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Diffstat (limited to 'arch/sh/mm/pmb.c')
-rw-r--r--arch/sh/mm/pmb.c140
1 files changed, 96 insertions, 44 deletions
diff --git a/arch/sh/mm/pmb.c b/arch/sh/mm/pmb.c
index 55d21902d707..75b8861ec624 100644
--- a/arch/sh/mm/pmb.c
+++ b/arch/sh/mm/pmb.c
@@ -128,13 +128,67 @@ static inline unsigned long pgprot_to_pmb_flags(pgprot_t prot)
return pmb_flags;
}
-static bool pmb_can_merge(struct pmb_entry *a, struct pmb_entry *b)
+static inline 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_mapping_exists(unsigned long vaddr, phys_addr_t phys,
+ unsigned long size)
+{
+ int i;
+
+ read_lock(&pmb_rwlock);
+
+ for (i = 0; i < ARRAY_SIZE(pmb_entry_list); i++) {
+ struct pmb_entry *pmbe, *iter;
+ unsigned long span;
+
+ if (!test_bit(i, pmb_map))
+ continue;
+
+ pmbe = &pmb_entry_list[i];
+
+ /*
+ * See if VPN and PPN are bounded by an existing mapping.
+ */
+ if ((vaddr < pmbe->vpn) || (vaddr >= (pmbe->vpn + pmbe->size)))
+ continue;
+ if ((phys < pmbe->ppn) || (phys >= (pmbe->ppn + pmbe->size)))
+ continue;
+
+ /*
+ * Now see if we're in range of a simple mapping.
+ */
+ if (size <= pmbe->size) {
+ read_unlock(&pmb_rwlock);
+ return true;
+ }
+
+ span = pmbe->size;
+
+ /*
+ * Finally for sizes that involve compound mappings, walk
+ * the chain.
+ */
+ for (iter = pmbe->link; iter; iter = iter->link)
+ span += iter->size;
+
+ /*
+ * Nothing else to do if the range requirements are met.
+ */
+ if (size <= span) {
+ read_unlock(&pmb_rwlock);
+ return true;
+ }
+ }
+
+ read_unlock(&pmb_rwlock);
+ return false;
+}
+
static bool pmb_size_valid(unsigned long size)
{
int i;
@@ -272,64 +326,62 @@ int pmb_bolt_mapping(unsigned long vaddr, phys_addr_t phys,
unsigned long size, pgprot_t prot)
{
struct pmb_entry *pmbp, *pmbe;
- unsigned long pmb_flags;
+ unsigned long flags, pmb_flags;
int i, mapped;
if (!pmb_addr_valid(vaddr, size))
return -EFAULT;
+ if (pmb_mapping_exists(vaddr, phys, size))
+ return 0;
pmb_flags = pgprot_to_pmb_flags(prot);
pmbp = NULL;
-again:
- for (i = mapped = 0; i < ARRAY_SIZE(pmb_sizes); i++) {
- unsigned long flags;
-
- if (size < pmb_sizes[i].size)
- continue;
-
- pmbe = pmb_alloc(vaddr, phys, pmb_flags | pmb_sizes[i].flag,
- PMB_NO_ENTRY);
- if (IS_ERR(pmbe)) {
- pmb_unmap_entry(pmbp, mapped);
- return PTR_ERR(pmbe);
- }
-
- spin_lock_irqsave(&pmbe->lock, flags);
+ do {
+ for (i = mapped = 0; i < ARRAY_SIZE(pmb_sizes); i++) {
+ if (size < pmb_sizes[i].size)
+ continue;
+
+ pmbe = pmb_alloc(vaddr, phys, pmb_flags |
+ pmb_sizes[i].flag, PMB_NO_ENTRY);
+ if (IS_ERR(pmbe)) {
+ pmb_unmap_entry(pmbp, mapped);
+ return PTR_ERR(pmbe);
+ }
- pmbe->size = pmb_sizes[i].size;
+ spin_lock_irqsave(&pmbe->lock, flags);
- __set_pmb_entry(pmbe);
+ pmbe->size = pmb_sizes[i].size;
- phys += pmbe->size;
- vaddr += pmbe->size;
- size -= pmbe->size;
+ __set_pmb_entry(pmbe);
- /*
- * Link adjacent entries that span multiple PMB entries
- * for easier tear-down.
- */
- if (likely(pmbp)) {
- spin_lock(&pmbp->lock);
- pmbp->link = pmbe;
- spin_unlock(&pmbp->lock);
- }
+ phys += pmbe->size;
+ vaddr += pmbe->size;
+ size -= pmbe->size;
- pmbp = pmbe;
+ /*
+ * Link adjacent entries that span multiple PMB
+ * entries for easier tear-down.
+ */
+ if (likely(pmbp)) {
+ spin_lock(&pmbp->lock);
+ pmbp->link = pmbe;
+ spin_unlock(&pmbp->lock);
+ }
- /*
- * Instead of trying smaller sizes on every iteration
- * (even if we succeed in allocating space), try using
- * pmb_sizes[i].size again.
- */
- i--;
- mapped++;
+ pmbp = pmbe;
- spin_unlock_irqrestore(&pmbe->lock, flags);
- }
+ /*
+ * Instead of trying smaller sizes on every
+ * iteration (even if we succeed in allocating
+ * space), try using pmb_sizes[i].size again.
+ */
+ i--;
+ mapped++;
- if (size >= SZ_16M)
- goto again;
+ spin_unlock_irqrestore(&pmbe->lock, flags);
+ }
+ } while (size >= SZ_16M);
return 0;
}
@@ -374,7 +426,7 @@ void __iomem *pmb_remap_caller(phys_addr_t phys, unsigned long size,
orig_addr = vaddr = (unsigned long)area->addr;
ret = pmb_bolt_mapping(vaddr, phys, size, prot);
- if (ret != 0)
+ if (unlikely(ret != 0))
return ERR_PTR(ret);
return (void __iomem *)(offset + (char *)orig_addr);