[MIPS] Make ioremap() work on TX39/49 special unmapped segment

TX39XX and TX49XX have "reserved" segment in CKSEG3 area.
0xff000000-0xff3fffff on TX49XX and 0xff000000-0xfffeffff on TX39XX
are reserved (unmapped, uncached).  Controllers on these SoCs are
placed in this segment.

This patch add plat_ioremap() and plat_iounmap() to override default
behavior and implement these hooks for TX39/TX49.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

6 files changed, 112 insertions, 0 deletions

diff --git a/arch/mips/Makefile b/arch/mips/Makefile
index 2b9af2fd5507..96d4abbd7b30 100644
--- a/arch/mips/Makefile
+++ b/arch/mips/Makefile
@@ -580,6 +580,7 @@ load-$(CONFIG_TOSHIBA_JMR3927)	+= 0xffffffff80050000
 #
 core-$(CONFIG_TOSHIBA_RBTX4927) += arch/mips/tx4927/toshiba_rbtx4927/
 core-$(CONFIG_TOSHIBA_RBTX4927) += arch/mips/tx4927/common/
+cflags-$(CONFIG_TOSHIBA_RBTX4927) += -Iinclude/asm-mips/mach-tx49xx
 load-$(CONFIG_TOSHIBA_RBTX4927) += 0xffffffff80020000
 
 #
@@ -587,6 +588,7 @@ load-$(CONFIG_TOSHIBA_RBTX4927)	+= 0xffffffff80020000
 #
 core-$(CONFIG_TOSHIBA_RBTX4938) += arch/mips/tx4938/toshiba_rbtx4938/
 core-$(CONFIG_TOSHIBA_RBTX4938) += arch/mips/tx4938/common/
+cflags-$(CONFIG_TOSHIBA_RBTX4938) += -Iinclude/asm-mips/mach-tx49xx
 load-$(CONFIG_TOSHIBA_RBTX4938) += 0xffffffff80100000
 
 cflags-y                        += -Iinclude/asm-mips/mach-generic
diff --git a/include/asm-mips/io.h b/include/asm-mips/io.h
index 92ec2618560c..12bcc1f9fba9 100644
--- a/include/asm-mips/io.h
+++ b/include/asm-mips/io.h
@@ -178,6 +178,11 @@ extern void __iounmap(const volatile void __iomem *addr);
 static inline void __iomem * __ioremap_mode(phys_t offset, unsigned long size,
         unsigned long flags)
 {
+        void __iomem *addr = plat_ioremap(offset, size, flags);
+
+        if (addr)
+                return addr;
+
 #define __IS_LOW512(addr) (!((phys_t)(addr) & (phys_t) ~0x1fffffffULL))
 
         if (cpu_has_64bit_addresses) {
@@ -282,6 +287,9 @@ static inline void __iomem * __ioremap_mode(phys_t offset, unsigned long size,
 
 static inline void iounmap(const volatile void __iomem *addr)
 {
+        if (plat_iounmap(addr))
+                return;
+
 #define __IS_KSEG1(addr) (((unsigned long)(addr) & ~0x1fffffffUL) == CKSEG1)
 
         if (cpu_has_64bit_addresses ||
diff --git a/include/asm-mips/mach-au1x00/ioremap.h b/include/asm-mips/mach-au1x00/ioremap.h
index 098fca4289bb..364cea2dc71f 100644
--- a/include/asm-mips/mach-au1x00/ioremap.h
+++ b/include/asm-mips/mach-au1x00/ioremap.h
@@ -28,4 +28,15 @@ static inline phys_t fixup_bigphys_addr(phys_t phys_addr, phys_t size)
         return __fixup_bigphys_addr(phys_addr, size);
 }
 
+static inline void __iomem *plat_ioremap(phys_t offset, unsigned long size,
+        unsigned long flags)
+{
+        return NULL;
+}
+
+static inline int plat_iounmap(const volatile void __iomem *addr)
+{
+        return 0;
+}
+
 #endif /* __ASM_MACH_AU1X00_IOREMAP_H */
diff --git a/include/asm-mips/mach-generic/ioremap.h b/include/asm-mips/mach-generic/ioremap.h
index 9b64ff6e485d..b379938d47f0 100644
--- a/include/asm-mips/mach-generic/ioremap.h
+++ b/include/asm-mips/mach-generic/ioremap.h
@@ -20,4 +20,15 @@ static inline phys_t fixup_bigphys_addr(phys_t phys_addr, phys_t size)
         return phys_addr;
 }
 
+static inline void __iomem *plat_ioremap(phys_t offset, unsigned long size,
+        unsigned long flags)
+{
+        return NULL;
+}
+
+static inline int plat_iounmap(const volatile void __iomem *addr)
+{
+        return 0;
+}
+
 #endif /* __ASM_MACH_GENERIC_IOREMAP_H */
diff --git a/include/asm-mips/mach-jmr3927/ioremap.h b/include/asm-mips/mach-jmr3927/ioremap.h
new file mode 100644
index 000000000000..aa131ad7f717
--- /dev/null
+++ b/include/asm-mips/mach-jmr3927/ioremap.h
@@ -0,0 +1,38 @@
+/*
+ *      include/asm-mips/mach-jmr3927/ioremap.h
+ *
+ *      This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ */
+#ifndef __ASM_MACH_JMR3927_IOREMAP_H
+#define __ASM_MACH_JMR3927_IOREMAP_H
+
+#include <linux/types.h>
+
+/*
+ * Allow physical addresses to be fixed up to help peripherals located
+ * outside the low 32-bit range -- generic pass-through version.
+ */
+static inline phys_t fixup_bigphys_addr(phys_t phys_addr, phys_t size)
+{
+        return phys_addr;
+}
+
+static inline void __iomem *plat_ioremap(phys_t offset, unsigned long size,
+        unsigned long flags)
+{
+#define TXX9_DIRECTMAP_BASE     0xff000000ul
+        if (offset >= TXX9_DIRECTMAP_BASE &&
+            offset < TXX9_DIRECTMAP_BASE + 0xf0000)
+                return (void __iomem *)offset;
+        return NULL;
+}
+
+static inline int plat_iounmap(const volatile void __iomem *addr)
+{
+        return (unsigned long)addr >= TXX9_DIRECTMAP_BASE;
+}
+
+#endif /* __ASM_MACH_JMR3927_IOREMAP_H */
diff --git a/include/asm-mips/mach-tx49xx/ioremap.h b/include/asm-mips/mach-tx49xx/ioremap.h
new file mode 100644
index 000000000000..88cf546719b8
--- /dev/null
+++ b/include/asm-mips/mach-tx49xx/ioremap.h
@@ -0,0 +1,42 @@
+/*
+ *      include/asm-mips/mach-tx49xx/ioremap.h
+ *
+ *      This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ */
+#ifndef __ASM_MACH_TX49XX_IOREMAP_H
+#define __ASM_MACH_TX49XX_IOREMAP_H
+
+#include <linux/types.h>
+
+/*
+ * Allow physical addresses to be fixed up to help peripherals located
+ * outside the low 32-bit range -- generic pass-through version.
+ */
+static inline phys_t fixup_bigphys_addr(phys_t phys_addr, phys_t size)
+{
+        return phys_addr;
+}
+
+static inline void __iomem *plat_ioremap(phys_t offset, unsigned long size,
+        unsigned long flags)
+{
+#ifdef CONFIG_64BIT
+#define TXX9_DIRECTMAP_BASE     0xfff000000ul
+#else
+#define TXX9_DIRECTMAP_BASE     0xff000000ul
+#endif
+        if (offset >= TXX9_DIRECTMAP_BASE &&
+            offset < TXX9_DIRECTMAP_BASE + 0x400000)
+                return (void __iomem *)(unsigned long)(int)offset;
+        return NULL;
+}
+
+static inline int plat_iounmap(const volatile void __iomem *addr)
+{
+        return (unsigned long)addr >= (unsigned long)(int)TXX9_DIRECTMAP_BASE;
+}
+
+#endif /* __ASM_MACH_TX49XX_IOREMAP_H */