Messages in this thread | | | Date | Mon, 17 Mar 2014 15:07:51 -0700 | Subject | Re: [PATCH v7 2/2] ARM hibernation / suspend-to-disk | From | Sebastian Capella <> |
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Thanks Russell!
On 16 March 2014 02:46, Russell King - ARM Linux <linux@arm.linux.org.uk> wrote: > On Mon, Mar 10, 2014 at 11:32:17AM -0700, Sebastian Capella wrote: ... > Let's look at the implementations... > > #define __pa(x) __virt_to_phys((unsigned long)(x)) > static inline phys_addr_t __virt_to_phys(unsigned long x) > { > return (phys_addr_t)x - PAGE_OFFSET + PHYS_OFFSET; > } > > So, __pa() returns a phys_addr_t (which may be either 32-bit or 64-bit). > > #define virt_to_pfn(kaddr) (__pa(kaddr) >> PAGE_SHIFT) > > And that will do an appropriate shift to convert the phys_addr_t to a PFN, > which will be fine to assign to an unsigned long variable. > > #define __phys_to_pfn(paddr) ((unsigned long)((paddr) >> PAGE_SHIFT)) > > This does the same thing, but has an explicit cast. > > So, the only difference between the two suggestions is that additional > cast, which has no effect here.
Sounds good, thanks!
I was a little unsure about the page sizes that could affect all of the implementations.
I'll make this change and repost, basically using virt_to_pfn in place of the previous __pa_symbol, and remove unused declarations.
Thanks again!
Sebastian
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