koskinen@iki.fi>
> > > > Signed-off-by: Christoph Hellwig <hch@lst.de>
> > > > ---
> > > >  arch/powerpc/include/asm/page.h         | 7 +++++++
> > > >  arch/powerpc/mm/mem.c                   | 3 ++-
> > > >  arch/powerpc/platforms/powermac/Kconfig | 1 +
> > > >  3 files changed, 10 insertions(+), 1 deletion(-)
> > > >
> > > > diff --git a/arch/powerpc/include/asm/page.h
> > > > b/arch/powerpc/include/asm/page.h
> > > > index b8286a2013b4..0d52f57fca04 100644
> > > > --- a/arch/powerpc/include/asm/page.h
> > > > +++ b/arch/powerpc/include/asm/page.h
> > > > @@ -319,6 +319,13 @@ struct vm_area_struct;
> > > >  #endif /* __ASSEMBLY__ */
> > > >  #include <asm/slice.h>
> > > >
> > > > +/*
> > > > + * Allow 30-bit DMA for very limited Broadcom wifi chips on many
> > > > powerbooks.
> > > > + */
> > > > +#ifdef CONFIG_PPC32
> > > > +#define ARCH_ZONE_DMA_BITS 30
> > > > +#else
> > > >  #define ARCH_ZONE_DMA_BITS 31
> > > > +#endif
> > > >
> > > >  #endif /* _ASM_POWERPC_PAGE_H */
> > > > diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
> > > > index cba29131bccc..2540d3b2588c 100644
> > > > --- a/arch/powerpc/mm/mem.c
> > > > +++ b/arch/powerpc/mm/mem.c
> > > > @@ -248,7 +248,8 @@ void __init paging_init(void)
> > > >          (long int)((top_of_ram - total_ram) >> 20));
> > > >
> > > >  #ifdef CONFIG_ZONE_DMA
> > > > - max_zone_pfns[ZONE_DMA] = min(max_low_pfn, 0x7fffffffUL
> > > > >> PAGE_SHIFT);
> > > > + max_zone_pfns[ZONE_DMA] = min(max_low_pfn,
> > > > +                 ((1UL << ARCH_ZONE_DMA_BITS) - 1) >>
> > > > PAGE_SHIFT);
> > > >  #endif
> > > >   max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
> > > >  #ifdef CONFIG_HIGHMEM
> > > > diff --git a/arch/powerpc/platforms/powermac/Kconfig
> > > > b/arch/powerpc/platforms/powermac/Kconfig
> > > > index f834a19ed772..c02d8c503b29 100644
> > > > --- a/arch/powerpc/platforms/powermac/Kconfig
> > > > +++ b/arch/powerpc/platforms/powermac/Kconfig
> > > > @@ -7,6 +7,7 @@ config PPC_PMAC
> > > >   select PPC_INDIRECT_PCI if PPC32
> > > >   select PPC_MPC106 if PPC32
> > > >   select PPC_NATIVE
> > > > + select ZONE_DMA if PPC32
> > > >   default y
> > > >
> > > >  config PPC_PMAC64
> > > > --
> > > > 2.20.1
> > >
> > > ---end quoted text---
>

Re: [PATCH] powerpc: enable a 30-bit ZONE_DMA for 32-bit pmac

[Michael Ellerman]

Benjamin Herrenschmidt <benh@kernel.crashing.org> writes:
> On Wed, 2019-06-19 at 22:32 +1000, Michael Ellerman wrote:
>> Christoph Hellwig <hch@lst.de> writes:
>> > Any chance this could get picked up to fix the regression?
>> 
>> Was hoping Ben would Ack it. He's still powermac maintainer :)
>> 
>> I guess he OK'ed it in the other thread, will add it to my queue.
>
> Yeah ack. If I had written it myself, I would have made the DMA bits a
> variable and only set it down to 30 if I see that device in the DT
> early on, but I can't be bothered now, if it works, ship it :-)

OK, we can do that next release if someone's motivated.

> Note: The patch affects all ppc32, though I don't think it will cause
> any significant issue on those who don't need it.

Yeah. We could always hide it behind CONFIG_PPC_PMAC if it becomes a problem.

cheers

Re: [PATCH] powerpc: enable a 30-bit ZONE_DMA for 32-bit pmac

[Michael Ellerman]

On Thu, 2019-06-13 at 08:24:46 UTC, Christoph Hellwig wrote:
> With the strict dma mask checking introduced with the switch to
> the generic DMA direct code common wifi chips on 32-bit powerbooks
> stopped working.  Add a 30-bit ZONE_DMA to the 32-bit pmac builds
> to allow them to reliably allocate dma coherent memory.
> 
> Fixes: 65a21b71f948 ("powerpc/dma: remove dma_nommu_dma_supported")
> Reported-by: Aaro Koskinen <aaro.koskinen@iki.fi>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> Tested-by: Larry Finger <Larry.Finger@lwfinger.net>
> Acked-by: Larry Finger <Larry.Finger@lwfinger.net>
> Tested-by: Aaro Koskinen <aaro.koskinen@iki.fi>

Applied to powerpc fixes, thanks.

https://git.kernel.org/powerpc/c/9739ab7eda459f0669ec9807e0d9be5020bab88c

cheers