[ARM] mm: enable sparsemem on clps7500 and RiscPC

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

4 files changed, 35 insertions, 3 deletions

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 4eb816c4df7d..83106c98755c 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -250,6 +250,7 @@ config ARCH_CLPS7500
         select TIMER_ACORN
         select ISA
         select NO_IOPORT
+        select ARCH_SPARSEMEM_ENABLE
         help
           Support for the Cirrus Logic PS7500FE system-on-a-chip.
 
@@ -470,6 +471,7 @@ config ARCH_RPC
         select HAVE_PATA_PLATFORM
         select ISA_DMA_API
         select NO_IOPORT
+        select ARCH_SPARSEMEM_ENABLE
         help
           On the Acorn Risc-PC, Linux can support the internal IDE disk and
           CD-ROM interface, serial and parallel port, and the floppy drive.
diff --git a/arch/arm/include/asm/sparsemem.h b/arch/arm/include/asm/sparsemem.h
index 277158191a0d..00098615c6f0 100644
--- a/arch/arm/include/asm/sparsemem.h
+++ b/arch/arm/include/asm/sparsemem.h
@@ -3,8 +3,22 @@
 
 #include <asm/memory.h>
 
-#define MAX_PHYSADDR_BITS       32
-#define MAX_PHYSMEM_BITS        32
-#define SECTION_SIZE_BITS       NODE_MEM_SIZE_BITS
+/*
+ * Two definitions are required for sparsemem:
+ *
+ * MAX_PHYSMEM_BITS: The number of physical address bits required
+ *   to address the last byte of memory.
+ *
+ * SECTION_SIZE_BITS: The number of physical address bits to cover
+ *   the maximum amount of memory in a section.
+ *
+ * Eg, if you have 2 banks of up to 64MB at 0x80000000, 0x84000000,
+ * then MAX_PHYSMEM_BITS is 32, SECTION_SIZE_BITS is 26.
+ *
+ * Define these in your mach/memory.h.
+ */
+#if !defined(SECTION_SIZE_BITS) || !defined(MAX_PHYSMEM_BITS)
+#error Sparsemem is not supported on this platform
+#endif
 
 #endif
diff --git a/arch/arm/mach-clps7500/include/mach/memory.h b/arch/arm/mach-clps7500/include/mach/memory.h
index 3326aa99d3ec..87b32db470c8 100644
--- a/arch/arm/mach-clps7500/include/mach/memory.h
+++ b/arch/arm/mach-clps7500/include/mach/memory.h
@@ -32,4 +32,12 @@
 #define FLUSH_BASE_PHYS         0x00000000
 #define FLUSH_BASE              0xdf000000
 
+/*
+ * Sparsemem support.  Each section is a maximum of 64MB.  The sections
+ * are offset by 128MB and can cover 128MB, so that gives us a maximum
+ * of 29 physmem bits.
+ */
+#define MAX_PHYSMEM_BITS        29
+#define SECTION_SIZE_BITS       26
+
 #endif
diff --git a/arch/arm/mach-rpc/include/mach/memory.h b/arch/arm/mach-rpc/include/mach/memory.h
index 05425d558ee7..9bf7e43e2863 100644
--- a/arch/arm/mach-rpc/include/mach/memory.h
+++ b/arch/arm/mach-rpc/include/mach/memory.h
@@ -36,4 +36,12 @@
 #define FLUSH_BASE_PHYS         0x00000000
 #define FLUSH_BASE              0xdf000000
 
+/*
+ * Sparsemem support.  Each section is a maximum of 64MB.  The sections
+ * are offset by 128MB and can cover 128MB, so that gives us a maximum
+ * of 29 physmem bits.
+ */
+#define MAX_PHYSMEM_BITS        29
+#define SECTION_SIZE_BITS       26
+
 #endif