LinuxPPC-Dev Archive on lore.kernel.org
 help / color / Atom feed
From: Michael Ellerman <mpe@ellerman.id.au>
To: Christoph Hellwig <hch@lst.de>,
	benh@kernel.crashing.org, paulus@samba.org
Cc: aaro.koskinen@iki.fi, linuxppc-dev@lists.ozlabs.org,
	linux-kernel@vger.kernel.org, Larry.Finger@lwfinger.net
Subject: Re: [PATCH] powerpc: enable a 30-bit ZONE_DMA for 32-bit pmac
Date: Wed, 19 Jun 2019 22:32:24 +1000
Message-ID: <87tvcldacn.fsf@concordia.ellerman.id.au> (raw)
In-Reply-To: <20190619105039.GA10118@lst.de>

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---

  reply index

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-06-13  8:24 Christoph Hellwig
2019-06-13 18:51 ` Larry Finger
2019-06-14  7:24 ` Mathieu Malaterre
2019-06-14 19:15   ` Aaro Koskinen
2019-06-14 20:26     ` Larry Finger
2019-06-14 19:02 ` Aaro Koskinen
2019-06-19 10:50 ` Christoph Hellwig
2019-06-19 12:32   ` Michael Ellerman [this message]
2019-06-19 13:31     ` Benjamin Herrenschmidt
2019-06-19 14:28       ` Mathieu Malaterre
2019-06-20 13:49       ` Michael Ellerman
2019-06-23 10:34 ` Michael Ellerman

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=87tvcldacn.fsf@concordia.ellerman.id.au \
    --to=mpe@ellerman.id.au \
    --cc=Larry.Finger@lwfinger.net \
    --cc=aaro.koskinen@iki.fi \
    --cc=benh@kernel.crashing.org \
    --cc=hch@lst.de \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linuxppc-dev@lists.ozlabs.org \
    --cc=paulus@samba.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

LinuxPPC-Dev Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linuxppc-dev/0 linuxppc-dev/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linuxppc-dev linuxppc-dev/ https://lore.kernel.org/linuxppc-dev \
		linuxppc-dev@lists.ozlabs.org linuxppc-dev@ozlabs.org linuxppc-dev@archiver.kernel.org
	public-inbox-index linuxppc-dev


Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.ozlabs.lists.linuxppc-dev


AGPL code for this site: git clone https://public-inbox.org/ public-inbox