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Commit 3d39cecc authored by David Woodhouse's avatar David Woodhouse
Browse files

intel-iommu: Remove superfluous iova_alloc_lock from IOVA code 



We only ever obtain this lock immediately before the iova_rbtree_lock,
and release it immediately after the iova_rbtree_lock. So ditch it and
just use iova_rbtree_lock.

[v2: Remove the lockdep bits this time too]
Signed-off-by: default avatarDavid Woodhouse <David.Woodhouse@intel.com>
parent 147202aa

drivers/pci/intel-iommu.c

+0 −3
Original line number Diff line number Diff line
@@ -1309,7 +1309,6 @@ static void iommu_detach_domain(struct dmar_domain *domain, 
}



static struct iova_domain reserved_iova_list;

static struct lock_class_key reserved_alloc_key;

static struct lock_class_key reserved_rbtree_key;



static void dmar_init_reserved_ranges(void)
@@ -1320,8 +1319,6 @@ static void dmar_init_reserved_ranges(void) 


	init_iova_domain(&reserved_iova_list, DMA_32BIT_PFN);



	lockdep_set_class(&reserved_iova_list.iova_alloc_lock,

		&reserved_alloc_key);

	lockdep_set_class(&reserved_iova_list.iova_rbtree_lock,

		&reserved_rbtree_key);

drivers/pci/iova.c

+4 −12
Original line number Diff line number Diff line
@@ -22,7 +22,6 @@ 
void

init_iova_domain(struct iova_domain *iovad, unsigned long pfn_32bit)

{

	spin_lock_init(&iovad->iova_alloc_lock);

	spin_lock_init(&iovad->iova_rbtree_lock);

	iovad->rbroot = RB_ROOT;

	iovad->cached32_node = NULL;
@@ -205,7 +204,6 @@ alloc_iova(struct iova_domain *iovad, unsigned long size, 
	unsigned long limit_pfn,

	bool size_aligned)

{

	unsigned long flags;

	struct iova *new_iova;

	int ret;
@@ -219,11 +217,9 @@ alloc_iova(struct iova_domain *iovad, unsigned long size, 
	if (size_aligned)

		size = __roundup_pow_of_two(size);



	spin_lock_irqsave(&iovad->iova_alloc_lock, flags);

	ret = __alloc_and_insert_iova_range(iovad, size, limit_pfn,

			new_iova, size_aligned);



	spin_unlock_irqrestore(&iovad->iova_alloc_lock, flags);

	if (ret) {

		free_iova_mem(new_iova);

		return NULL;
@@ -381,8 +377,7 @@ reserve_iova(struct iova_domain *iovad, 
	struct iova *iova;

	unsigned int overlap = 0;



	spin_lock_irqsave(&iovad->iova_alloc_lock, flags);

	spin_lock(&iovad->iova_rbtree_lock);

	spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);

	for (node = rb_first(&iovad->rbroot); node; node = rb_next(node)) {

		if (__is_range_overlap(node, pfn_lo, pfn_hi)) {

			iova = container_of(node, struct iova, node);
@@ -402,8 +397,7 @@ reserve_iova(struct iova_domain *iovad, 
	iova = __insert_new_range(iovad, pfn_lo, pfn_hi);

finish:



	spin_unlock(&iovad->iova_rbtree_lock);

	spin_unlock_irqrestore(&iovad->iova_alloc_lock, flags);

	spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);

	return iova;

}
@@ -420,8 +414,7 @@ copy_reserved_iova(struct iova_domain *from, struct iova_domain *to) 
	unsigned long flags;

	struct rb_node *node;



	spin_lock_irqsave(&from->iova_alloc_lock, flags);

	spin_lock(&from->iova_rbtree_lock);

	spin_lock_irqsave(&from->iova_rbtree_lock, flags);

	for (node = rb_first(&from->rbroot); node; node = rb_next(node)) {

		struct iova *iova = container_of(node, struct iova, node);

		struct iova *new_iova;
@@ -430,6 +423,5 @@ copy_reserved_iova(struct iova_domain *from, struct iova_domain *to) 
			printk(KERN_ERR "Reserve iova range %lx@%lx failed\n",

				iova->pfn_lo, iova->pfn_lo);

	}

	spin_unlock(&from->iova_rbtree_lock);

	spin_unlock_irqrestore(&from->iova_alloc_lock, flags);

	spin_unlock_irqrestore(&from->iova_rbtree_lock, flags);

}

include/linux/iova.h

+0 −1
Original line number Diff line number Diff line
@@ -28,7 +28,6 @@ struct iova { 


/* holds all the iova translations for a domain */

struct iova_domain {

	spinlock_t	iova_alloc_lock;/* Lock to protect iova  allocation */

	spinlock_t	iova_rbtree_lock; /* Lock to protect update of rbtree */

	struct rb_root	rbroot;		/* iova domain rbtree root */

	struct rb_node	*cached32_node; /* Save last alloced node */