iommu/arm-smmu-v3: Add SVA device feature

Implement the IOMMU device feature callbacks to support the SVA feature.
At the moment dev_has_feat() returns false since I/O Page Faults and BTM
aren't yet implemented.

Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20200918101852.582559-12-jean-philippe@linaro.org
Signed-off-by: Will Deacon <will@kernel.org>

1 files changed, 49 insertions, 0 deletions

diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
index cb94c0924196..9255c9600fb8 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
@@ -10,6 +10,8 @@
 #include "arm-smmu-v3.h"
 #include "../../io-pgtable-arm.h"
 
+static DEFINE_MUTEX(sva_lock);
+
 /*
  * Check if the CPU ASID is available on the SMMU side. If a private context
  * descriptor is using it, try to replace it.
@@ -197,3 +199,50 @@ bool arm_smmu_sva_supported(struct arm_smmu_device *smmu)
 
 	return true;
 }
+
+static bool arm_smmu_iopf_supported(struct arm_smmu_master *master)
+{
+	return false;
+}
+
+bool arm_smmu_master_sva_supported(struct arm_smmu_master *master)
+{
+	if (!(master->smmu->features & ARM_SMMU_FEAT_SVA))
+		return false;
+
+	/* SSID and IOPF support are mandatory for the moment */
+	return master->ssid_bits && arm_smmu_iopf_supported(master);
+}
+
+bool arm_smmu_master_sva_enabled(struct arm_smmu_master *master)
+{
+	bool enabled;
+
+	mutex_lock(&sva_lock);
+	enabled = master->sva_enabled;
+	mutex_unlock(&sva_lock);
+	return enabled;
+}
+
+int arm_smmu_master_enable_sva(struct arm_smmu_master *master)
+{
+	mutex_lock(&sva_lock);
+	master->sva_enabled = true;
+	mutex_unlock(&sva_lock);
+
+	return 0;
+}
+
+int arm_smmu_master_disable_sva(struct arm_smmu_master *master)
+{
+	mutex_lock(&sva_lock);
+	if (!list_empty(&master->bonds)) {
+		dev_err(master->dev, "cannot disable SVA, device is bound\n");
+		mutex_unlock(&sva_lock);
+		return -EBUSY;
+	}
+	master->sva_enabled = false;
+	mutex_unlock(&sva_lock);
+
+	return 0;
+}