From: Christoph Hellwig <hch@lst.de>
To: benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au
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 12:50:39 +0200 [thread overview]
Message-ID: <20190619105039.GA10118@lst.de> (raw)
In-Reply-To: <20190613082446.18685-1-hch@lst.de>
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---
next prev parent reply other threads:[~2019-06-19 10:53 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-13 8:24 [PATCH] powerpc: enable a 30-bit ZONE_DMA for 32-bit pmac 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 [this message]
2019-06-19 12:32 ` Michael Ellerman
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
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