[RFC PATCH v2 45/58] iommu/arm-smmu-v3-kvm: Allocate structures and reset device

[Mostafa Saleh]

From: Jean-Philippe Brucker <jean-philippe at linaro.org>

Allocate the structures that will be shared between hypervisor and SMMU:
command queue and stream table. Install them in the MMIO registers,
along with some configuration bits. After hyp initialization, the host
won't have access to those pages anymore.

Signed-off-by: Jean-Philippe Brucker <jean-philippe at linaro.org>
Signed-off-by: Mostafa Saleh <smostafa at google.com>
---
 .../iommu/arm/arm-smmu-v3/arm-smmu-v3-kvm.c   | 53 +++++++++++++++++++
 1 file changed, 53 insertions(+)

diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-kvm.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-kvm.c
index 4b0c9ff6e7f1..e4a5bdc830bc 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-kvm.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-kvm.c
@@ -18,6 +18,7 @@ extern struct kvm_iommu_ops kvm_nvhe_sym(smmu_ops);
 struct host_arm_smmu_device {
 	struct arm_smmu_device		smmu;
 	pkvm_handle_t			id;
+	u32				boot_gbpa;
 };
 
 #define smmu_to_host(_smmu) \
@@ -66,6 +67,35 @@ static bool kvm_arm_smmu_validate_features(struct arm_smmu_device *smmu)
 	return true;
 }
 
+static int kvm_arm_smmu_device_reset(struct host_arm_smmu_device *host_smmu)
+{
+	int ret;
+	u32 reg;
+	struct arm_smmu_device *smmu = &host_smmu->smmu;
+
+	reg = readl_relaxed(smmu->base + ARM_SMMU_CR0);
+	if (reg & CR0_SMMUEN)
+		dev_warn(smmu->dev, "SMMU currently enabled! Resetting...\n");
+
+	/* Disable bypass */
+	host_smmu->boot_gbpa = readl_relaxed(smmu->base + ARM_SMMU_GBPA);
+	ret = arm_smmu_update_gbpa(smmu, GBPA_ABORT, 0);
+	if (ret)
+		return ret;
+
+	ret = arm_smmu_device_disable(smmu);
+	if (ret)
+		return ret;
+
+	/* Stream table */
+	arm_smmu_write_strtab(smmu);
+
+	/* Command queue */
+	writeq_relaxed(smmu->cmdq.q.q_base, smmu->base + ARM_SMMU_CMDQ_BASE);
+
+	return 0;
+}
+
 static int kvm_arm_smmu_probe(struct platform_device *pdev)
 {
 	int ret;
@@ -113,6 +143,20 @@ static int kvm_arm_smmu_probe(struct platform_device *pdev)
 	if (!kvm_arm_smmu_validate_features(smmu))
 		return -ENODEV;
 
+	ret = arm_smmu_init_one_queue(smmu, &smmu->cmdq.q, smmu->base,
+				      ARM_SMMU_CMDQ_PROD, ARM_SMMU_CMDQ_CONS,
+				      CMDQ_ENT_DWORDS, "cmdq");
+	if (ret)
+		return ret;
+
+	ret = arm_smmu_init_strtab(smmu);
+	if (ret)
+		return ret;
+
+	ret = kvm_arm_smmu_device_reset(host_smmu);
+	if (ret)
+		return ret;
+
 	platform_set_drvdata(pdev, smmu);
 
 	/* Hypervisor parameters */
@@ -129,6 +173,15 @@ static int kvm_arm_smmu_probe(struct platform_device *pdev)
 
 static void kvm_arm_smmu_remove(struct platform_device *pdev)
 {
+	struct arm_smmu_device *smmu = platform_get_drvdata(pdev);
+	struct host_arm_smmu_device *host_smmu = smmu_to_host(smmu);
+
+	/*
+	 * There was an error during hypervisor setup. The hyp driver may
+	 * have already enabled the device, so disable it.
+	 */
+	arm_smmu_device_disable(smmu);
+	arm_smmu_update_gbpa(smmu, host_smmu->boot_gbpa, GBPA_ABORT);
 }
 
 static const struct of_device_id arm_smmu_of_match[] = {
-- 
2.47.0.338.g60cca15819-goog