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authorJuergen Gross <jgross@suse.com>2014-11-28 11:53:57 +0100
committerDavid Vrabel <david.vrabel@citrix.com>2014-12-04 14:09:09 +0000
commit0aad5689837c882d2539f50f42f686b74046c0a0 (patch)
tree5367d28f3b43ed9dba583106ffc2364e3ef67c23 /arch/x86/include/asm/xen/page.h
parent792230c3a66b3d17d6dcca712866d24f2283d4a6 (diff)
xen: Hide get_phys_to_machine() to be able to tune common path
Today get_phys_to_machine() is always called when the mfn for a pfn is to be obtained. Add a wrapper __pfn_to_mfn() as inline function to be able to avoid calling get_phys_to_machine() when possible as soon as the switch to a linear mapped p2m list has been done. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: David Vrabel <david.vrabel@citrix.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Diffstat (limited to 'arch/x86/include/asm/xen/page.h')
-rw-r--r--arch/x86/include/asm/xen/page.h26
1 files changed, 20 insertions, 6 deletions
diff --git a/arch/x86/include/asm/xen/page.h b/arch/x86/include/asm/xen/page.h
index a4a265fcab17..57aba6ba6f92 100644
--- a/arch/x86/include/asm/xen/page.h
+++ b/arch/x86/include/asm/xen/page.h
@@ -59,6 +59,21 @@ extern int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops,
struct page **pages, unsigned int count);
extern unsigned long m2p_find_override_pfn(unsigned long mfn, unsigned long pfn);
+/*
+ * When to use pfn_to_mfn(), __pfn_to_mfn() or get_phys_to_machine():
+ * - pfn_to_mfn() returns either INVALID_P2M_ENTRY or the mfn. No indicator
+ * bits (identity or foreign) are set.
+ * - __pfn_to_mfn() returns the found entry of the p2m table. A possibly set
+ * identity or foreign indicator will be still set. __pfn_to_mfn() is
+ * encapsulating get_phys_to_machine().
+ * - get_phys_to_machine() is to be called by __pfn_to_mfn() only to allow
+ * for future optimizations.
+ */
+static inline unsigned long __pfn_to_mfn(unsigned long pfn)
+{
+ return get_phys_to_machine(pfn);
+}
+
static inline unsigned long pfn_to_mfn(unsigned long pfn)
{
unsigned long mfn;
@@ -66,7 +81,7 @@ static inline unsigned long pfn_to_mfn(unsigned long pfn)
if (xen_feature(XENFEAT_auto_translated_physmap))
return pfn;
- mfn = get_phys_to_machine(pfn);
+ mfn = __pfn_to_mfn(pfn);
if (mfn != INVALID_P2M_ENTRY)
mfn &= ~(FOREIGN_FRAME_BIT | IDENTITY_FRAME_BIT);
@@ -79,7 +94,7 @@ static inline int phys_to_machine_mapping_valid(unsigned long pfn)
if (xen_feature(XENFEAT_auto_translated_physmap))
return 1;
- return get_phys_to_machine(pfn) != INVALID_P2M_ENTRY;
+ return __pfn_to_mfn(pfn) != INVALID_P2M_ENTRY;
}
static inline unsigned long mfn_to_pfn_no_overrides(unsigned long mfn)
@@ -113,7 +128,7 @@ static inline unsigned long mfn_to_pfn(unsigned long mfn)
return mfn;
pfn = mfn_to_pfn_no_overrides(mfn);
- if (get_phys_to_machine(pfn) != mfn) {
+ if (__pfn_to_mfn(pfn) != mfn) {
/*
* If this appears to be a foreign mfn (because the pfn
* doesn't map back to the mfn), then check the local override
@@ -129,8 +144,7 @@ static inline unsigned long mfn_to_pfn(unsigned long mfn)
* entry doesn't map back to the mfn and m2p_override doesn't have a
* valid entry for it.
*/
- if (pfn == ~0 &&
- get_phys_to_machine(mfn) == IDENTITY_FRAME(mfn))
+ if (pfn == ~0 && __pfn_to_mfn(mfn) == IDENTITY_FRAME(mfn))
pfn = mfn;
return pfn;
@@ -176,7 +190,7 @@ static inline unsigned long mfn_to_local_pfn(unsigned long mfn)
return mfn;
pfn = mfn_to_pfn(mfn);
- if (get_phys_to_machine(pfn) != mfn)
+ if (__pfn_to_mfn(pfn) != mfn)
return -1; /* force !pfn_valid() */
return pfn;
}