xen/blkback: simplify address translations
Cherry-pick and modified from 69d64727c42eecd47fdf82c15a54474d21a4012a
("blkback/blktap2: simplify address translations"):
"There are quite a number of places where e.g. page->va->page
translations happen.
Besides yielding smaller code (source and binary), a second goal is to
make it easier to determine where virtual addresses of pages allocated
through alloc_empty_pages_and_pagevec() are really used (in turn in
order to determine whether using highmem pages would be possible
there)."
The second goal is not the purpose of this patch - it is just to
make it easier to read the code.
linux-2.6-pvops:
* Stripped drivers/xen/gntdev/*
* Stripped drivers/xen/netback/*
[v2: Stripped blktap off]
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Daniel Stodden <daniel.stodden@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
diff --git a/drivers/xen/blkback/blkback.c b/drivers/xen/blkback/blkback.c
index cb844f7..7c9421c 100644
--- a/drivers/xen/blkback/blkback.c
+++ b/drivers/xen/blkback/blkback.c
@@ -99,9 +99,11 @@
return (req - pending_reqs) * BLKIF_MAX_SEGMENTS_PER_REQUEST + seg;
}
+#define pending_page(req, seg) pending_pages[vaddr_pagenr(req, seg)]
+
static inline unsigned long vaddr(pending_req_t *req, int seg)
{
- unsigned long pfn = page_to_pfn(pending_pages[vaddr_pagenr(req, seg)]);
+ unsigned long pfn = page_to_pfn(pending_page(req, seg));
return (unsigned long)pfn_to_kaddr(pfn);
}
@@ -463,8 +465,8 @@
if (ret)
continue;
- set_phys_to_machine(__pa(vaddr(
- pending_req, i)) >> PAGE_SHIFT,
+ set_phys_to_machine(
+ page_to_pfn(pending_page(pending_req, i)),
FOREIGN_FRAME(map[i].dev_bus_addr >> PAGE_SHIFT));
seg[i].buf = map[i].dev_bus_addr |
(req->seg[i].first_sect << 9);
@@ -495,7 +497,7 @@
while ((bio == NULL) ||
(bio_add_page(bio,
- virt_to_page(vaddr(pending_req, i)),
+ pending_page(pending_req, i),
seg[i].nsec << 9,
seg[i].buf & ~PAGE_MASK) == 0)) {
if (bio) {