sh: reworked dynamic PMB mapping.

This implements a fairly significant overhaul of the dynamic PMB mapping
code. The primary change here is that the PMB gets its own VMA that
follows the uncached mapping and we attempt to be a bit more intelligent
with dynamic sizing, multi-entry mapping, and so forth.

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

arch/sh/include/asm/io.h

@@ -291,21 +291,21 @@ unsigned long long poke_real_address_q(unsigned long long addr,
  * doesn't exist, so everything must go through page tables.
  */
 #ifdef CONFIG_MMU
-void __iomem *__ioremap_caller(unsigned long offset, unsigned long size,
+void __iomem *__ioremap_caller(phys_addr_t offset, unsigned long size,
 			       pgprot_t prot, void *caller);
 void __iounmap(void __iomem *addr);
 
 static inline void __iomem *
-__ioremap(unsigned long offset, unsigned long size, pgprot_t prot)
+__ioremap(phys_addr_t offset, unsigned long size, pgprot_t prot)
 {
 	return __ioremap_caller(offset, size, prot, __builtin_return_address(0));
 }
 
 static inline void __iomem *
-__ioremap_29bit(unsigned long offset, unsigned long size, pgprot_t prot)
+__ioremap_29bit(phys_addr_t offset, unsigned long size, pgprot_t prot)
 {
 #ifdef CONFIG_29BIT
-	unsigned long last_addr = offset + size - 1;
+	phys_addr_t last_addr = offset + size - 1;
 
 	/*
 	 * For P1 and P2 space this is trivial, as everything is already
@@ -329,7 +329,7 @@ __ioremap_29bit(unsigned long offset, unsigned long size, pgprot_t prot)
 }
 
 static inline void __iomem *
-__ioremap_mode(unsigned long offset, unsigned long size, pgprot_t prot)
+__ioremap_mode(phys_addr_t offset, unsigned long size, pgprot_t prot)
 {
 	void __iomem *ret;
 
@@ -349,35 +349,32 @@ __ioremap_mode(unsigned long offset, unsigned long size, pgprot_t prot)
 #define __iounmap(addr)				do { } while (0)
 #endif /* CONFIG_MMU */
 
-static inline void __iomem *
-ioremap(unsigned long offset, unsigned long size)
+static inline void __iomem *ioremap(phys_addr_t offset, unsigned long size)
 {
 	return __ioremap_mode(offset, size, PAGE_KERNEL_NOCACHE);
 }
 
 static inline void __iomem *
-ioremap_cache(unsigned long offset, unsigned long size)
+ioremap_cache(phys_addr_t offset, unsigned long size)
 {
 	return __ioremap_mode(offset, size, PAGE_KERNEL);
 }
 
 #ifdef CONFIG_HAVE_IOREMAP_PROT
 static inline void __iomem *
-ioremap_prot(resource_size_t offset, unsigned long size, unsigned long flags)
+ioremap_prot(phys_addr_t offset, unsigned long size, unsigned long flags)
 {
 	return __ioremap_mode(offset, size, __pgprot(flags));
 }
 #endif
 
 #ifdef CONFIG_IOREMAP_FIXED
-extern void __iomem *ioremap_fixed(resource_size_t, unsigned long,
-				   unsigned long, pgprot_t);
+extern void __iomem *ioremap_fixed(phys_addr_t, unsigned long, pgprot_t);
 extern int iounmap_fixed(void __iomem *);
 extern void ioremap_fixed_init(void);
 #else
 static inline void __iomem *
-ioremap_fixed(resource_size_t phys_addr, unsigned long offset,
-	      unsigned long size, pgprot_t prot)
+ioremap_fixed(phys_addr_t phys_addr, unsigned long size, pgprot_t prot)
 {
 	BUG();
 	return NULL;

arch/sh/include/asm/mmu.h

@@ -55,19 +55,29 @@ typedef struct {
 
 #ifdef CONFIG_PMB
 /* arch/sh/mm/pmb.c */
-long pmb_remap(unsigned long virt, unsigned long phys,
-	       unsigned long size, pgprot_t prot);
-void pmb_unmap(unsigned long addr);
-void pmb_init(void);
 bool __in_29bit_mode(void);
+
+void pmb_init(void);
+int pmb_bolt_mapping(unsigned long virt, phys_addr_t phys,
+		     unsigned long size, pgprot_t prot);
+void __iomem *pmb_remap_caller(phys_addr_t phys, unsigned long size,
+			       pgprot_t prot, void *caller);
+int pmb_unmap(void __iomem *addr);
+
 #else
-static inline long pmb_remap(unsigned long virt, unsigned long phys,
-			     unsigned long size, pgprot_t prot)
+
+static inline void __iomem *
+pmb_remap_caller(phys_addr_t phys, unsigned long size,
+		 pgprot_t prot, void *caller)
+{
+	return NULL;
+}
+
+static inline int pmb_unmap(void __iomem *addr)
 {
 	return -EINVAL;
 }
 
-#define pmb_unmap(addr)		do { } while (0)
 #define pmb_init(addr)		do { } while (0)
 
 #ifdef CONFIG_29BIT
@@ -77,6 +87,13 @@ static inline long pmb_remap(unsigned long virt, unsigned long phys,
 #endif
 
 #endif /* CONFIG_PMB */
+
+static inline void __iomem *
+pmb_remap(phys_addr_t phys, unsigned long size, pgprot_t prot)
+{
+	return pmb_remap_caller(phys, size, prot, __builtin_return_address(0));
+}
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* __MMU_H */

arch/sh/mm/ioremap.c

@@ -34,30 +34,39 @@
  * caller shouldn't need to know that small detail.
  */
 void __iomem * __init_refok
-__ioremap_caller(unsigned long phys_addr, unsigned long size,
+__ioremap_caller(phys_addr_t phys_addr, unsigned long size,
 		 pgprot_t pgprot, void *caller)
 {
 	struct vm_struct *area;
 	unsigned long offset, last_addr, addr, orig_addr;
+	void __iomem *mapped;
 
 	/* Don't allow wraparound or zero size */
 	last_addr = phys_addr + size - 1;
 	if (!size || last_addr < phys_addr)
 		return NULL;
 
+	/*
+	 * If we can't yet use the regular approach, go the fixmap route.
+	 */
+	if (!mem_init_done)
+		return ioremap_fixed(phys_addr, size, pgprot);
+
+	/*
+	 * First try to remap through the PMB.
+	 * PMB entries are all pre-faulted.
+	 */
+	mapped = pmb_remap_caller(phys_addr, size, pgprot, caller);
+	if (mapped && !IS_ERR(mapped))
+		return mapped;
+
 	/*
 	 * Mappings have to be page-aligned
 	 */
 	offset = phys_addr & ~PAGE_MASK;
 	phys_addr &= PAGE_MASK;
 	size = PAGE_ALIGN(last_addr+1) - phys_addr;
 
-	/*
-	 * If we can't yet use the regular approach, go the fixmap route.
-	 */
-	if (!mem_init_done)
-		return ioremap_fixed(phys_addr, offset, size, pgprot);
-
 	/*
 	 * Ok, go for it..
 	 */
@@ -67,33 +76,10 @@ __ioremap_caller(unsigned long phys_addr, unsigned long size,
 	area->phys_addr = phys_addr;
 	orig_addr = addr = (unsigned long)area->addr;
 
-#ifdef CONFIG_PMB
-	/*
-	 * First try to remap through the PMB once a valid VMA has been
-	 * established. Smaller allocations (or the rest of the size
-	 * remaining after a PMB mapping due to the size not being
-	 * perfectly aligned on a PMB size boundary) are then mapped
-	 * through the UTLB using conventional page tables.
-	 *
-	 * PMB entries are all pre-faulted.
-	 */
-	if (unlikely(phys_addr >= P1SEG)) {
-		unsigned long mapped;
-
-		mapped = pmb_remap(addr, phys_addr, size, pgprot);
-		if (likely(mapped)) {
-			addr		+= mapped;
-			phys_addr	+= mapped;
-			size		-= mapped;
-		}
+	if (ioremap_page_range(addr, addr + size, phys_addr, pgprot)) {
+		vunmap((void *)orig_addr);
+		return NULL;
 	}
-#endif
-
-	if (likely(size))
-		if (ioremap_page_range(addr, addr + size, phys_addr, pgprot)) {
-			vunmap((void *)orig_addr);
-			return NULL;
-		}
 
 	return (void __iomem *)(offset + (char *)orig_addr);
 }
@@ -133,23 +119,11 @@ void __iounmap(void __iomem *addr)
 	if (iounmap_fixed(addr) == 0)
 		return;
 
-#ifdef CONFIG_PMB
 	/*
-	 * Purge any PMB entries that may have been established for this
-	 * mapping, then proceed with conventional VMA teardown.
-	 *
-	 * XXX: Note that due to the way that remove_vm_area() does
-	 * matching of the resultant VMA, we aren't able to fast-forward
-	 * the address past the PMB space until the end of the VMA where
-	 * the page tables reside. As such, unmap_vm_area() will be
-	 * forced to linearly scan over the area until it finds the page
-	 * tables where PTEs that need to be unmapped actually reside,
-	 * which is far from optimal. Perhaps we need to use a separate
-	 * VMA for the PMB mappings?
-	 *					-- PFM.
+	 * If the PMB handled it, there's nothing else to do.
 	 */
-	pmb_unmap(vaddr);
-#endif
+	if (pmb_unmap(addr) == 0)
+		return;
 
 	p = remove_vm_area((void *)(vaddr & PAGE_MASK));
 	if (!p) {

arch/sh/mm/ioremap_fixed.c

@@ -45,14 +45,21 @@ void __init ioremap_fixed_init(void)
 }
 
 void __init __iomem *
-ioremap_fixed(resource_size_t phys_addr, unsigned long offset,
-	      unsigned long size, pgprot_t prot)
+ioremap_fixed(phys_addr_t phys_addr, unsigned long size, pgprot_t prot)
 {
 	enum fixed_addresses idx0, idx;
 	struct ioremap_map *map;
 	unsigned int nrpages;
+	unsigned long offset;
 	int i, slot;
 
+	/*
+	 * Mappings have to be page-aligned
+	 */
+	offset = phys_addr & ~PAGE_MASK;
+	phys_addr &= PAGE_MASK;
+	size = PAGE_ALIGN(phys_addr + size) - phys_addr;
+
 	slot = -1;
 	for (i = 0; i < FIX_N_IOREMAPS; i++) {
 		map = &ioremap_maps[i];