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authorJeremy Fitzhardinge <jeremy@goop.org>2007-05-02 21:27:15 +0400
committerAndi Kleen <andi@basil.nowhere.org>2007-05-02 21:27:15 +0400
commitce6234b5298902aaec831a67d5f8d9bd2ef5a488 (patch)
tree939c22684e11a4f5f17abb89c4898f016e878e21 /include/linux/highmem.h
parenta27fe809b82c5e18932fcceded28d0d1481ce7bb (diff)
downloadlinux-ce6234b5298902aaec831a67d5f8d9bd2ef5a488.tar.xz
[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.h6
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 */