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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 /include/linux/highmem.h | |
| parent | a27fe809b82c5e18932fcceded28d0d1481ce7bb (diff) | |
| download | kernel-common-ce6234b5298902aaec831a67d5f8d9bd2ef5a488.tar.gz kernel-common-ce6234b5298902aaec831a67d5f8d9bd2ef5a488.tar.bz2 kernel-common-ce6234b5298902aaec831a67d5f8d9bd2ef5a488.zip | |
[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 'include/linux/highmem.h')
| -rw-r--r-- | include/linux/highmem.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/include/linux/highmem.h b/include/linux/highmem.h index 645d440807c2..bca8e2dfa355 100644 --- a/include/linux/highmem.h +++ b/include/linux/highmem.h @@ -27,6 +27,8 @@ static inline void flush_kernel_dcache_page(struct page *page) unsigned int nr_free_highpages(void); extern unsigned long totalhigh_pages; +void kmap_flush_unused(void); + #else /* CONFIG_HIGHMEM */ static inline unsigned int nr_free_highpages(void) { return 0; } @@ -44,9 +46,13 @@ static inline void *kmap(struct page *page) #define kmap_atomic(page, idx) \ ({ pagefault_disable(); page_address(page); }) +#define kmap_atomic_prot(page, idx, prot) kmap_atomic(page, idx) + #define kunmap_atomic(addr, idx) do { pagefault_enable(); } while (0) #define kmap_atomic_pfn(pfn, idx) kmap_atomic(pfn_to_page(pfn), (idx)) #define kmap_atomic_to_page(ptr) virt_to_page(ptr) + +#define kmap_flush_unused() do {} while(0) #endif #endif /* CONFIG_HIGHMEM */ |