[PATCH v2 3/3] iommu: Allow drivers to say if they use report_iommu_fault()

[Jason Gunthorpe <jgg@nvidia.com>]

report_iommu_fault() is an older API that has been superseded by
iommu_report_device_fault() which is capable to support PRI.

Only two external drivers consume this, drivers/remoteproc and
drivers/gpu/drm/msm. Ideally they would move over to the new APIs, but for
now protect against accidentally mix and matching the wrong components.

The iommu drivers support either the old iommu_set_fault_handler() via the
driver calling report_iommu_fault(), or they are newer server focused
drivers that call iommu_report_device_fault().

Include a flag in the iommu_ops if the driver calls report_iommu_fault()
and block iommu_set_fault_handler() for domain's of iommu drivers that
can't support it.

Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
---
 drivers/iommu/arm/arm-smmu/arm-smmu.c   | 1 +
 drivers/iommu/arm/arm-smmu/qcom_iommu.c | 1 +
 drivers/iommu/iommu.c                   | 6 +++++-
 drivers/iommu/ipmmu-vmsa.c              | 1 +
 drivers/iommu/mtk_iommu.c               | 1 +
 drivers/iommu/mtk_iommu_v1.c            | 1 +
 drivers/iommu/omap-iommu.c              | 1 +
 drivers/iommu/rockchip-iommu.c          | 1 +
 drivers/iommu/sun50i-iommu.c            | 1 +
 include/linux/iommu.h                   | 3 +++
 10 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c b/drivers/iommu/arm/arm-smmu/arm-smmu.c
index 4ced4b5bee4df3..f68a0576b9a3a6 100644
--- a/drivers/iommu/arm/arm-smmu/arm-smmu.c
+++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c
@@ -1643,6 +1643,7 @@ static const struct iommu_ops arm_smmu_ops = {
 	.get_resv_regions	= arm_smmu_get_resv_regions,
 	.def_domain_type	= arm_smmu_def_domain_type,
 	.owner			= THIS_MODULE,
+	.report_iommu_fault_supported = true,
 	.default_domain_ops = &(const struct iommu_domain_ops) {
 		.attach_dev		= arm_smmu_attach_dev,
 		.map_pages		= arm_smmu_map_pages,
diff --git a/drivers/iommu/arm/arm-smmu/qcom_iommu.c b/drivers/iommu/arm/arm-smmu/qcom_iommu.c
index c5be95e560317e..173d5957796790 100644
--- a/drivers/iommu/arm/arm-smmu/qcom_iommu.c
+++ b/drivers/iommu/arm/arm-smmu/qcom_iommu.c
@@ -597,6 +597,7 @@ static const struct iommu_ops qcom_iommu_ops = {
 	.probe_device	= qcom_iommu_probe_device,
 	.device_group	= generic_device_group,
 	.of_xlate	= qcom_iommu_of_xlate,
+	.report_iommu_fault_supported = true,
 	.default_domain_ops = &(const struct iommu_domain_ops) {
 		.attach_dev	= qcom_iommu_attach_dev,
 		.map_pages	= qcom_iommu_map,
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 59244c744eabd2..8d9086a37671e1 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -2005,6 +2005,9 @@ EXPORT_SYMBOL_GPL(iommu_group_has_isolated_msi);
  * This function should be used by IOMMU users which want to be notified
  * whenever an IOMMU fault happens.
  *
+ * This is a legacy API not supported by all drivers. New users should look
+ * to using domain->iopf_handler for the modern API.
+ *
  * The fault handler itself should return 0 on success, and an appropriate
  * error code otherwise.
  */
@@ -2012,7 +2015,8 @@ void iommu_set_fault_handler(struct iommu_domain *domain,
 					iommu_fault_handler_t handler,
 					void *token)
 {
-	if (WARN_ON(!domain || domain->cookie_type != IOMMU_COOKIE_NONE))
+	if (WARN_ON(!domain || domain->cookie_type != IOMMU_COOKIE_NONE ||
+		    !domain->owner->report_iommu_fault_supported))
 		return;
 
 	domain->cookie_type = IOMMU_COOKIE_FAULT_HANDLER;
diff --git a/drivers/iommu/ipmmu-vmsa.c b/drivers/iommu/ipmmu-vmsa.c
index ffa892f6571406..04a5836bf36000 100644
--- a/drivers/iommu/ipmmu-vmsa.c
+++ b/drivers/iommu/ipmmu-vmsa.c
@@ -884,6 +884,7 @@ static const struct iommu_ops ipmmu_ops = {
 	.device_group = IS_ENABLED(CONFIG_ARM) && !IS_ENABLED(CONFIG_IOMMU_DMA)
 			? generic_device_group : generic_single_device_group,
 	.of_xlate = ipmmu_of_xlate,
+	.report_iommu_fault_supported = true,
 	.default_domain_ops = &(const struct iommu_domain_ops) {
 		.attach_dev	= ipmmu_attach_device,
 		.map_pages	= ipmmu_map,
diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index 0e0285348d2b8e..ccf6fdeb64a261 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -1018,6 +1018,7 @@ static const struct iommu_ops mtk_iommu_ops = {
 	.of_xlate	= mtk_iommu_of_xlate,
 	.get_resv_regions = mtk_iommu_get_resv_regions,
 	.owner		= THIS_MODULE,
+	.report_iommu_fault_supported = true,
 	.default_domain_ops = &(const struct iommu_domain_ops) {
 		.attach_dev	= mtk_iommu_attach_device,
 		.map_pages	= mtk_iommu_map,
diff --git a/drivers/iommu/mtk_iommu_v1.c b/drivers/iommu/mtk_iommu_v1.c
index 10cc0b1197e801..3dd6222d210921 100644
--- a/drivers/iommu/mtk_iommu_v1.c
+++ b/drivers/iommu/mtk_iommu_v1.c
@@ -581,6 +581,7 @@ static const struct iommu_ops mtk_iommu_v1_ops = {
 	.release_device	= mtk_iommu_v1_release_device,
 	.device_group	= generic_device_group,
 	.owner          = THIS_MODULE,
+	.report_iommu_fault_supported = true,
 	.default_domain_ops = &(const struct iommu_domain_ops) {
 		.attach_dev	= mtk_iommu_v1_attach_device,
 		.map_pages	= mtk_iommu_v1_map,
diff --git a/drivers/iommu/omap-iommu.c b/drivers/iommu/omap-iommu.c
index 5c6f5943f44b1f..7ba67600f32915 100644
--- a/drivers/iommu/omap-iommu.c
+++ b/drivers/iommu/omap-iommu.c
@@ -1723,6 +1723,7 @@ static const struct iommu_ops omap_iommu_ops = {
 	.release_device	= omap_iommu_release_device,
 	.device_group	= generic_single_device_group,
 	.of_xlate	= omap_iommu_of_xlate,
+	.report_iommu_fault_supported = true,
 	.default_domain_ops = &(const struct iommu_domain_ops) {
 		.attach_dev	= omap_iommu_attach_dev,
 		.map_pages	= omap_iommu_map,
diff --git a/drivers/iommu/rockchip-iommu.c b/drivers/iommu/rockchip-iommu.c
index 0861dd469bd866..932b5a62bac572 100644
--- a/drivers/iommu/rockchip-iommu.c
+++ b/drivers/iommu/rockchip-iommu.c
@@ -1173,6 +1173,7 @@ static const struct iommu_ops rk_iommu_ops = {
 	.release_device = rk_iommu_release_device,
 	.device_group = generic_single_device_group,
 	.of_xlate = rk_iommu_of_xlate,
+	.report_iommu_fault_supported = true,
 	.default_domain_ops = &(const struct iommu_domain_ops) {
 		.attach_dev	= rk_iommu_attach_device,
 		.map_pages	= rk_iommu_map,
diff --git a/drivers/iommu/sun50i-iommu.c b/drivers/iommu/sun50i-iommu.c
index de10b569d9a940..13c37b1be481d7 100644
--- a/drivers/iommu/sun50i-iommu.c
+++ b/drivers/iommu/sun50i-iommu.c
@@ -848,6 +848,7 @@ static const struct iommu_ops sun50i_iommu_ops = {
 	.domain_alloc_paging = sun50i_iommu_domain_alloc_paging,
 	.of_xlate	= sun50i_iommu_of_xlate,
 	.probe_device	= sun50i_iommu_probe_device,
+	.report_iommu_fault_supported = true,
 	.default_domain_ops = &(const struct iommu_domain_ops) {
 		.attach_dev	= sun50i_iommu_attach_device,
 		.flush_iotlb_all = sun50i_iommu_flush_iotlb_all,
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index c30d12e16473df..941e4971b05fd3 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -659,6 +659,8 @@ __iommu_copy_struct_to_user(const struct iommu_user_data *dst_data,
  *                    no user domain for each PASID and the I/O page faults are
  *                    forwarded through the user domain attached to the device
  *                    RID.
+ * @report_iommu_fault_supported: True if the domain supports
+ *                                iommu_set_fault_handler()
  */
 struct iommu_ops {
 	bool (*capable)(struct device *dev, enum iommu_cap);
@@ -710,6 +712,7 @@ struct iommu_ops {
 	struct iommu_domain *release_domain;
 	struct iommu_domain *default_domain;
 	u8 user_pasid_table:1;
+	u8 report_iommu_fault_supported:1;
 };
 
 /**
-- 
2.43.0