x86, AMD IOMMU: add functions to find IOMMU device resources

This patch adds functions necessary to find the IOMMU resources for a specific
device.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Cc: iommu@lists.linux-foundation.org
Cc: bhavna.sarathy@amd.com
Cc: Sebastian.Biemueller@amd.com
Cc: robert.richter@amd.com
Cc: joro@8bytes.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 75 insertions, 0 deletions

diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c
index c43d15dbc8fa..47e80b5814bf 100644
--- a/arch/x86/kernel/amd_iommu.c
+++ b/arch/x86/kernel/amd_iommu.c
@@ -461,3 +461,78 @@ free_dma_dom:
         return NULL;
 }
 
+static struct protection_domain *domain_for_device(u16 devid)
+{
+        struct protection_domain *dom;
+        unsigned long flags;
+
+        read_lock_irqsave(&amd_iommu_devtable_lock, flags);
+        dom = amd_iommu_pd_table[devid];
+        read_unlock_irqrestore(&amd_iommu_devtable_lock, flags);
+
+        return dom;
+}
+
+static void set_device_domain(struct amd_iommu *iommu,
+                              struct protection_domain *domain,
+                              u16 devid)
+{
+        unsigned long flags;
+
+        u64 pte_root = virt_to_phys(domain->pt_root);
+
+        pte_root |= (domain->mode & 0x07) << 9;
+        pte_root |= IOMMU_PTE_IR | IOMMU_PTE_IW | IOMMU_PTE_P | 2;
+
+        write_lock_irqsave(&amd_iommu_devtable_lock, flags);
+        amd_iommu_dev_table[devid].data[0] = pte_root;
+        amd_iommu_dev_table[devid].data[1] = pte_root >> 32;
+        amd_iommu_dev_table[devid].data[2] = domain->id;
+
+        amd_iommu_pd_table[devid] = domain;
+        write_unlock_irqrestore(&amd_iommu_devtable_lock, flags);
+
+        iommu_queue_inv_dev_entry(iommu, devid);
+
+        iommu->need_sync = 1;
+}
+
+static int get_device_resources(struct device *dev,
+                                struct amd_iommu **iommu,
+                                struct protection_domain **domain,
+                                u16 *bdf)
+{
+        struct dma_ops_domain *dma_dom;
+        struct pci_dev *pcidev;
+        u16 _bdf;
+
+        BUG_ON(!dev || dev->bus != &pci_bus_type || !dev->dma_mask);
+
+        pcidev = to_pci_dev(dev);
+        _bdf = (pcidev->bus->number << 8) | pcidev->devfn;
+
+        if (_bdf >= amd_iommu_last_bdf) {
+                *iommu = NULL;
+                *domain = NULL;
+                *bdf = 0xffff;
+                return 0;
+        }
+
+        *bdf = amd_iommu_alias_table[_bdf];
+
+        *iommu = amd_iommu_rlookup_table[*bdf];
+        if (*iommu == NULL)
+                return 0;
+        dma_dom = (*iommu)->default_dom;
+        *domain = domain_for_device(*bdf);
+        if (*domain == NULL) {
+                *domain = &dma_dom->domain;
+                set_device_domain(*iommu, *domain, *bdf);
+                printk(KERN_INFO "AMD IOMMU: Using protection domain %d for "
+                                "device ", (*domain)->id);
+                print_devid(_bdf, 1);
+        }
+
+        return 1;
+}
+