[Patch Part2 V2 06/17] iommu/vt-d: simplify function get_domain_for_dev()

From: Jiang Liu
Date: Wed Feb 19 2014 - 01:11:32 EST


Function get_domain_for_dev() is a little complex, simplify it
by factoring out dmar_search_domain_by_dev_info() and
dmar_insert_dev_info().

Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxxxxxxx>
---
drivers/iommu/intel-iommu.c | 142 ++++++++++++++++++++-----------------------
1 file changed, 66 insertions(+), 76 deletions(-)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index fffe3d1..67b114e 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -1957,18 +1957,71 @@ find_domain(struct pci_dev *pdev)
return NULL;
}

+static inline struct dmar_domain *
+dmar_search_domain_by_dev_info(int segment, int bus, int devfn)
+{
+ struct device_domain_info *info;
+
+ list_for_each_entry(info, &device_domain_list, global)
+ if (info->segment == segment && info->bus == bus &&
+ info->devfn == devfn)
+ return info->domain;
+
+ return NULL;
+}
+
+static int dmar_insert_dev_info(int segment, int bus, int devfn,
+ struct pci_dev *dev, struct dmar_domain **domp)
+{
+ struct dmar_domain *found, *domain = *domp;
+ struct device_domain_info *info;
+ unsigned long flags;
+
+ info = alloc_devinfo_mem();
+ if (!info)
+ return -ENOMEM;
+
+ info->segment = segment;
+ info->bus = bus;
+ info->devfn = devfn;
+ info->dev = dev;
+ info->domain = domain;
+ if (!dev)
+ domain->flags |= DOMAIN_FLAG_P2P_MULTIPLE_DEVICES;
+
+ spin_lock_irqsave(&device_domain_lock, flags);
+ if (dev)
+ found = find_domain(dev);
+ else
+ found = dmar_search_domain_by_dev_info(segment, bus, devfn);
+ if (found) {
+ spin_unlock_irqrestore(&device_domain_lock, flags);
+ free_devinfo_mem(info);
+ if (found != domain) {
+ domain_exit(domain);
+ *domp = found;
+ }
+ } else {
+ list_add(&info->link, &domain->devices);
+ list_add(&info->global, &device_domain_list);
+ if (dev)
+ dev->dev.archdata.iommu = info;
+ spin_unlock_irqrestore(&device_domain_lock, flags);
+ }
+
+ return 0;
+}
+
/* domain is initialized */
static struct dmar_domain *get_domain_for_dev(struct pci_dev *pdev, int gaw)
{
- struct dmar_domain *domain, *found = NULL;
+ struct dmar_domain *domain;
struct intel_iommu *iommu;
struct dmar_drhd_unit *drhd;
- struct device_domain_info *info, *tmp;
struct pci_dev *dev_tmp;
unsigned long flags;
int bus = 0, devfn = 0;
int segment;
- int ret;

domain = find_domain(pdev);
if (domain)
@@ -1986,41 +2039,29 @@ static struct dmar_domain *get_domain_for_dev(struct pci_dev *pdev, int gaw)
devfn = dev_tmp->devfn;
}
spin_lock_irqsave(&device_domain_lock, flags);
- list_for_each_entry(info, &device_domain_list, global) {
- if (info->segment == segment &&
- info->bus == bus && info->devfn == devfn) {
- found = info->domain;
- break;
- }
- }
+ domain = dmar_search_domain_by_dev_info(segment, bus, devfn);
spin_unlock_irqrestore(&device_domain_lock, flags);
/* pcie-pci bridge already has a domain, uses it */
- if (found) {
- domain = found;
+ if (domain)
goto found_domain;
- }
}

- domain = alloc_domain();
- if (!domain)
- goto error;
-
- /* Allocate new domain for the device */
drhd = dmar_find_matched_drhd_unit(pdev);
if (!drhd) {
printk(KERN_ERR "IOMMU: can't find DMAR for device %s\n",
pci_name(pdev));
- free_domain_mem(domain);
return NULL;
}
iommu = drhd->iommu;

- ret = iommu_attach_domain(domain, iommu);
- if (ret) {
+ /* Allocate and intialize new domain for the device */
+ domain = alloc_domain();
+ if (!domain)
+ goto error;
+ if (iommu_attach_domain(domain, iommu)) {
free_domain_mem(domain);
goto error;
}
-
if (domain_init(domain, gaw)) {
domain_exit(domain);
goto error;
@@ -2028,67 +2069,16 @@ static struct dmar_domain *get_domain_for_dev(struct pci_dev *pdev, int gaw)

/* register pcie-to-pci device */
if (dev_tmp) {
- info = alloc_devinfo_mem();
- if (!info) {
+ if (dmar_insert_dev_info(segment, bus, devfn, NULL, &domain)) {
domain_exit(domain);
goto error;
}
- info->segment = segment;
- info->bus = bus;
- info->devfn = devfn;
- info->dev = NULL;
- info->domain = domain;
- /* This domain is shared by devices under p2p bridge */
- domain->flags |= DOMAIN_FLAG_P2P_MULTIPLE_DEVICES;
-
- /* pcie-to-pci bridge already has a domain, uses it */
- found = NULL;
- spin_lock_irqsave(&device_domain_lock, flags);
- list_for_each_entry(tmp, &device_domain_list, global) {
- if (tmp->segment == segment &&
- tmp->bus == bus && tmp->devfn == devfn) {
- found = tmp->domain;
- break;
- }
- }
- if (found) {
- spin_unlock_irqrestore(&device_domain_lock, flags);
- free_devinfo_mem(info);
- domain_exit(domain);
- domain = found;
- } else {
- list_add(&info->link, &domain->devices);
- list_add(&info->global, &device_domain_list);
- spin_unlock_irqrestore(&device_domain_lock, flags);
- }
}

found_domain:
- info = alloc_devinfo_mem();
- if (!info)
- goto error;
- info->segment = segment;
- info->bus = pdev->bus->number;
- info->devfn = pdev->devfn;
- info->dev = pdev;
- info->domain = domain;
- spin_lock_irqsave(&device_domain_lock, flags);
- /* somebody is fast */
- found = find_domain(pdev);
- if (found != NULL) {
- spin_unlock_irqrestore(&device_domain_lock, flags);
- if (found != domain) {
- domain_exit(domain);
- domain = found;
- }
- free_devinfo_mem(info);
+ if (dmar_insert_dev_info(segment, pdev->bus->number, pdev->devfn,
+ pdev, &domain) == 0)
return domain;
- }
- list_add(&info->link, &domain->devices);
- list_add(&info->global, &device_domain_list);
- pdev->dev.archdata.iommu = info;
- spin_unlock_irqrestore(&device_domain_lock, flags);
- return domain;
error:
/* recheck it here, maybe others set it */
return find_domain(pdev);
--
1.7.10.4

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