# HG changeset patch
# User Keir Fraser <keir.fraser@xxxxxxxxxx>
# Date 1225114489 0
# Node ID 03a4b2b9d85d37e7851b2020dcff692e6801d5fd
# Parent 61eafcbeaeb4c37bd7f2fa8b1ca790ab5326c3bd
linux/i386: utilize hypervisor highmem handling helpers
Signed-off-by: Jan Beulich <jbeulich@xxxxxxxxxx>
---
arch/i386/mm/highmem-xen.c | 47 ++++++++++++++++++++++++++++++++
include/asm-i386/mach-xen/asm/highmem.h | 17 +++++++++++
include/linux/highmem.h | 8 +++++
3 files changed, 72 insertions(+)
diff -r 61eafcbeaeb4 -r 03a4b2b9d85d arch/i386/mm/highmem-xen.c
--- a/arch/i386/mm/highmem-xen.c Mon Oct 27 13:34:34 2008 +0000
+++ b/arch/i386/mm/highmem-xen.c Mon Oct 27 13:34:49 2008 +0000
@@ -128,9 +128,56 @@ struct page *kmap_atomic_to_page(void *p
return pte_page(*pte);
}
+void clear_highpage(struct page *page)
+{
+ void *kaddr;
+
+ if (likely(xen_feature(XENFEAT_highmem_assist))
+ && PageHighMem(page)) {
+ struct mmuext_op meo;
+
+ meo.cmd = MMUEXT_CLEAR_PAGE;
+ meo.arg1.mfn = pfn_to_mfn(page_to_pfn(page));
+ if (HYPERVISOR_mmuext_op(&meo, 1, NULL, DOMID_SELF) == 0)
+ return;
+ }
+
+ kaddr = kmap_atomic(page, KM_USER0);
+ clear_page(kaddr);
+ kunmap_atomic(kaddr, KM_USER0);
+}
+
+void copy_highpage(struct page *to, struct page *from)
+{
+ void *vfrom, *vto;
+
+ if (likely(xen_feature(XENFEAT_highmem_assist))
+ && (PageHighMem(from) || PageHighMem(to))) {
+ unsigned long from_pfn = page_to_pfn(from);
+ unsigned long to_pfn = page_to_pfn(to);
+ struct mmuext_op meo;
+
+ meo.cmd = MMUEXT_COPY_PAGE;
+ meo.arg1.mfn = pfn_to_mfn(to_pfn);
+ meo.arg2.src_mfn = pfn_to_mfn(from_pfn);
+ if (mfn_to_pfn(meo.arg2.src_mfn) == from_pfn
+ && mfn_to_pfn(meo.arg1.mfn) == to_pfn
+ && HYPERVISOR_mmuext_op(&meo, 1, NULL, DOMID_SELF) == 0)
+ return;
+ }
+
+ vfrom = kmap_atomic(from, KM_USER0);
+ vto = kmap_atomic(to, KM_USER1);
+ copy_page(vto, vfrom);
+ kunmap_atomic(vfrom, KM_USER0);
+ kunmap_atomic(vto, KM_USER1);
+}
+
EXPORT_SYMBOL(kmap);
EXPORT_SYMBOL(kunmap);
EXPORT_SYMBOL(kmap_atomic);
EXPORT_SYMBOL(kmap_atomic_pte);
EXPORT_SYMBOL(kunmap_atomic);
EXPORT_SYMBOL(kmap_atomic_to_page);
+EXPORT_SYMBOL(clear_highpage);
+EXPORT_SYMBOL(copy_highpage);
diff -r 61eafcbeaeb4 -r 03a4b2b9d85d include/asm-i386/mach-xen/asm/highmem.h
--- a/include/asm-i386/mach-xen/asm/highmem.h Mon Oct 27 13:34:34 2008 +0000
+++ b/include/asm-i386/mach-xen/asm/highmem.h Mon Oct 27 13:34:49 2008 +0000
@@ -75,6 +75,23 @@ struct page *kmap_atomic_to_page(void *p
#define flush_cache_kmaps() do { } while (0)
+void clear_highpage(struct page *);
+static inline void clear_user_highpage(struct page *page, unsigned long vaddr)
+{
+ clear_highpage(page);
+}
+#define __HAVE_ARCH_CLEAR_HIGHPAGE
+#define __HAVE_ARCH_CLEAR_USER_HIGHPAGE
+
+void copy_highpage(struct page *to, struct page *from);
+static inline void copy_user_highpage(struct page *to, struct page *from,
+ unsigned long vaddr, struct vm_area_struct *vma)
+{
+ copy_highpage(to, from);
+}
+#define __HAVE_ARCH_COPY_HIGHPAGE
+#define __HAVE_ARCH_COPY_USER_HIGHPAGE
+
#endif /* __KERNEL__ */
#endif /* _ASM_HIGHMEM_H */
diff -r 61eafcbeaeb4 -r 03a4b2b9d85d include/linux/highmem.h
--- a/include/linux/highmem.h Mon Oct 27 13:34:34 2008 +0000
+++ b/include/linux/highmem.h Mon Oct 27 13:34:49 2008 +0000
@@ -50,6 +50,7 @@ static inline void *kmap(struct page *pa
#endif /* CONFIG_HIGHMEM */
+#ifndef __HAVE_ARCH_CLEAR_USER_HIGHPAGE
/* when CONFIG_HIGHMEM is not set these will be plain clear/copy_page */
static inline void clear_user_highpage(struct page *page, unsigned long vaddr)
{
@@ -59,6 +60,7 @@ static inline void clear_user_highpage(s
/* Make sure this page is cleared on other CPU's too before using it */
smp_wmb();
}
+#endif
#ifndef __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE
static inline struct page *
@@ -73,12 +75,14 @@ alloc_zeroed_user_highpage(struct vm_are
}
#endif
+#ifndef __HAVE_ARCH_CLEAR_HIGHPAGE
static inline void clear_highpage(struct page *page)
{
void *kaddr = kmap_atomic(page, KM_USER0);
clear_page(kaddr);
kunmap_atomic(kaddr, KM_USER0);
}
+#endif
/*
* Same but also flushes aliased cache contents to RAM.
@@ -95,6 +99,7 @@ static inline void memclear_highpage_flu
kunmap_atomic(kaddr, KM_USER0);
}
+#ifndef __HAVE_ARCH_COPY_USER_HIGHPAGE
static inline void copy_user_highpage(struct page *to, struct page *from,
unsigned long vaddr)
{
char *vfrom, *vto;
@@ -107,7 +112,9 @@ static inline void copy_user_highpage(st
/* Make sure this page is cleared on other CPU's too before using it */
smp_wmb();
}
+#endif
+#ifndef __HAVE_ARCH_COPY_HIGHPAGE
static inline void copy_highpage(struct page *to, struct page *from)
{
char *vfrom, *vto;
@@ -118,5 +125,6 @@ static inline void copy_highpage(struct
kunmap_atomic(vfrom, KM_USER0);
kunmap_atomic(vto, KM_USER1);
}
+#endif
#endif /* _LINUX_HIGHMEM_H */
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