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>

diff --git a/arch/sh/mm/pmb.c b/arch/sh/mm/pmb.c
index 233c011c4d224226ac210aaee6ceee5acc233da6..b20b1b3eee4b267778102e0420f9119a88cf959e 100644 (file)
--- 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);