[PATCH v2 09/25] iommu/fsl_pamu: Implement an IDENTITY domain

[Jason Gunthorpe]

Robin was able to check the documentation and what fsl_pamu has
historically called detach_dev() is really putting the IOMMU into an
IDENTITY mode.

Move to the new core support for ARM_DMA_USE_IOMMU by defining
ops->identity_domain. This is a ppc driver without any dma_ops, so ensure
the identity translation is the default domain.

Signed-off-by: Jason Gunthorpe <jgg at nvidia.com>
---
 drivers/iommu/fsl_pamu_domain.c | 32 +++++++++++++++++++++++++++++---
 1 file changed, 29 insertions(+), 3 deletions(-)

diff --git a/drivers/iommu/fsl_pamu_domain.c b/drivers/iommu/fsl_pamu_domain.c
index bce37229709965..ca4f5ebf028783 100644
--- a/drivers/iommu/fsl_pamu_domain.c
+++ b/drivers/iommu/fsl_pamu_domain.c
@@ -283,15 +283,21 @@ static int fsl_pamu_attach_device(struct iommu_domain *domain,
 	return ret;
 }
 
-static void fsl_pamu_set_platform_dma(struct device *dev)
+static int fsl_pamu_identity_attach(struct iommu_domain *platform_domain,
+				    struct device *dev)
 {
 	struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
-	struct fsl_dma_domain *dma_domain = to_fsl_dma_domain(domain);
+	struct fsl_dma_domain *dma_domain;
 	const u32 *prop;
 	int len;
 	struct pci_dev *pdev = NULL;
 	struct pci_controller *pci_ctl;
 
+	if (domain == platform_domain || !domain)
+		return 0;
+
+	dma_domain = to_fsl_dma_domain(domain);
+
 	/*
 	 * Use LIODN of the PCI controller while detaching a
 	 * PCI device.
@@ -312,8 +318,18 @@ static void fsl_pamu_set_platform_dma(struct device *dev)
 		detach_device(dev, dma_domain);
 	else
 		pr_debug("missing fsl,liodn property at %pOF\n", dev->of_node);
+	return 0;
 }
 
+static struct iommu_domain_ops fsl_pamu_identity_ops = {
+	.attach_dev = fsl_pamu_identity_attach,
+};
+
+static struct iommu_domain fsl_pamu_identity_domain = {
+	.type = IOMMU_DOMAIN_IDENTITY,
+	.ops = &fsl_pamu_identity_ops,
+};
+
 /* Set the domain stash attribute */
 int fsl_pamu_configure_l1_stash(struct iommu_domain *domain, u32 cpu)
 {
@@ -447,12 +463,22 @@ static struct iommu_device *fsl_pamu_probe_device(struct device *dev)
 	return &pamu_iommu;
 }
 
+static int fsl_pamu_def_domain_type(struct device *dev)
+{
+	/*
+	 * This platform does not use dma_ops at all so the normally the iommu
+	 * must be in identity mode
+	 */
+	return IOMMU_DOMAIN_IDENTITY;
+}
+
 static const struct iommu_ops fsl_pamu_ops = {
+	.identity_domain = &fsl_pamu_identity_domain,
+	.def_domain_type = &fsl_pamu_def_domain_type,
 	.capable	= fsl_pamu_capable,
 	.domain_alloc	= fsl_pamu_domain_alloc,
 	.probe_device	= fsl_pamu_probe_device,
 	.device_group   = fsl_pamu_device_group,
-	.set_platform_dma_ops = fsl_pamu_set_platform_dma,
 	.default_domain_ops = &(const struct iommu_domain_ops) {
 		.attach_dev	= fsl_pamu_attach_device,
 		.iova_to_phys	= fsl_pamu_iova_to_phys,
-- 
2.40.1