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From: Robin Murphy <robin.murphy@arm.com>
To: Christoph Hellwig <hch@lst.de>,
	Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: iommu@lists.linux-foundation.org
Subject: Re: [PATCH 2/2] dma-direct: improve DMA mask overflow reporting
Date: Tue, 4 Feb 2020 15:14:06 +0000	[thread overview]
Message-ID: <b4ff1d6c-6dcb-3f7b-3935-451bdbffdcc3@arm.com> (raw)
In-Reply-To: <20200204063205.652456-3-hch@lst.de>

On 04/02/2020 6:32 am, Christoph Hellwig wrote:
> Remove the unset dma_mask case as that won't get into mapping calls
> anymore, and also report the other errors unconditonally and with a
> slightly improved message.  Remove the now pointless report_addr helper.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>   kernel/dma/direct.c | 22 ++++++++--------------
>   1 file changed, 8 insertions(+), 14 deletions(-)
> 
> diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c
> index 82ad50aaf42c..04f308a47fc3 100644
> --- a/kernel/dma/direct.c
> +++ b/kernel/dma/direct.c
> @@ -23,18 +23,6 @@
>    */
>   unsigned int zone_dma_bits __ro_after_init = 24;
>   
> -static void report_addr(struct device *dev, dma_addr_t dma_addr, size_t size)
> -{
> -	if (!dev->dma_mask) {
> -		dev_err_once(dev, "DMA map on device without dma_mask\n");
> -	} else if (*dev->dma_mask >= DMA_BIT_MASK(32) || dev->bus_dma_limit) {
> -		dev_err_once(dev,
> -			"overflow %pad+%zu of DMA mask %llx bus limit %llx\n",
> -			&dma_addr, size, *dev->dma_mask, dev->bus_dma_limit);
> -	}
> -	WARN_ON_ONCE(1);
> -}
> -
>   static inline dma_addr_t phys_to_dma_direct(struct device *dev,
>   		phys_addr_t phys)
>   {
> @@ -371,7 +359,10 @@ dma_addr_t dma_direct_map_page(struct device *dev, struct page *page,
>   		if (swiotlb_force != SWIOTLB_NO_FORCE)
>   			return swiotlb_map(dev, phys, size, dir, attrs);
>   
> -		report_addr(dev, dma_addr, size);
> +		dev_err_once(dev,
> +			     "DMA addr %pad+%zu overflow (mask %llx, bus limit %llx).\n",
> +			     &dma_addr, size, *dev->dma_mask, dev->bus_dma_limit);
> +		WARN_ON_ONCE(1);

Or even dev_WARN_ONCE() to make them even simpler?

Robin.

>   		return DMA_MAPPING_ERROR;
>   	}
>   
> @@ -409,7 +400,10 @@ dma_addr_t dma_direct_map_resource(struct device *dev, phys_addr_t paddr,
>   	dma_addr_t dma_addr = paddr;
>   
>   	if (unlikely(!dma_capable(dev, dma_addr, size, false))) {
> -		report_addr(dev, dma_addr, size);
> +		dev_err_once(dev,
> +			     "DMA addr %pad+%zu overflow (mask %llx, bus limit %llx).\n",
> +			     &dma_addr, size, *dev->dma_mask, dev->bus_dma_limit);
> +		WARN_ON_ONCE(1);
>   		return DMA_MAPPING_ERROR;
>   	}
>   
> 
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  parent reply	other threads:[~2020-02-04 15:14 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-04  6:32 improve dma-direct / swiotlb error reporting Christoph Hellwig
2020-02-04  6:32 ` [PATCH 1/2] dma-direct: improve " Christoph Hellwig
2020-02-04 14:54   ` Konrad Rzeszutek Wilk
2020-02-04  6:32 ` [PATCH 2/2] dma-direct: improve DMA mask overflow reporting Christoph Hellwig
2020-02-04 14:55   ` Konrad Rzeszutek Wilk
2020-02-04 15:14   ` Robin Murphy [this message]
2020-02-04 15:58     ` Christoph Hellwig

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