[PATCH v4 15/20] iommu/tegra: gart: Allow only one active domain at a time
From: Dmitry Osipenko <digetx@gmail.com>
Date: 2018-09-24 00:47:29
Also in:
linux-iommu, linux-tegra, lkml
Subsystem:
iommu subsystem, tegra iommu drivers, the rest · Maintainers:
Joerg Roedel, Will Deacon, Thierry Reding, Linus Torvalds
GART has a single address space that is shared by all devices, hence only one domain could be active at a time. Signed-off-by: Dmitry Osipenko <digetx@gmail.com> --- drivers/iommu/tegra-gart.c | 9 +++++++++ 1 file changed, 9 insertions(+)
diff --git a/drivers/iommu/tegra-gart.c b/drivers/iommu/tegra-gart.c
index 1d45b023adea..9f7d3afb686f 100644
--- a/drivers/iommu/tegra-gart.c
+++ b/drivers/iommu/tegra-gart.c@@ -55,6 +55,7 @@ struct gart_device { spinlock_t pte_lock; /* for pagetable */ struct list_head client; spinlock_t client_lock; /* for client list */ + struct iommu_domain *active_domain; /* current active domain */ struct device *dev; struct iommu_device iommu; /* IOMMU Core handle */
@@ -184,6 +185,12 @@ static int gart_iommu_attach_dev(struct iommu_domain *domain, goto fail; } } + if (gart->active_domain && gart->active_domain != domain) { + dev_err(gart->dev, "Only one domain can be active at a time\n"); + err = -EINVAL; + goto fail; + } + gart->active_domain = domain; list_add(&client->list, &gart->client); spin_unlock(&gart->client_lock); dev_dbg(gart->dev, "Attached %s\n", dev_name(dev));
@@ -206,6 +213,8 @@ static void __gart_iommu_detach_dev(struct iommu_domain *domain, if (c->dev == dev) { list_del(&c->list); devm_kfree(gart->dev, c); + if (list_empty(&gart->client)) + gart->active_domain = NULL; dev_dbg(gart->dev, "Detached %s\n", dev_name(dev)); return; }
--
2.19.0