From 1ee0186b9a128a872887e16e2d1520ea37a95dc4 Mon Sep 17 00:00:00 2001 From: Lu Baolu Date: Sat, 21 Sep 2019 15:06:44 +0800 Subject: [PATCH] iommu/vt-d: Refactor find_domain() helper Current find_domain() helper checks and does the deferred domain attachment and return the domain in use. This isn't always the use case for the callers. Some callers only want to retrieve the current domain in use. This refactors find_domain() into two helpers: 1) find_domain() only returns the domain in use; 2) deferred_attach_domain() does the deferred domain attachment if required and return the domain in use. Cc: Ashok Raj Cc: Jacob Pan Cc: Kevin Tian Signed-off-by: Lu Baolu Signed-off-by: Joerg Roedel --- drivers/iommu/intel-iommu.c | 31 ++++++++++++++++++------------- 1 file changed, 18 insertions(+), 13 deletions(-) diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index 3f974919d3bd..e70cc1c5055f 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -2420,14 +2420,24 @@ static void domain_remove_dev_info(struct dmar_domain *domain) spin_unlock_irqrestore(&device_domain_lock, flags); } -/* - * find_domain - * Note: we use struct device->archdata.iommu stores the info - */ static struct dmar_domain *find_domain(struct device *dev) { struct device_domain_info *info; + if (unlikely(dev->archdata.iommu == DEFER_DEVICE_DOMAIN_INFO || + dev->archdata.iommu == DUMMY_DEVICE_DOMAIN_INFO)) + return NULL; + + /* No lock here, assumes no domain exit in normal case */ + info = dev->archdata.iommu; + if (likely(info)) + return info->domain; + + return NULL; +} + +static struct dmar_domain *deferred_attach_domain(struct device *dev) +{ if (unlikely(dev->archdata.iommu == DEFER_DEVICE_DOMAIN_INFO)) { struct iommu_domain *domain; @@ -2437,12 +2447,7 @@ static struct dmar_domain *find_domain(struct device *dev) intel_iommu_attach_device(domain, dev); } - /* No lock here, assumes no domain exit in normal case */ - info = dev->archdata.iommu; - - if (likely(info)) - return info->domain; - return NULL; + return find_domain(dev); } static inline struct device_domain_info * @@ -3512,7 +3517,7 @@ static dma_addr_t __intel_map_single(struct device *dev, phys_addr_t paddr, BUG_ON(dir == DMA_NONE); - domain = find_domain(dev); + domain = deferred_attach_domain(dev); if (!domain) return DMA_MAPPING_ERROR; @@ -3732,7 +3737,7 @@ static int intel_map_sg(struct device *dev, struct scatterlist *sglist, int nele if (!iommu_need_mapping(dev)) return dma_direct_map_sg(dev, sglist, nelems, dir, attrs); - domain = find_domain(dev); + domain = deferred_attach_domain(dev); if (!domain) return 0; @@ -3819,7 +3824,7 @@ bounce_map_single(struct device *dev, phys_addr_t paddr, size_t size, int prot = 0; int ret; - domain = find_domain(dev); + domain = deferred_attach_domain(dev); if (WARN_ON(dir == DMA_NONE || !domain)) return DMA_MAPPING_ERROR;