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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>
This commit is contained in:
Paul Mundt 2010-10-14 03:49:15 +09:00
parent 47da88f366
commit f7fcec93b6
1 changed files with 15 additions and 16 deletions
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31
arch/sh/mm/pmb.c
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@ -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);