[PATCH 4 of 9] x86: Add conversion from a xen map to an mfn

[Andres Lagar-Cavilla <andres@lagarcavilla.org>]

 xen/include/asm-x86/page.h        |   1 +
 xen/include/asm-x86/x86_32/page.h |  11 +++++++++++
 xen/include/asm-x86/x86_64/page.h |   5 +++++
 3 files changed, 17 insertions(+), 0 deletions(-)


This conversion is a trivial invocation of virt_to_mfn in 64 bits.
In 32 bits it uses the linear_map.

Signed-off-by: Andres Lagar-Cavilla <andres@lagarcavilla.org>

diff -r bea03a7fe212 -r 42e6ceb8138d xen/include/asm-x86/page.h
--- a/xen/include/asm-x86/page.h
+++ b/xen/include/asm-x86/page.h
@@ -272,6 +272,7 @@ void copy_page_sse2(void *, const void *
 #define pfn_to_paddr(pfn)   __pfn_to_paddr(pfn)
 #define paddr_to_pfn(pa)    __paddr_to_pfn(pa)
 #define paddr_to_pdx(pa)    pfn_to_pdx(paddr_to_pfn(pa))
+#define xen_map_to_mfn(va)  __xen_map_to_mfn(va)
 
 #endif /* !defined(__ASSEMBLY__) */
 
diff -r bea03a7fe212 -r 42e6ceb8138d xen/include/asm-x86/x86_32/page.h
--- a/xen/include/asm-x86/x86_32/page.h
+++ b/xen/include/asm-x86/x86_32/page.h
@@ -71,6 +71,17 @@ static inline void *__maddr_to_virt(unsi
     return (void *)(ma + DIRECTMAP_VIRT_START);
 }
 
+static inline unsigned long __xen_map_to_mfn(void *va)
+{
+    l1_pgentry_t *l1e;
+
+    ASSERT( (((unsigned long) va) >= MAPCACHE_VIRT_START) &&
+            (((unsigned long) va) <= MAPCACHE_VIRT_END) );
+    l1e = &__linear_l1_table[
+            l1_linear_offset((unsigned long) va)];
+    return l1e_get_pfn(*l1e);
+}
+
 /* read access (should only be used for debug printk's) */
 typedef u64 intpte_t;
 #define PRIpte "016llx"
diff -r bea03a7fe212 -r 42e6ceb8138d xen/include/asm-x86/x86_64/page.h
--- a/xen/include/asm-x86/x86_64/page.h
+++ b/xen/include/asm-x86/x86_64/page.h
@@ -104,6 +104,11 @@ static inline void *__maddr_to_virt(unsi
                      ((ma & ma_top_mask) >> pfn_pdx_hole_shift)));
 }
 
+static inline unsigned long __xen_map_to_mfn(void *va)
+{
+    return (__virt_to_maddr((unsigned long) va) >> PAGE_SHIFT);
+}
+
 /* read access (should only be used for debug printk's) */
 typedef u64 intpte_t;
 #define PRIpte "016lx"