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iommu/amd: Put IOMMUv2 capable devices in pt_domain 

If the device starts to use IOMMUv2 features the dma handles
need to stay valid. The only sane way to do this is to use a
identity mapping for the device and not translate it by the
iommu. This is implemented with this patch. Since this lifts
the device-isolation there is also a new kernel parameter
which allows to disable that feature.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
This commit is contained in:
Joerg Roedel 2011-12-01 15:49:45 +01:00
parent 400a28a05f
commit 5abcdba4fa
4 changed files with 91 additions and 16 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
Documentation/kernel-parameters.txt
View File

@ -329,6 +329,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
is a lot of faster
off - do not initialize any AMD IOMMU found in
the system
force_isolation - Force device isolation for all
devices. The IOMMU driver is not
allowed anymore to lift isolation
requirements as needed. This option
does not override iommu=pt
amijoy.map= [HW,JOY] Amiga joystick support
Map of devices attached to JOY0DAT and JOY1DAT

94
drivers/iommu/amd_iommu.c
View File

@ -67,6 +67,7 @@ struct iommu_cmd {
};
static void update_domain(struct protection_domain *domain);
static int __init alloc_passthrough_domain(void);
/****************************************************************************
*
@ -147,6 +148,24 @@ static struct iommu_dev_data *get_dev_data(struct device *dev)
return dev->archdata.iommu;
}
static bool pci_iommuv2_capable(struct pci_dev *pdev)
{
static const int caps[] = {
PCI_EXT_CAP_ID_ATS,
PCI_PRI_CAP,
PCI_PASID_CAP,
};
int i, pos;
for (i = 0; i < 3; ++i) {
pos = pci_find_ext_capability(pdev, caps[i]);
if (pos == 0)
return false;
}
return true;
}
/*
* In this function the list of preallocated protection domains is traversed to
* find the domain for a specific device
@ -204,6 +223,7 @@ static bool check_device(struct device *dev)
static int iommu_init_device(struct device *dev)
{
struct pci_dev *pdev = to_pci_dev(dev);
struct iommu_dev_data *dev_data;
u16 alias;
@ -228,6 +248,13 @@ static int iommu_init_device(struct device *dev)
dev_data->alias_data = alias_data;
}
if (pci_iommuv2_capable(pdev)) {
struct amd_iommu *iommu;
iommu = amd_iommu_rlookup_table[dev_data->devid];
dev_data->iommu_v2 = iommu->is_iommu_v2;
}
dev->archdata.iommu = dev_data;
return 0;
@ -1762,7 +1789,7 @@ static void __detach_device(struct iommu_dev_data *dev_data)
* passthrough domain if it is detached from any other domain.
* Make sure we can deassign from the pt_domain itself.
*/
if (iommu_pass_through &&
if (dev_data->passthrough &&
(dev_data->domain == NULL && domain != pt_domain))
__attach_device(dev_data, pt_domain);
}
@ -1820,18 +1847,20 @@ static struct protection_domain *domain_for_device(struct device *dev)
static int device_change_notifier(struct notifier_block *nb,
unsigned long action, void *data)
{
struct device *dev = data;
u16 devid;
struct protection_domain *domain;
struct dma_ops_domain *dma_domain;
struct protection_domain *domain;
struct iommu_dev_data *dev_data;
struct device *dev = data;
struct amd_iommu *iommu;
unsigned long flags;
u16 devid;
if (!check_device(dev))
return 0;
devid = get_device_id(dev);
iommu = amd_iommu_rlookup_table[devid];
devid = get_device_id(dev);
iommu = amd_iommu_rlookup_table[devid];
dev_data = get_dev_data(dev);
switch (action) {
case BUS_NOTIFY_UNBOUND_DRIVER:
@ -1840,7 +1869,7 @@ static int device_change_notifier(struct notifier_block *nb,
if (!domain)
goto out;
if (iommu_pass_through)
if (dev_data->passthrough)
break;
detach_device(dev);
break;
@ -2436,8 +2465,9 @@ static int amd_iommu_dma_supported(struct device *dev, u64 mask)
*/
static void prealloc_protection_domains(void)
{
struct pci_dev *dev = NULL;
struct iommu_dev_data *dev_data;
struct dma_ops_domain *dma_dom;
struct pci_dev *dev = NULL;
u16 devid;
for_each_pci_dev(dev) {
@ -2446,6 +2476,16 @@ static void prealloc_protection_domains(void)
if (!check_device(&dev->dev))
continue;
dev_data = get_dev_data(&dev->dev);
if (!amd_iommu_force_isolation && dev_data->iommu_v2) {
/* Make sure passthrough domain is allocated */
alloc_passthrough_domain();
dev_data->passthrough = true;
attach_device(&dev->dev, pt_domain);
pr_info("AMD-Vi: Using passthough domain for device %s\n",
dev_name(&dev->dev));
}
/* Is there already any domain for it? */
if (domain_for_device(&dev->dev))
continue;
@ -2476,6 +2516,7 @@ static struct dma_map_ops amd_iommu_dma_ops = {
static unsigned device_dma_ops_init(void)
{
struct iommu_dev_data *dev_data;
struct pci_dev *pdev = NULL;
unsigned unhandled = 0;
@ -2485,7 +2526,12 @@ static unsigned device_dma_ops_init(void)
continue;
}
pdev->dev.archdata.dma_ops = &amd_iommu_dma_ops;
dev_data = get_dev_data(&pdev->dev);
if (!dev_data->passthrough)
pdev->dev.archdata.dma_ops = &amd_iommu_dma_ops;
else
pdev->dev.archdata.dma_ops = &nommu_dma_ops;
}
return unhandled;
@ -2612,6 +2658,20 @@ out_err:
return NULL;
}
static int __init alloc_passthrough_domain(void)
{
if (pt_domain != NULL)
return 0;
/* allocate passthrough domain */
pt_domain = protection_domain_alloc();
if (!pt_domain)
return -ENOMEM;
pt_domain->mode = PAGE_MODE_NONE;
return 0;
}
static int amd_iommu_domain_init(struct iommu_domain *dom)
{
struct protection_domain *domain;
@ -2798,21 +2858,23 @@ static struct iommu_ops amd_iommu_ops = {
int __init amd_iommu_init_passthrough(void)
{
struct amd_iommu *iommu;
struct iommu_dev_data *dev_data;
struct pci_dev *dev = NULL;
struct amd_iommu *iommu;
u16 devid;
int ret;
/* allocate passthrough domain */
pt_domain = protection_domain_alloc();
if (!pt_domain)
return -ENOMEM;
pt_domain->mode |= PAGE_MODE_NONE;
ret = alloc_passthrough_domain();
if (ret)
return ret;
for_each_pci_dev(dev) {
if (!check_device(&dev->dev))
continue;
dev_data = get_dev_data(&dev->dev);
dev_data->passthrough = true;
devid = get_device_id(&dev->dev);
iommu = amd_iommu_rlookup_table[devid];

4
drivers/iommu/amd_iommu_init.c
View File

@ -146,6 +146,8 @@ u32 amd_iommu_max_pasids __read_mostly = ~0;
bool amd_iommu_v2_present __read_mostly;
bool amd_iommu_force_isolation __read_mostly;
/*
* The ACPI table parsing functions set this variable on an error
*/
@ -1642,6 +1644,8 @@ static int __init parse_amd_iommu_options(char *str)
amd_iommu_unmap_flush = true;
if (strncmp(str, "off", 3) == 0)
amd_iommu_disabled = true;
if (strncmp(str, "force_isolation", 15) == 0)
amd_iommu_force_isolation = true;
}
return 1;

4
drivers/iommu/amd_iommu_types.h
View File

@ -330,6 +330,8 @@ struct iommu_dev_data {
struct protection_domain *domain; /* Domain the device is bound to */
atomic_t bind; /* Domain attach reverent count */
u16 devid; /* PCI Device ID */
bool iommu_v2; /* Device can make use of IOMMUv2 */
bool passthrough; /* Default for device is pt_domain */
struct {
bool enabled;
int qdep;
@ -575,6 +577,8 @@ extern u32 amd_iommu_max_pasids;
extern bool amd_iommu_v2_present;
extern bool amd_iommu_force_isolation;
/* takes bus and device/function and returns the device id
* FIXME: should that be in generic PCI code? */
static inline u16 calc_devid(u8 bus, u8 devfn)