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>

1 files changed, 158 insertions, 98 deletions

diff --git a/arch/sh/mm/pmb.c b/arch/sh/mm/pmb.c
index 35b364f931ea..9a516b89839a 100644
--- a/arch/sh/mm/pmb.c
+++ b/arch/sh/mm/pmb.c
@@ -23,6 +23,7 @@
 #include <linux/err.h>
 #include <linux/io.h>
 #include <linux/spinlock.h>
+#include <linux/vmalloc.h>
 #include <asm/sizes.h>
 #include <asm/system.h>
 #include <asm/uaccess.h>
@@ -51,6 +52,16 @@ struct pmb_entry {
 	struct pmb_entry *link;
 };
 
+static struct {
+	unsigned long size;
+	int flag;
+} pmb_sizes[] = {
+	{ .size	= SZ_512M, .flag = PMB_SZ_512M, },
+	{ .size = SZ_128M, .flag = PMB_SZ_128M, },
+	{ .size = SZ_64M,  .flag = PMB_SZ_64M,  },
+	{ .size = SZ_16M,  .flag = PMB_SZ_16M,  },
+};
+
 static void pmb_unmap_entry(struct pmb_entry *, int depth);
 
 static DEFINE_RWLOCK(pmb_rwlock);
@@ -72,6 +83,88 @@ static __always_inline unsigned long mk_pmb_data(unsigned int entry)
 	return mk_pmb_entry(entry) | PMB_DATA;
 }
 
+static __always_inline unsigned int pmb_ppn_in_range(unsigned long ppn)
+{
+	return ppn >= __pa(memory_start) && ppn < __pa(memory_end);
+}
+
+/*
+ * Ensure that the PMB entries match our cache configuration.
+ *
+ * When we are in 32-bit address extended mode, CCR.CB becomes
+ * invalid, so care must be taken to manually adjust cacheable
+ * translations.
+ */
+static __always_inline unsigned long pmb_cache_flags(void)
+{
+	unsigned long flags = 0;
+
+#if defined(CONFIG_CACHE_OFF)
+	flags |= PMB_WT | PMB_UB;
+#elif defined(CONFIG_CACHE_WRITETHROUGH)
+	flags |= PMB_C | PMB_WT | PMB_UB;
+#elif defined(CONFIG_CACHE_WRITEBACK)
+	flags |= PMB_C;
+#endif
+
+	return flags;
+}
+
+/*
+ * Convert typical pgprot value to the PMB equivalent
+ */
+static inline unsigned long pgprot_to_pmb_flags(pgprot_t prot)
+{
+	unsigned long pmb_flags = 0;
+	u64 flags = pgprot_val(prot);
+
+	if (flags & _PAGE_CACHABLE)
+		pmb_flags |= PMB_C;
+	if (flags & _PAGE_WT)
+		pmb_flags |= PMB_WT | PMB_UB;
+
+	return pmb_flags;
+}
+
+static bool pmb_can_merge(struct pmb_entry *a, struct pmb_entry *b)
+{
+	return (b->vpn == (a->vpn + a->size)) &&
+	       (b->ppn == (a->ppn + a->size)) &&
+	       (b->flags == a->flags);
+}
+
+static bool pmb_size_valid(unsigned long size)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(pmb_sizes); i++)
+		if (pmb_sizes[i].size == size)
+			return true;
+
+	return false;
+}
+
+static inline bool pmb_addr_valid(unsigned long addr, unsigned long size)
+{
+	return (addr >= P1SEG && (addr + size - 1) < P3SEG);
+}
+
+static inline bool pmb_prot_valid(pgprot_t prot)
+{
+	return (pgprot_val(prot) & _PAGE_USER) == 0;
+}
+
+static int pmb_size_to_flags(unsigned long size)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(pmb_sizes); i++)
+		if (pmb_sizes[i].size == size)
+			return pmb_sizes[i].flag;
+
+	return 0;
+}
+
 static int pmb_alloc_entry(void)
 {
 	int pos;
@@ -139,33 +232,13 @@ static void pmb_free(struct pmb_entry *pmbe)
 }
 
 /*
- * Ensure that the PMB entries match our cache configuration.
- *
- * When we are in 32-bit address extended mode, CCR.CB becomes
- * invalid, so care must be taken to manually adjust cacheable
- * translations.
- */
-static __always_inline unsigned long pmb_cache_flags(void)
-{
-	unsigned long flags = 0;
-
-#if defined(CONFIG_CACHE_WRITETHROUGH)
-	flags |= PMB_C | PMB_WT | PMB_UB;
-#elif defined(CONFIG_CACHE_WRITEBACK)
-	flags |= PMB_C;
-#endif
-
-	return flags;
-}
-
-/*
  * Must be run uncached.
  */
 static void __set_pmb_entry(struct pmb_entry *pmbe)
 {
-	writel_uncached(pmbe->vpn | PMB_V, mk_pmb_addr(pmbe->entry));
-	writel_uncached(pmbe->ppn | pmbe->flags | PMB_V,
-			mk_pmb_data(pmbe->entry));
+	/* Set V-bit */
+	__raw_writel(pmbe->ppn | pmbe->flags | PMB_V, mk_pmb_data(pmbe->entry));
+	__raw_writel(pmbe->vpn | PMB_V, mk_pmb_addr(pmbe->entry));
 }
 
 static void __clear_pmb_entry(struct pmb_entry *pmbe)
@@ -193,39 +266,56 @@ static void set_pmb_entry(struct pmb_entry *pmbe)
 	spin_unlock_irqrestore(&pmbe->lock, flags);
 }
 
-static struct {
-	unsigned long size;
-	int flag;
-} pmb_sizes[] = {
-	{ .size	= SZ_512M, .flag = PMB_SZ_512M, },
-	{ .size = SZ_128M, .flag = PMB_SZ_128M, },
-	{ .size = SZ_64M,  .flag = PMB_SZ_64M,  },
-	{ .size = SZ_16M,  .flag = PMB_SZ_16M,  },
-};
+int pmb_bolt_mapping(unsigned long vaddr, phys_addr_t phys,
+		     unsigned long size, pgprot_t prot)
+{
+	return 0;
+}
 
-long pmb_remap(unsigned long vaddr, unsigned long phys,
-	       unsigned long size, pgprot_t prot)
+void __iomem *pmb_remap_caller(phys_addr_t phys, unsigned long size,
+			       pgprot_t prot, void *caller)
 {
 	struct pmb_entry *pmbp, *pmbe;
-	unsigned long wanted;
-	int pmb_flags, i;
-	long err;
-	u64 flags;
+	unsigned long pmb_flags;
+	int i, mapped;
+	unsigned long orig_addr, vaddr;
+	phys_addr_t offset, last_addr;
+	phys_addr_t align_mask;
+	unsigned long aligned;
+	struct vm_struct *area;
 
-	flags = pgprot_val(prot);
+	/*
+	 * Small mappings need to go through the TLB.
+	 */
+	if (size < SZ_16M)
+		return ERR_PTR(-EINVAL);
+	if (!pmb_prot_valid(prot))
+		return ERR_PTR(-EINVAL);
 
-	pmb_flags = PMB_WT | PMB_UB;
+	pmbp = NULL;
+	pmb_flags = pgprot_to_pmb_flags(prot);
+	mapped = 0;
 
-	/* Convert typical pgprot value to the PMB equivalent */
-	if (flags & _PAGE_CACHABLE) {
-		pmb_flags |= PMB_C;
+	for (i = 0; i < ARRAY_SIZE(pmb_sizes); i++)
+		if (size >= pmb_sizes[i].size)
+			break;
 
-		if ((flags & _PAGE_WT) == 0)
-			pmb_flags &= ~(PMB_WT | PMB_UB);
-	}
+	last_addr = phys + size;
+	align_mask = ~(pmb_sizes[i].size - 1);
+	offset = phys & ~align_mask;
+	phys &= align_mask;
+	aligned = ALIGN(last_addr, pmb_sizes[i].size) - phys;
 
-	pmbp = NULL;
-	wanted = size;
+	area = __get_vm_area_caller(aligned, VM_IOREMAP, uncached_end,
+				    P3SEG, caller);
+	if (!area)
+		return NULL;
+
+	area->phys_addr = phys;
+	orig_addr = vaddr = (unsigned long)area->addr;
+
+	if (!pmb_addr_valid(vaddr, aligned))
+		return ERR_PTR(-EFAULT);
 
 again:
 	for (i = 0; i < ARRAY_SIZE(pmb_sizes); i++) {
@@ -237,19 +327,19 @@ again:
 		pmbe = pmb_alloc(vaddr, phys, pmb_flags | pmb_sizes[i].flag,
 				 PMB_NO_ENTRY);
 		if (IS_ERR(pmbe)) {
-			err = PTR_ERR(pmbe);
-			goto out;
+			pmb_unmap_entry(pmbp, mapped);
+			return pmbe;
 		}
 
 		spin_lock_irqsave(&pmbe->lock, flags);
 
+		pmbe->size = pmb_sizes[i].size;
+
 		__set_pmb_entry(pmbe);
 
-		phys	+= pmb_sizes[i].size;
-		vaddr	+= pmb_sizes[i].size;
-		size	-= pmb_sizes[i].size;
-
-		pmbe->size = pmb_sizes[i].size;
+		phys	+= pmbe->size;
+		vaddr	+= pmbe->size;
+		size	-= pmbe->size;
 
 		/*
 		 * Link adjacent entries that span multiple PMB entries
@@ -269,6 +359,7 @@ again:
 		 * pmb_sizes[i].size again.
 		 */
 		i--;
+		mapped++;
 
 		spin_unlock_irqrestore(&pmbe->lock, flags);
 	}
@@ -276,61 +367,35 @@ again:
 	if (size >= SZ_16M)
 		goto again;
 
-	return wanted - size;
-
-out:
-	pmb_unmap_entry(pmbp, NR_PMB_ENTRIES);
-
-	return err;
+	return (void __iomem *)(offset + (char *)orig_addr);
 }
 
-void pmb_unmap(unsigned long addr)
+int pmb_unmap(void __iomem *addr)
 {
 	struct pmb_entry *pmbe = NULL;
-	int i;
+	unsigned long vaddr = (unsigned long __force)addr;
+	int i, found = 0;
 
 	read_lock(&pmb_rwlock);
 
 	for (i = 0; i < ARRAY_SIZE(pmb_entry_list); i++) {
 		if (test_bit(i, pmb_map)) {
 			pmbe = &pmb_entry_list[i];
-			if (pmbe->vpn == addr)
+			if (pmbe->vpn == vaddr) {
+				found = 1;
 				break;
+			}
 		}
 	}
 
 	read_unlock(&pmb_rwlock);
 
-	pmb_unmap_entry(pmbe, NR_PMB_ENTRIES);
-}
-
-static bool pmb_can_merge(struct pmb_entry *a, struct pmb_entry *b)
-{
-	return (b->vpn == (a->vpn + a->size)) &&
-	       (b->ppn == (a->ppn + a->size)) &&
-	       (b->flags == a->flags);
-}
-
-static bool pmb_size_valid(unsigned long size)
-{
-	int i;
-
-	for (i = 0; i < ARRAY_SIZE(pmb_sizes); i++)
-		if (pmb_sizes[i].size == size)
-			return true;
-
-	return false;
-}
-
-static int pmb_size_to_flags(unsigned long size)
-{
-	int i;
-
-	for (i = 0; i < ARRAY_SIZE(pmb_sizes); i++)
-		if (pmb_sizes[i].size == size)
-			return pmb_sizes[i].flag;
+	if (found) {
+		pmb_unmap_entry(pmbe, NR_PMB_ENTRIES);
+		return 0;
+	}
 
-	return 0;
+	return -EINVAL;
 }
 
 static void __pmb_unmap_entry(struct pmb_entry *pmbe, int depth)
@@ -368,11 +433,6 @@ static void pmb_unmap_entry(struct pmb_entry *pmbe, int depth)
 	write_unlock_irqrestore(&pmb_rwlock, flags);
 }
 
-static __always_inline unsigned int pmb_ppn_in_range(unsigned long ppn)
-{
-	return ppn >= __pa(memory_start) && ppn < __pa(memory_end);
-}
-
 static void __init pmb_notify(void)
 {
 	int i;