[PATCH v6 14/25] iommu/msm: Implement an IDENTITY domain

Jason Gunthorpe
2023-08-03T00:10:12Z

What msm does during msm_iommu_set_platform_dma() is actually putting the
iommu into identity mode.

Move to the new core support for ARM_DMA_USE_IOMMU by defining
ops->identity_domain.

This driver does not support IOMMU_DOMAIN_DMA, however it cannot be
compiled on ARM64 either. Most likely it is fine to support dma-iommu.c

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
---
drivers/iommu/msm_iommu.c | 23 +++++++++++++++++++----
1 file changed, 19 insertions(+), 4 deletions(-)

diff --git a/drivers/iommu/msm_iommu.c b/drivers/iommu/msm_iommu.c
index 79d89bad5132b7..26ed81cfeee897 100644
--- a/drivers/iommu/msm_iommu.c
+++ b/drivers/iommu/msm_iommu.c
@@ -443,15 +443,20 @@ static int msm_iommu_attach_dev(struct iommu_domain *domain, struct device *dev)
return ret;
}

-static void msm_iommu_set_platform_dma(struct device *dev)
+static int msm_iommu_identity_attach(struct iommu_domain *identity_domain,
+ struct device *dev)
{
struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
- struct msm_priv *priv = to_msm_priv(domain);
+ struct msm_priv *priv;
unsigned long flags;
struct msm_iommu_dev *iommu;
struct msm_iommu_ctx_dev *master;
- int ret;
+ int ret = 0;

+ if (domain == identity_domain || !domain)
+ return 0;
+
+ priv = to_msm_priv(domain);
free_io_pgtable_ops(priv->iop);

spin_lock_irqsave(&msm_iommu_lock, flags);
@@ -468,8 +473,18 @@ static void msm_iommu_set_platform_dma(struct device *dev)
}
fail:
spin_unlock_irqrestore(&msm_iommu_lock, flags);
+ return ret;
}

+static struct iommu_domain_ops msm_iommu_identity_ops = {
+ .attach_dev = msm_iommu_identity_attach,
+};
+
+static struct iommu_domain msm_iommu_identity_domain = {
+ .type = IOMMU_DOMAIN_IDENTITY,
+ .ops = &msm_iommu_identity_ops,
+};
+
static int msm_iommu_map(struct iommu_domain *domain, unsigned long iova,
phys_addr_t pa, size_t pgsize, size_t pgcount,
int prot, gfp_t gfp, size_t *mapped)
@@ -675,10 +690,10 @@ irqreturn_t msm_iommu_fault_handler(int irq, void *dev_id)
}

static struct iommu_ops msm_iommu_ops = {
+ .identity_domain = &msm_iommu_identity_domain,
.domain_alloc = msm_iommu_domain_alloc,
.probe_device = msm_iommu_probe_device,
.device_group = generic_device_group,
- .set_platform_dma_ops = msm_iommu_set_platform_dma,
.pgsize_bitmap = MSM_IOMMU_PGSIZES,
.of_xlate = qcom_iommu_of_xlate,
.default_domain_ops = &(const struct iommu_domain_ops) {
--
2.41.0