[PATCH 1/6] xen/arm: introduce map_phys_range

[Stefano Stabellini <stefano.stabellini@eu.citrix.com>]

Introduce a function to map a physical memory into virtual memory.
It is going to be used later to map the videoram.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
---
 xen/arch/arm/mm.c        |   23 +++++++++++++++++++++++
 xen/include/asm-arm/mm.h |    3 +++
 2 files changed, 26 insertions(+), 0 deletions(-)

diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c
index 68ee9da..418a414 100644
--- a/xen/arch/arm/mm.c
+++ b/xen/arch/arm/mm.c
@@ -376,6 +376,29 @@ void __init setup_frametable_mappings(paddr_t ps, paddr_t pe)
     frametable_virt_end = FRAMETABLE_VIRT_START + (nr_pages * sizeof(struct page_info));
 }
 
+/* Map the physical memory range start -  end at the virtual address
+ * virt_start in 2MB chunks. start and virt_start have to be 2MB
+ * aligned.
+ */
+void map_phys_range(paddr_t start, paddr_t end,
+        unsigned long virt_start, unsigned attributes)
+{
+    ASSERT(!(start & ((1 << 21) - 1)));
+    ASSERT(!(virt_start & ((1 << 21) - 1)));
+
+    while ( start < end )
+    {
+        lpae_t e = mfn_to_xen_entry(start >> PAGE_SHIFT);
+        e.pt.ai = attributes;
+        write_pte(xen_second + second_table_offset(virt_start), e);
+        
+        start += (1<<21);
+        virt_start += (1<<21);
+    }
+
+    flush_xen_data_tlb();
+}
+
 enum mg { mg_clear, mg_ro, mg_rw, mg_rx };
 static void set_pte_flags_on_range(const char *p, unsigned long l, enum mg mg)
 {
diff --git a/xen/include/asm-arm/mm.h b/xen/include/asm-arm/mm.h
index 3549c83..a11f20b 100644
--- a/xen/include/asm-arm/mm.h
+++ b/xen/include/asm-arm/mm.h
@@ -152,6 +152,9 @@ extern void setup_frametable_mappings(paddr_t ps, paddr_t pe);
 extern void set_fixmap(unsigned map, unsigned long mfn, unsigned attributes);
 /* Remove a mapping from a fixmap entry */
 extern void clear_fixmap(unsigned map);
+/* map a 2MB aligned physical range in virtual memory. */
+extern void map_phys_range(paddr_t start, paddr_t end,
+		unsigned long virt_start, unsigned attributes);
 
 
 #define mfn_valid(mfn)        ({                                              \
-- 
1.7.2.5