[PATCH v2 6/6] iommu/vt-d: Cleanup si_domain

Lu Baolu
2023-12-05T01:27:15Z

The static identity domain has been introduced, rendering the si_domain
obsolete. Remove si_domain and cleanup the code accordingly.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
drivers/iommu/intel/iommu.c | 118 +++++++-----------------------------
1 file changed, 23 insertions(+), 95 deletions(-)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 3c747d19495e..91443b34111b 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -97,15 +97,6 @@ static phys_addr_t root_entry_uctp(struct root_entry *re)
return re->hi & VTD_PAGE_MASK;
}

-/*
- * This domain is a statically identity mapping domain.
- * 1. This domain creats a static 1:1 mapping to all usable memory.
- * 2. It maps to each iommu if successful.
- * 3. Each iommu mapps to this domain if successful.
- */
-static struct dmar_domain *si_domain;
-static int hw_pass_through = 1;
-
struct dmar_rmrr_unit {
struct list_head list; /* list of rmrr units */
struct acpi_dmar_header *hdr; /* ACPI header */
@@ -240,11 +231,6 @@ void free_pgtable_page(void *vaddr)
free_page((unsigned long)vaddr);
}

-static int domain_type_is_si(struct dmar_domain *domain)
-{
- return domain->domain.type == IOMMU_DOMAIN_IDENTITY;
-}
-
static int domain_pfn_supported(struct dmar_domain *domain, unsigned long pfn)
{
int addr_width = agaw_to_width(domain->agaw) - VTD_PAGE_SHIFT;
@@ -1795,9 +1781,6 @@ static int domain_context_mapping_one(struct dmar_domain *domain,
struct context_entry *context;
int agaw, ret;

- if (hw_pass_through && domain_type_is_si(domain))
- translation = CONTEXT_TT_PASS_THROUGH;
-
pr_debug("Set context mapping for %02x:%02x.%d\n",
bus, PCI_SLOT(devfn), PCI_FUNC(devfn));

@@ -1816,34 +1799,24 @@ static int domain_context_mapping_one(struct dmar_domain *domain,

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);
+ /*
+ * 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);
context_set_translation_type(context, translation);
context_set_fault_enable(context);
context_set_present(context);
@@ -2077,14 +2050,10 @@ static void domain_context_clear_one(struct device_domain_info *info, u8 bus, u8
return;
}

- if (sm_supported(iommu)) {
- if (hw_pass_through && domain_type_is_si(info->domain))
- did_old = FLPT_DEFAULT_DID;
- else
- did_old = domain_id_iommu(info->domain, iommu);
- } else {
- did_old = context_domain_id(context);
- }
+ if (info->domain)
+ did_old = domain_id_iommu(info->domain, iommu);
+ else
+ did_old = FLPT_DEFAULT_DID;

context_clear_entry(context);
__iommu_flush_cache(iommu, context, sizeof(*context));
@@ -2147,23 +2116,6 @@ static bool dev_is_real_dma_subdevice(struct device *dev)
pci_real_dma_dev(to_pci_dev(dev)) != to_pci_dev(dev);
}

-static int md_domain_init(struct dmar_domain *domain, int guest_width);
-
-static int __init si_domain_init(int hw)
-{
- si_domain = alloc_domain(IOMMU_DOMAIN_IDENTITY);
- if (!si_domain)
- return -EFAULT;
-
- if (md_domain_init(si_domain, DEFAULT_DOMAIN_ADDRESS_WIDTH)) {
- domain_exit(si_domain);
- si_domain = NULL;
- return -EFAULT;
- }
-
- return 0;
-}
-
static int dmar_domain_attach_device(struct dmar_domain *domain,
struct device *dev)
{
@@ -2185,8 +2137,6 @@ static int dmar_domain_attach_device(struct dmar_domain *domain,

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
@@ -2197,8 +2147,7 @@ static int dmar_domain_attach_device(struct dmar_domain *domain,
return ret;
}

- if (sm_supported(info->iommu) || !domain_type_is_si(info->domain))
- iommu_enable_pci_caps(info);
+ iommu_enable_pci_caps(info);

return 0;
}
@@ -2548,8 +2497,6 @@ static int __init init_dmars(void)
}
}

- if (!ecap_pass_through(iommu->ecap))
- hw_pass_through = 0;
intel_svm_check(iommu);
}

@@ -2572,10 +2519,6 @@ static int __init init_dmars(void)

check_tylersburg_isoch();

- ret = si_domain_init(hw_pass_through);
- if (ret)
- goto free_iommu;
-
/*
* for each drhd
* enable fault log
@@ -2621,10 +2564,6 @@ static int __init init_dmars(void)
disable_dmar_iommu(iommu);
free_dmar_iommu(iommu);
}
- if (si_domain) {
- domain_exit(si_domain);
- si_domain = NULL;
- }

return ret;
}
@@ -2999,12 +2938,6 @@ static int intel_iommu_add(struct dmar_drhd_unit *dmaru)
if (ret)
goto out;

- if (hw_pass_through && !ecap_pass_through(iommu->ecap)) {
- pr_warn("%s: Doesn't support hardware pass through.\n",
- iommu->name);
- return -ENXIO;
- }
-
sp = domain_update_iommu_superpage(NULL, iommu) - 1;
if (sp >= 0 && !(cap_super_page_val(iommu->cap) & (1 << sp))) {
pr_warn("%s: Doesn't support large page.\n",
@@ -3718,8 +3651,6 @@ static struct iommu_domain *intel_iommu_domain_alloc(unsigned type)
domain->geometry.force_aperture = true;

return domain;
- case IOMMU_DOMAIN_IDENTITY:
- return &si_domain->domain;
case IOMMU_DOMAIN_SVA:
return intel_svm_domain_alloc();
default:
@@ -3779,8 +3710,7 @@ intel_iommu_domain_alloc_user(struct device *dev, u32 flags,

static void intel_iommu_domain_free(struct iommu_domain *domain)
{
- if (domain != &si_domain->domain)
- domain_exit(to_dmar_domain(domain));
+ domain_exit(to_dmar_domain(domain));
}

int prepare_domain_attach_device(struct iommu_domain *domain,
@@ -4487,9 +4417,7 @@ static int intel_iommu_set_dev_pasid(struct iommu_domain *domain,
if (ret)
goto out_free;

- if (domain_type_is_si(dmar_domain))
- ret = intel_pasid_setup_pass_through(iommu, dev, pasid);
- else if (dmar_domain->use_first_level)
+ if (dmar_domain->use_first_level)
ret = domain_setup_first_level(iommu, dmar_domain,
dev, pasid);
else
--
2.34.1