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| author | Jeremy Fitzhardinge <jeremy@goop.org> | 2007-05-02 19:27:15 +0200 |
|---|---|---|
| committer | Andi Kleen <andi@basil.nowhere.org> | 2007-05-02 19:27:15 +0200 |
| commit | ce6234b5298902aaec831a67d5f8d9bd2ef5a488 (patch) | |
| tree | 939c22684e11a4f5f17abb89c4898f016e878e21 /mm/highmem.c | |
| parent | a27fe809b82c5e18932fcceded28d0d1481ce7bb (diff) | |
| download | linux-ce6234b5298902aaec831a67d5f8d9bd2ef5a488.tar.bz2 | |
[PATCH] i386: PARAVIRT: add kmap_atomic_pte for mapping highpte pages
Xen and VMI both have special requirements when mapping a highmem pte
page into the kernel address space. These can be dealt with by adding
a new kmap_atomic_pte() function for mapping highptes, and hooking it
into the paravirt_ops infrastructure.
Xen specifically wants to map the pte page RO, so this patch exposes a
helper function, kmap_atomic_prot, which maps the page with the
specified page protections.
This also adds a kmap_flush_unused() function to clear out the cached
kmap mappings. Xen needs this to clear out any potential stray RW
mappings of pages which will become part of a pagetable.
[ Zach - vmi.c will need some attention after this patch. It wasn't
immediately obvious to me what needs to be done. ]
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Zachary Amsden <zach@vmware.com>
Diffstat (limited to 'mm/highmem.c')
| -rw-r--r-- | mm/highmem.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/mm/highmem.c b/mm/highmem.c index 51e1c1995fec..be8f8d36a8b9 100644 --- a/mm/highmem.c +++ b/mm/highmem.c @@ -99,6 +99,15 @@ static void flush_all_zero_pkmaps(void) flush_tlb_kernel_range(PKMAP_ADDR(0), PKMAP_ADDR(LAST_PKMAP)); } +/* Flush all unused kmap mappings in order to remove stray + mappings. */ +void kmap_flush_unused(void) +{ + spin_lock(&kmap_lock); + flush_all_zero_pkmaps(); + spin_unlock(&kmap_lock); +} + static inline unsigned long map_new_virtual(struct page *page) { unsigned long vaddr; |