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iommu/vt-d: Use RCU to protect global resources in interrupt context

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Global DMA and interrupt remapping resources may be accessed in
interrupt context, so use RCU instead of rwsem to protect them
in such cases.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: Joerg Roedel <joro@8bytes.org>
This commit is contained in:
Jiang Liu
2014-02-19 14:07:34 +08:00
committed by Joerg Roedel
parent 3a5670e8ac
commit 0e242612d9
3 changed files with 53 additions and 23 deletions
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20
drivers/iommu/intel-iommu.c
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@@ -385,14 +385,14 @@ struct dmar_rmrr_unit {
struct acpi_dmar_header *hdr; /* ACPI header */
u64 base_address; /* reserved base address*/
u64 end_address; /* reserved end address */
struct pci_dev **devices; /* target devices */
struct pci_dev __rcu **devices; /* target devices */
int devices_cnt; /* target device count */
};
struct dmar_atsr_unit {
struct list_head list; /* list of ATSR units */
struct acpi_dmar_header *hdr; /* ACPI header */
struct pci_dev **devices; /* target devices */
struct pci_dev __rcu **devices; /* target devices */
int devices_cnt; /* target device count */
u8 include_all:1; /* include all ports */
};
@@ -634,12 +634,15 @@ static void domain_update_iommu_superpage(struct dmar_domain *domain)
}
/* set iommu_superpage to the smallest common denominator */
rcu_read_lock();
for_each_active_iommu(iommu, drhd) {
mask &= cap_super_page_val(iommu->cap);
if (!mask) {
break;
}
}
rcu_read_unlock();
domain->iommu_superpage = fls(mask);
}
@@ -658,6 +661,7 @@ static struct intel_iommu *device_to_iommu(int segment, u8 bus, u8 devfn)
struct pci_dev *dev;
int i;
rcu_read_lock();
for_each_active_iommu(iommu, drhd) {
if (segment != drhd->segment)
continue;
@@ -677,6 +681,7 @@ static struct intel_iommu *device_to_iommu(int segment, u8 bus, u8 devfn)
}
iommu = NULL;
out:
rcu_read_unlock();
return iommu;
}
@@ -1535,10 +1540,12 @@ static void domain_exit(struct dmar_domain *domain)
dma_pte_free_pagetable(domain, 0, DOMAIN_MAX_PFN(domain->gaw));
/* clear attached or cached domains */
rcu_read_lock();
for_each_active_iommu(iommu, drhd)
if (domain->flags & DOMAIN_FLAG_VIRTUAL_MACHINE ||
test_bit(iommu->seq_id, domain->iommu_bmp))
iommu_detach_domain(domain, iommu);
rcu_read_unlock();
free_domain_mem(domain);
}
@@ -2338,6 +2345,7 @@ static bool device_has_rmrr(struct pci_dev *dev)
struct pci_dev *tmp;
int i;
rcu_read_lock();
for_each_rmrr_units(rmrr) {
/*
* Return TRUE if this RMRR contains the device that
@@ -2346,9 +2354,11 @@ static bool device_has_rmrr(struct pci_dev *dev)
for_each_active_dev_scope(rmrr->devices,
rmrr->devices_cnt, i, tmp)
if (tmp == dev) {
rcu_read_unlock();
return true;
}
}
rcu_read_unlock();
return false;
}
@@ -3512,7 +3522,7 @@ int __init dmar_parse_one_atsr(struct acpi_dmar_header *hdr)
atsru->hdr = hdr;
atsru->include_all = atsr->flags & 0x1;
list_add(&atsru->list, &dmar_atsr_units);
list_add_rcu(&atsru->list, &dmar_atsr_units);
return 0;
}
@@ -3574,6 +3584,7 @@ int dmar_find_matched_atsr_unit(struct pci_dev *dev)
if (!bridge)
return 0;
rcu_read_lock();
list_for_each_entry_rcu(atsru, &dmar_atsr_units, list) {
atsr = container_of(atsru->hdr, struct acpi_dmar_atsr, header);
if (atsr->segment != pci_domain_nr(dev->bus))
@@ -3588,6 +3599,7 @@ int dmar_find_matched_atsr_unit(struct pci_dev *dev)
}
ret = 0;
out:
rcu_read_unlock();
return ret;
}
@@ -3604,7 +3616,7 @@ int __init dmar_parse_rmrr_atsr_dev(void)
return ret;
}
list_for_each_entry(atsr, &dmar_atsr_units, list) {
list_for_each_entry_rcu(atsr, &dmar_atsr_units, list) {
ret = atsr_parse_dev(atsr);
if (ret)
return ret;