[PATCH v2 21/24] iommu/dma: Factor out flush queue init

[Robin Murphy <robin.murphy@arm.com>]

Factor out flush queue setup from the initial domain init so that we
can potentially trigger it from sysfs later on in a domain's lifetime.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
---
 drivers/iommu/dma-iommu.c | 30 ++++++++++++++++++++----------
 include/linux/dma-iommu.h |  9 ++++++---
 2 files changed, 26 insertions(+), 13 deletions(-)

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 7f3968865387..304a3ec71223 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -310,6 +310,25 @@ static bool dev_is_untrusted(struct device *dev)
 	return dev_is_pci(dev) && to_pci_dev(dev)->untrusted;
 }
 
+int iommu_dma_init_fq(struct iommu_domain *domain)
+{
+	struct iommu_dma_cookie *cookie = domain->iova_cookie;
+
+	if (domain->type != IOMMU_DOMAIN_DMA_FQ)
+		return -EINVAL;
+	if (cookie->fq_domain)
+		return 0;
+
+	if (init_iova_flush_queue(&cookie->iovad, iommu_dma_flush_iotlb_all,
+				  iommu_dma_entry_dtor)) {
+		pr_warn("iova flush queue initialization failed\n");
+		domain->type = IOMMU_DOMAIN_DMA;
+		return -ENODEV;
+	}
+	cookie->fq_domain = domain;
+	return 0;
+}
+
 /**
  * iommu_dma_init_domain - Initialise a DMA mapping domain
  * @domain: IOMMU domain previously prepared by iommu_get_dma_cookie()
@@ -362,16 +381,7 @@ static int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base,
 	}
 
 	init_iova_domain(iovad, 1UL << order, base_pfn);
-
-	if (domain->type == IOMMU_DOMAIN_DMA_FQ && !cookie->fq_domain) {
-		if (init_iova_flush_queue(iovad, iommu_dma_flush_iotlb_all,
-					  iommu_dma_entry_dtor)) {
-			pr_warn("iova flush queue initialization failed\n");
-			domain->type = IOMMU_DOMAIN_DMA;
-		} else {
-			cookie->fq_domain = domain;
-		}
-	}
+	iommu_dma_init_fq(domain);
 
 	return iova_reserve_iommu_regions(dev, domain);
 }
diff --git a/include/linux/dma-iommu.h b/include/linux/dma-iommu.h
index 758ca4694257..81ab647f1618 100644
--- a/include/linux/dma-iommu.h
+++ b/include/linux/dma-iommu.h
@@ -20,6 +20,7 @@ void iommu_put_dma_cookie(struct iommu_domain *domain);
 
 /* Setup call for arch DMA mapping code */
 void iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 dma_limit);
+int iommu_dma_init_fq(struct iommu_domain *domain);
 
 /* The DMA API isn't _quite_ the whole story, though... */
 /*
@@ -37,9 +38,6 @@ void iommu_dma_compose_msi_msg(struct msi_desc *desc,
 
 void iommu_dma_get_resv_regions(struct device *dev, struct list_head *list);
 
-void iommu_dma_free_cpu_cached_iovas(unsigned int cpu,
-		struct iommu_domain *domain);
-
 extern bool iommu_dma_forcedac;
 
 #else /* CONFIG_IOMMU_DMA */
@@ -54,6 +52,11 @@ static inline void iommu_setup_dma_ops(struct device *dev, u64 dma_base,
 {
 }
 
+static inline int iommu_dma_init_fq(struct iommu_domain *domain)
+{
+	return -EINVAL;
+}
+
 static inline int iommu_get_dma_cookie(struct iommu_domain *domain)
 {
 	return -ENODEV;
-- 
2.25.1