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| author | Daniel De Graaf <dgdegra@tycho.nsa.gov> | 2011-12-14 21:12:11 +0100 |
|---|---|---|
| committer | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2011-12-20 23:07:27 +0100 |
| commit | 7d17e84bb8356b1d9f4402dd82a0e270a3d59a4f (patch) | |
| tree | 52e6dfc37a288e7181503d3f6596ce569d725b89 /drivers/xen | |
| parent | xenbus: Use grant-table wrapper functions (diff) | |
| download | linux-7d17e84bb8356b1d9f4402dd82a0e270a3d59a4f.tar.xz linux-7d17e84bb8356b1d9f4402dd82a0e270a3d59a4f.zip | |
xen/grant-table: Support mappings required by blkback
Add support for mappings without GNTMAP_contains_pte. This was not
supported because the unmap operation assumed that this flag was being
used; adding a parameter to the unmap operation to allow the PTE
clearing to be disabled is sufficient to make unmap capable of
supporting either mapping type.
Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
[v1: Fix cleanpatch warnings]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Diffstat (limited to 'drivers/xen')
| -rw-r--r-- | drivers/xen/gntdev.c | 3 | ||||
| -rw-r--r-- | drivers/xen/grant-table.c | 24 |
2 files changed, 7 insertions, 20 deletions
diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c index f52f661f8f82..99d8151c824a 100644 --- a/drivers/xen/gntdev.c +++ b/drivers/xen/gntdev.c @@ -314,7 +314,8 @@ static int __unmap_grant_pages(struct grant_map *map, int offset, int pages) } } - err = gnttab_unmap_refs(map->unmap_ops + offset, map->pages + offset, pages); + err = gnttab_unmap_refs(map->unmap_ops + offset, map->pages + offset, + pages, true); if (err) return err; diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c index a3d0e1e278c1..1cd94daa71db 100644 --- a/drivers/xen/grant-table.c +++ b/drivers/xen/grant-table.c @@ -761,24 +761,10 @@ int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops, (map_ops[i].host_addr & ~PAGE_MASK)); mfn = pte_mfn(*pte); } else { - /* If you really wanted to do this: - * mfn = PFN_DOWN(map_ops[i].dev_bus_addr); - * - * The reason we do not implement it is b/c on the - * unmap path (gnttab_unmap_refs) we have no means of - * checking whether the page is !GNTMAP_contains_pte. - * - * That is without some extra data-structure to carry - * the struct page, bool clear_pte, and list_head next - * tuples and deal with allocation/delallocation, etc. - * - * The users of this API set the GNTMAP_contains_pte - * flag so lets just return not supported until it - * becomes neccessary to implement. - */ - return -EOPNOTSUPP; + mfn = PFN_DOWN(map_ops[i].dev_bus_addr); } - ret = m2p_add_override(mfn, pages[i], &kmap_ops[i]); + ret = m2p_add_override(mfn, pages[i], kmap_ops ? + &kmap_ops[i] : NULL); if (ret) return ret; } @@ -788,7 +774,7 @@ int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops, EXPORT_SYMBOL_GPL(gnttab_map_refs); int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops, - struct page **pages, unsigned int count) + struct page **pages, unsigned int count, bool clear_pte) { int i, ret; @@ -800,7 +786,7 @@ int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops, return ret; for (i = 0; i < count; i++) { - ret = m2p_remove_override(pages[i], true /* clear the PTE */); + ret = m2p_remove_override(pages[i], clear_pte); if (ret) return ret; } |