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| author | Zoltan Kiss <zoltan.kiss@citrix.com> | 2014-02-27 19:55:30 +0400 |
|---|---|---|
| committer | David Vrabel <david.vrabel@citrix.com> | 2014-03-18 18:40:19 +0400 |
| commit | 1429d46df4c538d28460d0b493997006a62a1093 (patch) | |
| tree | 81e177be951fd3134d2e475307af278a1951061a /arch/x86/include/asm/xen | |
| parent | 395edbb80b049884df075be54ef46cc742c3e266 (diff) | |
| download | linux-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/x86/include/asm/xen')
| -rw-r--r-- | arch/x86/include/asm/xen/page.h | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/arch/x86/include/asm/xen/page.h b/arch/x86/include/asm/xen/page.h index 3e276eb23d1b..c949923a5668 100644 --- a/arch/x86/include/asm/xen/page.h +++ b/arch/x86/include/asm/xen/page.h @@ -49,10 +49,17 @@ extern bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn); extern unsigned long set_phys_range_identity(unsigned long pfn_s, unsigned long pfn_e); +extern 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); extern int m2p_add_override(unsigned long mfn, struct page *page, struct gnttab_map_grant_ref *kmap_op); +extern 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); extern int m2p_remove_override(struct page *page, - struct gnttab_map_grant_ref *kmap_op); + struct gnttab_map_grant_ref *kmap_op, + unsigned long mfn); extern struct page *m2p_find_override(unsigned long mfn); extern unsigned long m2p_find_override_pfn(unsigned long mfn, unsigned long pfn); @@ -121,7 +128,7 @@ static inline unsigned long mfn_to_pfn(unsigned long mfn) pfn = m2p_find_override_pfn(mfn, ~0); } - /* + /* * pfn is ~0 if there are no entries in the m2p for mfn or if the * entry doesn't map back to the mfn and m2p_override doesn't have a * valid entry for it. |