iommu/amd: Use iommu_group_get_for_dev()

The common iommu_group_get_for_dev() allows us to greatly simplify
our group lookup for a new device.  Also, since we insert IVRS
aliases into the PCI DMA alias quirks, we should alway come up with
the same results as the existing code.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Cc: Joerg Roedel <joro@8bytes.org>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

2 files changed, 5 insertions, 160 deletions

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 25d7571dfc1c..2e03c17c2499 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -46,7 +46,6 @@
 #include "amd_iommu_proto.h"
 #include "amd_iommu_types.h"
 #include "irq_remapping.h"
-#include "pci.h"
 
 #define CMD_SET_TYPE(cmd, t) ((cmd)->data[1] |= ((t) << 28))
 
@@ -133,9 +132,6 @@ static void free_dev_data(struct iommu_dev_data *dev_data)
         list_del(&dev_data->dev_data_list);
         spin_unlock_irqrestore(&dev_data_list_lock, flags);
 
-        if (dev_data->group)
-                iommu_group_put(dev_data->group);
-
         kfree(dev_data);
 }
 
@@ -264,167 +260,17 @@ static bool check_device(struct device *dev)
         return true;
 }
 
-static struct pci_bus *find_hosted_bus(struct pci_bus *bus)
-{
-        while (!bus->self) {
-                if (!pci_is_root_bus(bus))
-                        bus = bus->parent;
-                else
-                        return ERR_PTR(-ENODEV);
-        }
-
-        return bus;
-}
-
-#define REQ_ACS_FLAGS   (PCI_ACS_SV | PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_UF)
-
-static struct pci_dev *get_isolation_root(struct pci_dev *pdev)
-{
-        struct pci_dev *dma_pdev = pdev;
-
-        /* Account for quirked devices */
-        swap_pci_ref(&dma_pdev, pci_get_dma_source(dma_pdev));
-
-        /*
-         * If it's a multifunction device that does not support our
-         * required ACS flags, add to the same group as lowest numbered
-         * function that also does not suport the required ACS flags.
-         */
-        if (dma_pdev->multifunction &&
-            !pci_acs_enabled(dma_pdev, REQ_ACS_FLAGS)) {
-                u8 i, slot = PCI_SLOT(dma_pdev->devfn);
-
-                for (i = 0; i < 8; i++) {
-                        struct pci_dev *tmp;
-
-                        tmp = pci_get_slot(dma_pdev->bus, PCI_DEVFN(slot, i));
-                        if (!tmp)
-                                continue;
-
-                        if (!pci_acs_enabled(tmp, REQ_ACS_FLAGS)) {
-                                swap_pci_ref(&dma_pdev, tmp);
-                                break;
-                        }
-                        pci_dev_put(tmp);
-                }
-        }
-
-        /*
-         * Devices on the root bus go through the iommu.  If that's not us,
-         * find the next upstream device and test ACS up to the root bus.
-         * Finding the next device may require skipping virtual buses.
-         */
-        while (!pci_is_root_bus(dma_pdev->bus)) {
-                struct pci_bus *bus = find_hosted_bus(dma_pdev->bus);
-                if (IS_ERR(bus))
-                        break;
-
-                if (pci_acs_path_enabled(bus->self, NULL, REQ_ACS_FLAGS))
-                        break;
-
-                swap_pci_ref(&dma_pdev, pci_dev_get(bus->self));
-        }
-
-        return dma_pdev;
-}
-
-static int use_pdev_iommu_group(struct pci_dev *pdev, struct device *dev)
-{
-        struct iommu_group *group = iommu_group_get(&pdev->dev);
-        int ret;
-
-        if (!group) {
-                group = iommu_group_alloc();
-                if (IS_ERR(group))
-                        return PTR_ERR(group);
-
-                WARN_ON(&pdev->dev != dev);
-        }
-
-        ret = iommu_group_add_device(group, dev);
-        iommu_group_put(group);
-        return ret;
-}
-
-static int use_dev_data_iommu_group(struct iommu_dev_data *dev_data,
-                                    struct device *dev)
-{
-        if (!dev_data->group) {
-                struct iommu_group *group = iommu_group_alloc();
-                if (IS_ERR(group))
-                        return PTR_ERR(group);
-
-                dev_data->group = group;
-        }
-
-        return iommu_group_add_device(dev_data->group, dev);
-}
-
 static int init_iommu_group(struct device *dev)
 {
-        struct iommu_dev_data *dev_data;
         struct iommu_group *group;
-        struct pci_dev *dma_pdev;
-        int ret;
 
-        group = iommu_group_get(dev);
-        if (group) {
-                iommu_group_put(group);
-                return 0;
-        }
+        group = iommu_group_get_for_dev(dev);
 
-        dev_data = find_dev_data(get_device_id(dev));
-        if (!dev_data)
-                return -ENOMEM;
-
-        if (dev_data->alias_data) {
-                u16 alias;
-                struct pci_bus *bus;
-
-                if (dev_data->alias_data->group)
-                        goto use_group;
+        if (IS_ERR(group))
+                return PTR_ERR(group);
 
-                /*
-                 * If the alias device exists, it's effectively just a first
-                 * level quirk for finding the DMA source.
-                 */
-                alias = amd_iommu_alias_table[dev_data->devid];
-                dma_pdev = pci_get_bus_and_slot(alias >> 8, alias & 0xff);
-                if (dma_pdev) {
-                        dma_pdev = get_isolation_root(dma_pdev);
-                        goto use_pdev;
-                }
-
-                /*
-                 * If the alias is virtual, try to find a parent device
-                 * and test whether the IOMMU group is actualy rooted above
-                 * the alias.  Be careful to also test the parent device if
-                 * we think the alias is the root of the group.
-                 */
-                bus = pci_find_bus(0, alias >> 8);
-                if (!bus)
-                        goto use_group;
-
-                bus = find_hosted_bus(bus);
-                if (IS_ERR(bus) || !bus->self)
-                        goto use_group;
-
-                dma_pdev = get_isolation_root(pci_dev_get(bus->self));
-                if (dma_pdev != bus->self || (dma_pdev->multifunction &&
-                    !pci_acs_enabled(dma_pdev, REQ_ACS_FLAGS)))
-                        goto use_pdev;
-
-                pci_dev_put(dma_pdev);
-                goto use_group;
-        }
-
-        dma_pdev = get_isolation_root(pci_dev_get(to_pci_dev(dev)));
-use_pdev:
-        ret = use_pdev_iommu_group(dma_pdev, dev);
-        pci_dev_put(dma_pdev);
-        return ret;
-use_group:
-        return use_dev_data_iommu_group(dev_data->alias_data, dev);
+        iommu_group_put(group);
+        return 0;
 }
 
 static int __last_alias(struct pci_dev *pdev, u16 alias, void *data)
diff --git a/drivers/iommu/amd_iommu_types.h b/drivers/iommu/amd_iommu_types.h
index f1a5abf11acf..7277a200d916 100644
--- a/drivers/iommu/amd_iommu_types.h
+++ b/drivers/iommu/amd_iommu_types.h
@@ -432,7 +432,6 @@ struct iommu_dev_data {
         struct iommu_dev_data *alias_data;/* The alias dev_data */
         struct protection_domain *domain; /* Domain the device is bound to */
         atomic_t bind;                    /* Domain attach reference count */
-        struct iommu_group *group;        /* IOMMU group for virtual aliases */
         u16 devid;                        /* PCI Device ID */
         bool iommu_v2;                    /* Device can make use of IOMMUv2 */
         bool passthrough;                 /* Default for device is pt_domain */