Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit f7fcec93 authored by Paul Mundt's avatar Paul Mundt
Browse files

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: default avatarPaul Mundt <lethal@linux-sh.org>
parent 47da88f3

arch/sh/mm/pmb.c

+15 −16
Original line number Diff line number Diff line
@@ -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);