From 3d39cecc4841e8d4c4abdb401d10180f5faaded0 Mon Sep 17 00:00:00 2001 From: David Woodhouse Date: Wed, 8 Jul 2009 15:23:30 +0100 Subject: [PATCH] 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: David Woodhouse --- drivers/pci/intel-iommu.c | 3 --- drivers/pci/iova.c | 16 ++++------------ include/linux/iova.h | 1 - 3 files changed, 4 insertions(+), 16 deletions(-) diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c index c5f7c73cbb55..d6a857397ec3 100644 --- a/drivers/pci/intel-iommu.c +++ b/drivers/pci/intel-iommu.c @@ -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); diff --git a/drivers/pci/iova.c b/drivers/pci/iova.c index 46dd440e2315..7914951ef29a 100644 --- a/drivers/pci/iova.c +++ b/drivers/pci/iova.c @@ -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); } diff --git a/include/linux/iova.h b/include/linux/iova.h index 228f6c94b69c..76a0759e88ec 100644 --- a/include/linux/iova.h +++ b/include/linux/iova.h @@ -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 */