[PATCH v4 10/14] iommu/amd: Introduce logic to enable/disable IOPF

[Vasant Hegde <vasant.hegde@amd.com>]

From: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>

Add support to enable/disable IOPF feature. So that PRI capable device
can make use of page fault handler in SVA mode.

Note that enable_feature(IOPF) just returns success, as this interface
is going away. IOPF handler will be setup in PASID bind path. Following
patch will add this support.

Also add IOMMU_IOPF as dependency to AMD_IOMMU driver.

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Co-developed-by: Vasant Hegde <vasant.hegde@amd.com>
Signed-off-by: Vasant Hegde <vasant.hegde@amd.com>
---
 drivers/iommu/amd/Kconfig     |  1 +
 drivers/iommu/amd/amd_iommu.h |  2 ++
 drivers/iommu/amd/iommu.c     |  8 +++--
 drivers/iommu/amd/ppr.c       | 61 +++++++++++++++++++++++++++++++++++
 4 files changed, 70 insertions(+), 2 deletions(-)

diff --git a/drivers/iommu/amd/Kconfig b/drivers/iommu/amd/Kconfig
index 443b2c13c37b..d563f6d496ca 100644
--- a/drivers/iommu/amd/Kconfig
+++ b/drivers/iommu/amd/Kconfig
@@ -10,6 +10,7 @@ config AMD_IOMMU
 	select IOMMU_API
 	select IOMMU_IOVA
 	select IOMMU_IO_PGTABLE
+	select IOMMU_IOPF
 	select IOMMUFD_DRIVER if IOMMUFD
 	depends on X86_64 && PCI && ACPI && HAVE_CMPXCHG_DOUBLE
 	help
diff --git a/drivers/iommu/amd/amd_iommu.h b/drivers/iommu/amd/amd_iommu.h
index e4c2618e7539..aed512c10052 100644
--- a/drivers/iommu/amd/amd_iommu.h
+++ b/drivers/iommu/amd/amd_iommu.h
@@ -54,6 +54,8 @@ int amd_iommu_iopf_remove_device(struct amd_iommu *iommu, struct device *dev);
 int amd_iommu_page_response(struct device *dev,
 			    struct iopf_fault *evt,
 			    struct iommu_page_response *resp);
+int amd_iommu_iopf_enable_device(struct device *dev);
+int amd_iommu_iopf_disable_device(struct device *dev);
 
 struct amd_iommu *get_amd_iommu(unsigned int idx);
 u8 amd_iommu_pc_get_max_banks(unsigned int idx);
diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index 2913b7e701cb..ec30cee33f3b 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -2780,9 +2780,11 @@ static const struct iommu_dirty_ops amd_dirty_ops = {
 static int amd_iommu_dev_enable_feature(struct device *dev,
 					enum iommu_dev_features feat)
 {
-	int ret;
+	int ret = 0;
 
 	switch (feat) {
+	case IOMMU_DEV_FEAT_IOPF:
+		break;
 	default:
 		ret = -EINVAL;
 		break;
@@ -2793,9 +2795,11 @@ static int amd_iommu_dev_enable_feature(struct device *dev,
 static int amd_iommu_dev_disable_feature(struct device *dev,
 					 enum iommu_dev_features feat)
 {
-	int ret;
+	int ret = 0;
 
 	switch (feat) {
+	case IOMMU_DEV_FEAT_IOPF:
+		break;
 	default:
 		ret = -EINVAL;
 		break;
diff --git a/drivers/iommu/amd/ppr.c b/drivers/iommu/amd/ppr.c
index c5f2a2b4128d..d7d98b3364be 100644
--- a/drivers/iommu/amd/ppr.c
+++ b/drivers/iommu/amd/ppr.c
@@ -299,3 +299,64 @@ int amd_iommu_iopf_remove_device(struct amd_iommu *iommu, struct device *dev)
 	raw_spin_unlock_irqrestore(&iommu->lock, flags);
 	return ret;
 }
+
+static int iopf_update_device(struct device *dev, bool enable)
+{
+	struct protection_domain *pdom;
+	struct pci_dev *pdev = dev_is_pci(dev) ? to_pci_dev(dev) : NULL;
+	struct amd_iommu *iommu = get_amd_iommu_from_dev(dev);
+	struct iommu_dev_data *dev_data = dev_iommu_priv_get(dev);
+	int ret = 0;
+
+	if (!pdev || !dev_data)
+		return -EINVAL;
+
+	pdom = dev_data->domain;
+	if (!dev_data->domain)
+		return -EINVAL;
+
+	spin_lock(&dev_data->lock);
+
+	if (enable) {
+		if (dev_data->ppr)
+			goto out;
+
+		ret = amd_iommu_iopf_add_device(iommu, dev);
+		if (ret)
+			goto out;
+
+		dev_data->ppr = true;
+	} else {
+		ret = amd_iommu_iopf_remove_device(iommu, dev);
+		dev_data->ppr = false;
+	}
+
+	amd_iommu_dev_update_dte(dev_data, true);
+
+out:
+	spin_unlock(&dev_data->lock);
+	return ret;
+}
+
+int amd_iommu_iopf_enable_device(struct device *dev)
+{
+	struct iommu_dev_data *dev_data = dev_iommu_priv_get(dev);
+
+	if (!dev_data)
+		return -EINVAL;
+
+	if (!dev_data->ats_enabled || !dev_data->pri_enabled)
+		return -EINVAL;
+
+	return iopf_update_device(dev, true);
+}
+
+int amd_iommu_iopf_disable_device(struct device *dev)
+{
+	struct iommu_dev_data *dev_data = dev_iommu_priv_get(dev);
+
+	if (!dev_data || !dev_data->pri_enabled)
+		return -EINVAL;
+
+	return iopf_update_device(dev, false);
+}
-- 
2.31.1