diff options
| -rw-r--r-- | drivers/iommu/dma-iommu.c | 17 |
1 files changed, 8 insertions, 9 deletions
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index 6e573d1cb8bf..c363294b3bb9 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -19,6 +19,7 @@ #include <linux/iova.h> #include <linux/irq.h> #include <linux/mm.h> +#include <linux/mutex.h> #include <linux/pci.h> #include <linux/scatterlist.h> #include <linux/vmalloc.h> @@ -44,7 +45,6 @@ struct iommu_dma_cookie { dma_addr_t msi_iova; }; struct list_head msi_page_list; - spinlock_t msi_lock; /* Domain for flush queue callback; NULL if flush queue not in use */ struct iommu_domain *fq_domain; @@ -63,7 +63,6 @@ static struct iommu_dma_cookie *cookie_alloc(enum iommu_dma_cookie_type type) cookie = kzalloc(sizeof(*cookie), GFP_KERNEL); if (cookie) { - spin_lock_init(&cookie->msi_lock); INIT_LIST_HEAD(&cookie->msi_page_list); cookie->type = type; } @@ -1176,7 +1175,7 @@ static struct iommu_dma_msi_page *iommu_dma_get_msi_page(struct device *dev, if (msi_page->phys == msi_addr) return msi_page; - msi_page = kzalloc(sizeof(*msi_page), GFP_ATOMIC); + msi_page = kzalloc(sizeof(*msi_page), GFP_KERNEL); if (!msi_page) return NULL; @@ -1206,7 +1205,7 @@ int iommu_dma_prepare_msi(struct msi_desc *desc, phys_addr_t msi_addr) struct iommu_domain *domain = iommu_get_domain_for_dev(dev); struct iommu_dma_cookie *cookie; struct iommu_dma_msi_page *msi_page; - unsigned long flags; + static DEFINE_MUTEX(msi_prepare_lock); /* see below */ if (!domain || !domain->iova_cookie) { desc->iommu_cookie = NULL; @@ -1216,13 +1215,13 @@ int iommu_dma_prepare_msi(struct msi_desc *desc, phys_addr_t msi_addr) cookie = domain->iova_cookie; /* - * We disable IRQs to rule out a possible inversion against - * irq_desc_lock if, say, someone tries to retarget the affinity - * of an MSI from within an IPI handler. + * In fact the whole prepare operation should already be serialised by + * irq_domain_mutex further up the callchain, but that's pretty subtle + * on its own, so consider this locking as failsafe documentation... */ - spin_lock_irqsave(&cookie->msi_lock, flags); + mutex_lock(&msi_prepare_lock); msi_page = iommu_dma_get_msi_page(dev, msi_addr, domain); - spin_unlock_irqrestore(&cookie->msi_lock, flags); + mutex_unlock(&msi_prepare_lock); msi_desc_set_iommu_cookie(desc, msi_page); |