[ARM] Clean up discontigmem support

Most architectures have fairly simple discontiguous memory - a
simple set of successive regions each containing some memory.
These can be described simply as a log2 of their maximum size,
along with the base address of the first region and the number
of regions.

The base address is already described by PHYS_PFN_OFFSET, and
the number of regions via the MAX_NUMNODES and the number of
online nodes.

If we then supply the log2 of their maximum size, all the other
discontigmem macros can move into generic code.

There is one exception: lh7a40x seems to have a more complicated
setup; this is left alone.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 39 insertions, 0 deletions

diff --git a/include/asm-arm/memory.h b/include/asm-arm/memory.h
index 91d536c215d7..d9bfb39adabf 100644
--- a/include/asm-arm/memory.h
+++ b/include/asm-arm/memory.h
@@ -215,6 +215,7 @@ static inline __deprecated void *bus_to_virt(unsigned long x)
  *  virt_addr_valid(k)  indicates whether a virtual address is valid
  */
 #ifndef CONFIG_DISCONTIGMEM
+
 #define ARCH_PFN_OFFSET         PHYS_PFN_OFFSET
 #define pfn_valid(pfn)          ((pfn) >= PHYS_PFN_OFFSET && (pfn) < (PHYS_PFN_OFFSET + max_mapnr))
 
@@ -230,6 +231,7 @@ static inline __deprecated void *bus_to_virt(unsigned long x)
  * around in memory.
  */
 #include <linux/numa.h>
+
 #define arch_pfn_to_nid(pfn)    PFN_TO_NID(pfn)
 #define arch_local_page_offset(pfn, nid) LOCAL_MAP_NR((pfn) << PAGE_SHIFT)
 
@@ -256,6 +258,43 @@ static inline __deprecated void *bus_to_virt(unsigned long x)
  */
 #define PHYS_TO_NID(addr)       PFN_TO_NID((addr) >> 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))
+
+#ifdef NODE_MEM_SIZE_BITS
+#define NODE_MEM_SIZE_MASK      ((1 << NODE_MEM_SIZE_BITS) - 1)
+
+/*
+ * Given a kernel address, find the home node of the underlying memory.
+ */
+#define KVADDR_TO_NID(addr) \
+        (((unsigned long)(addr) - PAGE_OFFSET) >> NODE_MEM_SIZE_BITS)
+
+/*
+ * Given a page frame number, convert it to a node id.
+ */
+#define PFN_TO_NID(pfn) \
+        (((pfn) - PHYS_PFN_OFFSET) >> (NODE_MEM_SIZE_BITS - PAGE_SHIFT))
+
+/*
+ * 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) & NODE_MEM_SIZE_MASK) >> PAGE_SHIFT)
+
+#endif /* NODE_MEM_SIZE_BITS */
+
 #endif /* !CONFIG_DISCONTIGMEM */
 
 /*