# HG changeset patch
# User Keir Fraser <keir.fraser@xxxxxxxxxx>
# Date 1260981852 0
# Node ID 317cdc16a674f4aa4c57b4fdae004ca5fcc24712
# Parent 6b5c16a30bc5e7d771dec05c7cee597b71a695c2
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).
Signed-off-by: Jan Beulich <jbeulich@xxxxxxxxxx>
linux-2.6-pvops:
* Stripped drivers/xen/gntdev/*
* Stripped drivers/xen/netback/*
Signed-off-by: Daniel Stodden <daniel.stodden@xxxxxxxxxx>
diff -r 6b5c16a30bc5 -r 317cdc16a674 drivers/xen/blkback/blkback.c
--- a/drivers/xen/blkback/blkback.c Fri Dec 11 08:47:19 2009 +0000
+++ b/drivers/xen/blkback/blkback.c Wed Dec 16 16:44:12 2009 +0000
@@ -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);
}
@@ -178,7 +180,7 @@
handle = pending_handle(req, i);
if (handle == BLKBACK_INVALID_HANDLE)
continue;
- blkback_pagemap_clear(virt_to_page(vaddr(req, i)));
+ blkback_pagemap_clear(pending_page(req, i));
gnttab_set_unmap_op(&unmap[invcount], vaddr(req, i),
GNTMAP_host_map, handle);
pending_handle(req, i) = BLKBACK_INVALID_HANDLE;
@@ -456,7 +458,7 @@
ret |= 1;
} else {
blkback_pagemap_set(vaddr_pagenr(pending_req, i),
- virt_to_page(vaddr(pending_req, i)),
+ pending_page(pending_req, i),
blkif->domid, req->handle,
req->seg[i].gref);
}
@@ -466,8 +468,8 @@
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);
@@ -498,7 +500,7 @@
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) {
diff -r 6b5c16a30bc5 -r 317cdc16a674 drivers/xen/blktap/blktap.h
--- a/drivers/xen/blktap/blktap.h Fri Dec 11 08:47:19 2009 +0000
+++ b/drivers/xen/blktap/blktap.h Wed Dec 16 16:44:12 2009 +0000
@@ -241,6 +241,13 @@
int blktap_request_pool_shrink(void);
struct blktap_request *blktap_request_allocate(struct blktap *);
void blktap_request_free(struct blktap *, struct blktap_request *);
-unsigned long request_to_kaddr(struct blktap_request *, int);
+struct page *request_to_page(struct blktap_request *, int);
+
+static inline unsigned long
+request_to_kaddr(struct blktap_request *req, int seg)
+{
+ unsigned long pfn = page_to_pfn(request_to_page(req, seg));
+ return (unsigned long)pfn_to_kaddr(pfn);
+}
#endif
diff -r 6b5c16a30bc5 -r 317cdc16a674 drivers/xen/blktap/device.c
--- a/drivers/xen/blktap/device.c Fri Dec 11 08:47:19 2009 +0000
+++ b/drivers/xen/blktap/device.c Wed Dec 16 16:44:12 2009 +0000
@@ -315,15 +315,14 @@
down_write(&tap->ring.vma->vm_mm->mmap_sem);
for (i = 0; i < request->nr_pages; i++) {
+ kvaddr = request_to_kaddr(request, i);
BTDBG("request: %p, seg: %d, kvaddr: 0x%08lx, khandle: %u, "
"uvaddr: 0x%08lx, uhandle: %u\n", request, i,
- request_to_kaddr(request, i),
- request->handles[i].kernel,
+ kvaddr, request->handles[i].kernel,
MMAP_VADDR(tap->ring.user_vstart, usr_idx, i),
request->handles[i].user);
if (request->handles[i].kernel == INVALID_GRANT_HANDLE) {
- kvaddr = request_to_kaddr(request, i);
blktap_umap_uaddr(&init_mm, kvaddr);
flush_tlb_kernel_page(kvaddr);
set_phys_to_machine(__pa(kvaddr) >> PAGE_SHIFT,
@@ -450,7 +449,7 @@
#ifdef BLKTAP_CHAINED_BLKTAP
/* enable chained tap devices */
- tap_page = pfn_to_page(__pa(kvaddr) >> PAGE_SHIFT);
+ tap_page = request_to_page(request, seg);
set_page_private(tap_page, page_private(page));
SetPageBlkback(tap_page);
#endif
@@ -480,7 +479,7 @@
struct page *page;
int i, grant, err, usr_idx;
struct blktap_ring *ring;
- unsigned long uvaddr, kvaddr, foreign_mfn;
+ unsigned long uvaddr, foreign_mfn;
if (!table->cnt)
return 0;
@@ -498,7 +497,6 @@
continue;
uvaddr = MMAP_VADDR(ring->user_vstart, usr_idx, i);
- kvaddr = request_to_kaddr(request, i);
if (unlikely(table->grants[grant].status)) {
BTERR("invalid kernel buffer: could not remap it\n");
@@ -526,18 +524,19 @@
if (err)
continue;
- page = pfn_to_page(__pa(kvaddr) >> PAGE_SHIFT);
+ page = request_to_page(request, i);
if (!xen_feature(XENFEAT_auto_translated_physmap))
- set_phys_to_machine(__pa(kvaddr) >> PAGE_SHIFT,
+ set_phys_to_machine(page_to_pfn(page),
FOREIGN_FRAME(foreign_mfn));
else if (vm_insert_page(ring->vma, uvaddr, page))
err |= 1;
BTDBG("pending_req: %p, seg: %d, page: %p, "
- "kvaddr: 0x%08lx, khandle: %u, uvaddr: 0x%08lx, "
+ "kvaddr: 0x%p, khandle: %u, uvaddr: 0x%08lx, "
"uhandle: %u\n", request, i, page,
- kvaddr, request->handles[i].kernel,
+ pfn_to_kaddr(page_to_pfn(page)),
+ request->handles[i].kernel,
uvaddr, request->handles[i].user);
}
@@ -585,7 +584,7 @@
struct scatterlist *sg;
struct blktap_grant_table table;
unsigned int fsect, lsect, nr_sects;
- unsigned long offset, uvaddr, kvaddr;
+ unsigned long offset, uvaddr;
struct blkif_request blkif_req, *target;
err = -1;
@@ -641,18 +640,17 @@
}
uvaddr = MMAP_VADDR(ring->user_vstart, usr_idx, i);
- kvaddr = request_to_kaddr(request, i);
offset = (uvaddr - ring->vma->vm_start) >> PAGE_SHIFT;
- page = pfn_to_page(__pa(kvaddr) >> PAGE_SHIFT);
+ page = request_to_page(request, i);
ring->foreign_map.map[offset] = page;
SetPageReserved(page);
BTDBG("mapped uaddr %08lx to page %p pfn 0x%lx\n",
- uvaddr, page, __pa(kvaddr) >> PAGE_SHIFT);
+ uvaddr, page, page_to_pfn(page));
BTDBG("offset: 0x%08lx, pending_req: %p, seg: %d, "
- "page: %p, kvaddr: 0x%08lx, uvaddr: 0x%08lx\n",
+ "page: %p, kvaddr: %p, uvaddr: 0x%08lx\n",
offset, request, i,
- page, kvaddr, uvaddr);
+ page, pfn_to_kaddr(page_to_pfn(page)), uvaddr);
request->nr_pages++;
}
diff -r 6b5c16a30bc5 -r 317cdc16a674 drivers/xen/blktap/request.c
--- a/drivers/xen/blktap/request.c Fri Dec 11 08:47:19 2009 +0000
+++ b/drivers/xen/blktap/request.c Wed Dec 16 16:44:12 2009 +0000
@@ -124,13 +124,12 @@
kfree(bucket);
}
-unsigned long
-request_to_kaddr(struct blktap_request *req, int seg)
+struct page *
+request_to_page(struct blktap_request *req, int seg)
{
struct blktap_request_handle *handle = blktap_request_to_handle(req);
int idx = handle->slot * BLKIF_MAX_SEGMENTS_PER_REQUEST + seg;
- unsigned long pfn = page_to_pfn(handle->bucket->foreign_pages[idx]);
- return (unsigned long)pfn_to_kaddr(pfn);
+ return handle->bucket->foreign_pages[idx];
}
int
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