vmwgfx: Add comments for buffer pinning code
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / xen / biomerge.c
blobba6eda4b51433e20e87f4ae977cdd565f7d3c300
1 #include <linux/bio.h>
2 #include <linux/io.h>
3 #include <xen/page.h>
5 bool xen_biovec_phys_mergeable(const struct bio_vec *vec1,
6 const struct bio_vec *vec2)
8 unsigned long mfn1 = pfn_to_mfn(page_to_pfn(vec1->bv_page));
9 unsigned long mfn2 = pfn_to_mfn(page_to_pfn(vec2->bv_page));
11 return __BIOVEC_PHYS_MERGEABLE(vec1, vec2) &&
12 ((mfn1 == mfn2) || ((mfn1+1) == mfn2));