[Patch Part3 V4 03/21] iommu/vt-d: Introduce helper functions to improve code readability

Jiang Liu
2014-07-11T06:23:55Z

Introduce domain_type_is_vm() and domain_type_is_vm_or_si() to improve
code readability.

Also kill useless macro DOMAIN_FLAG_P2P_MULTIPLE_DEVICES.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
---
drivers/iommu/intel-iommu.c | 59 +++++++++++++++++++------------------------
1 file changed, 26 insertions(+), 33 deletions(-)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index d77009bdade5..52250b3e58d1 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -320,16 +320,13 @@ static inline int first_pte_in_page(struct dma_pte *pte)
static struct dmar_domain *si_domain;
static int hw_pass_through = 1;

-/* devices under the same p2p bridge are owned in one domain */
-#define DOMAIN_FLAG_P2P_MULTIPLE_DEVICES (1 << 0)
-
/* domain represents a virtual machine, more than one devices
* across iommus may be owned in one domain, e.g. kvm guest.
*/
-#define DOMAIN_FLAG_VIRTUAL_MACHINE (1 << 1)
+#define DOMAIN_FLAG_VIRTUAL_MACHINE (1 << 0)

/* si_domain contains mulitple devices */
-#define DOMAIN_FLAG_STATIC_IDENTITY (1 << 2)
+#define DOMAIN_FLAG_STATIC_IDENTITY (1 << 1)

/* define the limit of IOMMUs supported in each domain */
#ifdef CONFIG_X86
@@ -539,6 +536,16 @@ void free_iova_mem(struct iova *iova)
kmem_cache_free(iommu_iova_cache, iova);
}

+static inline int domain_type_is_vm(struct dmar_domain *domain)
+{
+ return domain->flags & DOMAIN_FLAG_VIRTUAL_MACHINE;
+}
+
+static inline int domain_type_is_vm_or_si(struct dmar_domain *domain)
+{
+ return domain->flags & (DOMAIN_FLAG_VIRTUAL_MACHINE |
+ DOMAIN_FLAG_STATIC_IDENTITY);
+}

static int __iommu_calculate_agaw(struct intel_iommu *iommu, int max_gaw)
{
@@ -579,9 +586,7 @@ static struct intel_iommu *domain_get_iommu(struct dmar_domain *domain)
int iommu_id;

/* si_domain and vm domain should not get here. */
- BUG_ON(domain->flags & DOMAIN_FLAG_VIRTUAL_MACHINE);
- BUG_ON(domain->flags & DOMAIN_FLAG_STATIC_IDENTITY);
-
+ BUG_ON(domain_type_is_vm_or_si(domain));
iommu_id = find_first_bit(domain->iommu_bmp, g_num_of_iommus);
if (iommu_id < 0 || iommu_id >= g_num_of_iommus)
return NULL;
@@ -1497,7 +1502,7 @@ static void free_dmar_iommu(struct intel_iommu *iommu)
free_context_table(iommu);
}

-static struct dmar_domain *alloc_domain(bool vm)
+static struct dmar_domain *alloc_domain(int flags)
{
/* domain id for virtual machine, it won't be set in context */
static atomic_t vm_domid = ATOMIC_INIT(0);
@@ -1507,16 +1512,13 @@ static struct dmar_domain *alloc_domain(bool vm)
if (!domain)
return NULL;

+ memset(domain, 0, sizeof(*domain));
domain->nid = -1;
- domain->iommu_count = 0;
- memset(domain->iommu_bmp, 0, sizeof(domain->iommu_bmp));
- domain->flags = 0;
+ domain->flags = flags;
spin_lock_init(&domain->iommu_lock);
INIT_LIST_HEAD(&domain->devices);
- if (vm) {
+ if (flags & DOMAIN_FLAG_VIRTUAL_MACHINE)
domain->id = atomic_inc_return(&vm_domid);
- domain->flags = DOMAIN_FLAG_VIRTUAL_MACHINE;
- }

return domain;
}
@@ -1704,7 +1706,7 @@ static void domain_exit(struct dmar_domain *domain)
/* clear attached or cached domains */
rcu_read_lock();
for_each_active_iommu(iommu, drhd)
- if (domain->flags & DOMAIN_FLAG_VIRTUAL_MACHINE ||
+ if (domain_type_is_vm(domain) ||
test_bit(iommu->seq_id, domain->iommu_bmp))
iommu_detach_domain(domain, iommu);
rcu_read_unlock();
@@ -1746,8 +1748,7 @@ static int domain_context_mapping_one(struct dmar_domain *domain,
id = domain->id;
pgd = domain->pgd;

- if (domain->flags & DOMAIN_FLAG_VIRTUAL_MACHINE ||
- domain->flags & DOMAIN_FLAG_STATIC_IDENTITY) {
+ if (domain_type_is_vm_or_si(domain)) {
int found = 0;

/* find an available domain id for this device in iommu */
@@ -2094,7 +2095,7 @@ static void domain_remove_dev_info(struct dmar_domain *domain)
iommu_disable_dev_iotlb(info);
iommu_detach_dev(info->iommu, info->bus, info->devfn);

- if (domain->flags & DOMAIN_FLAG_VIRTUAL_MACHINE) {
+ if (domain_type_is_vm(domain)) {
iommu_detach_dependent_devices(info->iommu, info->dev);
/* clear this iommu in iommu_bmp, update iommu count
* and capabilities
@@ -2160,8 +2161,6 @@ static struct dmar_domain *dmar_insert_dev_info(struct intel_iommu *iommu,
info->dev = dev;
info->domain = domain;
info->iommu = iommu;
- if (!dev)
- domain->flags |= DOMAIN_FLAG_P2P_MULTIPLE_DEVICES;

spin_lock_irqsave(&device_domain_lock, flags);
if (dev)
@@ -2233,7 +2232,7 @@ static struct dmar_domain *get_domain_for_dev(struct device *dev, int gaw)
}

/* Allocate and initialize new domain for the device */
- domain = alloc_domain(false);
+ domain = alloc_domain(0);
if (!domain)
return NULL;

@@ -2408,12 +2407,10 @@ static int __init si_domain_init(int hw)
struct intel_iommu *iommu;
int nid, ret = 0;

- si_domain = alloc_domain(false);
+ si_domain = alloc_domain(DOMAIN_FLAG_STATIC_IDENTITY);
if (!si_domain)
return -EFAULT;

- si_domain->flags = DOMAIN_FLAG_STATIC_IDENTITY;
-
for_each_active_iommu(iommu, drhd) {
ret = iommu_attach_domain(si_domain, iommu);
if (ret) {
@@ -3860,9 +3857,7 @@ static int device_notifier(struct notifier_block *nb,

down_read(&dmar_global_lock);
domain_remove_one_dev_info(domain, dev);
- if (!(domain->flags & DOMAIN_FLAG_VIRTUAL_MACHINE) &&
- !(domain->flags & DOMAIN_FLAG_STATIC_IDENTITY) &&
- list_empty(&domain->devices))
+ if (!domain_type_is_vm_or_si(domain) && list_empty(&domain->devices))
domain_exit(domain);
up_read(&dmar_global_lock);

@@ -4167,8 +4162,7 @@ static void domain_remove_one_dev_info(struct dmar_domain *domain,
domain_update_iommu_cap(domain);
spin_unlock_irqrestore(&domain->iommu_lock, tmp_flags);

- if (!(domain->flags & DOMAIN_FLAG_VIRTUAL_MACHINE) &&
- !(domain->flags & DOMAIN_FLAG_STATIC_IDENTITY)) {
+ if (!domain_type_is_vm_or_si(domain)) {
spin_lock_irqsave(&iommu->lock, tmp_flags);
clear_bit(domain->id, iommu->domain_ids);
iommu->domains[domain->id] = NULL;
@@ -4206,7 +4200,7 @@ static int intel_iommu_domain_init(struct iommu_domain *domain)
{
struct dmar_domain *dmar_domain;

- dmar_domain = alloc_domain(true);
+ dmar_domain = alloc_domain(DOMAIN_FLAG_VIRTUAL_MACHINE);
if (!dmar_domain) {
printk(KERN_ERR
"intel_iommu_domain_init: dmar_domain == NULL\n");
@@ -4250,8 +4244,7 @@ static int intel_iommu_attach_device(struct iommu_domain *domain,

old_domain = find_domain(dev);
if (old_domain) {
- if (dmar_domain->flags & DOMAIN_FLAG_VIRTUAL_MACHINE ||
- dmar_domain->flags & DOMAIN_FLAG_STATIC_IDENTITY)
+ if (domain_type_is_vm_or_si(dmar_domain))
domain_remove_one_dev_info(old_domain, dev);
else
domain_remove_dev_info(old_domain);
--
1.7.10.4