[ARM PATCH] 1782/1: discontigmem support for PXA chips

Patch from Nicolas Pitre

include/asm-arm/arch-pxa/memory.h

@@ -55,4 +55,52 @@
 #define __virt_to_bus(x)	 __virt_to_phys(x)
 #define __bus_to_virt(x)	 __phys_to_virt(x)
 
+#ifdef CONFIG_DISCONTIGMEM
+/*
+ * The nodes are matched with the physical SDRAM banks as follows:
+ *
+ * 	node 0:  0xa0000000-0xa3ffffff	-->  0xc0000000-0xc3ffffff
+ * 	node 1:  0xa4000000-0xa7ffffff	-->  0xc4000000-0xc7ffffff
+ * 	node 2:  0xa8000000-0xabffffff	-->  0xc8000000-0xcbffffff
+ * 	node 3:  0xac000000-0xafffffff	-->  0xcc000000-0xcfffffff
+ */
+
+#define NR_NODES	4
+
+/*
+ * Given a kernel address, find the home node of the underlying memory.
+ */
+#define KVADDR_TO_NID(addr) (((unsigned long)(addr) - PAGE_OFFSET) >> 26)
+
+/*
+ * Given a page frame number, convert it to a node id.
+ */
+#define PFN_TO_NID(pfn)		(((pfn) - PHYS_PFN_OFFSET) >> (26 - PAGE_SHIFT))
+
+/*
+ * Given a kaddr, ADDR_TO_MAPBASE finds the owning node of the memory
+ * and returns the mem_map of that node.
+ */
+#define ADDR_TO_MAPBASE(kaddr)	NODE_MEM_MAP(KVADDR_TO_NID(kaddr))
+
+/*
+ * Given a page frame number, find the owning node of the memory
+ * and returns the mem_map of that node.
+ */
+#define PFN_TO_MAPBASE(pfn)	NODE_MEM_MAP(PFN_TO_NID(pfn))
+
+/*
+ * Given a kaddr, LOCAL_MEM_MAP finds the owning node of the memory
+ * and returns the index corresponding to the appropriate page in the
+ * node's mem_map.
+ */
+#define LOCAL_MAP_NR(addr) \
+	(((unsigned long)(addr) & 0x03ffffff) >> PAGE_SHIFT)
+
+#else
+
+#define PFN_TO_NID(addr)	(0)
+
+#endif
+
 #endif