sh: fixed PMB mode refactoring.

This introduces some much overdue chainsawing of the fixed PMB support.
fixed PMB was introduced initially to work around the fact that dynamic
PMB mode was relatively broken, though they were never intended to
converge. The main areas where there are differences are whether the
system is booted in 29-bit mode or 32-bit mode, and whether legacy
mappings are to be preserved. Any system booting in true 32-bit mode will
not care about legacy mappings, so these are roughly decoupled.

Regardless of the entry point, PMB and 32BIT are directly related as far
as the kernel is concerned, so we also switch back to having one select
the other.

With legacy mappings iterated through and applied in the initialization
path it's now possible to finally merge the two implementations and
permit dynamic remapping overtop of remaining entries regardless of
whether boot mappings are crafted by hand or inherited from the boot
loader.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

4 files changed, 39 insertions, 12 deletions

diff --git a/arch/sh/include/asm/addrspace.h b/arch/sh/include/asm/addrspace.h
index 99d6b3ecbe22..bcd7d4d78f6b 100644
--- a/arch/sh/include/asm/addrspace.h
+++ b/arch/sh/include/asm/addrspace.h
@@ -28,7 +28,7 @@
 /* Returns the privileged segment base of a given address  */
 #define PXSEG(a)	(((unsigned long)(a)) & 0xe0000000)
 
-#if defined(CONFIG_29BIT) || defined(CONFIG_PMB_FIXED)
+#ifdef CONFIG_29BIT
 /*
  * Map an address to a certain privileged segment
  */
@@ -40,7 +40,7 @@
 	((__typeof__(a))(((unsigned long)(a) & 0x1fffffff) | P3SEG))
 #define P4SEGADDR(a)	\
 	((__typeof__(a))(((unsigned long)(a) & 0x1fffffff) | P4SEG))
-#endif /* 29BIT || PMB_FIXED */
+#endif /* 29BIT */
 #endif /* P1SEG */
 
 /* Check if an address can be reached in 29 bits */
diff --git a/arch/sh/include/asm/io.h b/arch/sh/include/asm/io.h
index 026dd659a640..f4314d8b05b8 100644
--- a/arch/sh/include/asm/io.h
+++ b/arch/sh/include/asm/io.h
@@ -244,18 +244,11 @@ __ioremap(unsigned long offset, unsigned long size, unsigned long flags)
 }
 
 static inline void __iomem *
-__ioremap_mode(unsigned long offset, unsigned long size, unsigned long flags)
+__ioremap_29bit(unsigned long offset, unsigned long size, unsigned long flags)
 {
-#if defined(CONFIG_SUPERH32) && !defined(CONFIG_PMB_FIXED) && !defined(CONFIG_PMB)
+#ifdef CONFIG_29BIT
 	unsigned long last_addr = offset + size - 1;
-#endif
-	void __iomem *ret;
 
-	ret = __ioremap_trapped(offset, size);
-	if (ret)
-		return ret;
-
-#if defined(CONFIG_SUPERH32) && !defined(CONFIG_PMB_FIXED) && !defined(CONFIG_PMB)
 	/*
 	 * For P1 and P2 space this is trivial, as everything is already
 	 * mapped. Uncached access for P1 addresses are done through P2.
@@ -274,6 +267,22 @@ __ioremap_mode(unsigned long offset, unsigned long size, unsigned long flags)
 		return (void __iomem *)P4SEGADDR(offset);
 #endif
 
+	return NULL;
+}
+
+static inline void __iomem *
+__ioremap_mode(unsigned long offset, unsigned long size, unsigned long flags)
+{
+	void __iomem *ret;
+
+	ret = __ioremap_trapped(offset, size);
+	if (ret)
+		return ret;
+
+	ret = __ioremap_29bit(offset, size, flags);
+	if (ret)
+		return ret;
+
 	return __ioremap(offset, size, flags);
 }
 #else
diff --git a/arch/sh/include/asm/mmu.h b/arch/sh/include/asm/mmu.h
index c7426ad9926e..4b0882bf5183 100644
--- a/arch/sh/include/asm/mmu.h
+++ b/arch/sh/include/asm/mmu.h
@@ -65,11 +65,29 @@ struct pmb_entry {
 	struct pmb_entry *link;
 };
 
+#ifdef CONFIG_PMB
 /* arch/sh/mm/pmb.c */
 long pmb_remap(unsigned long virt, unsigned long phys,
 	       unsigned long size, unsigned long flags);
 void pmb_unmap(unsigned long addr);
 int pmb_init(void);
+#else
+static inline long pmb_remap(unsigned long virt, unsigned long phys,
+			     unsigned long size, unsigned long flags)
+{
+	return -EINVAL
+}
+
+static inline void pmb_unmap(unsigned long addr)
+{
+}
+
+static inline int pmb_init(void)
+{
+	return -ENODEV;
+}
+#endif /* CONFIG_PMB */
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* __MMU_H */
diff --git a/arch/sh/include/asm/page.h b/arch/sh/include/asm/page.h
index 81bffc0d6860..a86c0f1d05d4 100644
--- a/arch/sh/include/asm/page.h
+++ b/arch/sh/include/asm/page.h
@@ -127,7 +127,7 @@ typedef struct page *pgtable_t;
  * is not visible (it is part of the PMB mapping) and so needs to be
  * added or subtracted as required.
  */
-#if defined(CONFIG_PMB_FIXED)
+#if defined(CONFIG_PMB_LEGACY)
 /* phys = virt - PAGE_OFFSET - (__MEMORY_START & 0xe0000000) */
 #define PMB_OFFSET	(PAGE_OFFSET - PXSEG(__MEMORY_START))
 #define __pa(x)	((unsigned long)(x) - PMB_OFFSET)