[PATCH v1.0 4/4] MM: Switch TS72XX to use sparemem

[cgagneraud@techworks.ie (Christian Gagneraud)]

Tested on TS7260 with 64MB SDRAM (8*8MB). (Other boards will be tested
soon-ish). Special thanks to Matthieu Crappet, Charlie M.

I'm not sure what's the impact for other machine based on EP93XX, it's likely
that SECTION_SIZE_BITS and MAX_PHYSMEM_BITS needs to be define with default
values that suits everyone

PS: Has to be apply on top of this patch:
http://lists.infradead.org/pipermail/linux-arm-kernel/2009-October/001706.html

Signed-off-by: Matthieu Crapet <mcrapet@gmail.com>
Signed-off-by: Christian Gagneraud <cgagneraud@techworks.ie>
---

 arch/arm/Kconfig                           |    1 +
 arch/arm/include/asm/memory.h              |    2 ++
 arch/arm/mach-ep93xx/include/mach/memory.h |   30 ++++++++++++++++++++++++++++
 3 files changed, 33 insertions(+), 0 deletions(-)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 1c4119c..0f1d52f 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -288,6 +288,7 @@ config ARCH_EP93XX
 	select CPU_ARM920T
 	select ARM_AMBA
 	select ARM_VIC
+	select ARCH_SPARSEMEM_ENABLE
 	select GENERIC_GPIO
 	select HAVE_CLK
 	select COMMON_CLKDEV
diff --git a/arch/arm/include/asm/memory.h b/arch/arm/include/asm/memory.h
index cefedf0..6be9d9b 100644
--- a/arch/arm/include/asm/memory.h
+++ b/arch/arm/include/asm/memory.h
@@ -125,8 +125,10 @@
  * private definitions which should NOT be used outside memory.h
  * files.  Use virt_to_phys/phys_to_virt/__pa/__va instead.
  */
+#ifndef __phys_to_virt
 #define __virt_to_phys(x)	((x) - PAGE_OFFSET + PHYS_OFFSET)
 #define __phys_to_virt(x)	((x) - PHYS_OFFSET + PAGE_OFFSET)
+#endif
 
 /*
  * Convert a physical address to a Page Frame Number and back
diff --git a/arch/arm/mach-ep93xx/include/mach/memory.h b/arch/arm/mach-ep93xx/include/mach/memory.h
index 554064e..4cb3329 100644
--- a/arch/arm/mach-ep93xx/include/mach/memory.h
+++ b/arch/arm/mach-ep93xx/include/mach/memory.h
@@ -19,4 +19,34 @@
 #error "Kconfig bug: No EP93xx PHYS_OFFSET set"
 #endif
 
+#ifdef CONFIG_MACH_TS72XX
+/*
+ * Non-linear mapping like so:
+ * phys       => virt
+ * 0x00000000 => 0xc0000000
+ * 0x01000000 => 0xc1000000
+ * 0x04000000 => 0xc4000000
+ * 0x05000000 => 0xc5000000
+ * 0xe0000000 => 0xc8000000
+ * 0xe1000000 => 0xc9000000
+ * 0xe4000000 => 0xcc000000
+ * 0xe5000000 => 0xcd000000
+ *
+ * As suggested here: http://marc.info/?l=linux-arm&m=122754446724900&w=2
+ *
+ * Note that static inline functions won't work here because
+ * arch/arm/include/asm/memory.h uses "#ifndef __virt_to_phys" to check whether to
+ * use generic functions or not.
+ */
+#define __phys_to_virt(p)   \
+            (((p) & 0x07ffffff) | (((p) & 0xe0000000) ? 0x08000000 : 0) | PAGE_OFFSET)
+
+#define __virt_to_phys(v)   \
+            (((v) & 0x07ffffff) | (((v) & 0x08000000) ? 0xe0000000 : 0 ))
+
+#define SECTION_SIZE_BITS 24
+#define MAX_PHYSMEM_BITS 32
+
+#endif /* CONFIG_ARCH_TS72XX */
+
 #endif