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authorZoltan Kiss <zoltan.kiss@citrix.com>2014-02-27 19:55:30 +0400
committerDavid Vrabel <david.vrabel@citrix.com>2014-03-18 18:40:19 +0400
commit1429d46df4c538d28460d0b493997006a62a1093 (patch)
tree81e177be951fd3134d2e475307af278a1951061a /arch/arm/xen/p2m.c
parent395edbb80b049884df075be54ef46cc742c3e266 (diff)
downloadlinux-1429d46df4c538d28460d0b493997006a62a1093.tar.xz
xen/grant-table: Refactor gnttab_[un]map_refs to avoid m2p_override
The grant mapping API does m2p_override unnecessarily: only gntdev needs it, for blkback and future netback patches it just cause a lock contention, as those pages never go to userspace. Therefore this series does the following: - the bulk of the original function (everything after the mapping hypercall) is moved to arch-dependent set/clear_foreign_p2m_mapping - the "if (xen_feature(XENFEAT_auto_translated_physmap))" branch goes to ARM - therefore the ARM function could be much smaller, the m2p_override stubs could be also removed - on x86 the set_phys_to_machine calls were moved up to this new funcion from m2p_override functions - and m2p_override functions are only called when there is a kmap_ops param It also removes a stray space from arch/x86/include/asm/xen/page.h. Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com> Suggested-by: Anthony Liguori <aliguori@amazon.com> Suggested-by: David Vrabel <david.vrabel@citrix.com> Suggested-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Diffstat (limited to 'arch/arm/xen/p2m.c')
-rw-r--r--arch/arm/xen/p2m.c32
1 files changed, 32 insertions, 0 deletions
diff --git a/arch/arm/xen/p2m.c b/arch/arm/xen/p2m.c
index b31ee1b275b0..97baf4427817 100644
--- a/arch/arm/xen/p2m.c
+++ b/arch/arm/xen/p2m.c
@@ -146,6 +146,38 @@ unsigned long __mfn_to_pfn(unsigned long mfn)
}
EXPORT_SYMBOL_GPL(__mfn_to_pfn);
+int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops,
+ struct gnttab_map_grant_ref *kmap_ops,
+ struct page **pages, unsigned int count)
+{
+ int i;
+
+ for (i = 0; i < count; i++) {
+ if (map_ops[i].status)
+ continue;
+ set_phys_to_machine(map_ops[i].host_addr >> PAGE_SHIFT,
+ map_ops[i].dev_bus_addr >> PAGE_SHIFT);
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(set_foreign_p2m_mapping);
+
+int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops,
+ struct gnttab_map_grant_ref *kmap_ops,
+ struct page **pages, unsigned int count)
+{
+ int i;
+
+ for (i = 0; i < count; i++) {
+ set_phys_to_machine(unmap_ops[i].host_addr >> PAGE_SHIFT,
+ INVALID_P2M_ENTRY);
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(clear_foreign_p2m_mapping);
+
bool __set_phys_to_machine_multi(unsigned long pfn,
unsigned long mfn, unsigned long nr_pages)
{