Re: [PATCH -mm -v4 1/3] i386/x86_64 boot: setup data

[Nick Piggin <nickpiggin@yahoo.com.au>]

On Tuesday 09 October 2007 16:40, Huang, Ying wrote:

> +unsigned long copy_from_phys(void *to, unsigned long from_phys,
> +			     unsigned long n)
> +{
> +	struct page *page;
> +	void *from;
> +	unsigned long remain = n, offset, trunck;
> +
> +	while (remain) {
> +		page = pfn_to_page(from_phys >> PAGE_SHIFT);
> +		from = kmap_atomic(page, KM_USER0);
> +		offset = from_phys & ~PAGE_MASK;
> +		if (remain > PAGE_SIZE - offset)
> +			trunck = PAGE_SIZE - offset;
> +		else
> +			trunck = remain;
> +		memcpy(to, from + offset, trunck);
> +		kunmap_atomic(from, KM_USER0);
> +		to += trunck;
> +		from_phys += trunck;
> +		remain -= trunck;
> +	}
> +	return n;
> +}


I suppose that's not unreasonable to put in mm/memory.c, although
it's not really considered a problem to do this kind of stuff in
a low level arch file...

You have no kernel virtual mapping for the source data?

Should it be __init?

Care to add a line of documentation if you keep it in mm/memory.c?

Thanks,
Nick

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