sh: Fix up PMB locking.

This first converts the PMB locking over to raw spinlocks, and secondly
fixes up a nested locking issue that was triggering lockdep early on:

 swapper/0 is trying to acquire lock:
  (&pmbe->lock){......}, at: [<806be9bc>] pmb_init+0xf4/0x4dc

 but task is already holding lock:
  (&pmbe->lock){......}, at: [<806be98e>] pmb_init+0xc6/0x4dc

 other info that might help us debug this:
 1 lock held by swapper/0:
  #0:  (&pmbe->lock){......}, at: [<806be98e>] pmb_init+0xc6/0x4dc

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

1 files changed, 15 insertions, 16 deletions

diff --git a/arch/sh/mm/pmb.c b/arch/sh/mm/pmb.c
index 233c011c4d22..b20b1b3eee4b 100644
--- a/arch/sh/mm/pmb.c
+++ b/arch/sh/mm/pmb.c
@@ -40,7 +40,7 @@ struct pmb_entry {
         unsigned long flags;
         unsigned long size;
 
-        spinlock_t lock;
+        raw_spinlock_t lock;
 
         /*
          * 0 .. NR_PMB_ENTRIES for specific entry selection, or
@@ -265,7 +265,7 @@ static struct pmb_entry *pmb_alloc(unsigned long vpn, unsigned long ppn,
 
         memset(pmbe, 0, sizeof(struct pmb_entry));
 
-        spin_lock_init(&pmbe->lock);
+        raw_spin_lock_init(&pmbe->lock);
 
         pmbe->vpn       = vpn;
         pmbe->ppn       = ppn;
@@ -327,9 +327,9 @@ static void set_pmb_entry(struct pmb_entry *pmbe)
 {
         unsigned long flags;
 
-        spin_lock_irqsave(&pmbe->lock, flags);
+        raw_spin_lock_irqsave(&pmbe->lock, flags);
         __set_pmb_entry(pmbe);
-        spin_unlock_irqrestore(&pmbe->lock, flags);
+        raw_spin_unlock_irqrestore(&pmbe->lock, flags);
 }
 #endif /* CONFIG_PM */
 
@@ -368,7 +368,7 @@ int pmb_bolt_mapping(unsigned long vaddr, phys_addr_t phys,
                                 return PTR_ERR(pmbe);
                         }
 
-                        spin_lock_irqsave(&pmbe->lock, flags);
+                        raw_spin_lock_irqsave(&pmbe->lock, flags);
 
                         pmbe->size = pmb_sizes[i].size;
 
@@ -383,9 +383,10 @@ int pmb_bolt_mapping(unsigned long vaddr, phys_addr_t phys,
                          * entries for easier tear-down.
                          */
                         if (likely(pmbp)) {
-                                spin_lock(&pmbp->lock);
+                                raw_spin_lock_nested(&pmbp->lock,
+                                                     SINGLE_DEPTH_NESTING);
                                 pmbp->link = pmbe;
-                                spin_unlock(&pmbp->lock);
+                                raw_spin_unlock(&pmbp->lock);
                         }
 
                         pmbp = pmbe;
@@ -398,7 +399,7 @@ int pmb_bolt_mapping(unsigned long vaddr, phys_addr_t phys,
                         i--;
                         mapped++;
 
-                        spin_unlock_irqrestore(&pmbe->lock, flags);
+                        raw_spin_unlock_irqrestore(&pmbe->lock, flags);
                 }
         } while (size >= SZ_16M);
 
@@ -627,15 +628,14 @@ static void __init pmb_synchronize(void)
                         continue;
                 }
 
-                spin_lock_irqsave(&pmbe->lock, irqflags);
+                raw_spin_lock_irqsave(&pmbe->lock, irqflags);
 
                 for (j = 0; j < ARRAY_SIZE(pmb_sizes); j++)
                         if (pmb_sizes[j].flag == size)
                                 pmbe->size = pmb_sizes[j].size;
 
                 if (pmbp) {
-                        spin_lock(&pmbp->lock);
-
+                        raw_spin_lock_nested(&pmbp->lock, SINGLE_DEPTH_NESTING);
                         /*
                          * Compare the previous entry against the current one to
                          * see if the entries span a contiguous mapping. If so,
@@ -644,13 +644,12 @@ static void __init pmb_synchronize(void)
                          */
                         if (pmb_can_merge(pmbp, pmbe))
                                 pmbp->link = pmbe;
-
-                        spin_unlock(&pmbp->lock);
+                        raw_spin_unlock(&pmbp->lock);
                 }
 
                 pmbp = pmbe;
 
-                spin_unlock_irqrestore(&pmbe->lock, irqflags);
+                raw_spin_unlock_irqrestore(&pmbe->lock, irqflags);
         }
 }
 
@@ -757,7 +756,7 @@ static void __init pmb_resize(void)
                 /*
                  * Found it, now resize it.
                  */
-                spin_lock_irqsave(&pmbe->lock, flags);
+                raw_spin_lock_irqsave(&pmbe->lock, flags);
 
                 pmbe->size = SZ_16M;
                 pmbe->flags &= ~PMB_SZ_MASK;
@@ -767,7 +766,7 @@ static void __init pmb_resize(void)
 
                 __set_pmb_entry(pmbe);
 
-                spin_unlock_irqrestore(&pmbe->lock, flags);
+                raw_spin_unlock_irqrestore(&pmbe->lock, flags);
         }
 
         read_unlock(&pmb_rwlock);