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| author | Zoltan Kiss <zoltan.kiss@citrix.com> | 2014-02-27 15:55:30 +0000 |
|---|---|---|
| committer | David Vrabel <david.vrabel@citrix.com> | 2014-03-18 14:40:19 +0000 |
| commit | 1429d46df4c538d28460d0b493997006a62a1093 (patch) | |
| tree | 81e177be951fd3134d2e475307af278a1951061a /arch/arm | |
| parent | 395edbb80b049884df075be54ef46cc742c3e266 (diff) | |
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')
| -rw-r--r-- | arch/arm/include/asm/xen/page.h | 15 | ||||
| -rw-r--r-- | arch/arm/xen/p2m.c | 32 |
2 files changed, 38 insertions, 9 deletions
diff --git a/arch/arm/include/asm/xen/page.h b/arch/arm/include/asm/xen/page.h index e0965abacb7d..cf4f3e867395 100644 --- a/arch/arm/include/asm/xen/page.h +++ b/arch/arm/include/asm/xen/page.h @@ -97,16 +97,13 @@ static inline pte_t *lookup_address(unsigned long address, unsigned int *level) return NULL; } -static inline int m2p_add_override(unsigned long mfn, struct page *page, - struct gnttab_map_grant_ref *kmap_op) -{ - return 0; -} +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); -static inline int m2p_remove_override(struct page *page, bool clear_pte) -{ - return 0; -} +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); bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn); bool __set_phys_to_machine_multi(unsigned long pfn, unsigned long mfn, 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) { |