@@ -17,20 +17,63 @@
*/
#include <linux/bug.h>
+#include <linux/device.h>
#include <linux/types.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/iommu.h>
+#include <linux/pci.h>
static struct iommu_ops *iommu_ops;
+static ssize_t show_iommu_group(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ unsigned int groupid;
+
+ if (iommu_device_group(dev, &groupid))
+ return 0;
+
+ return sprintf(buf, "%u", groupid);
+}
+static DEVICE_ATTR(iommu_group, S_IRUGO, show_iommu_group, NULL);
+
+static int add_iommu_group(struct device *dev, void *unused)
+{
+ unsigned int groupid;
+
+ if (iommu_device_group(dev, &groupid) == 0)
+ return device_create_file(dev, &dev_attr_iommu_group);
+
+ return 0;
+}
+
+static int device_notifier(struct notifier_block *nb,
+ unsigned long action, void *data)
+{
+ struct device *dev = data;
+
+ if (action == BUS_NOTIFY_ADD_DEVICE)
+ return add_iommu_group(dev, NULL);
+
+ return 0;
+}
+
+static struct notifier_block device_nb = {
+ .notifier_call = device_notifier,
+};
+
void register_iommu(struct iommu_ops *ops)
{
if (iommu_ops)
BUG();
iommu_ops = ops;
+
+ /* FIXME - non-PCI, really want for_each_bus() */
+ bus_register_notifier(&pci_bus_type, &device_nb);
+ bus_for_each_dev(&pci_bus_type, NULL, NULL, add_iommu_group);
}
bool iommu_found(void)
@@ -94,6 +137,14 @@ int iommu_domain_has_cap(struct iommu_domain *domain,
}
EXPORT_SYMBOL_GPL(iommu_domain_has_cap);
+int iommu_device_group(struct device *dev, unsigned int *groupid)
+{
+ if (iommu_ops->device_group)
+ return iommu_ops->device_group(dev, groupid);
+ return -ENODEV;
+}
+EXPORT_SYMBOL_GPL(iommu_device_group);
+
int iommu_map(struct iommu_domain *domain, unsigned long iova,
phys_addr_t paddr, int gfp_order, int prot)
{
@@ -45,6 +45,7 @@ struct iommu_ops {
unsigned long iova);
int (*domain_has_cap)(struct iommu_domain *domain,
unsigned long cap);
+ int (*device_group)(struct device *dev, unsigned int *groupid);
};
#ifdef CONFIG_IOMMU_API
@@ -65,6 +66,7 @@ extern phys_addr_t iommu_iova_to_phys(struct iommu_domain *domain,
unsigned long iova);
extern int iommu_domain_has_cap(struct iommu_domain *domain,
unsigned long cap);
+extern int iommu_device_group(struct device *dev, unsigned int *groupid);
#else /* CONFIG_IOMMU_API */
@@ -121,6 +123,10 @@ static inline int domain_has_cap(struct iommu_domain *domain,
return 0;
}
+static inline int iommu_device_group(struct device *dev, unsigned int *groupid);
+{
+ return -ENODEV;
+}
#endif /* CONFIG_IOMMU_API */
#endif /* __LINUX_IOMMU_H */
An IOMMU group is a set of devices for which the IOMMU cannot distinguish transactions. For PCI devices, a group often occurs when a PCI bridge is involved. Transactions from any device behind the bridge appear to be sourced from the bridge itself. We leave it to the IOMMU driver to define the grouping restraints for their platform. Using this new interface, the group for a device can be retrieved using the iommu_device_group() callback. Users will compare the value returned against the value returned for other devices to determine whether they are part of the same group. Devices with no group are not translated by the IOMMU. There should be no expectations about the group numbers as they may be arbitrarily assigned by the IOMMU driver and may not be persistent across boots. We also provide a sysfs interface to the group numbers here so that user space can understand IOMMU dependencies between devices for managing safe, user space drivers. Signed-off-by: Alex Williamson <alex.williamson@redhat.com> --- drivers/base/iommu.c | 51 +++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/iommu.h | 6 ++++++ 2 files changed, 57 insertions(+), 0 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html