[PATCH v5 02/10] iommu/vt-d: Use per-device dma_ops

Lu Baolu
2019-07-25T03:18:10Z

Current Intel IOMMU driver sets the system level dma_ops hence
each dma API will go through the IOMMU driver even the devices
are using an identity mapped domain. This applies per-device
dma_ops in this driver and leave the system level dma_ops for
direct dma.

Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Kevin Tian <kevin.tian@intel.com>\
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
drivers/iommu/intel-iommu.c | 43 ++++++-------------------------------
1 file changed, 7 insertions(+), 36 deletions(-)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 8064af607d3b..11474bd2e348 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -3419,43 +3419,10 @@ static struct dmar_domain *get_private_domain_for_dev(struct device *dev)
/* Check if the dev needs to go through non-identity map and unmap process.*/
static bool iommu_need_mapping(struct device *dev)
{
- int ret;
-
if (iommu_dummy(dev))
return false;

- ret = identity_mapping(dev);
- if (ret) {
- u64 dma_mask = *dev->dma_mask;
-
- if (dev->coherent_dma_mask && dev->coherent_dma_mask < dma_mask)
- dma_mask = dev->coherent_dma_mask;
-
- if (dma_mask >= dma_get_required_mask(dev))
- return false;
-
- /*
- * 32 bit DMA is removed from si_domain and fall back to
- * non-identity mapping.
- */
- dmar_remove_one_dev_info(dev);
- ret = iommu_request_dma_domain_for_dev(dev);
- if (ret) {
- struct iommu_domain *domain;
- struct dmar_domain *dmar_domain;
-
- domain = iommu_get_domain_for_dev(dev);
- if (domain) {
- dmar_domain = to_dmar_domain(domain);
- dmar_domain->flags |= DOMAIN_FLAG_LOSE_CHILDREN;
- }
- get_private_domain_for_dev(dev);
- }
-
- dev_info(dev, "32bit DMA uses non-identity mapping\n");
- }
-
- return true;
+ return !identity_mapping(dev);
}

static dma_addr_t __intel_map_single(struct device *dev, phys_addr_t paddr,
@@ -4706,8 +4673,6 @@ int __init intel_iommu_init(void)
}
up_write(&dmar_global_lock);

- dma_ops = &intel_dma_ops;
-
init_iommu_pm_ops();

for_each_active_iommu(iommu, drhd) {
@@ -5280,6 +5245,8 @@ static int intel_iommu_add_device(struct device *dev)
dev_info(dev,
"Device uses a private identity domain.\n");
}
+ } else {
+ set_dma_ops(dev, &intel_dma_ops);
}
} else {
if (device_def_domain_type(dev) == IOMMU_DOMAIN_DMA) {
@@ -5295,6 +5262,8 @@ static int intel_iommu_add_device(struct device *dev)
dev_info(dev,
"Device uses a private dma domain.\n");
}
+
+ set_dma_ops(dev, &intel_dma_ops);
}
}

@@ -5313,6 +5282,8 @@ static void intel_iommu_remove_device(struct device *dev)
iommu_group_remove_device(dev);

iommu_device_unlink(&iommu->iommu, dev);
+
+ set_dma_ops(dev, NULL);
}

static void intel_iommu_get_resv_regions(struct device *device,
--
2.17.1