[PATCH] ppc64: sparsemem memory model

Provide the architecture specific implementation for SPARSEMEM for PPC64
systems.

Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Mike Kravetz <kravetz@us.ibm.com> (in part)
Signed-off-by: Martin Bligh <mbligh@aracnet.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

3 files changed, 41 insertions, 14 deletions

diff --git a/include/asm-ppc64/mmzone.h b/include/asm-ppc64/mmzone.h
index ecc4b07507d6..ed473f4b0152 100644
--- a/include/asm-ppc64/mmzone.h
+++ b/include/asm-ppc64/mmzone.h
@@ -10,9 +10,20 @@
 #include <linux/config.h>
 #include <asm/smp.h>
 
-#ifdef CONFIG_DISCONTIGMEM
+/* generic non-linear memory support:
+ *
+ * 1) we will not split memory into more chunks than will fit into the
+ *    flags field of the struct page
+ */
+
+
+#ifdef CONFIG_NEED_MULTIPLE_NODES
 
 extern struct pglist_data *node_data[];
+/*
+ * Return a pointer to the node data for node n.
+ */
+#define NODE_DATA(nid)          (node_data[nid])
 
 /*
  * Following are specific to this numa platform.
@@ -47,30 +58,27 @@ static inline int pa_to_nid(unsigned long pa)
         return nid;
 }
 
-#define pfn_to_nid(pfn)         pa_to_nid((pfn) << PAGE_SHIFT)
-
-/*
- * Return a pointer to the node data for node n.
- */
-#define NODE_DATA(nid)          (node_data[nid])
-
 #define node_localnr(pfn, nid)  ((pfn) - NODE_DATA(nid)->node_start_pfn)
 
 /*
  * Following are macros that each numa implmentation must define.
  */
 
-/*
- * Given a kernel address, find the home node of the underlying memory.
- */
-#define kvaddr_to_nid(kaddr)    pa_to_nid(__pa(kaddr))
-
 #define node_start_pfn(nid)     (NODE_DATA(nid)->node_start_pfn)
 #define node_end_pfn(nid)       (NODE_DATA(nid)->node_end_pfn)
 
 #define local_mapnr(kvaddr) \
         ( (__pa(kvaddr) >> PAGE_SHIFT) - node_start_pfn(kvaddr_to_nid(kvaddr)) 
 
+#ifdef CONFIG_DISCONTIGMEM
+
+/*
+ * Given a kernel address, find the home node of the underlying memory.
+ */
+#define kvaddr_to_nid(kaddr)    pa_to_nid(__pa(kaddr))
+
+#define pfn_to_nid(pfn)         pa_to_nid((unsigned long)(pfn) << PAGE_SHIFT)
+
 /* Written this way to avoid evaluating arguments twice */
 #define discontigmem_pfn_to_page(pfn) \
 ({ \
@@ -91,6 +99,8 @@ static inline int pa_to_nid(unsigned long pa)
 
 #endif /* CONFIG_DISCONTIGMEM */
 
+#endif /* CONFIG_NEED_MULTIPLE_NODES */
+
 #ifdef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
 #define early_pfn_to_nid(pfn)  pa_to_nid(((unsigned long)pfn) << PAGE_SHIFT)
 #endif
diff --git a/include/asm-ppc64/page.h b/include/asm-ppc64/page.h
index 257d87eb7c34..a5893a305a09 100644
--- a/include/asm-ppc64/page.h
+++ b/include/asm-ppc64/page.h
@@ -217,7 +217,8 @@ extern u64 ppc64_pft_size;		/* Log 2 of page table size */
 #define page_to_pfn(page)       discontigmem_page_to_pfn(page)
 #define pfn_to_page(pfn)        discontigmem_pfn_to_page(pfn)
 #define pfn_valid(pfn)          discontigmem_pfn_valid(pfn)
-#else
+#endif
+#ifdef CONFIG_FLATMEM
 #define pfn_to_page(pfn)        (mem_map + (pfn))
 #define page_to_pfn(page)       ((unsigned long)((page) - mem_map))
 #define pfn_valid(pfn)          ((pfn) < max_mapnr)
diff --git a/include/asm-ppc64/sparsemem.h b/include/asm-ppc64/sparsemem.h
new file mode 100644
index 000000000000..c5bd47e57f17
--- /dev/null
+++ b/include/asm-ppc64/sparsemem.h
@@ -0,0 +1,16 @@
+#ifndef _ASM_PPC64_SPARSEMEM_H
+#define _ASM_PPC64_SPARSEMEM_H 1
+
+#ifdef CONFIG_SPARSEMEM
+/*
+ * SECTION_SIZE_BITS            2^N: how big each section will be
+ * MAX_PHYSADDR_BITS            2^N: how much physical address space we have
+ * MAX_PHYSMEM_BITS             2^N: how much memory we can have in that space
+ */
+#define SECTION_SIZE_BITS       24
+#define MAX_PHYSADDR_BITS       38
+#define MAX_PHYSMEM_BITS        36
+
+#endif /* CONFIG_SPARSEMEM */
+
+#endif /* _ASM_PPC64_SPARSEMEM_H */