[PATCH v2 2/6] iommu/vt-d: Remove scalable mode context entry setup from attach_dev

Lu Baolu
2023-12-05T01:26:54Z

The scalable mode context entry is now setup in the probe_device path,
eliminating the need to configure it in the attach_dev path. Removes the
redundant code from the attach_dev path to avoid dead code.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
drivers/iommu/intel/iommu.c | 156 ++++++++++--------------------------
1 file changed, 44 insertions(+), 112 deletions(-)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 9dc005031dd2..a324b3a3a005 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -1727,34 +1727,17 @@ static void domain_exit(struct dmar_domain *domain)
kfree(domain);
}

-/*
- * Get the PASID directory size for scalable mode context entry.
- * Value of X in the PDTS field of a scalable mode context entry
- * indicates PASID directory with 2^(X + 7) entries.
- */
-static unsigned long context_get_sm_pds(struct pasid_table *table)
-{
- unsigned long pds, max_pde;
-
- max_pde = table->max_pasid >> PASID_PDE_SHIFT;
- pds = find_first_bit(&max_pde, MAX_NR_PASID_BITS);
- if (pds < 7)
- return 0;
-
- return pds - 7;
-}
-
static int domain_context_mapping_one(struct dmar_domain *domain,
struct intel_iommu *iommu,
- struct pasid_table *table,
u8 bus, u8 devfn)
{
struct device_domain_info *info =
domain_lookup_dev_info(domain, iommu, bus, devfn);
u16 did = domain_id_iommu(domain, iommu);
int translation = CONTEXT_TT_MULTI_LEVEL;
+ struct dma_pte *pgd = domain->pgd;
struct context_entry *context;
- int ret;
+ int agaw, ret;

if (hw_pass_through && domain_type_is_si(domain))
translation = CONTEXT_TT_PASS_THROUGH;
@@ -1797,65 +1780,37 @@ static int domain_context_mapping_one(struct dmar_domain *domain,
}

context_clear_entry(context);
+ context_set_domain_id(context, did);

- if (sm_supported(iommu)) {
- unsigned long pds;
-
- /* Setup the PASID DIR pointer: */
- pds = context_get_sm_pds(table);
- context->lo = (u64)virt_to_phys(table->table) |
- context_pdts(pds);
-
- /* Setup the RID_PASID field: */
- context_set_sm_rid2pasid(context, IOMMU_NO_PASID);
-
+ if (translation != CONTEXT_TT_PASS_THROUGH) {
/*
- * Setup the Device-TLB enable bit and Page request
- * Enable bit:
+ * Skip top levels of page tables for iommu which has
+ * less agaw than default. Unnecessary for PT mode.
*/
+ for (agaw = domain->agaw; agaw > iommu->agaw; agaw--) {
+ ret = -ENOMEM;
+ pgd = phys_to_virt(dma_pte_addr(pgd));
+ if (!dma_pte_present(pgd))
+ goto out_unlock;
+ }
+
if (info && info->ats_supported)
- context_set_sm_dte(context);
- if (info && info->pri_supported)
- context_set_sm_pre(context);
- if (info && info->pasid_supported)
- context_set_pasid(context);
+ translation = CONTEXT_TT_DEV_IOTLB;
+ else
+ translation = CONTEXT_TT_MULTI_LEVEL;
+
+ context_set_address_root(context, virt_to_phys(pgd));
+ context_set_address_width(context, agaw);
} else {
- struct dma_pte *pgd = domain->pgd;
- int agaw;
-
- context_set_domain_id(context, did);
-
- if (translation != CONTEXT_TT_PASS_THROUGH) {
- /*
- * Skip top levels of page tables for iommu which has
- * less agaw than default. Unnecessary for PT mode.
- */
- for (agaw = domain->agaw; agaw > iommu->agaw; agaw--) {
- ret = -ENOMEM;
- pgd = phys_to_virt(dma_pte_addr(pgd));
- if (!dma_pte_present(pgd))
- goto out_unlock;
- }
-
- if (info && info->ats_supported)
- translation = CONTEXT_TT_DEV_IOTLB;
- else
- translation = CONTEXT_TT_MULTI_LEVEL;
-
- context_set_address_root(context, virt_to_phys(pgd));
- context_set_address_width(context, agaw);
- } else {
- /*
- * In pass through mode, AW must be programmed to
- * indicate the largest AGAW value supported by
- * hardware. And ASR is ignored by hardware.
- */
- context_set_address_width(context, iommu->msagaw);
- }
-
- context_set_translation_type(context, translation);
+ /*
+ * In pass through mode, AW must be programmed to
+ * indicate the largest AGAW value supported by
+ * hardware. And ASR is ignored by hardware.
+ */
+ context_set_address_width(context, iommu->msagaw);
}

+ context_set_translation_type(context, translation);
context_set_fault_enable(context);
context_set_present(context);
if (!ecap_coherent(iommu->ecap))
@@ -1885,43 +1840,29 @@ static int domain_context_mapping_one(struct dmar_domain *domain,
return ret;
}

-struct domain_context_mapping_data {
- struct dmar_domain *domain;
- struct intel_iommu *iommu;
- struct pasid_table *table;
-};
-
static int domain_context_mapping_cb(struct pci_dev *pdev,
u16 alias, void *opaque)
{
- struct domain_context_mapping_data *data = opaque;
+ struct device_domain_info *info = dev_iommu_priv_get(&pdev->dev);
+ struct intel_iommu *iommu = info->iommu;
+ struct dmar_domain *domain = opaque;

- return domain_context_mapping_one(data->domain, data->iommu,
- data->table, PCI_BUS_NUM(alias),
- alias & 0xff);
+ return domain_context_mapping_one(domain, iommu,
+ PCI_BUS_NUM(alias), alias & 0xff);
}

static int
domain_context_mapping(struct dmar_domain *domain, struct device *dev)
{
struct device_domain_info *info = dev_iommu_priv_get(dev);
- struct domain_context_mapping_data data;
struct intel_iommu *iommu = info->iommu;
u8 bus = info->bus, devfn = info->devfn;
- struct pasid_table *table;
-
- table = intel_pasid_get_table(dev);

if (!dev_is_pci(dev))
- return domain_context_mapping_one(domain, iommu, table,
- bus, devfn);
-
- data.domain = domain;
- data.iommu = iommu;
- data.table = table;
+ return domain_context_mapping_one(domain, iommu, bus, devfn);

return pci_for_each_dma_alias(to_pci_dev(dev),
- &domain_context_mapping_cb, &data);
+ domain_context_mapping_cb, domain);
}

/* Returns a number of VTD pages, but aligned to MM page size */
@@ -2278,28 +2219,19 @@ static int dmar_domain_attach_device(struct dmar_domain *domain,
list_add(&info->link, &domain->devices);
spin_unlock_irqrestore(&domain->lock, flags);

- /* PASID table is mandatory for a PCI device in scalable mode. */
- if (sm_supported(iommu) && !dev_is_real_dma_subdevice(dev)) {
- /* Setup the PASID entry for requests without PASID: */
- if (hw_pass_through && domain_type_is_si(domain))
- ret = intel_pasid_setup_pass_through(iommu,
- dev, IOMMU_NO_PASID);
- else if (domain->use_first_level)
- ret = domain_setup_first_level(iommu, domain, dev,
- IOMMU_NO_PASID);
- else
- ret = intel_pasid_setup_second_level(iommu, domain,
- dev, IOMMU_NO_PASID);
- if (ret) {
- dev_err(dev, "Setup RID2PASID failed\n");
- device_block_translation(dev);
- return ret;
- }
- }
+ if (dev_is_real_dma_subdevice(dev))
+ return 0;
+
+ if (!sm_supported(iommu))
+ ret = domain_context_mapping(domain, dev);
+ else if (hw_pass_through && domain_type_is_si(domain))
+ ret = intel_pasid_setup_pass_through(iommu, dev, IOMMU_NO_PASID);
+ else if (domain->use_first_level)
+ ret = domain_setup_first_level(iommu, domain, dev, IOMMU_NO_PASID);
+ else
+ ret = intel_pasid_setup_second_level(iommu, domain, dev, IOMMU_NO_PASID);

- ret = domain_context_mapping(domain, dev);
if (ret) {
- dev_err(dev, "Domain context map failed\n");
device_block_translation(dev);
return ret;
}
--
2.34.1