Re: remove the ->mapping_error method from dma_map_ops V2

From: Russell King - ARM Linux
Date: Thu Nov 22 2018 - 12:15:00 EST


On Thu, Nov 22, 2018 at 09:09:47AM -0800, Linus Torvalds wrote:
> On Thu, Nov 22, 2018 at 9:07 AM Russell King - ARM Linux
> <linux@xxxxxxxxxxxxxxx> wrote:
> >
> > I'm afraid that won't work very well - 32 bit platforms with 64-bit
> > addresses (LPAE) would have dma_addr_t as a 64-bit value, which
> > wouldn't fit into an unsigned long.
>
> Good point. So we'd have to have a special IS_DMA_ERR() function that
> takes a dma_addr_t and checks the same "is it the top 4095 values".

No problem with that.

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