xen: make phys_to_machine structure dynamic

We now support the use of memory hotplug, so the physical to machine
page mapping structure must be dynamic.  This is implemented as a
two-level radix tree structure, which allows us to efficiently
incrementally allocate memory for the p2m table as new pages are
added.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 6 insertions, 14 deletions

diff --git a/include/asm-x86/xen/page.h b/include/asm-x86/xen/page.h
index e11f24038b1d..293344f8102e 100644
--- a/include/asm-x86/xen/page.h
+++ b/include/asm-x86/xen/page.h
@@ -26,15 +26,15 @@ typedef struct xpaddr {
 #define FOREIGN_FRAME_BIT       (1UL<<31)
 #define FOREIGN_FRAME(m)        ((m) | FOREIGN_FRAME_BIT)
 
-extern unsigned long *phys_to_machine_mapping;
+extern unsigned long get_phys_to_machine(unsigned long pfn);
+extern void set_phys_to_machine(unsigned long pfn, unsigned long mfn);
 
 static inline unsigned long pfn_to_mfn(unsigned long pfn)
 {
         if (xen_feature(XENFEAT_auto_translated_physmap))
                 return pfn;
 
-        return phys_to_machine_mapping[(unsigned int)(pfn)] &
-                ~FOREIGN_FRAME_BIT;
+        return get_phys_to_machine(pfn) & ~FOREIGN_FRAME_BIT;
 }
 
 static inline int phys_to_machine_mapping_valid(unsigned long pfn)
@@ -42,7 +42,7 @@ static inline int phys_to_machine_mapping_valid(unsigned long pfn)
         if (xen_feature(XENFEAT_auto_translated_physmap))
                 return 1;
 
-        return (phys_to_machine_mapping[pfn] != INVALID_P2M_ENTRY);
+        return get_phys_to_machine(pfn) != INVALID_P2M_ENTRY;
 }
 
 static inline unsigned long mfn_to_pfn(unsigned long mfn)
@@ -106,20 +106,12 @@ static inline unsigned long mfn_to_local_pfn(unsigned long mfn)
         unsigned long pfn = mfn_to_pfn(mfn);
         if ((pfn < max_mapnr)
             && !xen_feature(XENFEAT_auto_translated_physmap)
-            && (phys_to_machine_mapping[pfn] != mfn))
+            && (get_phys_to_machine(pfn) != mfn))
                 return max_mapnr; /* force !pfn_valid() */
+        /* XXX fixme; not true with sparsemem */
         return pfn;
 }
 
-static inline void set_phys_to_machine(unsigned long pfn, unsigned long mfn)
-{
-        if (xen_feature(XENFEAT_auto_translated_physmap)) {
-                BUG_ON(pfn != mfn && mfn != INVALID_P2M_ENTRY);
-                return;
-        }
-        phys_to_machine_mapping[pfn] = mfn;
-}
-
 /* VIRT <-> MACHINE conversion */
 #define virt_to_machine(v)      (phys_to_machine(XPADDR(__pa(v))))
 #define virt_to_mfn(v)          (pfn_to_mfn(PFN_DOWN(__pa(v))))