diff options
author | Zoltan Kiss <zoltan.kiss@citrix.com> | 2014-02-27 15:55:30 (GMT) |
---|---|---|
committer | David Vrabel <david.vrabel@citrix.com> | 2014-03-18 14:40:19 (GMT) |
commit | 1429d46df4c538d28460d0b493997006a62a1093 (patch) | |
tree | 81e177be951fd3134d2e475307af278a1951061a /drivers | |
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 'drivers')
-rw-r--r-- | drivers/xen/grant-table.c | 73 |
1 files changed, 3 insertions, 70 deletions
diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c index b84e3ab..6d325bd 100644 --- a/drivers/xen/grant-table.c +++ b/drivers/xen/grant-table.c @@ -933,9 +933,6 @@ int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops, struct page **pages, unsigned int count) { int i, ret; - bool lazy = false; - pte_t *pte; - unsigned long mfn; ret = HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, map_ops, count); if (ret) @@ -947,45 +944,7 @@ int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops, gnttab_retry_eagain_gop(GNTTABOP_map_grant_ref, map_ops + i, &map_ops[i].status, __func__); - /* this is basically a nop on x86 */ - if (xen_feature(XENFEAT_auto_translated_physmap)) { - 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 ret; - } - - if (!in_interrupt() && paravirt_get_lazy_mode() == PARAVIRT_LAZY_NONE) { - arch_enter_lazy_mmu_mode(); - lazy = true; - } - - for (i = 0; i < count; i++) { - /* Do not add to override if the map failed. */ - if (map_ops[i].status) - continue; - - if (map_ops[i].flags & GNTMAP_contains_pte) { - pte = (pte_t *) (mfn_to_virt(PFN_DOWN(map_ops[i].host_addr)) + - (map_ops[i].host_addr & ~PAGE_MASK)); - mfn = pte_mfn(*pte); - } else { - mfn = PFN_DOWN(map_ops[i].dev_bus_addr); - } - ret = m2p_add_override(mfn, pages[i], kmap_ops ? - &kmap_ops[i] : NULL); - if (ret) - goto out; - } - - out: - if (lazy) - arch_leave_lazy_mmu_mode(); - - return ret; + return set_foreign_p2m_mapping(map_ops, kmap_ops, pages, count); } EXPORT_SYMBOL_GPL(gnttab_map_refs); @@ -993,39 +952,13 @@ int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops, struct gnttab_map_grant_ref *kmap_ops, struct page **pages, unsigned int count) { - int i, ret; - bool lazy = false; + int ret; ret = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, unmap_ops, count); if (ret) return ret; - /* this is basically a nop on x86 */ - if (xen_feature(XENFEAT_auto_translated_physmap)) { - for (i = 0; i < count; i++) { - set_phys_to_machine(unmap_ops[i].host_addr >> PAGE_SHIFT, - INVALID_P2M_ENTRY); - } - return ret; - } - - if (!in_interrupt() && paravirt_get_lazy_mode() == PARAVIRT_LAZY_NONE) { - arch_enter_lazy_mmu_mode(); - lazy = true; - } - - for (i = 0; i < count; i++) { - ret = m2p_remove_override(pages[i], kmap_ops ? - &kmap_ops[i] : NULL); - if (ret) - goto out; - } - - out: - if (lazy) - arch_leave_lazy_mmu_mode(); - - return ret; + return clear_foreign_p2m_mapping(unmap_ops, kmap_ops, pages, count); } EXPORT_SYMBOL_GPL(gnttab_unmap_refs); |